Neurologists routinely encounter patients with symptoms of sleepiness or sleeplessness and unrecognized sleep disorders in outpatient and inpatient settings. Poor or disrupted sleep may result from symptoms such as pain or discomfort related to their primary neurologic condition, and many of the medications used for chronic neurologic conditions can have side effects such as sleepiness, fatigue, or insomnia. Neurologic diseases can affect specific areas of the brain responsible for alertness and sleep, causing sleep symptoms in these patients. Just as clinicians are demonstrating a growing appreciation for sleep in the role of neurologic function and recovery, patients are also becoming more interested in improving their sleep to better their health. Consumer sleep and health trackers are increasing in popularity and often are a point of discussion during a clinic visit with their neurologist or another medical provider. Clinical evaluation and objective testing are critical for clinicians trying to address and improve their patients’ sleep symptoms.
THE SLEEPY PATIENT
Excessive daytime sleepiness is defined as the inability to stay awake and alert during the major waking episodes of the day, resulting in periods of irrepressible need for sleep or unintended lapses into drowsiness or sleep. Approximately 20% to 25% of the general population has excessive daytime sleepiness. Sleepiness is found to be even more common in patients with chronic neurologic disorders. Excessive daytime sleepiness can lead to reduced performance at school, work, or other activities such as driving where alertness is vital for safety. An estimated 1 in 25 adult drivers reports having fallen asleep while driving in the previous 30 days. Excessive daytime sleepiness is one of the most common chief complaints in patients presenting to sleep centers and is a common symptom in patients with neurologic disorders. The differential diagnosis is lengthy for excessive daytime sleepiness (table 2-1), and it is important to use different clinical tools and laboratory tests to narrow in on a diagnosis.
When approaching a patient who seeks evaluation of excessive daytime sleepiness, a thorough and detailed history is paramount in helping decide if and which subsequent testing or laboratory evaluation is appropriate. Numerous disorders can lead to excessive daytime sleepiness (table 2-1), and the history and physical examination can help the clinician narrow the differential diagnosis. Even when objective testing is complete, the history and physical examination are critical in interpreting the objective data to formulate a diagnosis and treatment plan.
It is imperative to gather information from not only the patient but collateral sources as well. Patients who have sleep disorders may not be aware of their sleepiness or may inaccurately judge their ability to remain alert during the daytime, as sleep disorders themselves have an effect on the brain’s ability to accurately self-assess. Patients may minimize the severity of their symptoms due to the long-standing, chronic nature of most sleep disorders. Their sleep issue may only come to clinical attention because of problems at work or a dangerous event such as a motor vehicle accident related to sleepiness. Spouses, other family members, coworkers, or friends may give more insight into how patients’ sleepiness may be affecting their job, social life, driving, or other activities. A bed partner may be the best person to provide details on what types of activities are occurring during sleep (eg, snoring, abnormal movements, and apneas).
It is essential for the clinician to obtain details on not only how severe or significant daytime sleepiness is for the patient but also when and how often it occurs. The timing and circumstances of the sleepiness may help determine the cause or which follow-up questions to ask. Careful questioning regarding drowsiness during driving and work or school should be investigated. The Epworth Sleepiness Scale is a commonly used tool to assess excessive daytime sleepiness in an outpatient setting, with a score greater than 10 signifying abnormal sleepiness during the day (sdc appendix a, links.lww.com/CONT/A379).
Sleepiness can present in various ways: hyperactivity, inattention, irritability, poor behavior, or fatigue. Although fatigue may lead the clinician to think that the etiology may not be related to a sleep disorder, many patients who have sleep disorders report more fatigue than sleepiness or may report “tiredness” or “lack of energy.” When patients report falling asleep during activities or at inappropriate times during the day, this points more toward a sleep disorder. For disorders causing fatigue, patients typically report not wanting to do activities due to lack of energy or low motivation.
Inquiring about patients’ sleep schedules, specifically bedtimes and wake times on both work/school days versus days they are off, is necessary to assess for possible insufficient sleep. Specifically, clinicians should ask about the use of electronics (phones or tablets) or other activities around bedtime instead of prioritizing sleep because these are among the most common reasons for patients not obtaining a sufficient amount of sleep at night. Clinicians should also ask about bedtime routine, latency to sleep, awakenings at night, wake after sleep onset, and any naps taken during the day. A consensus statement from the Sleep Research Society and the American Academy of Sleep Medicine recommends that adults should sleep at least 7 or more hours per night on a regular basis for optimal health. Children require more hours of sleep based on age. Insufficient sleep is the most common cause of sleepiness in the United States with an estimated one-third of Americans not getting an adequate duration of sleep. Obtaining the patient’s work schedule and whether or not the patient works evening or night shifts will also be helpful in learning if the patient is allowing adequate timing and duration of sleep.
