Baseline levels of bioavailable testosterone in older men can predict a lower risk of developing Alzheimer’s disease, researchers reported in the October Journal of Alzheimer’s Disease. The study of 153 community-dwelling Chinese older men without dementia at baseline compared the effects of serum total testosterone, bioavailable testosterone, and sex hormone binding globulin on the risk of subsequent Alzheimer’s disease. At one-year follow-up, 10 subjects had been diagnosed with Alzheimer’s disease. After the investigators adjusted for age, education, BMI, fasting plasma glucose, and serum HDL cholesterol levels, logistic regression analysis determined independent predictors of the disease, including baseline serum bioavailable testosterone levels (adjusted relative risk [RR], 0.22), systolic blood pressure (RR, 1.04), and apolipoprotein ε4 genotype (RR, 5.04).

Exposure to multiple antiepileptic drugs (AEDs), older age, and lower education levels are important predictors of infertility in women with epilepsy, per research in the October 12 Neurology. The study followed 375 women with epilepsy who enrolled in the Kerala Registry of Epilepsy and Pregnancy in India during their preconception examination. The majority of subjects became pregnant within two years; however, 38.4% of the women remained infertile. Infertility rates were lowest for those with no exposure to AEDs and higher for those with exposure to AEDs. “Those exposed to phenobarbital had significant risk of infertility, but no such trend was observed with valproate or other drugs,” the researchers noted. Use of three or more AEDs was associated with a 2.91 odds ratio of infertility.

One oral dose of 200 mg to 400 mg of ibuprofen is an effective treatment for acute migraine headaches, according to a review of nine studies published October 6 in the Cochrane Database of Systematic Reviews. The analysis included 4,373 participants and 5,223 migraine attacks and compared ibuprofen with placebo or other active comparators. Two hours after taking 400 mg of ibuprofen, one in four subjects reported that their pain level went from moderate or severe to no pain, and about half of subjects reported that their pain level diminished to no greater than mild. One in 10 subjects taking placebo were pain free at two hours, while one in four subjects taking placebo reported pain levels no greater than mild. Adverse events reported in patients taking ibuprofen were mild, transient, and similar to those of subjects taking placebo.

Botox (onabotulinumtoxinA) has received FDA approval as a prophylactic treatment for headaches among adult patients with chronic migraine. The treatment is indicated for use in adult patients who experience 15 or more headache days per month that last four hours a day or longer. According to manufacturer Allergan (Irvine, California), when injected at labeled doses and in the recommended locations in the head and neck, Botox can prevent migraine headaches for up to three months, depending on the patient. It is the first clinically studied prophylactic treatment to be approved specifically for patients with chronic migraine.

Brain changes evident on neuroimaging may detect subclinical changes in patients with idiopathic rapid-eye-movement sleep behavior disorder (IRBD) before clinical manifestations of parkinsonism, per research in the October Lancet Neurology. In a prospective study of 43 patients with IRBD, investigators assessed dopamine transporters uptake using 123I-FP-CIT SPECT and echogenicity of the substantia nigra using transcranial sonography. A total of 27 subjects (63%) had reduced 123I-FP-CIT binding or substantial nigra hyperechogenicity at baseline. At follow-up 2.5 years later, eight of these individuals (30%) had been diagnosed with a neurodegenerative disorder (five with Parkinson’s disease, two with dementia with Lewy bodies, and one with multiple system atrophy). All subjects with normal neuroimaging results at baseline did not develop a neurodegenerative disorder by follow-up.

Insulin resistance is a marker of increased risk of ischemic stroke, as reported in the October Archives of Neurology. In a prospective, population-based cohort study of 1,509 nondiabetic participants of the Northern Manhattan Study, researchers measured insulin sensitivity as expressed by the homeostasis model assessment of insulin resistance (HOMA-IR). Mean HOMA-IR was 2.3, and the highest quartile was at least 2.8. During a follow-up of 8.5 years, vascular events occurred in 180 subjects, with 46 ischemic strokes, 45 myocardial infarctions, and a total of 121 deaths due to vascular causes. Having a HOMA-IR in the highest quartile significantly predicted ischemic stroke risk, but not other vascular events. The researchers noted that this effect was independent of sex, race/ethnicity, traditional vascular risk factors, and components of metabolic syndrome.

Carotid artery stenting was associated with an increased risk of both periprocedural and intermediate to long-term outcomes but also with reductions in periprocedural myocardial infarction and cranial nerve injury, according to a large, comprehensive meta-analysis in the October 11 online Archives of Neurology. The analysis combined data from 13 randomized clinical trials, with a total of 7,477 participants, and found that stenting was associated with a 65% increase in death or stroke and 67% increase in any stroke. Stenting was associated with a 55% reduced risk of myocardial infarction and with an 85% reduction in risk of cranial nerve injury. “Strategies are urgently needed to identify patients who are best served by carotid artery stenting versus carotid endarterectomy,” the authors concluded.

—Rebecca K. Abma

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