Article 1: The Migraine Premonitory Phase
Nazia Karsan, MBBS, MRCP; Pyari Bose, MD, MRCP; Peter J. Goadsby, MD, PhD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):996–1008.
PURPOSE OF REVIEW
The premonitory phase of migraine is defined as the presence of nonpainful symptomatology occurring hours to days before the onset of headache. Symptoms can include neck stiffness, yawning, thirst, and increased frequency of micturition. Clinical recognition of these symptoms is important to ensure early and effective attack management. Further understanding of the clinical phenotype and neurobiological mediation of these symptoms is important in the advancement of therapeutics research in both acute and preventive treatments of migraine.
Since 2014, functional imaging studies have been conducted during the premonitory stage of migraine and have provided novel insights into the early neurobiology and anatomy of the earliest stage of the migraine attack. These studies have shown early involvement of subcortical brain areas including the hypothalamus, substantia nigra, dorsal pons, and various limbic cortical areas, including the anterior cingulate cortex during the premonitory phase. More recent work has revealed altered hypothalamic-brainstem functional connectivity during migraine, which starts before the onset of pain. These exciting findings have provided functional correlation of the symptoms experienced by patients and changes seen on functional brain imaging.
This article focuses on the prevalence, phenotype, and proposed neurobiology of premonitory symptomatology in migraineurs as well as the scope of future research.
- Prospective studies have shown that the presence of symptoms prior to the onset of headache can occur reliably and can predict pain onset in some individuals.
- The premonitory phase of migraine is likely more common than is currently reported in the literature.
- Premonitory symptoms can be experienced in the lead-up to headache or during headache itself, and similar symptoms can present in the postdrome after headache resolution.
- Physicians should ask about the presence of premonitory symptoms as a standard part of the migraine history.
- Premonitory symptoms of migraine can be experienced by adults, adolescents, and children as young as 18 months old.
- Common premonitory symptoms of migraine are fatigue, yawning, neck discomfort, and concentration difficulty.
- Pharmacologic triggering models in human experimental research and functional neuroimaging have enabled the neurobiology of the premonitory phase of migraine to be studied and have provided functional correlation between the clinical phenotype and areas of brain seen to be activated on imaging.
- The engagement of limbic and subcortical brain areas prior to the onset of headache in migraine is, to date, unique to this as an acute pain condition and provides interesting insights into how the migraine attack starts and progresses to pain.
- Increasing evidence exists for the role of the hypothalamus and its connections in mediating the premonitory symptoms of migraine, as well as the role of these connections in trigeminal nociceptive signaling.
- Understanding of the brain areas and pathways involved in the premonitory phase of migraine, including the dopaminergic pathway, provide novel insights into targeted neurochemical therapeutic targets.
- Understanding the mechanisms behind the mediation of premonitory symptoms within the brain may lead to therapeutic advances for effective abortive migraine agents, as well as for agents that may treat disabling nonpainful symptomatology as well as headache.
Article 2: The Migraine Aura
Andrew Charles, MD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1009–1022.
PURPOSE OF REVIEW
This article discusses the basic mechanisms of migraine aura and its clinical significance based upon evidence from human studies and animal models.
Prospective clinical studies have reinforced the understanding that migraine aura is highly variable from one individual to the next as well as from attack to attack in an individual. While migraine with aura clearly has a higher heritability than migraine without aura, population studies have not identified specific genes that underlie this heritability for typical migraine with aura. Imaging studies reveal hypoperfusion associated with migraine aura, although the timing and distribution of this hypoperfusion is not strictly correlated with migraine symptoms. Mapping of migraine visual aura symptoms onto the visual cortex suggests that the mechanisms underlying the aura propagate in a linear fashion along gyri or sulci rather than as a concentric wave and also suggests that aura may propagate in the absence of clinical symptoms. Cortical spreading depression in animal models continues to be a translational model for migraine, and the study of spreading depolarizations in the injured human brain has provided new insight into potential mechanisms of cortical spreading depression in migraine. Migraine with aura has multiple comorbidities including patent foramen ovale, stroke, and psychiatric disorders; the shared mechanisms underlying these comorbidities remains a topic of active investigation.
Although it occurs in the minority of patients with migraine, aura may have much to teach us about basic mechanisms of migraine. In addition, its occurrence may influence clinical management regarding comorbid conditions and acute and preventive therapy.
- Migraine aura symptoms include visual, sensory, language, motor, or brainstem symptoms that begin and progress gradually, which reflect a slowly propagating physiologic phenomenon in the brain.
- The symptoms of migraine aura are highly variable from person to person and may vary significantly from attack to attack in a given individual.
- Characteristics of the visual percept of the migraine aura indicate that the brain activity underlying aura can begin in different parts of the visual cortex in the same individual and that the activity spreads in a linear fashion along a sulcus or gyrus rather than as a concentric wave.
- The diagnosis of migraine with brainstem aura has replaced the diagnosis of basilar migraine in the most recent version of the International Classification of Headache Disorders, Third Edition, reflecting an understanding that the symptoms included in this diagnosis are not necessarily produced by changes in perfusion through the basilar artery.
- Migraine with aura has greater heritability than migraine without aura, but thus far the only genes that have been identified in association with migraine are those responsible for monogenic familial hemiplegic migraine disorders.
- Although migrainous infarction is rare, migraine aura mechanisms occurring in response to ischemia may worsen stroke when it does occur.
- Cortical spreading depression has long been assumed to be the physiologic phenomenon underlying the migraine aura, and cortical spreading depression in animal models appears to be a valid translational model for migraine, but it has never been definitively demonstrated with migraine aura in humans.
- Cortical spreading depression can activate trigeminal pain pathways in animal models, but the variable relationship between migraine aura and headache does not support aura as a mechanism that triggers headache.
- Migraine with aura is associated with patent foramen ovale and increased risk of stroke; patent foramen ovale could play a significant role in the increased stroke risk associated with migraine with aura.
- No evidence supports a contraindication to triptans as acute therapies in attacks of migraine that include aura.
Article 3: The Migraine Postdrome
Pyari Bose, MD, MRCP; Nazia Karsan, MBBS, MRCP; Peter J. Goadsby, MD, PhD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1023–1031.