When evaluating a patient for sleepiness, it is important to screen for common sleep disorders such as obstructive sleep apnea as well as more rare disorders such as narcolepsy. Asking about snoring, noisy breathing, apneas during sleep, or nonspecific symptoms such as night sweats, nocturia, morning headaches, and mouth breathing can assist in assessing the patient’s risk of possible obstructive sleep apnea. When investigating for possible narcolepsy, it is important to ask about key clinical features such as sleep paralysis, sleep-related hallucinations, and cataplexy (table 2-2). Sleep paralysis and sleep-related hallucinations are nonspecific and can be seen in various sleep disorders and in healthy patients. Cataplexy is characteristic of narcolepsy and consists of brief episodes of transient muscle weakness triggered by usually positive emotions (typically laughter). This can involve a few muscles (ie, face, legs, neck) or lead to the patient slowly falling to the ground due to loss of control of multiple muscle groups. The patient should be asked about any abnormal motor activity during sleep, as periodic limb movements of sleep or parasomnias such as rapid eye movement (REM) sleep behavior disorder or sleepwalking can also lead to nonrestorative sleep or hypersomnia as well as insomnia.
Obtaining an accurate past medical history may also be useful in evaluation for hypersomnia. Certain medical conditions, such as heart failure, stroke, or chronic obstructive pulmonary disease, may put the patient at higher risk of sleep-disordered breathing. A history of central nervous system conditions such as traumatic brain injury or neurodegenerative diseases (eg, Parkinson disease) places patients at higher risk of central nervous system hypersomnias and narcolepsylike conditions, especially if the onset of sleepiness correlates with the onset of other neurologic signs and symptoms. Asking the patient about a past surgical history of adenotonsillectomy or previous upper airway surgery is important as these types of surgery can have an effect on snoring and possible future management of sleep-disordered breathing.
Reviewing the patient’s medications (prescribed and over the counter) may assist in identifying contributors to excessive daytime sleepiness. The following medications are most likely to be associated with excessive daytime sleepiness: antiepileptics, antidepressants, anxiolytics, blood pressure medications, dopamine agonists, and pain medications.
A detailed social history, specifically about substance use, is important due to the significant sleep-altering effects of both intoxication and withdrawal of certain recreational drugs. Smoking cigarettes puts patients at risk of sleep-disordered breathing, can be stimulating, and can cause problems with insomnia if done close to bedtime. It is essential to ask about the use of caffeine (frequency and amount), as many patients will try to mask their symptoms of sleepiness with the alerting properties of caffeine. Alcohol use, especially close to bedtime, can lead to poor-quality sleep and insomnia. Occupational history may be relevant if a patient’s employment is in a “high-consequence” industry where sleepiness may lead to serious morbidity or mortality. Occupations such as pilot and commercial driver (eg, truck driver, taxi driver) come with specific regulations regarding the diagnosis and treatment of sleep disorders to ensure safety in the air and on roads.
Certain sleep disorders that cause sleepiness run in families. Narcolepsy, sleep apnea, RLS, and certain parasomnias are seen in greater proportions in family members of patients with these conditions. Due to poor recognition of sleep disorders such as sleep apnea and narcolepsy in the past, it is important to ask about certain symptoms of these conditions, as some family members may not have been formally diagnosed. For example, patients may comment that siblings and aunts or uncles have had snoring and apneas during sleep but do not carry a formal diagnosis of sleep apnea.
A systematic review of systems is indispensable given the vast effect sleep disorders can have on almost any organ system or body function. In addition, correctly recognizing an underlying medical or psychiatric disorder may help clarify some patients’ sleep complaints.
Important findings on physical examination may assist in the evaluation of a sleepy patient. Some striking findings of hypersomnia, although uncommonly encountered, include a patient asleep in the waiting room or nodding off while the clinician is taking a history in clinic. Most of the time, clues from the physical examination lead to some of the more common causes of excessive daytime sleepiness, such as obstructive sleep apnea or central nervous system hypersomnias.
Regarding vital signs, low oxygen saturation at rest or an increased respiratory rate may point to an underlying pulmonary condition putting the patient at risk of sleep-disordered breathing. High blood pressure, an elevated BMI (obesity), or an enlarged neck circumference (greater than 43 centimeters [17 inches] in men and greater than 41 centimeters [16 inches] in women) is also seen in higher rates in patients with obstructive sleep apnea.
