Being happy seems to reduce the risk of stroke for older people, according to the findings of a questionnaire-based study in the March Psychosomatic Medicine. Participants were asked whether 20 statements described their emotions over the past week. Each “yes” to one of the four descriptions of a positive attitude was associated with a 41% decreased stroke risk for the 772 men and an 18% decreased risk for the 1,706 women in the cohort. “Individuals who report high levels of positive affect may be more likely to exercise, to maintain a healthy lifestyle, and adhere to medical therapy,” said the authors.

Reminyl® (galantamine hydrobro-mide) was approved by the Food and Drug Administration for the treatment of mild to moderate Alzheimer’s disease. Data from four placebo-controlled, double-blind clinical trials involving about 2,650 patients showed that the drug, which is derived from daffodil bulbs, can have a beneficial effect on daily function and cognitive ability. “In studies lasting up to six months, many patients’ symptoms initially improved or stabilized; and even when they begin to decline, they remained better than those who were treated with placebo,” according to Gary Small, MD, of the University of California at Los Angeles.

The apolipoprotein, APOE*E4, gene may contribute to unexplained weight loss in women with Alzheimer’s disease, according to a study in the March 13 Neurology. In a study of nearly 1,000 people, “both patients and controls with the APOE*E4 allele experienced more often clinically significant weight loss than the non-carriers during the three and a half year follow-up period,” said lead author Matti Vanhanen, MD, of the Kuopio University Hospital in Finland. The APOE*E4 allele is associated with an impaired sense of smell, which could cause a decrease of appetite.

The basal ganglia and parietal lobe play critical roles in time perception, according to a study in the March Nature Neuroscience. The authors used functional magnetic resonance imaging to monitor brain activity in 17 volunteers who were asked to listen to four sounds and judge whether the length of time between the first two sounds was shorter or longer than the time between the second two sounds. Faulty time perception and abnormal basal ganglia function are associated with Alzheimer’s disease and attention deficit hyperactivity disorder, noted lead author Stephen M. Rao, PhD, of the Medical College of Wisconsin, Milwaukee.

Outcomes were similar among children with cerebral palsy who were treated with hyperbaric oxygen and those treated with slightly pressurized oxygen, according to a study in the February 24 Lancet. Both groups improved slightly. One hundred and eleven children, ages 3 to 12, were randomly assigned to 40 treatments of either hyperbaric oxygen (100% oxygen at 1.75 atmospheres absolute) or slightly pressurized air (at 1.3 atmospheres absolute) over two months. “The global improvements seen in both treatments during the course of the study might be related to the context of the intervention and the selection of very motivated parents,” suggested the authors.

Hypothermia is not an effective therapy for severe brain injury, according to a study in the February 22 New England Journal of Medicine. Three hundred and ninety-two patients with coma due to closed head injury were randomly assigned to either hypothermia, within six hours of the injury, or to normothermia. Hypothermia, wherein the body temperature reaches 33°C, was maintained for 48 hours. The outcome was poor in 57% of patients in both treatment groups.

Internal globus pallidus deep brain stimulation may selectively improve different aspects of motor performance in patients with Parkinson’s disease, according to a study in the February Annals of Neurology. Six patients with advanced Parkinson’s disease were studied over a three-day period. Left internal globus pallidus deep brain stimulation produced significant motor improvements as measured by the United Parkinson’s Disease Rating Scale over bilateral stimulation. The authors suggested that left internal globus pallidus deep brain stimulation “may enhance movement accuracy, and perhaps other aspects of motor performance, by augmenting the function of the cerebellum and its output pathways to the primary motor cortex.”

Beta-Secretase BACE1 is involved in the development of the amyloid plaques that are found in patients with Alzheimer’s disease, indicate the results of a murine model reported in the March Nature Neuroscience. ß-Amyloid peptides were not produced in mice from which the gene for the BACE1 enzyme was eliminated. “Blocking ß-secretase could have the same effect in people at risk for Alzheimer’s disease as the vaccines that already are known to keep plaque from forming in tests on lab animals,” said coauthor Philip Wong, PhD.

