Patients with Parkinson’s disease who also have high levels of homocysteine are more likely to be depressed than are other patients with Parkinson’s disease who have normal levels of the amino acid, according to a report in the June Archives of Neurology. “An elevated plasma homocysteine concentration … was present in 31 (32%) of our 97 patients with fairly recent onset Parkinson’s disease,” the investigators said. These patients were older, more depressed, and had worse cognitive functioning than patients in the control group but were not different in terms of physical functioning. Elevated homocysteine levels have a significant association with disease burden in Parkinson’s disease and were most likely due to levodopa use, the researchers concluded.

Mutant SOD1—the protein responsible for amyotrophic lateral sclerosis—specifically targets the mitochondria of large motor neurons, according to researchers from the University of California, San Diego. The investigators used tissue from animals and humans to determine that mutant SOD1 ignores all other mitochondria in cells and tissues outside the spinal cord, where it was present both inside the mitochondria and coated on their external components. “We believe that when the mutant SOD1 binds to mitochondria, it affects the ability of these components to generate cell energy,” they said. The mutant protein may also induce mitochondria to signal cell death in the motor neurons, they postulated. The results of the study were reported in the July 8 Neuron.

Elderly white women with diabetes had a more rapid decline in performance on the Verbal Fluency test compared with women with impaired or normal glucose tolerance, according to a report in the June 28 Archives of Internal Medicine. At baseline, mean cognitive function scores on three tests did not differ between the three glucose-tolerance groups, but at a four-year follow-up, women with diabetes had a four-fold increased risk of major cognitive decline, the investigators said. Glycohemoglobin attenuated this effect, they noted, but lipid levels, blood pressure, and microvascular or macrovascular disease did not. The researchers proposed that “better glucose control might ameliorate this decline.”

Gene therapy can prevent physical symptoms and neurologic damage in a mouse model of spinocerebellar ataxia 1 (SCA1). A viral vector delivered small fragments of RNA designed to suppress the SCA1 gene to the brains of mice with the disease. Treated mice had normal movement and coordination, and their brain cells were protected from the destruction normally associated with SCA1. In contrast, untreated mice progressed through the normal course of the disease, investigators reported in the August Nature Medicine. “This is the first example of targeted gene silencing of a disease gene in the brains of live animals, and it suggests that this approach may eventually be useful for human therapies,” the researchers said.

Clock setting is a sensitive task that may prove to be a valuable tool when screening for dementia, according to a report in the July Journal of the American Geriatrics Society. Researchers compared 30 patients with dementia, 30 patients with depression, and 30 healthy controls using general neuropsychological tests, clock-drawing tests, and three additional clock tasks: clock reading, clock setting, and judgment of clock faces. They found that patients with dementia differed significantly from the control and depression groups on all clock tasks; controls and patients with depression differed only on clock setting. A comparison between tasks revealed that clock setting was the most difficult task and the one that differentiated best between diagnostic groups.

Patients with Parkinson’s disease who underwent embryonic stem cell implantation demonstrated better motor functioning than patients who underwent sham surgery, according to a report in the June Archives of Neurology. Researchers from Columbia University Medical Center in New York City measured changes in motor performance in patients with Parkinson’s disease who received embryonic nigral cell implantation. They found that the difference in average combined reaction time and motor time scores between the sham surgery and implant groups was statistically significant and was greatest in patients 60 and older. “The physiologic measures detected significant changes in patients undergoing embryonic nigral cell implants and correlated directly with clinical outcome measures,” they said.

Results from the Women’s Health Initiative Memory Study (WHIMS) indicated that hormone therapy is not effective in preventing dementia in older women. The study investigated the effects of two hormone therapies—estrogen alone and estrogen combined with progestin—on about 7,500 women between the ages of 65 and 79. Last spring, a report indicated that the use of estrogen plus progestin doubled the risk of dementia in older women. More recently—in the June 23 JAMA—researchers reported that women who took estrogen alone had similar, though weaker, effects as those who took estrogen plus progestin. In response to the WHI and WHIMS data, the FDA now recommends that women use lower doses of hormone therapy to treat hot flashes, vaginal dryness, or osteoporosis.

By combining the results of 22 studies, researchers at the University of North Carolina, Chapel Hill, demonstrated that the apolipoprotein E (APOE) ε2 allele—which is thought to be protective against Alzheimer’s disease—“conveyed a slight but statistically significant risk for Parkinson’s disease, with an odds ratio of 1.2.” Additional results of the meta-analysis, which assessed study results for nearly 2,000 patients with Parkinson’s disease and some 8,000 controls without the disease, revealed that the APOE ε4 allele was not statistically related to the risk for Parkinson’s disease. The results—published in the June 22 Neurology—underscore the possibility of major differences in underlying disease processes among neurodegenerative disorders such as Alzheimer’s disease and Parkinson’s disease, which are often viewed as similar, age-related disorders.

About half of all women who seek treatment for migraines have reported an association between migraine and menstruation, and a recent study confirms their experience. Researchers from the City of London Migraine Clinic analyzed diary data from 155 female patients who tracked their headaches through at least two menstrual cycles. According to a report in the July 27 Neurology, severe attacks were more likely to occur during the premenstruation intervals compared to all other times of a woman’s cycle. Women were nearly five times more likely to have a migraine associated with vomiting during days 1 to 3 of menstruation. In the same issue, researchers from Thomas Jefferson University in Philadelphia reported an effective new treatment for menstrual migraine. Results of a double-blind, placebo-controlled, three-way crossover trial indicated that compared to placebo, frovatriptan reduced the frequency, severity, and duration of migraine.

NR