PURPOSE OF REVIEW
The migraine postdrome is the least studied and least understood phase of migraine. This article covers the salient features of the migraine postdrome and provides insight into the history, clinical symptoms, and future implications of this phase of migraine.
Prospective electronic diary studies have shown that patients are left disabled with various nonheadache symptoms in the migraine postdrome, and 81% of patients report at least one nonheadache symptom in the postdrome. Hence, it is important to understand this phase better and ensure that more effective treatments become available in the future to lessen the morbidity associated with this phase. Functional imaging shows widespread reduction in brain-blood flow in the postdrome, which explains the multitudes of symptoms experienced by patients.
The disability related to migraine is not exclusive to the headache phase but extends into the postdrome phase and is associated with several nonheadache symptoms that prolong the symptoms experienced by patients with migraine. Further research into the postdrome is crucial to improve our overall understanding of migraine mechanisms. This knowledge may also help to treat the concurrent nonheadache symptoms better in the future. Novel neuroimaging techniques provide a valuable noninvasive tool to push the frontiers in the understanding of migraine pathophysiology. These methods may help shed further light onto the possible links between key brain structures and networks that could be implicated in the pathophysiology of the various migraine phases.
- Tiredness, concentration difficulty, and neck stiffness are the most typically reported postdrome symptoms of migraine.
- Postdrome symptoms appear to be common, with 81% to 94% of patients with migraine reporting these symptoms.
- Treatment with triptans does not appear to alter the underlying diencephalic and brainstem mechanisms involved in migraine pathophysiology, and persistent activation of these networks may explain some of the symptoms in the migraine postdrome.
- Comorbidities such as anxiety and depression do not appear to influence the presence or absence of the migraine postdrome.
- Assigning postdrome symptoms into four main groups (neuropsychiatric, sensory, gastrointestinal, and general symptoms) gives clarity in classifying and assessing the symptoms.
- Based on the similarity of symptoms, one can hypothesize that a shared neural network may be active in the postdrome and premonitory phases of migraine.
- Not recognizing the typical postdrome symptoms may lead to patients undergoing unnecessary investigations and hospital visits, and recognition and reassurance regarding postdrome symptoms may alleviate the patient’s concerns.
- The role of brainstem noradrenergic mechanisms and cortical spreading depression in the postdrome pathophysiology needs to be explored further. Functional neuroimaging may hold the key.
- The lack of literature surrounding the postdrome phase of migraine and its significant burden for patients in terms of returning to normal function indicate a vital need to understand it better.
Article 4: Acute Treatment of Migraine
Bert B. Vargas, MD, FAAN, FAHS. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1032–1051.
PURPOSE OF REVIEW
This article provides a framework to help providers formulate a plan for the acute treatment of migraine. Topics covered include the cost-effective patient-centered approach known as stratified care and a summary of evidence-based treatment options that are currently available. Strategies for improving treatment response, troubleshooting suboptimal results, and addressing the needs of special populations are also reviewed.
Both the American Headache Society and the Canadian Headache Society have released evidence-based assessments and reviews of acute treatments for migraine that can be used to help guide treatment decisions. Although several older medications have been re-released with new formulations or new delivery systems, several new medications have also become available or are in the final phases of study, further increasing the number of options available for patients.
The acute management of migraine should incorporate a stratified care model in concert with evidence-based treatment options. The response to treatment should be monitored regularly, and measures should be taken to identify suboptimal tolerability or efficacy.
- Inadequate acute treatment of migraine exerts a significant socioeconomic burden and has also been associated with transition from an episodic to a chronic pattern of migraine.
- Stratified care considers individual variance in headache severity and associated features such as nausea or vomiting and allows patients the ability to make their own treatment decisions based on their unique needs.
- Stratified care of patients with migraine is equated with higher patient satisfaction but also with decreased health care costs.
- Acute treatments of migraine with the highest level of evidence include all triptans as well as nonspecific analgesics including acetaminophen and certain nonsteroidal anti-inflammatory drugs.
- Triptans are contraindicated in individuals with a history of stroke, heart attack, coronary artery disease, hemiplegic migraine, uncontrolled hypertension, migraine with brainstem aura, and peripheral vascular disease.
- A number of nonspecific analgesics have been shown to be efficacious when compared to placebo in the acute treatment of migraine.
- In situations where standard evidence-based oral medications are ineffective, poorly tolerated, or contraindicated, it may be necessary to consider nonoral treatment options for migraine.
- Despite a relative lack of evidence, peripheral nerve blocks are easily performed in the outpatient setting, are generally accepted as safe and well tolerated, and continue to be a commonly employed treatment for acute migraine.
- A large body of research supports the significant role of calcitonin gene-related peptide in the pathophysiology of migraine, which has led to the development of a new class of calcitonin gene-related peptide antagonists.
- Existing data are conflicting or inadequate to support the concern that coadministration of triptans with selective serotonin reuptake inhibitors or serotonin norepinephrine reuptake inhibitors confer any additional risk of serotonin syndrome in patients treated for migraine.
- Some common causes of suboptimal treatment include (but are not limited to): inadequate dosing, delay in treatment, not repeating treatment, suboptimal route of administration, and headache with a rapid time to peak severity.
Article 5: Preventive Therapy of Migraine
Todd J. Schwedt, MD, FAAN. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1052–1065.
PURPOSE OF REVIEW
This article reviews the preventive therapy of migraine, including indications, strategies for use, and available treatments.
Lifestyle modifications and migraine trigger avoidance are recommended as preventive measures for all individuals with migraine. The decision to recommend additional migraine preventive therapy should consider the frequency of migraine attacks and headaches, extent of migraine-associated disability, frequency of using acute migraine treatments and the responsiveness to such treatments, and patient preferences. Additional therapies include prescription medications, nutraceuticals, neurostimulation, and behavioral therapy. Considering evidence for efficacy and the risk of potential side effects and adverse events, treatments with the most favorable profiles include (in alphabetical order): amitriptyline, beta-blockers (several), biofeedback, candesartan, coenzyme Q10, cognitive-behavioral therapy, magnesium citrate, onabotulinumtoxinA (for chronic migraine only), relaxation therapy, riboflavin, and topiramate. In addition, erenumab, a calcitonin gene-related peptide (CGRP) receptor monoclonal antibody, received approval from the US Food and Drug Administration (FDA) for the prevention of migraine in May 2018.