Oropharyngeal examination should evaluate for a crowded upper airway, dental malocclusion, craniofacial abnormalities, and presence of tonsils or adenoids. Abnormalities to look for include micrognathia, retrognathia, macroglossia, scalloping of the tongue, and significant overjet. All of these features increase the risk of obstructive sleep apnea. One method of categorizing the size of the airway is the Mallampati classification, which correlates with the risk of obstructive sleep apnea and serves as a useful tool in describing the posterior pharyngeal structure and airway. The score is obtained by asking a seated patient to open his or her mouth and fully protrude his or her tongue (no phonation) and examining the airway. In a Mallampati class I airway, the soft palate, hard palate, uvula, and tonsillar pillars can be seen. In a Mallampati class II airway, all structures except the tonsillar pillars can be seen. In a Mallampati class III airway, only the soft and hard palate and base of the uvula are seen. In a Mallampati class IV airway, only the hard palate is visualized, suggesting a crowded airway and putting the patient at the highest risk of sleep apnea (figure 2-1). A nasal examination may demonstrate a deviated septum, nasal polyps, or other causes of chronic nasal congestion that lead to mouth breathing and higher risk of sleep apnea.
A detailed cardiac and pulmonary examination will be helpful in looking for any arrhythmias, murmurs, signs of heart failure, or abnormal pulmonary findings that put the patient at risk of sleep apnea (central or obstructive). In addition, signs indicating respiratory dysfunction may point toward other causes of sleep-disordered breathing such as sleep-related hypoventilation or hypoxia.
A comprehensive neurologic examination is helpful as many neurologic disorders result in symptoms of excessive daytime sleepiness. Focal deficits may raise concern for multiple sclerosis or stroke, both putting the patient at risk of central sleep apnea or central nervous system hypersomnias. Resting tremor, rigidity, or bradykinesia may be a sign of a neurodegenerative condition such as Parkinson disease, putting the patient at risk of a variety of sleep disorders, namely REM sleep behavior disorder.
To help augment the clinical history and examination, a variety of useful questionnaires can serve as tools in identifying sleep disorders that cause hypersomnia. The Functional Outcomes of Sleep Questionnaire, Berlin Questionnaire, and STOP-BANG questionnaire (table 2-3) are just a few that are useful in helping to identify patients at risk of specifically obstructive sleep apnea.
A clinical history and examination assist the clinician in streamlining an otherwise lengthy differential diagnosis of hypersomnia. However, because of the nonspecific symptoms of certain sleep disorders, objective testing is often necessary to make a formal diagnosis. Objective testing can include simple sleep diaries or more extensive testing such as polysomnography, home sleep apnea tests, multiple sleep latency tests (MSLTs), or the maintenance of wakefulness test.
Having patients complete sleep diaries for days or weeks can be helpful in determining if they are getting an adequate amount of sleep or have insufficient sleep syndrome. The diaries can also assist with evaluation of circadian rhythm disorders as a cause of sleepiness by reviewing the timing of patients’ main period of sleep. With sleep diaries, patients not only record how much sleep they get but may include information such as medications taken, bedtime, time to sleep onset, number of awakenings, time of waking, time out of bed, and length and timing of any naps (sdc appendix b, links.lww.com/CONT/A380, shows an example of a 2-week sleep diary that can be used in the clinical evaluation of a patient with sleepiness or sleeplessness). Some commercially available consumer sleep tracking devices may also help patients track how much time they are dedicating to sleep on a regular basis, but their appropriate clinical use is still uncertain. Actigraphy, a wrist-worn accelerometer that is a noninvasive measure of rest and activity by recording movement, is a proven method for helping augment the information from sleep diaries. Collected data can be downloaded for review and analysis of activity to help determine the duration and timing of sleep (figure 2-2).
Overnight attended polysomnography is considered the gold standard in evaluation of sleep and includes the patient spending the night at a sleep center in a monitored environment. The test typically consists of video, EEG, and monitoring eye movements (with electrooculography), chin and leg motor activity (with electromyography [EMG]), airflow parameters (typically with a nasal pressure transducer and nasal-oral thermistor), respiratory effort parameters (both thoracic and abdominal), oxygen saturation, and body position (figure 2-3). Additional sensors may also include transcutaneous carbon dioxide monitoring, added EEG leads, or upper extremity leads. With attended polysomnography, a qualified technologist places all probes and wires on the patient prior to the study initiation and observes the patient throughout the night, ensuring that the patient is medically stable and that the recorded data are accurately obtained.
