Diabetes prevention and glucose control in midlife may protect against late-life cognitive decline, according to a study published December 2 in Annals of Internal Medicine. Researchers analyzed data from the Atherosclerosis Risk in Communities Study (ARIC). The investigators compared the amount of cognitive decline associated with aging with the amount of decline found in the ARIC participants. The study authors determined that participants with poorly controlled diabetes had 19% more cognitive decline than expected. They also observed declines for participants with controlled diabetes and prediabetes. “Knowing that the risk for cognitive impairments begins with diabetes and other risk factors in midlife can be a strong motivator for patients and their doctors to adopt and maintain long-term healthy practices,” stated the researchers.

The likelihood of receiving a clinical cognitive evaluation in elderly individuals with dementia depends on patient-specific factors such as severity of cognitive impairment and current marital status, according to a study published online ahead of print November 26 in Neurology. The investigation was part of the Health and Retirement Study. Eight hundred forty-five people age 70 and older were evaluated for dementia, and 297 met the criteria for dementia. Of those people, 45% had seen a doctor about their memory problems, compared with 5% of those with memory and thinking problems that did not meet the criteria for dementia, and 1% of those with normal memory and thinking skills. People who were married were more than twice as likely to undergo screening as people who were not married.

Stimwave Technologies (Miami Beach, Florida) has received FDA clearance to market the Stimwave Freedom Spinal Cord Stimulator System, a wireless, microtechnology neuromodulation device for the relief of chronic back pain and leg pain. The device, a long-term implant, is between 2 and 11 cm long and can be inserted through a standard needle. The Stimwave Freedom Spinal Cord Stimulator System also eliminates the need for long wires to be tunneled through the body and connected to the battery source. Patients who receive the system can undergo whole-body 3-T or 1.5-T MRI without removing the implant. The Stimwave technology is also fixed in place by an anchor that allows it to move only when the body moves. The device contains no internal batteries or toxic materials.

Chronic impairment of glymphatic pathway function after traumatic brain injury (TBI) may be a key factor that renders the post-traumatic brain vulnerable to tau aggregation and the onset of neurodegeneration, according to a study published December 3 in Journal of Neuroscience. Previously, investigators defined a network of paravascular channels called the glymphatic pathway that facilitates the clearance of solutes such as amyloid-β from the brain. The researchers demonstrated that extracellular tau in mice is cleared from the brain along the paravascular pathways. After TBI, glymphatic pathway function was reduced by 60%, and this impairment persisted for at least one month after injury. Knockout of the gene encoding the astroglial water channel aquaporin-4 exacerbated glymphatic pathway dysfunction after TBI and promoted the development of neurofibrillary pathology and neurodegeneration in the post-traumatic brain.

In patients with transient ischemic attack (TIA), CT evidence of acute ischemia alone or acute ischemia with chronic ischemia is associated with increased subsequent stroke risk within 90 days, according to a study published online ahead of print December 4 in Stroke. Of 2,028 patients who received CT scans within 24 hours of a TIA, 814 (40.1%) had brain damage resulting from ischemia. In addition, 3.4% of the people in the study group had a subsequent stroke within 90 days, and 25% of patients with CT scans showing three types of damage to their brain had strokes. “These findings should prompt physicians to be more aggressive in managing patients with TIA or nondisabling stroke who are diagnosed with acute ischemia, especially if there is additional chronic ischemia and microangiopathy,” the researchers said.

People who have sleep apnea or spend less time in deep sleep may be more likely to have changes in the brain that are associated with dementia, according to a study published December 10 in Neurology. A total of 167 Japanese–American men had sleep tests in their homes at an average age of 84. All men were followed until they died at an average of six years later. Autopsies were conducted on their brains to look for microinfarcts. Of the 41 men who spent the least sleep time with low blood oxygen levels, four had microinfarcts in the brain. Fourteen of the 42 men with the most sleep time with low blood oxygen levels had the abnormalities; thus, they were nearly four times more likely to develop brain damage.