Successful migraine preventive therapy reduces the frequency and burden of attacks while causing limited side effects. Individual treatment recommendations are determined based upon evidence for efficacy, side effect and adverse event profiles, medication interactions, patient comorbidity, costs, and patient preferences. Patients must be counseled on reasonable expectations for their preventive therapy and the importance of adhering to the recommended treatment plan for a period of time that is sufficient to determine outcomes.
- Migraine prevention is multifaceted and includes lifestyle modifications, migraine attack trigger identification and avoidance, avoidance of risk factors for developing more frequent migraine attacks, and, when indicated, medications, nutraceuticals, neurostimulation, and behavioral therapies.
- The goal of preventive therapy is to reduce the frequency of migraine attacks, days with migraine and headache, severity of symptoms, frequency of taking acute migraine therapy, and migraine-related disability.
- When formulating recommendations for specific preventive therapies, clinicians must consider the likelihood for effectiveness and side effects as well as other factors such as potential interactions with other therapies that the patient uses, the patient’s comorbidities, the cost of the therapy, and the patient’s ability to adhere to the recommended treatment schedule.
- Lifestyle modifications and migraine attack trigger identification and avoidance should be discussed with all patients with migraine.
- Moderate-intensity aerobic exercise (150 minutes per week, generally divided among three to five sessions) should be considered for migraine prevention in adults.
- Maintenance of a daily headache diary is recommended to obtain an accounting of migraine frequency, treatment patterns, and potential migraine attack triggers.
- Commonly cited migraine triggers include: high stress, stress let down (moving from high-stress to low-stress environments, such as might occur during a vacation), weather changes, sex hormone fluctuations in women, not eating, alcohol, sleep disturbance, odors, light, smoke, heat, and certain foods.
- Caffeine overuse and caffeine withdrawal are both associated with headaches and migraine.
- Several factors are associated with increased risk for developing more frequent headaches (eg, transitioning from episodic migraine to chronic migraine), including obesity, sleep disorders, excessive caffeine intake, psychiatric disease, higher baseline headache frequency, the frequent use of abortive migraine medications, female sex, lower socioeconomic status, comorbid pain disorders, major life events, history of head or neck injury, ineffective acute treatment of migraine attacks, and presence of cutaneous allodynia.
- A period of caffeine cessation lasting at least 2 to 3 months is recommended for individuals with frequent migraine.
- Medication overuse is a risk factor for developing more frequent headaches and can lead to medication-overuse headache.
- Sleep is an effective treatment for migraine attacks. Sleep disturbances are common among individuals with migraine, and poor sleep is positively associated with the occurrence and frequency of migraine attacks.
- Identification and treatment of sleep disturbances is recommended as part of a comprehensive preventive treatment plan for patients with migraine.
- Obesity is associated with a moderately higher risk of migraine and with an increasing number of headache days among those with migraine.
- Weight loss may be associated with reductions in headache frequency and severity.
- The decision to recommend migraine preventive therapy to a patient is based upon headache frequency, migraine attack frequency and duration, the severity of symptoms, the frequency of taking migraine acute therapies, a patient’s responsiveness to migraine acute therapies, extent of migraine-related disability, and patient preference.
- Transcutaneous supraorbital nerve stimulation, transcranial magnetic stimulation, and caloric vestibular stimulation have received clearance from the US Food and Drug Administration for migraine prevention.
- Behavioral therapies for migraine are used with the intent of reducing the frequency of migraine attacks and the impact of such attacks on the individual, such as headache-related disability, quality of life, and psychological comorbidity.
- Although behavioral therapies should be considered for all patients significantly impacted by migraine, special consideration should be given when a patient prefers nonpharmacologic therapy; does not tolerate, respond well, or has contraindications to pharmacologic therapy; and when patient behaviors and stress are triggers for migraine attacks or add significantly to migraine-related disability.
- A combination of treatments can be used for migraine prevention when a patient has inadequate response to a single therapy.
- In addition to therapy with combinations of prescription medications, combination therapy that includes combining a medication with a nutraceutical or neurobehavioral therapy or noninvasive neurostimulation can be considered and may be necessary for the effective treatment of patients who are refractory to single treatments.
- Rates of adherence and persistence with migraine preventive therapies are low.
- When assessing response to migraine preventive therapy, it is essential to determine the patient’s level of adherence with the treatment before determining that the therapy was ineffective.
Article 6: Headaches Due to Low and High Intracranial Pressure
Deborah I. Friedman, MD, MPH, FAAN. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1066–1091.
PURPOSE OF REVIEW
Headache disorders attributed to low and high intracranial pressure are commonly encountered in specialty headache practices and may occur more frequently than realized. While the headaches resulting from intracranial pressure disorders have what are conventionally thought of as defining characteristics, a substantial minority of patients do not manifest the “typical” features. Moreover, patients with intracranial pressure disorders may also have a preexisting primary headache disorder. Heightening the complexity of the presentation, the headaches of intracranial pressure disorders can resemble the phenotype of a primary disorder. Lastly, patients with so-called intracranial “hypotension” often have normal CSF pressure and neuroimaging studies. Thus, a high index of suspicion is needed. The published literature has inherent bias as many types of specialists evaluate and treat these conditions. This article reviews the key points to emphasize the history, examination, and laboratory evaluation of patients with intracranial pressure disorders from a neurologist’s perspective.
Lumbar puncture opening pressure in patients with spontaneous intracranial hypotension was low enough to meet diagnostic criteria (≤60 mm CSF) in only 34% of patients in one study. Most patients had an opening pressure in the low normal to normal range, and 5% had an opening pressure of 200 mm CSF or more. Diskogenic microspurs are a common cause of this syndrome. The Idiopathic Intracranial Hypertension Treatment Trial found that most participants had a headache phenotype resembling migraine or tension-type headache. No “typical” or characteristic headache phenotype was found, and headache-related disability was severe at baseline. Headache disability did not correlate with the lumbar puncture opening pressure at baseline or at the 6-month primary outcome period. Although participants who were randomly assigned to acetazolamide had a lower mean CSF opening pressure at 6 months, headache disability in that group was similar to the group who received placebo.