Polysomnography is most commonly used for evaluation of obstructive sleep apnea or to determine optimal treatment for sleep-disordered breathing (positive airway pressure titration). In-laboratory sleep studies, which allow for monitoring and capturing limb movement on video, are also helpful to evaluate abnormal movements such as periodic limb movements of sleep. Polysomnography can be helpful in evaluating for REM sleep without atonia, which is necessary for a diagnosis of REM sleep behavior disorder. REM sleep without atonia is characterized by an abnormally elevated chin or limb EMG tone during REM sleep. Polysomnography may assist in the detection of interictal or ictal abnormalities on EEG to diagnose seizures. Polysomnography is also used in the evaluation for central nervous system hypersomnias, such as narcolepsy, in addition to MSLTs. Besides measuring the time asleep and in each stage of sleep, polysomnography typically provides information such as the apnea-hypopnea index, the number of apneas and hypopneas per hour of sleep used to make a diagnosis of sleep-disordered breathing.
Home sleep apnea tests have become more common as a tool for diagnosing obstructive sleep apnea in adults. Home monitoring of sleep-related breathing was approved by the Centers for Medicare & Medicaid Services (CMS) in 2007 and is not only accepted but many times preferred by private payers (due to reduced cost) as the first diagnostic test in evaluating adults for obstructive sleep apnea. Home sleep apnea tests are variable in the number and types of signals they record, but most measure airflow, respiratory effort, and oximetry in a portable device that patients take home and set up themselves. Alternatively, other devices use the peripheral arterial tone signal from a finger as a noninvasive measure of the arterial pulsatile volume changes at the fingertip. Specific patterns of change in sympathetic nervous system activity, along with changes in heart rate and oxygen desaturation, can be used to detect obstructive respiratory events during sleep. With any type of home sleep apnea test, the patient places the sensors, turns on the device, sleeps through the night, and then typically returns the device and the recorded data for interpretation by the sleep specialist. One of the limitations of most home sleep apnea tests is that they do not measure EEG or sleep directly because they typically do not measure sleep stages or respiratory events that lead to arousal or sleep fragmentation but focus primarily on respiratory events that cause oxygen desaturation. In addition, the tests are performed at home without technologists available to ensure good recording signals, which leads to a higher rate of failure and artifact as compared with attended polysomnography. Home sleep apnea tests provide clinicians with information such as a respiratory event index, which is the number of apneas and hypopneas per recording time of the test, and minimum oxygen saturation during the recording. Overall, home sleep apnea tests can underestimate or even miss a diagnosis of obstructive sleep apnea; attended polysomnography is usually required as the next step in the evaluation of obstructive sleep apnea if the home sleep apnea test is negative or inconclusive. Due to these limitations, home sleep apnea tests should be used only for patients thought to be at moderate or high risk of obstructive sleep apnea and should not be used to screen the general population. Patients who have comorbidities such as stroke or heart failure (where central sleep apnea is a concern), significant intrinsic lung disease, or neuromuscular conditions that may cause hypoventilation are also not candidates for home sleep apnea testing. Patients who are at risk of hypoventilation require a sleep study at a sleep center for diagnosis and treatment that is complex and may require varying treatment modalities or supplemental oxygen. Despite some of these limitations, home sleep apnea testing is growing, is less expensive than polysomnography, and allows patients who are uninterested in testing at a sleep center to be evaluated at home in their own beds. table 2-4 lists indications for home sleep apnea testing per American Academy of Sleep Medicine guidelines.
The MSLT remains the gold standard as an objective measure of excessive daytime sleepiness and the key test available for the diagnosis of narcolepsy and idiopathic hypersomnia. No other serum markers, imaging tests, or sleep studies available at this time are better validated measures of sleepiness. The MSLT measures the physiologic tendency for a patient to fall asleep while in a quiet environment during the day and following an in-center polysomnogram.
