Investigators have found that seizures in children can be controlled nearly as effectively with a modified version of the Atkins diet as with the highly restrictive ketogenic diet, according to findings presented at the 2005 Joint Annual Meeting of the American Epilepsy Society and American Clinical Neurophysiology Society. Sixteen children ages 3 to 18 who had between four and 470 seizures a week completed the six-month study. When put on a regimen with fewer carbohydrates than allotted in the standard Atkins diet, 13 children experienced greater than 50% improvement in the number of seizures, seven experienced greater than 90% improvement in seizure frequency, and four did not have seizures during the six-month period.

Being overweight or obese increases an individual’s likelihood of developing Alzheimer’s disease, as reported in the December 2005 Journal of Alzheimer’s Disease. Researchers measured body mass index and ß-amyloid levels in the blood and examined the inflammatory marker C-reactive protein, insulin, and HDL levels in 18 patients who were either extremely overweight or obese but otherwise healthy. Results suggested that proteins implicated in inflammation, cardiovascular disease, and type 2 diabetes mellitus may contribute to a statistically significant correlation between body mass index and ß-amyloid levels. However, a theory that claims reducing body mass and maintaining normal body weight might also reduce the risk of Alzheimer’s disease has not yet been proven.

Discontinuation of regular blood transfusions for children with sickle cell disease and a high risk of stroke will result in a return of stroke risk, according to findings published in the December 29, 2005, New England Journal of Medicine. A total of 79 children with sickle cell disease whose risk of stroke had been reduced by blood transfusions for 30 months or longer were included in the study. Of 41 children whose transfusions were halted, 14 patients resumed at-risk status and two had strokes within a few months after transfusions were discontinued. Of the 38 children whose transfusions were continued, none had indications of at-risk status or had strokes.

Surgery can improve sleep apnea in patients with Arnold-Chiari malformation, per a study in the January 10 Neurology. Twelve patients with Arnold-Chiari malformation type 1, syringomyelia, and sleep apnea underwent full-night polysomnography; six were found to have central sleep apnea. Eight of the patients then underwent decompression surgery, and polysomnography was repeated for six patients with sleep apnea syndrome an average of 203 days after the decompression surgery. Results showed that central sleep apnea episodes decreased by more than 90%, from an average of 15 occurrences per hour of sleep to an average of one occurrence per hour of sleep. In addition, the number of microarousals also decreased by 30%.

Memantine treatment for patients who have moderate to severe Alzheimer’s disease appears to be safe and efficacious, researchers reported in the January Archives of Neurology. In a 24-week, open-label extension of a 28-week, double-blind study, 175 patients were given a daily dose of 20 mg of memantine. Eighty of these patients had received placebo in the initial study. Results showed that patients who switched from placebo to memantine experienced a significant benefit in functional, global, and cognitive skills compared with their mean rate of decline with placebo in the double-blind study. Patients who continued to receive memantine treatment appeared to maintain those benefits. The researchers noted that "the favorable adverse event profile for memantine therapy was similar to that seen in the double-blind study."

Subjective complaints in motor skill functions may signal an increased risk of Parkinson’s disease in elderly persons, according to a study in the January 9 online Archives of Neurology. Researchers examined 6,038 elderly persons without Parkinson’s disease or dementia for subjective complaints of stiffness, slowness of movement, tremors, or imbalance. After conducting two follow-up visits per patient during a mean of 5.8 years, the investigators found that these subjective complaints were associated with an increased risk of future Parkinson’s disease. Of the 56 people who developed Parkinson’s disease, 71.8% reported at least one motor skill complaint, and 41% reported at least two.

Exposure to neurotropic viruses shortly before and after birth is associated with cerebral palsy, according to findings published in the January 6 online BMJ. The investigators tested newborn-screening cards for viral nucleic acids from 443 white children with cerebral palsy and 883 white control babies. Results showed a high prevalence of viral nucleic acids in the control group, with 39.8% babies testing positive. The highest prevalence of viral nucleic acids was observed in preterm babies. In addition, herpes group B viral nucleic acids increased the risk of developing cerebral palsy by nearly twofold.

Reduced volume in the hippocampus and amygdala may help predict which cognitively healthy elderly persons are at risk of developing dementia within six years, as reported in the January Archives of General Psychiatry. A total of 511 participants ages 60 to 90 who did not have dementia at baseline were followed up for a mean of six years. Results showed that of the 35 participants who developed dementia, baseline brain volumes were 17% smaller in persons who received a clinical diagnosis of dementia within two to three years after MRI and 5% smaller in those diagnosed six years after MRI, compared with brain volumes in patients who did not develop dementia. "Our study suggests that structural brain imaging can help identify people at high risk for developing dementia," said the researchers.

Researchers have created a mouse model for lissencephaly to understand why children with the disease develop seizures and mental retardation. According to a report in the January 5 Neuron, investigators removed two genes from the mouse—doublecortin and doublecortin-like kinase—and observed features in the animals similar to those associated with human lissencephaly. The researchers, who previously had shown that mutations in doublecortin account for nearly 20% of lissencephaly in humans, noted that this latest study is the first to "establish a link between the human and mouse disease that clearly shows we can model this condition in the lab."

Alzheimer’s disease may be triggered when adult neurons attempt to divide, as reported in the January 18 Journal of Neuroscience. Researchers compared the brains of three different mouse models of Alzheimer’s disease, all of which had mutations in the gene that codes for amyloid precursor protein, with brains of healthy mice. The investigators found that in the mouse models, cell cycle–related proteins appeared in neurons six months before the first amyloid plaques or disease-related immune reactions developed in the brain. The affected neurons appeared to live for many months in a near-functional state, with mild behavioral changes observed in the mouse models. These findings help bolster the theory that the accumulation of ß-amyloid in the brain causes neuron death in patients with Alzheimer’s disease.

Independent predictors of intracerebral hemorrhage are increasing age, blood glucose level, and systolic blood pressure, as well as use of antihypertensive drugs. According to findings in the January Journal of Neurology, Neurosurgery, and Psychiatry, researchers developed a model identifying patients with previous cerebral ischemia who were at risk for intracerebral hemorrhage. A total of 107 intracerebral hemorrhages were observed among 12,648 patients. Though it was possible to select a group of individuals at higher risk for intracerebral hemorrhage, the absolute risk was still low, the researchers noted. Further studies are needed to better determine the validity of the predictors and to better guide decisions concerning antithrombotic treatment strategies.

Elderly patients with essential tremor have poorer memory and cognitive performance, as reported in the January 10 Neurology. A total of 232 patients with essential tremor and 696 matched controls 65 and older underwent neuropsychological assessment, including tests of global cognitive performance, frontal executive function, verbal fluency, and memory and were asked if they experienced forgetfulness. Fifty-six patients (24%) with essential tremor were previously undiagnosed, and 14 (6%) were taking medication for the tremor. Most neuropsychological tests—especially global cognitive performance and frontal executive function—elicited poorer performance from patients with essential tremor than from those without. In addition, forgetfulness was reported in 117 patients with essential tremor (50%) and in 300 controls (43%).

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