Significant overlap is seen in the symptoms of high and low CSF pressure disorders and in those of primary headache disorders. Neurologists are frequently challenged by patients with headaches who lack the typical clinical signs or imaging features of the pseudotumor cerebri syndrome or spontaneous intracranial hypotension. Even when characteristic symptoms and signs are initially present, the typical features of both syndromes tend to lessen or resolve over time; consider these diagnoses in patients with long-standing “chronic migraine” who do not improve with conventional headache treatment. While the diagnostic criteria for pseudotumor cerebri syndrome accurately identify most patients with the disorder, at least 25% of patients with spontaneous intracranial hypotension have normal imaging and over half have a normal lumbar puncture opening pressure. Detailed history taking will often give clues that suggest a CSF pressure disorder. That said, misdiagnosis can lead to significant patient morbidity and inappropriate therapy.
- Although they represent opposite ends of a spectrum, spontaneous intracranial hypotension and pseudotumor cerebri syndrome share many clinical similarities.
- Neurologists are often faced with the dilemma of evaluating patients who may have either spontaneous intracranial hypotension or pseudotumor cerebri syndrome, but are “atypical.”
- When evaluating a patient with possible spontaneous intracranial hypotension or pseudotumor cerebri syndrome, there is a fine line between being hypervigilant when considering the two diagnoses in clinical practice and overdiagnosing the conditions, which can lead to inappropriate investigations and treatments, potentially causing harm.
- Spontaneous intracranial hypotension is not necessarily spontaneous, is not of intracranial origin, and may not arise solely from low CSF pressure. CSF volume and compliance of the caudal dura may also be contributing factors.
- Typical orthostatic and “end of the day” headaches may be less prominent in spontaneous intracranial hypotension over time.
- A marked variability occurs in the location and character of spontaneous intracranial hypotension–related headaches.
- Patients with spontaneous intracranial hypotension may be asymptomatic or experience visual, vestibulocochlear, and cognitive problems, as well as an altered level of consciousness, movement disorders, and intracranial hemorrhage.
- Patients who have a typical headache pattern or abnormal brain imaging are generally identified early. The lack or subtle nature of orthostatic symptoms coupled with normal brain imaging leads to considerable delay in diagnosis, sometimes for decades. Spontaneous intracranial hypotension should be considered in patients with headaches of any phenotype that are refractory to conventional headache therapies.
- Brain sag may be erroneously diagnosed as a Chiari malformation type I, leading to unnecessary surgery that may make the patient worse.
- In cases of spontaneous intracranial hypotension, the leak site cannot be identified in about half of cases, and intermittent leaking may occur, which can make identification of the leak site challenging.
- Nerve sheath diverticula and osseous changes are indirect signs of a potential leak site.
- In cases of spontaneous intracranial hypotension, a large pool of epidural contrast suggests a high-flow leak.
- CT myelography performed immediately after the instillation of intrathecal contrast is the preferred technique for detecting fast leaks in cases of spontaneous intracranial hypotension; delayed MRI myelography is more sensitive for detecting slow leaks.
- Close collaboration with a neuroradiologist who is experienced in the diagnostic imaging modalities, interpretation of findings, and interventional treatments of spontaneous intracranial hypotension is imperative.
- A retrospinal fluid collection at C1-C2 is a false localizing sign of a spinal CSF leak.
- A nontargeted lower thoracic or lumbar high-volume epidural blood patch is successful in alleviating symptoms in about 30% of patients with spontaneous intracranial hypotension. However, the symptoms may recur over time.
- Of the neurointerventional procedures for spontaneous intracranial hypotension, targeted epidural blood patches with fibrin sealant have the best chance of alleviating the patient’s symptoms.
- Headache is the most common symptom of pseudotumor cerebri syndrome and may persist after other symptoms resolve and the CSF pressure normalizes.
- When present, the headache of pseudotumor cerebri syndrome is heterogeneous in phenotype, severe, and disabling.
- The presence of pulse-synchronous tinnitus and transient obscurations of vision supports a diagnosis of pseudotumor cerebri syndrome.
- A history of migraine was over twice as common in participants in the Idiopathic Intracranial Hypertension Treatment Trial as in the general population.
- Elevated CSF pressure in patients with pseudotumor cerebri syndrome may lead to skull base CSF leaks or intracranial hypotension.
- A comprehensive ophthalmic examination, including perimetry, is of prime importance for patients with suspected or confirmed pseudotumor cerebri syndrome. Confrontation visual field testing is inadequate to detect subtle defects, but the presence of a visual field abnormality on confrontation testing is highly concerning for significant visual loss.
- Body mass index has a negligible effect on lumbar puncture opening pressure.
- The position of the legs during a lumbar puncture has little impact (approximately 10 mm CSF) on the opening pressure, although the most accurate measurement is produced with the patient relaxed and legs extended.
- Sedation and Valsalva maneuvers can substantially increase the CSF opening pressure during a lumbar puncture.
- If the CSF pressure is elevated, remove enough CSF to achieve a closing pressure in the mid-normal range.
- Evaluate patients with pseudotumor cerebri syndrome for obstructive sleep apnea. This process may include screening questionnaires, asking the patient (and bed partner) about sleep apnea symptoms, assessing the Mallampati score, and polysomnography. Treatment of sleep apnea often helps lower the intracranial pressure.
- A randomized treatment trial comparing maximal medical therapy with and without ventriculoperitoneal shunting or optic nerve sheath fenestration was funded by the National Eye Institute and is expected to begin enrollment in 2018.
- Although headache disability improved overall in the Idiopathic Intracranial Hypertension Treatment Trial, no benefit of acetazolamide treatment was shown compared to placebo in Headache Impact Test-6 scores. Lowering the CSF pressure does not always result in improvement in headaches; no correlation existed between Headache Impact Test-6 score and lumbar puncture opening pressure at baseline or at 6-month follow-up.
