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Monday, October 24, 2016


Younger women — not older women — had an increased risk of stroke during pregnancy and the postpartum period compared to non-pregnant women of the same age, according to the results of a new study published online October 24, 2016 in JAMA Neurology.

Overall, pregnancy-associated stroke (PAS) accounted for 15 percent of strokes in women aged 12 to 24 years; 20 percent of strokes in women aged 25 to 34 years; 5 percent of strokes in women aged 35 to 44 years; and 0.05 percent of strokes in women aged 45 to 50 years.

Previous studies have suggested that the risk of PAS increases with older maternal age, probably due to increased prevalence of vascular risk factors like hypertension and diabetes, the study authors noted. But those studies rarely used age-matched non-pregnant control groups to determine age-related risks of PAS. The findings suggest that although there is a higher incidence of PAS among older women, pregnancy imparts an increased risk of stroke only for younger women compared to their non-pregnant, age-matched counterparts.

"Although older women have an increased risk of many pregnancy complications, a higher risk of stroke may not be one of them," the study authors, led by Eliza C. Miller, MD, a neurology resident at the Columbia University College of Physicians and Surgeons, wrote. "These results have potential implications for research aimed at better characterizing and preventing PAS and clinically in term of counselling patients."

For their study, the researchers used billing codes from the New York State Department of Health inpatient database to identify all women between the ages of 12 and 55 who were admitted to a hospital with a stroke between 2003 and 2012. The stroke types in the analysis included transient ischemic attack or ischemic stroke, intracerebral hemorrhage, subarachnoid hemorrhage, cerebral venous thrombosis, and nonspecified PAS, including postpartum stroke. The researchers used delivery codes to identify women who were pregnant or postpartum.

They found that 19,146 women were hospitalized with stroke during the study period; of these, 797 were pregnant or postpartum at the time of stroke. The incidence of PAS increased with age; for every 100,000 pregnant or postpartum women, PAS occurred in 14 women aged 12 to 24 years compared to 46.9 women aged 45 to 55 years.

However, the increase in PAS risk — as determined by the incidence risk ratio (IRR) generated using comparisons to age-matched non-pregnant control groups — decreased with increasing age. Among women in the 12-to-24 age group, non-pregnancy-associated strokes occurred in 6.4 of every 100,000 non-pregnant women, corresponding to an IRR of 2.2; by contrast, non-pregnancy-associated strokes occurred in 73.7 of every 100,000 non-pregnant women, corresponding to an IRR of 0.6.

A number of underlying stroke mechanisms may factor into the increased risk of stroke during pregnancy among younger women, the study authors noted. Compared to strokes in older people, strokes in young people often have rarer mechanisms. These include reversible cerebral vasoconstriction syndrome, which is linked to pre-eclampsia — a known risk factor for PAS. Additionally, inflammatory effects related to fetal DNA in maternal circulation may also raise stroke risk for very young women.

The authors noted several limitations to their study, including that the billing data used to assess outcomes were not specific, especially in regard to PAS, although the researchers validated the codes with medical records to keep false-negatives low. Also, other underlying risk factors or medication effects were not accounted for in the analysis.


Friday, October 14, 2016


​​Courtesy of Neuronetics, Malvern, PA


High-frequency repetitive transcranial magnetic stimulation proved effective for treating motor but not nonmotor symptoms in people with Parkinson's disease and comorbid depression, according to a new study published online on October 5 in Neurology.

Transcranial magnetic stimulation noninvasively uses a magnetic field generator or coil placed near the patient's head to deliver electrical currents — generating changes in cortical excitability — to regions of the brain. Previous studies have shown that repetitive TMS (rTMS) improves motor symptoms of PD (when administered to the bilateral primary motor, or M1, cortex) and mood symptoms of PD (when administered to the left dorsolateral prefrontal, or DLPFC, cortex). The researchers hypothesized that administering rTMS to both areas might improve mood and motor symptoms, but the findings did not confirm their hypothesis.

"The combined protocol used here does not appear to be a promising therapeutic avenue, and future work should consider alternative protocols," the study authors, led by Miroslaw Brys, MD, PhD, associate professor of neurology at New York University Langone Medical Center, wrote.

For the multi-center, double-blind, sham-controlled, parallel-group study, researchers enrolled 61 patients with Parkinson's disease and depression; 50 patients completed all study visits. They randomized the patients to four groups: those who received rTMS over the bilateral motor (M1) cortex, the left dorsolateral prefrontal cortex (DLPFC), both cortices, or neither (sham therapy).