The MSLT consists of four or five nap opportunities at 2-hour intervals spread out throughout the day. EEG from central and occipital locations, two electrooculograms (left and right) at the outer canthi, a mental or submental EMG, and an ECG are recorded during the MSLT to help determine sleep stages. The patient is given 20 minutes to fall asleep with each nap opportunity. As mentioned earlier, an overnight attended polysomnogram the night before is necessary to evaluate for other causes of sleepiness and to ensure that the patient achieved adequate sleep the night before testing. It is equally important to ensure that the patient had sufficient sleep the 1 to 2 weeks leading up to the test, as insufficient sleep can also invalidate findings on the MSLT. For this reason, the use of actigraphy or sleep diaries or both may help track the patient’s sleep patterns before testing. Medications taken before or during the test may also affect results, such as REM-suppressing (many antidepressants) or wake-promoting medications or stimulants. It may be necessary to discontinue these medications, if safe to do so, at least 15 days or 5 half-lives before the patient undergoes the MSLT to avoid rebound effects of withdrawal of the medication. Urine drug screening is also recommended the morning after the overnight study and before the MSLT to ensure that findings of the test are not altered pharmacologically. The procedure is described in detail in the American Academy of Sleep Medicine practice parameter on MSLT.
In the MSLT, the latency to sleep is measured for each nap opportunity and eventually used to calculate a mean sleep latency for the test. In addition, the presence or absence of the appearance of REM sleep during the naps is recorded as a sleep-onset REM period. The test is typically performed to evaluate for narcolepsy but can be used to evaluate for other causes of hypersomnia. A diagnosis of narcolepsy can be confirmed when a clinical history of narcolepsy is obtained and an MSLT demonstrates a mean sleep latency of 8 minutes or less and at least two sleep-onset REM periods. A sleep-onset REM period may also be counted if the patient enters REM sleep within 15 minutes during the overnight polysomnogram. case 2-1 is an example of a patient who meets these criteria.
A 28-year-old woman presented to clinic reporting excessive daytime sleepiness. She described falling asleep in meetings at work and frequently fell asleep with sedentary activities at home such as reading or watching television. Her Epworth Sleepiness Scale score was 16. She felt she has had this same degree of sleepiness since entering her teens. She said she did not snore or have apneas during sleep. She usually went to bed on weekdays at 10:30 pm and woke up at 6:00 am. She fell asleep within 10 minutes and had up to two brief awakenings at night but quickly fell back asleep within minutes. She reported at least monthly episodes of sleep paralysis and sleep-related hallucinations. She denied having cataplexy.
Her past medical history was significant for asthma, which was treated with an albuterol inhaler as needed; she was not on any other medications. Her father had obstructive sleep apnea, but she had no other significant family history. She did not smoke or use alcohol or recreational drugs. She was married and worked as a teacher.
Examination revealed a normal BMI of 25 and a Mallampati class II airway on oropharyngeal examination. Cardiac, pulmonary, and neurologic examinations were otherwise unremarkable.
The patient filled out 2 weeks of sleep logs leading up to a polysomnogram and multiple sleep latency test (MSLT). The polysomnogram did not show obstructive sleep apnea with a normal apnea-hypopnea index of 2.5. Total sleep time was 415 minutes, and no periodic limb movements of sleep were recorded. The next morning, the MSLT demonstrated a short mean sleep latency of 5 minutes with two sleep-onset REM periods. Sleep logs demonstrated at least 7 and usually 8 hours of sleep daily leading up to the study. A diagnosis of narcolepsy type 2 was made.
The history and examination were most concerning for narcolepsy given the age of onset of the patient’s sleepiness (in her teenage years) and her reports of sleep paralysis and sleep-related hallucinations. History and sleep logs confirmed that she was getting a sufficient amount of sleep. She had very few risk factors for sleep apnea, with the absence of snoring, apneas, and obesity, along with an unobstructed airway on examination. Moreover, the overnight sleep study confirmed she did not have sleep apnea. The MSLT results were consistent with narcolepsy, especially given the high clinical suspicion for this disorder after taking a history and performing a physical examination.
The maintenance of wakefulness test is less often used in clinical practice but tests the ability of a patient to stay awake during the day. This test is sometimes used by federal agencies or other employers when trying to assess if patients are alert enough to safely work (driving or flying) by ensuring that they are able to stay awake when instructed to do so. In contrast to the MSLT, with the maintenance of wakefulness test, the patient is asked to stay awake during four testing opportunities lasting 40 minutes each. This test is seldom used clinically due to difficulties in interpretation of the results and no clear demonstration that it is predictive of motor vehicle accidents or other activities where reduced alertness may impact safety.