Estrogen replacement therapy was not associated with a reduced risk of Alzheimer’s disease in postmenopausal women, according to a study in the March Archives of Neurology. The cohort included 112,481 women who received estrogen replacement therapy and 108,925 women who did not. Current estrogen recipients were at a 1.18 risk for developing Alzheimer’s disease compared to nonrecipients. Women who received only estrogen were at the same risk as women who received estrogen and progestin.

A formula for the progression rate of Alzheimer’s disease was described in the March issue of Archives of Neurology. The formula is based on expected Mini-Mental State Examination (MMSE) scores, scores at presentation, and a standardized estimate of duration. Patients with Alzheimer’s disease can be stratified according to the formula as slow, intermediate, or rapid progressors to clinically meaningful deterioration (an MMSE score decrease of at least five points).

Subthalamic nucleus stimulation was more effective than globus pallidus internus stimulation for patients with Parkinson’s disease, according to the results of a study in the April Journal of Neurology, Neurosurgery and Psychiatry. Bilateral deep brain stimulators were implanted in the subthalamic nucleus in 12 patients and in the globus pallidus internus in six patients with severe Parkinson’s disease. All parkinsonian symptoms were ameliorated and daily drug intake was reduced by subthalamic nucleus stimulation; although side effects were reduced, bradykinesia and tremor were not improved with globus pallidus internus stimulation. “The subthalamic nucleus is the target of choice for treating patients with severe Parkinson’s disease who have side effects from drugs,” concluded the authors.

The incidence of dementia and Alzheimer’s disease is two or three times lower among the Yoruba of Ibadan, Nigeria, than among African Americans of Indianapolis, Indiana, according to a study led by Hugh Hendrie, MD, and Andesola Ogunniyi, MD. However, the incidence in both populations may be underestimated, as mortality rates were higher among Yorubans and refusal rates and lost-to-followup rates were higher among African Americans, noted Lindsay A. Farrer, PhD, in an editorial in the February 14 JAMA. As genetic factors are similar in both groups (APOE*E4 allele frequency is comparable in Indianapolis and Nigeria), this study suggests that environmental factors contribute to the difference in rates, said Dr. Farrer.

Nonsteroidal anti-inflammatory drugs may inhibit cyclooxygenase (COX) -1 and -2 production at the site of inflammation and in the central nervous system, according to Massachusetts researchers. The centralized production of COX-2 leads to the centralized production of prostaglandin E2 (PGE2), the authors proposed in the March 22 Nature. “We believe that to have maximum efficacy, the next generation of pain killers will need to focus on inhibiting central as well as peripheral production of PGE2,” said researcher Clifford Woolf, MD, PhD.

The protein CBP may be linked to cell death in Huntington’s disease, according to a study in the March 22 Science. The abnormally shaped huntingtin protein pulls CBP away from its station near DNA. The entangled CBP is thus unable to regulate cell survival. Although the researchers have been able to reverse the process in vitro, they have not yet reversed the process in a live mouse model.

Gaze-evoked tinnitus is associated with plastic changes in multiple neural systems that allow eye movement to stimulate the auditory system, according to a study in the March Neurology. Using positron emission tomography, the authors compared brain activity in eight patients with gaze-evoked tinnitus to brain activity in seven controls. All eight patients had developed the condition following posterior fossa surgery to remove an acoustic neuroma (cochleovestibular schwannoma); unilateral deafness, end-gaze nystagnus, and facial nerve dysfunction were also noted in this group. Neural activity linked to gaze-evoked tinnitus was seen in the auditory lateral pontine tegmentum or auditory cortex, while nystagmus associated with gaze-evoked tinnitus may activate the cuneus and cerebellar vermis, the authors wrote.

The neurotrophic effect of adenosine may be explained by its ability to activate the P13-kinase/Akt cascade, inducing a survival response in PC12 and hippocampal cells. “This response is similar to the effect of nerve growth factor and brain-derived neurotrophic factor on their Trk receptors, but differs in the longer time course,” noted the authors of a study in the March 13 Proceedings of the National Academy of Sciences. They added that adenosine is thought to have potential as a therapy for a number of neurological disorders, including cerebral ischemia, sleep disorders, hyperalgesia, and Parkinson’s disease.

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