They measured the patients' scores on two tests – the Unified Parkinson's Disease Rating Scale (UPDRS) part III (UPDRS-III), a clinician-scored, monitored evaluation of Parkinson's disease motor symptoms, and the Hamilton Depression Rating Scale (HAM-D), a questionnaire that tests for mood symptoms of depression – at baseline and at one week, one month, three months, and six months after baseline.

They found that at one month after baseline, real M1 rTMS was associated with greater improvement in motor function compared to the sham procedure (p<0.05). However, they did not observe an improvement in mood symptoms in the DLPFC group compared to the sham group, and combining M1 and DLPFC stimulation did not result in an improvement of motor or mood symptoms.

Finally, they observed a greater antidepressant effect in the sham group than in the real DLPFC group, which was "likely the result of a pronounced placebo response."

The results, the study authors concluded, show that rTMS to the M1 cortex "appears promising for improving motor symptoms in PD." However, there was "no evidence of synergistic effects" resulting from combining rTMS to the left DLPFC or M1 cortices.

They noted that the duration of rTMS in their study was only 10 days, although major clinical trials of primary depression normally last 20 to 30 days, and in those trials, if often takes 15 days for patients to experience a significant response beyond the sham group. Therefore, they hypothesized, "a longer course of rTMS could still be beneficial for PD-associated depression," and "future work should consider longer-duration trials."

The study authors noted several important limitations. The trial was terminated early because of recruitment challenges, and they observed no efficacy in an interim trial of patients who received rTMS in both cortices, which reduced the study's statistical power.


Thursday, October 13, 2016


Patients who had an acute stroke and comorbid aphasia upon admission to the hospital stayed more than one extra day at the hospital compared to patients who did not have a stroke,  and they were more likely to have sepsis and other signs of neurological deterioration, according to a study published online on October 7 ahead of the print edition of Neurology.

Aphasia affects up to 38 percent of all acute stroke patients in the United States, the researchers noted. While much is known about how aphasia affects stroke patients after they are discharged from the hospital – with an associated increased risk of recurrent stroke and higher costs of care – comparatively little is known about how aphasia affects stroke outcomes during hospital admission.

The findings "demonstrate the underrecognized consequences of a communication disorder during acute stroke hospitalization," the study authors, led by Amelia K. Boehme, PhD, MSPH, assistant professor of epidemiology in neurology at the Gertrude H. Sergievsky Center at Columbia University, wrote.

For their study, the researchers assessed data from the Tulane Stroke Registry on 1,847 patients who presented at a comprehensive stroke center with an acute ischemic stroke or intracerebral hemorrhage between July 2008 and December 2014; 866 of the patients had aphasia when they were admitted to the hospital, as defined by the NIH Stroke Scale (NIHSS).

The researchers found that patients who had a stroke with aphasia upon hospital admission stayed at the hospital an average of 1.22 days longer compared to people who had a stroke and did not have aphasia.

They also found that stroke patients with aphasia were more likely to have complications related to a stroke (odds ratio 1.44, p=0.0174). The complications included a recurrent stroke, myocardial infarction, pulmonary embolus, deep vein thrombosis, sepsis, hospital-acquired infection, systemic bleeding, ventriculitis, and neurological deterioration.

The increased risk of complications associated with stroke-related aphasia were comparable to, and sometimes greater than, the increased risk of complications associated with hemiparesis (one-sided facial weakening) upon hospital admission, the study authors added.

The results show that aphasia "significantly add[s] to the burden of the health care system," the researchers concluded. Aphasia may add as much as $2.16 billion to annual health care costs in the United States, assuming a 30 percent aphasia rate among all stroke cases and a $9,100 cost per day of hospital admission, they added.

The study authors noted several limitations to their analysis. They were unable to delineate subtypes of aphasia, such as disorders of receptive or expressive language, using the NIHSS tool, and they did not know whether patients received aphasia therapy during their hospitalization for acute stroke.


Thursday, October 6, 2016


Researchers have developed an assay that detects prion protein isoforms associated with sporadic forms of Creutzfeldt-Jakob disease in patient urine, opening the pathway for a noninvasive diagnostic test that could improve early diagnosis of the disease, they reported in a new study published online on October 3 in JAMA Neurology.

Sporadic Creutzfeldt-Jakob disease (sCJD) is a rapidly progressive prion disease with a median survival of around four months. Unlike the less-common variant Creutzfeldt-Jakob disease (vCJD), sCJD occurs without obvious exposure to an infectious source. Currently, the only available tests for sCJD are invasive, requiring a sampling of cerebrospinal fluid, and are often only given to patients who already have advanced disease. A recent report found that a urine assay was able to detect the abnormal prion proteins that accumulate as a result of vCJD; the current research suggests a similar assay can be used to detect sCJD.

