Depression and migraine headaches appear to share a common genetic factor, a Dutch study of 2,652 people found. As reported in the January 26 Neurology, researchers compared heritability estimates among members of the Erasmus Rucphen family for migraine with and without depression, and depression rates between migraineurs and controls. Of the total study population, 360 had migraines, 151 of whom experienced migraine aura as well. One-quarter of migraineurs also had depression, compared with 13% of the controls. Odds ratios for depression in patients with migraine were 1.29 for those without aura and 1.70 for those with aura. “There is a bidirectional association between depression and migraine, in particular migraine with aura, which can be explained, at least partly, by shared genetic factors,” the study authors noted.
The FDA has approved Ampyra (dalfampridine) extended-release tablets to improve walking in patients with multiple sclerosis (MS). In clinical trials, patients treated with dalfampridine had faster walking speeds than those treated with a placebo. It is the first report in which a drug for MS improved function that was lost as a result of the disease. The most common side effects reported were urinary tract infection, insomnia, dizziness, headache, nausea, and others. When taken in doses greater than 10 mg twice a day, seizures may occur. It should not be used in patients with moderate to severe kidney disease. Dalfampridine is distributed by Acorda Therapeutics Inc of Hawthorne, New York.
Black patients with multiple sclerosis showed increased tissue damage and higher lesion volumes compared with white patients, according to research in the February 16 Neurology. In a study of 567 patients, 488 of whom were white and 79 were black, investigators compared quantitative MRI evaluations including T1-, T2-, and gadolinium contrast-enhancing lesion volumes and contrast-enhancing number, global and tissue-specific brain atrophy, and magnetization transfer ratios (MTR) in lesions and normal-appearing gray matter (NAGM) and white matter (NAWM). The researchers found that MTR values in lesions and in NAGM and NAWM were significantly lower in black subjects than in whites, and T1- and T2- lesion volumes were greater, both of which indicate a more aggressive clinical disease.
Dopamine agonists can cause or exacerbate compulsive behaviors in patients with Parkinson’s, according to research published in the January 14 Neuron. “A constellation of pathological behaviors, including gambling, shopping, binge eating, and hypersexuality is seen in 17% of patients on dopamine agonists,” the study authors wrote. Because reinforcement learning algorithms allow for computation of prediction error, the researchers used a reinforcement learning model to deconstruct decision-making processes dysregulated by dopamine agonists in patients who are susceptible to compulsive behaviors. The investigators found that the medications increased the rate of learning from gain outcomes and increased striatal prediction error activity, signifying a “better than expected” outcome.
Patients with acute ischemic stroke admitted to the hospital on the weekend are more likely to receive t-PA than those admitted on a weekday, a study in the January Archives of Neurology reported. Researchers analyzed rates of t-PA administration, as well as death rates, among 78,657stroke patients admitted to Virginia hospitals between 1998 and 2006 and found weekend patients (n=20,279) were 20% more likely to receive t-PA than weekday patients (n=58,378). There was no statistically significant difference in patient mortality based on day of admission; however, because a greater percentage of weekend patients received t-PA while death rates remained equal, the study authors noted that those treated with t-PA may be more likely to die in the hospital.
Impaired cognitive function in elderly men may be an independent predictor of subsequent stroke, according to a report in the February 2 Neurology. In a study of 930 elderly men (mean age, 70), Swedish researchers found that taking longer to complete the Trail Making Test B increased stroke risk by as much as 300% for those in the highest quartile, compared with those in the lowest quartile. Each time increase of 1 SD was associated with a 1.48 higher risk of stroke. “Our results extend previous findings of cognitive decline as an independent predictor of stroke and indicate that the risk of brain infarction is increased already in the subclinical phase of cognitive deficit,” the study authors wrote.