- Many patients with pseudotumor cerebri syndrome require headache treatment in addition to intracranial pressure–lowering therapies. Preventive therapies should be selected based on headache phenotype with attention to side effect profile.
- A team approach is needed for the management of patients with pseudotumor cerebri syndrome, with a neurologist (or neuro-ophthalmologist) directing the coordination of care.
- The visual prognosis in patients with pseudotumor cerebri syndrome is generally good, but up to 10% of patients have permanent severe visual loss. Male sex, high-grade papilledema, profound anemia, renal failure, and uncontrolled systemic hypertension are risk factors associated with a poor visual outcome. Patients who present with loss of visual acuity require aggressive treatment.
- Headaches may persist after the CSF pressure is controlled and pseudotumor cerebri syndrome seems otherwise quiescent. This may be related to central sensitization occurring early in the course.
Article 7: Headache in Pregnancy
Matthew S. Robbins, MD, FAAN, FAHS. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1092–1107.
PURPOSE OF REVIEW
Headache disorders are extraordinarily common and disproportionately impact women of childbearing age. This article reviews the importance of proper diagnosis, natural history, and management of headache disorders in pregnant and postpartum women.
Red flags for secondary headache specifically among pregnant women include elevated blood pressure and lack of a previous headache history, as well as a prolonged duration of the headache attack in those with a prior history of migraine. Migraine improvement is typical for most pregnant women, but the prognosis for women who have migraine with aura or chronic migraine is less predictable. Migraine is now an established risk factor for the development of preeclampsia. Recent data suggest hazards for compounds containing butalbital and possibly a better safety profile for triptans than previously believed during pregnancy. Peripheral nerve blocks and noninvasive neurostimulation devices are procedural and emerging therapies that have promising safety profiles for pregnant women with headache disorders.
Acute headache occurring in pregnancy and the postpartum period is a red flag requiring diagnostic vigilance. Migraine frequency in women typically improves during pregnancy, although this trend is less certain when aura is present and after delivery. Acute and preventive treatment plans during pregnancy and lactation are plausible but may require shifts in therapeutic hierarchy. Relatively safe oral, parenteral, and procedural therapies are available for pregnant women. Noninvasive neuromodulation devices are already available and will likely play a greater role in the coming years. Migraine is associated with medical and obstetrical complications during pregnancy, and women with frequent migraine attacks may need to be considered high risk.
- Recent evidence suggests that new headache in pregnancy and in the puerperium (within 6 weeks postpartum) is a red flag for secondary headache.
- Among women with a history of headache, a changed feature of a longer attack duration was associated with a secondary headache disorder diagnosis.
- A diagnostic strategy for acute headache in pregnant women should feature liberal use of noncontrast MRI and monitoring for preeclampsia, particularly in those with an elevated blood pressure and without a headache history.
- Migraine without aura typically improves or remits altogether in most women when pregnant, with improvement or remission observed in nearly 47% of women during the first trimester, in 83% of women during the second trimester, and in 87% of women during the third trimester.
- Migraine with aura is less likely to improve during pregnancy than migraine without aura. New-onset migraine with aura and even aura without headache may occur in the later stages of pregnancy.
- Management of migraine during pregnancy always starts with preconception counseling whenever feasible.
- Nonpharmacologic therapies should always be emphasized as an important aspect of migraine management, especially during pregnancy.
- Migraine prophylactic medication may be unnecessary in pregnancy because of the generally good prognosis and should be avoided because of teratogenic concerns.
- Butalbital compounds that are used in combination with acetaminophen or aspirin and caffeine have recently been associated with congenital heart defects and are generally not recommended.
- The majority of evidence suggests triptans intrinsically may not adversely impact labor and delivery outcomes, but more studies among pregnant women stratified by migraine severity may provide further clarity.
- Occipital and trigeminal pericranial nerve blocks are a treatment used for migraine, cluster headache, and other headache disorders as an acute therapy as well as for short-term prevention and are appealing to use in pregnancy because of their peripheral administration and presumed safety.
- Headaches associated with spinal or epidural anesthesia could take two forms: post–dural puncture headache and pneumocephalus.
- Over half of all women who have migraine will have an attack postpartum, so the management of postpartum headache, particularly in breast-feeding women, is an important clinical problem.
- Of the triptans, eletriptan is likely the most compatible medication with breast-feeding based on its low milk to plasma ratio.
- The evaluation of a pregnant or postpartum woman with suspected preeclampsia is also confounded by migraine serving as a preeclampsia risk factor. The distinction is crucial as migraine and preeclampsia are managed differently, with antepartum severe preeclampsia managed by expedited delivery.
Article 8: Pediatric and Adolescent Headache
Amy A. Gelfand, MD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1108–1136.
PURPOSE OF REVIEW
This article provides the practicing neurologist with a comprehensive, evidence-based approach to the diagnosis and management of headache in children and adolescents, with a focus on migraine.
Four triptans are now labeled by the US Food and Drug Administration (FDA) for acute migraine treatment in adolescents, and rizatriptan is labeled for use in children age 6 and older. For preventive migraine treatment, the Childhood and Adolescent Migraine Prevention trial demonstrated that approximately 60% of children and adolescents with migraine will improve with a three-pronged treatment approach that includes: (1) lifestyle management counseling (on sleep, exercise, hydration, caffeine, and avoidance of meal skipping); (2) optimally dosed acute therapy, specifically nonsteroidal anti-inflammatory drugs and triptans; and (3) a preventive treatment that has some evidence for efficacy. For the remaining 40% of children and adolescents, and for those who would not have qualified for the Childhood and Adolescent Migraine Prevention trial because of having continuous headache or medication-overuse headache, the clinician’s judgment remains the best guide to preventive therapy selection.
Randomized placebo-controlled trials have been conducted to guide first-line acute and preventive migraine treatments in children and adolescents. Future research is needed to guide treatment for those with more refractory migraine, as well as for children and adolescents who have other primary headache disorders.
- New headaches, or new types of headaches, are more concerning for secondary pathology than old headaches.
- By age 10, migraine prevalence in children is approximately 5%. This means that by fifth grade, almost every classroom contains at least one child with migraine.