Other laboratory tests may be helpful in certain cases when evaluating a sleepy patient. CSF orexin (hypocretin) can also be used to diagnose narcolepsy type 1. Buccal swab samples can be used to genetically test for the presence of human leukocyte antigen DQB1*06:02 in the evaluation for narcolepsy type 1. Looking for other medical causes of fatigue by checking thyroid functions, blood cell counts, or vitamin D level may be helpful for patients who report sleepiness. Pulmonary function tests may be helpful along with EMG and nerve conduction studies if there is a concern about intrinsic lung disease or neuromuscular weakness in respiratory muscles putting the patient at risk of sleep-related hypoventilation. If focal signs on examination raise concerns about secondary causes of hypersomnia such as masses, strokes, or other processes involving the brain, MRI may be necessary.
THE SLEEPLESS PATIENT
Insomnia (and sleeplessness) is prevalent in the United States with up to one-third of the population reporting some insomnia and up to 10% of the population meeting the criteria for chronic insomnia disorder. Insomnia is even more common in patients with neurologic disorders such as multiple sclerosis, dementia, Parkinson disease, and stroke. Diseases affecting the brain not only cause numerous symptoms that can disrupt sleep but also may cause direct damage to sleep-controlling areas of the brain. Insomnia can lead to fatigue, sleepiness, poor attention, and depression, which can result in decreased performance at school or work. One study estimated that employees with insomnia lose about 8 days of work performance each year, leading to an estimated $63 billion annual loss. Insomnia has many causes, and a detailed history and laboratory evaluation are helpful in narrowing the differential diagnosis.
Getting a good history from patients reporting poor sleep or insomnia can be time consuming, especially if different patterns of sleep occur from night to night, which is often the case. However, this information is critical to the correct diagnosis and eventual management of the condition. Gathering information about patients’ sleep schedules on both work or school days and off days is important, including their usual bedtime, wake time, bedtime routines, number of awakenings from sleep, and how long it takes them to return to sleep with each awakening. Sometimes, a patient’s inability to provide this information points toward poor sleep habits and having an irregular schedule or routine. Other times, it may be difficult for patients to describe what happens during the night due to large night-to-night pattern variability. In this case, having patients fill out sleep logs for 1 to 2 weeks before evaluation can be useful. The patients or their families should be asked about possible exacerbating or alleviating factors for poor nights of sleep, including work schedule, sleeping environment, or diet and exercise. The clinician should ask what patients typically do 1 or 2 hours before sleep (ie, their bedtime routine); if their sleep environment is quiet, dark, and a comfortable temperature; and about the use of electronics such as tablets and smartphones that can emit light and disrupt sleep (case 2-2). If patients are having problems falling asleep or staying asleep, the clinician should ask if pain or discomfort is part of the reason. Comorbid medical symptoms should be inquired about, such as chronic pain, untreated reflux, uncontrolled nocturnal asthma, or headaches, as these may contribute to insomnia. Asking directly about symptoms of RLS is important as this can be a common cause of insomnia. Other sleep disorders such as obstructive sleep apnea, parasomnias, or even narcolepsy can present as insomnia and need to be evaluated by asking about key clinical symptoms of these disorders.
A 19-year-old man who was being treated for migraines with topiramate presented for follow-up after reporting persistent headaches and poor sleep. He reported difficulties falling asleep almost every night, taking 1 or 2 hours to fall asleep, even if he tried to go to bed later. He admitted to drinking caffeinated soda about 1 hour before bedtime and using his tablet to play games and stream videos before trying to go to sleep. He completed sleep diaries for 2 weeks and brought them to the next appointment (figure 2-4a). Sleep diaries showed varying bedtimes anywhere from 10:00 pm during the week to 2:00 am on weekends with sleep latencies of 1 to 2 hours.
He was instructed to set a regular bedtime and wake time. He was educated about the effects of caffeine on sleep and advised to not use caffeine after lunch. He was also instructed to discontinue use of electronic devices such as phones or tablets at least 1 or 2 hours before bedtime and to do something relaxing and calming before bedtime. He returned to clinic in 1 month with sleep diaries showing a much more regular sleep pattern with shorter latencies to sleep and less frequent headaches (figure 2-4b).
This patient’s insomnia and poor sleep were contributing to worsened headaches. After taking a history and collecting information from sleep diaries, it was clear that the patient was not practicing good sleep hygiene. He was not keeping a regular sleep schedule and was using caffeine and electronics too close to bedtime. Improving sleep hygiene and removing activities not conducive to sleep helped improve this patient’s insomnia and headaches.