Brains affected by autism share a pattern of increased immune responses, according to a data analysis published December 10 in Nature Communications. The researchers examined gene expression in samples from two tissue banks, comparing gene expression in people with autism with that in controls without the condition. Data from 104 brain samples from 72 individuals were analyzed. The investigators focused their analysis on microglial cells. In the brains with autism, the microglial cells appeared to be perpetually activated, and their genes for inflammation responses were activated. The results highlight “the lack of current understanding about how innate immunity controls neural circuits,” stated the study authors. Given the known genetic contributors to autism, inflammation is unlikely to be its root cause, they added.

Compared with placebo, progesterone did not improve outcomes when administered to patients with acute traumatic brain injury (TBI), according to a study published online ahead of print December 10 in the New England Journal of Medicine. Patients were randomly assigned to IV progesterone or placebo, and study treatment was initiated within four hours after injury and administered for 96 hours. The trial was stopped for futility. The researchers found no significant difference between the progesterone group and the placebo group in the proportion of patients with a favorable outcome. Favorable outcomes occurred in 51% of patients who received progesterone and in 56% of those who received placebo. Mortality after six months was 18.8% for participants receiving progesterone and 15.7% for those receiving placebo. Phlebitis was more common in the progesterone group.

Learning-related brain activity in patients with Parkinson’s disease improves as much in response to placebo as to medication, according to a study published in the December issue of Nature Neuroscience. For the study, researchers used functional MRI to scan the brains of 18 patients with Parkinson’s disease as they played a computer game that measures reward learning. In the game, participants discover through trial and error which of two symbols is more likely to lead to a better outcome. Participants played the game when they were not taking medication, when they took medication, and when they took placebo. The researchers found that the dopamine-rich areas of the brain associated with reward learning became equally active when patients took either the real medication or the placebo.

Oral fingolimod may improve outcomes for patients with acute and anterior cerebral circulation occlusion stroke, according to a study published online ahead of print December 8 in Proceedings of the National Academy of Sciences. The researchers conducted an open-label, evaluator-blinded, parallel-group clinical pilot trial of 22 patients with anterior cerebral circulation occlusion, among whom stroke onset had occurred more than 4.5 hours previously. Participants received standard management alone or standard management plus 0.5 mg of oral fingolimod per day for three consecutive days. Patients receiving fingolimod had lower circulating lymphocyte counts, milder neurologic deficits, and better recovery of neurologic functions. Neurologic rehabilitation was faster among participants who received fingolimod. In addition, enlargement of lesion size was less pronounced between baseline and day seven among patients who received fingolimod.

Migraine headache may double the risk of Bell’s palsy, according to a study published online ahead of print December 17 in Neurology. Two groups of 136,704 people age 18 and older, one group with migraine and one without, were followed for an average of three years. During that time, 671 people in the migraine group and 365 people in the control group were diagnosed with Bell’s palsy. Participants with migraine were twice as likely to develop Bell’s palsy, even after researchers accounted for other factors that could increase the risk of the condition, such as sex, high blood pressure, and diabetes. “Infection, inflammation, or heart and vascular problems could be shared causes for these diseases,” stated the researchers.

Struggling to balance on one leg for 20 seconds or longer is linked to an increased risk for small blood vessel damage in the brain and reduced cognitive function in healthy people with no clinical symptoms, according to a study published online ahead of print December 18 in Stroke. Investigators examined 841 women and 546 men with an average age of 67. To measure one-leg standing time, participants stood with their eyes open and raised one leg. In all, 34.5% of participants with more than two lacunar infarction lesions had trouble balancing, 16% of people with one lacunar infarction lesion had trouble balancing, 30% of participants with more than two microbleed lesions had trouble balancing, and 15.3% of people with one microbleed lesion had trouble balancing.

—Kimberly D. Williams

New and Noteworthy Information—January 2015