- The Pediatric Migraine Disability Assessment questionnaire is a six-question validated instrument for measuring headache-related disability in children and adolescents.
- Common premonitory symptoms in pediatric migraine include fatigue, irritability/mood changes, neck stiffness, and facial change.
- Differentiating premonitory symptom from migraine triggers can be challenging.
- Chocolate does not appear to be a migraine trigger.
- Cannabinoid hyperemesis syndrome can mimic cyclic vomiting syndrome in adolescents.
- Combine cognitive-behavioral therapy with pharmacologic preventive treatment for chronic migraine in children and adolescents ages 10 to 17 years.
- First-line pharmacologic preventives for pediatric and adolescent migraine should have a side effect profile comparable to that of placebo.
- In the United States, 504 plans allow children and teenagers to have necessary accommodations at school for management of a medical condition, such as migraine. All children and adolescents with migraine should have an annual letter from their doctor stating their diagnosis and supporting accommodations for their 504 plan.
- Four triptans are labeled by the US Food and Drug Administration for acute migraine in adolescents 12 to 17 years of age: almotriptan (oral), zolmitriptan (nasal spray), rizatriptan (melt), and sumatriptan/naproxen (oral); and one medication, rizatriptan (melt), is labeled for use in children age 6 and older.
- Children and adolescents who are on selective serotonin reuptake inhibitors or serotonin norepinephrine reuptake inhibitors generally do not need to have their access to triptans restricted.
- While tension-type headache exists in the general pediatric population, it is not a common reason for clinical presentation.
- Nausea is not present in tension-type headache. The presence of nausea in children with headaches has high specificity for a diagnosis of migraine.
- Primary stabbing headache is a particularly common reason for clinical presentation in children younger than the age of 6 years.
- Primary stabbing headache pain intensity can be severe in children.
Article 9: Cluster Headache and Other Trigeminal Autonomic Cephalalgias
Mark Burish, MD, PhD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1137–1156.
PURPOSE OF REVIEW
This article covers the clinical features, differential diagnosis, and management of the trigeminal autonomic cephalalgias (TACs). The TACs are composed of five diseases: cluster headache, paroxysmal hemicrania, short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing (SUNCT), short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms (SUNA), and hemicrania continua.
New classifications for the TACs have two important updates; chronic cluster headache is now defined as remission periods lasting less than 3 months (formerly less than 1 month), and hemicrania continua is now classified as a TAC (formerly classified as other primary headache). The first-line treatments of TACs have not changed in recent years: cluster headache is managed with oxygen, triptans, and verapamil; paroxysmal hemicrania and hemicrania continua are managed with indomethacin; and SUNCT and SUNA are managed with lamotrigine. However, advancements in neuromodulation have recently provided additional options for patients with cluster headache, which include noninvasive devices for abortive therapy and invasive devices for refractory cluster headache. Patient selection for these devices is key.
The TACs are a group of diseases that appear similar to each other and to other headache disorders but have important differences. Proper diagnosis is crucial for proper treatment. This article reviews the pathophysiology, epidemiology, differential diagnosis, and treatment of the TACs.
- The trigeminal and autonomic systems are connected through the trigeminal autonomic reflex.
- Functional imaging has shown activation of the posterior hypothalamus at the onset of a cluster headache attack.
- Cluster headache is 3 times more common in men, with a typical age of onset between 20 and 40 years of age. The two forms of cluster headache are an episodic version, where patients have a headache-free period of more than 3 months, and a chronic version, where the headache-free period is less than 3 months.
- The pain in cluster headache is excruciating, anecdotally worse than migraine, childbirth, or kidney stones.
- Cluster headache has well-defined criteria. Other features that are common in cluster headache include rapid escalation and de-escalation of pain, alcohol as a trigger during the headache period (but not during the remission period), a positive response to subcutaneous sumatriptan, a positive response to high-flow oxygen, and a clocklike daily pattern of headaches.
- Cluster headache may include short frequent headaches (mimicking paroxysmal hemicrania) or a mild interictal headache (mimicking hemicrania continua). An indomethacin trial is warranted in these situations.
- Patients with cluster headache may have migrainous features such as photophobia, phonophobia, and nausea. Patients with migraine likewise may have cranial autonomic symptoms.
- The differential diagnosis between cluster headache and migraine can often be made based on the duration, frequency, and associated factors such as restlessness.
- When using triptans to treat cluster headache, quicker routes are better: subcutaneous is more effective than nasal, which is more effective than oral.
- For the acute treatment of cluster headache, oxygen and noninvasive vagus nerve stimulation are good options for patients with multiple attacks per day.
- Unlike cluster headache, paroxysmal hemicrania has shorter and more frequent attacks, has a slight female predominance, is more likely to be chronic, is less likely to be circadian, can be triggered by neck movements, and responds completely to indomethacin.
- Indomethacin is not always well tolerated. A gastroprotective medication should be considered. In addition, indomethacin should be downtitrated to find the minimal effective dose, which is often less than a total daily dose of 100 mg.
- In comparison to short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms, trigeminal neuralgia does not have prominent cranial autonomic features, and has a refractory period for tactile stimuli.
- Hemicrania continua has more prominent migrainous features and less prominent cranial autonomic features than other trigeminal autonomic cephalalgias.
- Patients with hemicrania continua on indomethacin should be gradually downtitrated approximately every 6 months, as remissions have been reported for hemicrania continua.
- If indomethacin is not effective after a solid 1- to 2-week course at 75 mg 3 times a day, the diagnosis of hemicrania continua or paroxysmal hemicrania should be reconsidered.
Article 10: Cranial Neuralgias
Stewart J. Tepper, MD, FAHS. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1157–1178.
PURPOSE OF REVIEW
This article describes the clinical features and diagnostic criteria, pathophysiology (when known), and treatment strategies of the major cranial neuralgias.
Abnormal vascular loops compressing cranial nerves are the most common known pathogenesis associated with the primary neuralgias.
The most frequently encountered primary neuralgias are trigeminal neuralgia, occipital neuralgia, and, rarely, glossopharyngeal neuralgia. Nervus intermedius neuralgia is even more rare. All neuralgias merit a careful workup for secondary causes. Drug treatment generally relies on antiepileptic drugs, antidepressants, and baclofen. OnabotulinumtoxinA can be useful in treating some cranial neuralgias. Surgical and invasive treatments include ablation, gamma knife treatment, and microvascular decompression.