It is important to ask about thoughts or worries patients’ have about their sleep that may keep them from being relaxed at night, which is a key feature of psychophysiological insomnia. Clock watching or sleeping better away from home are also indicative of this type of insomnia. Further questioning on anxiety or ruminating thoughts about work, school, or relationships are also important when taking a history. Finding out if patients are “night owls” or “morning larks” can help determine if an underlying circadian rhythm disorder is the cause of sleeplessness. If insomnia resolves or improves when following their own schedule or “body clock” during breaks or vacations, it is also a sign of a circadian rhythm disorder.
A good sleep history should also better characterize how often and how long a patient has experienced insomnia. Asking how many nights per week insomnia occurs and if the poor sleep is intermittent or progressive can assist in the evaluation, as can inquiring how the patient feels during the daytime, asking specifically about fatigue, lack of energy, poor attention, or sleepiness. Some tools can help gauge the severity of insomnia and detect treatment response. One such tool is the Insomnia Severity Index (ISI), which is a seven-item questionnaire designed to assess the nature, severity, and impact of insomnia and monitor treatment response in adults. Another commonly used tool is the Pittsburgh Sleep Quality Index (PSQI), which is a self-rated questionnaire that assesses sleep quality and disturbances over a 1-month interval.
As mentioned earlier, getting a good medical and psychiatric history of other diagnoses or disorders can help determine if they are part of the cause of the poor sleep. For example, any neurologic disorder causing pain or immobility can also disrupt sleep. Psychiatric disorders such as major depressive disorder or anxiety disorder almost always involve some sleep disruption or insomnia. Reviewing both over-the-counter and prescription medications that may disrupt sleep or cause insomnia is important. Asking about caffeine, smoking, alcohol, and other drug use, especially close to bedtime, may help explain difficulties with insomnia. Alcohol is commonly used before bedtime to help initiate sleep but can cause frequent and prolonged nighttime awakenings.
In many cases, the physical examination may be unremarkable in patients presenting with insomnia and sleeplessness. Other times, signs and evidence may point to chronic medical conditions such as chronic obstructive pulmonary disease, heart failure, or osteoarthritis that commonly disrupt sleep. An abnormal neurologic examination may provide evidence of underlying neurologic diseases such as multiple sclerosis, neurodegenerative conditions, or neuromuscular conditions that have high rates of insomnia. Loss of vibration or other sensations in the distal lower extremities may be a sign of a peripheral neuropathy, which is commonly associated in patients with RLS. Looking for signs and risk factors for obstructive sleep apnea such as high blood pressure, elevated BMI, a narrow upper airway, or an enlarged neck circumference may be helpful in deciding if further evaluation for obstructive sleep apnea is necessary. A thorough mental status examination should provide insight into the mood, memory, concentration, and alertness of the patient that may indicate underlying psychiatric disease that could lead to sleeplessness.
As mentioned previously, gathering data about sleep patterns is crucial in the evaluation of insomnia. Sleep logs or sleep diaries can be useful tools in identifying shifts in circadian rhythms, severity and frequency of insomnia, or possible exacerbating or alleviating factors. Logs and diaries kept by the patient report the subjective impression and are prone to error and bias of the person filling it out. Using actigraphy in addition to sleep logs may be helpful in getting a more accurate picture of a patient’s sleep patterns. Actigraphy uses a wristwatchlike portable device that contains an accelerometer, a clock, and internal memory. It records the rest-activity cycle, which may correspond to the sleep-wake cycle. Recent clinical practice guidelines from the American Academy of Sleep Medicine recommend the use of actigraphy in the assessment of patients with insomnia and circadian rhythm disorders.
Polysomnography and home sleep apnea testing are not indicated in the routine evaluation of insomnia. Per the American Academy of Sleep Medicine clinical guideline on insomnia, polysomnography may be indicated if a clinical suspicion exists for obstructive sleep apnea or movement disorders or if treatments (both pharmacologic and nonpharmacologic) fail. Unless the clinician is looking for sleep-disordered breathing or a sleep-related movement disorder, the polysomnogram is unlikely to provide much useful information because the test is performed at a sleep center in a circumstance and environment different from a usual night of sleep at home. The use of home sleep apnea tests when investigating for obstructive sleep apnea in patients with insomnia should also be used cautiously. The American Academy of Sleep Medicine recommends in-laboratory polysomnography when evaluating a patient for obstructive sleep apnea who also has severe insomnia, as most home sleep apnea tests are not able to measure sleep (because of the absence of EEG), and the calculated respiratory event index may underestimate the severity of sleep-disordered breathing due to the use of a denominator of recording time instead of sleep time. Serum laboratory tests such as iron studies and ferritin levels should be considered if RLS is a concern. Checking vitamin D and magnesium levels can also be considered as some evidence shows that low levels can adversely affect sleep and increase RLS symptoms. Investigation into other causes of fatigue and sleeplessness can be helpful if other clinical features suggest an underlying condition, such as thyroid disease or other endocrinopathies.