"This is the first demonstration of an assay that can detect sCJD infection in urine or any target analyte outside of the central nervous system," the study authors, led by Connie Luk, PhD, postdoctoral fellow at the MRC Prion Unit at the University College London Institute of Neurology, wrote. "Urine detection could allow for the development of rapid, molecular diagnostics for sCJD."

For their cross-sectional study, researchers adapted an assay developed for vCJD detection in blood to detect disease-associated misfolded prion protein in the urine of patients with sCJD. The assay works by capturing disease-associated protein proteins in urine on a stainless steel matrix and detecting the presence of anti-prion protein monoclonal antibodies.

The researchers enrolled 37 patients with prion disease, of which 20 had sCJD; 34 patients with non-prion neurodegenerative diseases; and 91 healthy controls. They then collected urine samples from all study participants.

They found that eight out of 20 sCJD urine samples were positive, corresponding to 40 percent diagnostic specificity. The assay itself had 100 percent specificity for prion disease, since none of the the healthy controls or the patients with non-prion neurodegenerative diseases had false-positive results. The assay's sensitivity to vCJD was low, at only 7.7 percent.

The findings suggest that it may be possible to develop urine tests for other neurodegenerative diseases associated with protein misfolding, such as Alzheimer's disease, the study authors added.

"Our findings are in marked contrast to those recently reported using the technique of protein misfolding by cyclic amplification, where a high sensitivity for the detection of vCJD infection in urine was observed and yet none of the 68 patient samples from sCJD tested positive," the researchers wrote. "A critical limitation to the interpretation of this finding is that the assay method (protein misfolding by cyclic amplification) has never been convincingly demonstrated to detect sCJD and indeed no positive controls were included in this finding."


Wednesday, October 5, 2016


​Credit: Tharakorn​


People who experience cluster headaches have a threefold increased risk of developing depression during their lifetimes, according to a new study published online on September 30 ahead of the print edition of Neurology.

Cluster headaches affect about one in 1,000 people and are distinguished by attacks of unilateral, periorbital, excruciating head pain. Eighty-five percent of patients experience headaches in clusters across periods of several weeks to months, and 25 to 55 percent of them report suicidal tendencies. Since cluster headaches share clinical and pathophysiologic features with migraine headaches, and because past research has linked migraines to an increased risk of depression, researchers sought to determine the link between cluster headaches and the lifetime incidence of depression.

The findings suggest that "early detection of comorbid depression in [patients with cluster headaches] may be important to prevent suicide in this painful primary headache disorder," the study authors, led by Mark A. Louter, MD, of Leiden University Medical Center in the Netherlands, wrote.

For their study, researchers identified 462 people participating in the Leiden University Cluster Headache Analysis program, an ongoing database of Danish people who have been diagnosed with a cluster headache according to the International Classification of Headache Disorders (ICHD)-III-beta criteria and, in almost all cases, by a physician. They also enrolled 177 healthy controls.

The researchers administered an extended cluster headache questionnaire that included questions about the frequency and duration of cluster headache attacks, symptoms of lifetime depression, and incidence of sleeping problems. The questionnaire included the Hospital Anxiety and Depression Scale the Center for Epidemiologic Studies Depression scale, the Pittsburgh Sleep Quality Index (PSQI), and supplementary questions.

They found that participants with cluster headaches had three times higher odds of developing depression compared to the controls. They also scored higher on the PSQI, indicating worse sleep quality. People who had active cluster headache attacks — defined as having had at least one cluster headache attack in the month preceding the survey — were more likely to have depression at the time of the survey compared to people who had been attack free for at least one month.

Additionally, the study authors found that only 17 percent of people who experienced cluster headaches and fit the criterion for current depression were treated with antidepressants, suggesting that depression was "considerably underdiagnosed and undertreated in cluster headache patients."

The results, the study authors concluded, demonstrate that cluster headaches pose a high risk of depression, and that poor sleep may at least partially explain the incidence of depression in their study cohort. They hypothesized that the relentlessly recurring pain of cluster headaches may also cause despair and stress, in turn leading to depression. In addition, they proposed that dysfunction in the hypothalamus may play a role, since depression, sleep disorders, and cluster headaches have all been associated with functional and structural changes in the hypothalamus.

The researchers noted several limitations to their study, including its cross-sectional design, which prevented them from drawing a firm conclusion about the direction of the comorbidity; that the study participants were largely Dutch/Caucasian, young, and well-educated, which limits extrapolation of the findings to a larger and more diverse population; and that depression was measured with questionnaires that were not specifically designed to diagnose depression in individuals.