- The International Classification of Headache Disorders, Third Edition uses the term classical trigeminal neuralgia for what was previously called primary trigeminal neuralgia.
- Classical trigeminal neuralgia can occur in two forms: a purely paroxysmal form and a form with concomitant persistent interictal facial pain in a trigeminal distribution.
- Most cases of trigeminal neuralgia involve the second or third division of cranial nerve V.
- An abnormal examination suggests a secondary cause of trigeminal or other neuralgias, but this is not invariable.
- Classical trigeminal neuralgia is almost never in a V1 distribution. Consider other diagnoses and ask about accompanying autonomic features to differentiate short-lasting unilateral neuralgiform headaches, which are usually in a V1 distribution.
- Most cases of classical trigeminal neuralgia are thought to be secondary to an abnormal vascular loop compressing the symptomatic trigeminal division around the dorsal root entry zone, also called neurovascular compression.
- Although most cases of classical trigeminal neuralgia respond initially to carbamazepine or oxcarbazepine, short-lasting unilateral neuralgiform headache attacks can also respond to these antiepileptic drugs, so that therapeutic response does not always yield a clear diagnosis.
- Numerous peripheral and central surgical and nonsurgical approaches can be tried for classical trigeminal neuralgias, including block or destruction of portions of the trigeminal nerve distal to the gasserian ganglia, percutaneous rhizotomies, gamma knife treatment, and microvascular
- The most common painful trigeminal neuropathy is herpetic.
- Pain related to any of the painful trigeminal neuropathies is best treated with antiepileptic drugs or tricyclic antidepressants. Early addition of gabapentin to the antiviral regimen in acute shingles may help prevent postherpetic trigeminal neuropathy.
- Proven pain-reducing medications for postherpetic trigeminal neuropathy begin with antiepileptic drugs. If these fail or are contraindicated, tricyclic antidepressants or serotonin norepinephrine reuptake inhibitors can be useful, as can topical capsaicin and lidocaine.
- Medical, not surgical, management is recommended for treatment of painful trigeminal neuropathies.
- Prevalence of painful trigeminal neuropathy attributed to a multiple sclerosis plaque ranges from 1.5% to 7.9% of patients with multiple sclerosis.
- The pain of glossopharyngeal neuralgia not only includes the distribution of the glossopharyngeal nerve but can extend into the pharyngeal and auricular vagal branches.
- Glossopharyngeal neuralgia is generally felt in the posterior tongue, pharynx, tonsillar fossa, or below the lower jaw angle and the ear. Clinical manifestations such as hoarseness, cough, neurocardiogenic bradycardia, sick sinus syndrome, asystole, seizures, and syncope suggest vagal involvement.
- Nervus intermedius neuralgia can present as either a set of brief, severe, stabbing, shooting, piercing, or sharp pains, or pains of longer duration, from 2 seconds to minutes in duration deep within the internal auditory canal. The patients usually have a trigger that occurs with touching the posterior wall of the external auditory canal or a zone around the ear.
- Occipital neuralgia is paroxysmal and generally occurs in the distribution of the greater occipital nerve. A different location or a continuous pain, especially with other associated symptoms, should call for a reconsideration of the diagnosis.
- Treatment of occipital neuralgia begins with a peripheral nerve block.
Article 11: Secondary Headache Syndromes
Denise E. Chou, MD. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1179–1191.
PURPOSE OF REVIEW
This article is intended to assist clinicians in distinguishing benign primary headache syndromes from serious headache presentations that arise from exogenous causes.
Although most cases of severe headache are benign, it is essential to recognize the signs and symptoms of potentially life-threatening conditions. Patients with primary headache disorders can also acquire secondary conditions that may present as a change in their baseline headache patterns and characteristics. Clinical clues in the history and examination can help guide the diagnosis and management of secondary headache disorders. Furthermore, advances in the understanding of basic mechanisms of headache may offer insight into the proposed pathophysiology of secondary headaches.
Several structural, vascular, infectious, inflammatory, and traumatic causes of headache are highlighted. Careful history taking and examination can enable prompt identification and treatment of underlying serious medical disorders causing secondary headache syndromes.
- A potentially serious cause is more likely with a new severe headache than with a headache that has been recurrent over years.
- In contrast to common belief, brain tumors constitute a rare cause of headache and even less frequently present with severe pain. Approximately 30% of patients diagnosed with a brain tumor report headache on presentation; however, only 1% to 2% report headache as the sole clinical symptom.
- Distinguishing headache features in cases of nontraumatic subarachnoid hemorrhage include occipital location, a “stabbing” quality, a rapid peak of intensity (within 1 second of onset), and associated meningismus.
- Headache occurs in 60% to 95% of cases of carotid artery dissections, is usually unilateral with face/neck pain on the same side, and may be accompanied by ipsilateral Horner syndrome or amaurosis fugax.
- Reversible cerebral vasoconstriction syndrome headaches are often bilateral, brief in duration (1 to 3 hours), recurrent over a span of days to weeks, and are sudden in onset, rapidly reaching a maximal severe intensity (thunderclap).
- Distinguishing cardiac cephalalgia from migraine, which may also be aggravated by exertion, is essential to avoid the inappropriate administration of triptan or ergot medications, which are contraindicated in coronary syndromes because of their vasoconstrictive effects.
- Blindness can be a complication of untreated temporal arteritis in approximately half of patients because of involvement of the ophthalmic artery and its branches; however, visual loss can be prevented with prompt glucocorticoid treatment.
- Contrast-enhanced MRI may demonstrate granulomatous inflammation of the cavernous sinus, superior orbital fissure, or orbit in Tolosa-Hunt syndrome.
- Risk factors for the development of posttraumatic headache include a prior history of headache, milder degree of head trauma, and age younger than 60 years.
- Intermittent angle-closure glaucoma may be mistaken for migraine, as both conditions can present with unilateral eye pain, nausea/vomiting, light sensitivity, and visual disturbances.