The role of consumer health and sleep trackers in this population is still uncertain. A recent position statement from the American Academy of Sleep Medicine asserted that, given the unknown potential of consumer sleep trackers to measure sleep or assess for sleep disorders, these tools are not substitutes for medical evaluation. However, they may be used to enhance the patient-clinician interaction when presented in the context of an appropriate clinical evaluation. Use of these devices can also increase awareness of the importance of sleep and the need to address any underlying sleep disorder. As these devices become more widespread and advanced, their use in clinical evaluation will also likely evolve. Appropriate validation regarding device accuracy and application within clinical practice is necessary if these devices are to be considered part of medical evaluation and treatment. Consumer sleep trackers are exceedingly popular, and the future holds promise that they can positively impact sleep in society.
The most important part of an evaluation of a patient with sleepiness or sleeplessness remains a good history and physical examination. After this step, if the clinician has concerns about specific sleep disorders such as sleep-disordered breathing, narcolepsy, or sleep-related movement disorders, further objective sleep testing may be necessary with in-laboratory polysomnography or home sleep apnea testing. Correctly identifying which sleep disorder is causing the patient’s sleep symptoms is critical in deciding on a treatment plan to improve the quality of sleep, daytime functioning, and possibly other underlying neurologic conditions.
- Patients with neurologic conditions frequently have poor-quality sleep and unrecognized sleep disorders.
- Excessive daytime sleepiness can lead to difficulties with school, work, and driving.
- Beyond obtaining the history from the patient, it can be equally important to ask a bed partner or other collateral source about the patient’s level of alertness during the day or abnormal behaviors during sleep, as patients are not always fully appreciative of their level of sleepiness or aware of what is occurring while they sleep.
- Patients should be getting a sufficient amount of sleep, at least 7 hours for adults, as insufficient sleep is the most common cause of excessive daytime sleepiness in the United States.
- Patients reporting excessive daytime sleepiness should be asked about snoring, apneas, morning headaches, and nocturia, which are all common symptoms of obstructive sleep apnea.
- Many medications used to treat neurologic conditions and other medical disorders can cause excessive daytime sleepiness.
- Obesity, enlarged neck circumference, and high blood pressure are more commonly seen in patients with obstructive sleep apnea.
- Abnormal findings on the cardiac, pulmonary, or neurologic examination place a patient at higher risk of sleep disorders such as sleep-disordered breathing (obstructive or central sleep apnea), sleep-related movement disorders, and parasomnias.
- Sleep diaries in conjunction with actigraphy are helpful in evaluating duration and timing of sleep and critical for diagnosing circadian rhythm disorders and insufficient sleep syndrome.
- Polysomnography can be helpful when evaluating patients for sleep-disordered breathing, hypersomnia, or abnormal movements during sleep. Polysomnography measures sleep time and the apnea-hypopnea index, which is used to make a diagnosis of sleep apnea.
- Home sleep apnea tests can be useful in the evaluation of obstructive sleep apnea in adult patients who are considered at risk of moderate or severe obstructive sleep apnea based on history and examination and in those who do not have other neurologic or cardiopulmonary disorders that put them at risk of other sleep-disordered breathing.
- The multiple sleep latency test (MSLT) is used to objectively measure hypersomnia and help make a diagnosis of narcolepsy. MSLTs demonstrating a mean sleep latency of 8 minutes or less and at least two sleep-onset rapid eye movement (REM) periods are found in patients with narcolepsy.
- Gathering information about a patient’s bedtime, wake time, and sleep routine is critical in determining the cause of a patient’s insomnia or sleeplessness. This information can be obtained during the clinic visit but sometimes requires sleep logs or diaries collected over several days or weeks.
- Neurologic and psychiatric disorders commonly cause insomnia. In addition, insomnia can be a side effect of many medications used to treat these disorders, and use and withdrawal of recreational drugs can also cause sleeplessness.
- Polysomnography and home sleep apnea testing are not routinely used for the evaluation of insomnia unless the clinician is concerned about another sleep disorder such as obstructive sleep apnea or periodic limb movement disorder contributing to sleep complaints.
- Consumer sleep trackers are not currently used in the routine evaluation of patients with sleep problems such as insomnia, although they may help increase awareness of the importance of sleep and may help patients start a conversation with their clinician.
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