- The occurrence of cranial autonomic symptoms in migraine (such as lacrimation, nasal congestion, and rhinorrhea) may contribute to the misdiagnosis of “sinus headache.”
- Although relatively infrequent, sphenoid sinusitis is a serious condition because of the potential complication of cavernous sinus thrombophlebitis.
- Headache attributed to temporomandibular disorders is usually unilateral and should be ipsilateral to the pathology when the temporomandibular complex is the source of pain, but can be bilateral when muscular involvement is present.
Article 12: Unusual Headache Disorders
Amaal Jilani Starling, MD, FAHS. Continuum (Minneap Minn). August 2018; 24 (4 Headache):1192–1208.
PURPOSE OF REVIEW
Unusual headache disorders are less commonly discussed and may be misdiagnosed. These headache disorders frequently have a benign natural history; however, without reassurance, therapeutic education, and treatment, they can negatively affect the health and function of patients.
This article reviews the clinical features, diagnosis, workup, and proposed treatments for several unusual headache disorders including primary cough headache, primary headache associated with sexual activity, primary exercise headache, cold-stimulus headache, primary stabbing headache, nummular headache, hypnic headache, and headache attributed to travel in space. Exploding head syndrome is also discussed, which is a sleep disorder commonly confused with a headache disorder.
Unusual headache disorders are usually benign, yet without the correct diagnosis can be very worrisome for many patients. Through greater awareness of these headache disorders, neurologists can evaluate and effectively manage unusual headache disorders, which offers significant benefits to patients and practice satisfaction to neurologists.
- Given that primary cough headache is rare, when a patient presents with a headache triggered by cough or some other Valsalva maneuver that may raise intracranial pressure, the most essential first step is to rule out a secondary cause based on red flags identified on history and examination.
- Since primary cough headaches are benign attacks of short duration, often reassurance is the only treatment needed.
- An explosive attack just before or with orgasm is a thunderclap headache, which is a headache red flag and a neurologic emergency.
- A diagnosis of primary headache associated with sexual activity can be considered once more alarming causes of headache have been ruled out; thus, it is a diagnosis of exclusion.
- Anticipatory treatment 30 minutes prior to sexual activity with indomethacin can be an effective treatment plan for most patients with primary headache associated with sexual activity. However, if longer term prevention is needed, beta-blockers have also been used successfully.
- Primary exercise headache is unique in that it is precipitated by sustained physically strenuous activity rather than short-duration precipitating factors such as cough, Valsalva maneuver, or orgasm.
- Given the high prevalence in athletes, primary exercise headache should be considered when evaluating an athlete with headache.
- Precipitation of headache by exercise or exertion is a headache red flag and should raise concern for a secondary cause of headache.
- Cardiac cephalalgia should be considered in older adults with vascular risk factors who present with a headache precipitated by exercise. The headache is a result of myocardial ischemia and can be the sole manifestation of ischemia. A stress test is diagnostic, and revascularization of coronary vessels is curative.
- Given that primary exercise headache is a self-limited, benign disorder, once a workup has been completed, treatment is often as simple as trigger avoidance. However, exercise is essential for healthy living, and if primary exercise headache is a barrier to exercise, then pharmacotherapy is available and typically effective.
- In headache attributed to ingestion or inhalation of a cold stimulus, intense pain typically begins within a few seconds of the rapid ingestion or inhalation of cold material and is short lasting, persisting only for seconds.
- In headache attributed to ingestion or inhalation of a cold stimulus, the exposure of the palate or the posterior pharyngeal wall to a very cold substance may trigger rapid constriction and dilation of vessels, thus activating the nociceptors in the vessel wall, resulting in referred pain to the head.
- Aside from trigger avoidance, no specific treatment is required for headache attributed to ingestion or inhalation of a cold stimulus. Cold substances should be ingested slowly while avoiding rapid exposure of cold substances to the posterior aspect of the palate if possible.
- Clinically, primary stabbing headaches are headaches with the shortest duration, with studies demonstrating that 80% of stabbing pains last 3 seconds or less.
- The differential diagnosis for primary stabbing headache includes trigeminal neuralgia and trigeminal autonomic cephalalgias, specifically short-lasting unilateral neuralgiform headache attacks with conjunctival injection and tearing and short-lasting unilateral neuralgiform headache attacks with cranial autonomic symptoms.
- Idiopathic primary stabbing headache is benign and typically does not require any specific treatment aside from reassurance. However, if the stabbing pains are more frequent, indomethacin is the medication of choice.
- Nummular headache is an unusual primary headache disorder characterized by head pain that occurs in a small, fixed, very well-circumscribed coin, oval, or elliptical shape.
- Entities to consider in the differential diagnosis for nummular headache include primary stabbing headache, although this is typically multifocal and not unifocal as in nummular headache; epicrania fugax, although this head pain is in motion and not a focal, coin-shaped area as occurs in nummular headache; and other cranial neuralgias, although these would follow the relevant nerve distribution and respond to anesthetic blocks, both of which do not occur in nummular headache.
- Hypnic headache is a recurrent primary headache disorder of short duration that typically occurs in older persons, typically after the age of 50. These headaches occur only during sleep and will cause the person to awaken.
- The differential diagnosis for nocturnal headaches includes nocturnal hypertension, increased intracranial pressure (mass lesion or idiopathic intracranial hypertension), trigeminal autonomic cephalalgias (specifically cluster headache), caffeine withdrawal headache and medication-overuse (rebound) headache, or sleep apnea headache.
- Treatment options for hypnic headache include caffeine, melatonin, and lithium. Although effective, lithium may be problematic especially for older patients because of the possibility for lithium toxicity. Fortunately, caffeine and/or melatonin are typically effective, thus avoiding use of lithium altogether.
- Space headache has been reported in all phases of space flight. It typically has a moderate to severe intensity with an exploding or heavy quality of pain requiring analgesics.
- During an acute attack of exploding head syndrome, the patient has a perception of a loud, explosive noise in the absence of objective acoustic stimulation that usually occurs during sleep transitions when going to sleep or awakening. It is sudden, causes fear, but is not associated with head pain.
- Exploding head syndrome is benign, and reassurance is the cornerstone of treatment.