Blood pressure reduction in the first 24 hours after stroke onset is independently associated with poor outcome after three months, according to a report in the October 28 Neurology. Brazilian researchers prospectively studied 115 patients admitted in the first 24 hours after stroke onset. After three months, 44 patients (39%) had a poor outcome. After multivariable analysis, NIH Stroke Scale score and degree of systolic blood pressure reduction in the first 24 hours remained independent predictors of poor outcome. There was an almost twofold increased risk of poor outcome for every 10% decrease in systolic blood pressure, the researchers noted. Although most patients received antihypertensive medications, this factor did not affect outcome, they added—though they did not rule out that further decrease of blood pressure with such medications might be harmful in this setting.

The genes that influence the risk of Alzheimer’s disease may vary over the course of an individual’s lifetime, according to investigators at Duke University Medical Center in Durham, North Carolina. The investigators found two chromosomal regions not previously known to influence Alzheimer’s disease: one linked to the disorder in families with early-onset of symptoms and another in families with late-onset Alzheimer’s disease. The study also indicated distinct genes that might determine the very late onset of Alzheimer’s disease (symptoms appearing after age 80). The findings were published in the November American Journal of Human Genetics.

Motor impairment is the strongest predictor of neuropathologic severity in Huntington’s disease, according to findings in the October Annals of Neurology. One hundred subjects in the Longitudinal Core Study of the Baltimore Huntington’s Disease Center were given annual neurologic, cognitive, and psychiatric examinations. All patients had completed an examination within 1,000 days of death. Postmortem neuropathologic grade was assigned using the Vonsattel system. Correlations were made between the Vonsattel score and scores on the Quantified Neurological Examination and its chorea and motor impairment subscales, the Mini-Mental State Examination, the Huntington’s Disease Activities of Daily Living Scale, and numerous demographic variables. The researchers reported that all measures showed significant correlation with Vonsattel score except chorea. The strongest effect was that of the motor impairment score, while the strongest demographic effect was age of onset. “Motor impairment appears to be a good clinical measure of neuronal cell loss, at least late in the course of Huntington’s disease, and therefore may prove useful in observational and treatment studies,” they noted.

Smoking is a risk factor for multiple sclerosis (MS), according to study conducted in collaboration by researchers at Harvard University Medical School in Boston and Bergen University College in Bergen, Norway. The authors analyzed data from a cohort of 22,312 persons living in Hordaland, Norway, in 1997. A total of 87 persons reported having MS. The risk of MS was higher among smokers than nonsmokers (rate ratio, 1.81). “Studies on how smoking interacts with disease onset may contribute to determining the causal agents of [MS],” the researchers concluded in the October 28 Neurology.

Coupling the insertion of stents with intraarterial t-PA is an effective way to prevent or limit damage from acute vertebrobasilar ischemic stroke, according to a study in the October American Journal of Neuroradiology. Four of six patients treated with the combination treatment at Johns Hopkins University Hospital in Baltimore experienced immediate improvement of neurologic symptoms that persisted after treatment. The other two patients—who were in critical condition at the time of the treatments—died. “Without treatment, as many as 90% of these patients will die,” remarked principal investigator Kieran Murphy, MD.

There is a strong relationship between in-hospital mortality following subarachnoid hemorrhage and the volume of such cases seen at the treating hospital, according to investigators publishing in the November Journal of Neurosurgery. The study found that the in-hospital mortality rate of low-volume hospitals (less than 10 subarachnoid hemorrhage cases per year) was 38.7% compared to 27% in high-volume centers (more than 35 subarachnoid hemorrhage cases per year). According to the authors, their results provide evidence that surviving a subarachnoid hemorrhage is more likely if a patient is admitted to a high-volume hospital and suggest that there may be significant benefits to centralizing subarachnoid hemorrhage care. “The key is specialization involving multidisciplinary teams, access to surgical and endovascular treatment, and dedicated specialized aftercare. Volume brings experience.”

British researchers found mixed evidence about the value of cannabis-derived treatments for persons with multiple sclerosis (MS) but concluded that such treatment may be of benefit for some patients. In a three-year trial of more than 600 patients, the investigators examined whether cannabinoids reduced spasticity in persons with MS and assessed the drug’s effect on general well-being in relation to other symptoms. Though the investigators reported little objective evidence of cannabis’ benefits—there was no overall change in spasticity between the treatment group and the placebo group—they did state that, subjectively, a majority of patients felt cannabis improved some of their symptoms. “Patients experienced very few side effects … and given that how a patient feels is an important part of improving health, cannabis-based treatments may be of benefit to some patients,” they noted in the November 8 Lancet.

While memory-enhancing drugs may be effective at improving some types of memory in the elderly, they may actually worsen working memory, according to a study in the November Neuron. The investigation by researchers at Yale University in New Haven, Connecticut, showed that the prefrontal cortex—the seat of working memory—and the hippocampus—where long-term memories are imprinted—have different chemical needs. Protein kinase A, which strengthens long-term memory when activated in the hippocampus and is the target of many memory-enhancing drugs, actually worsened working memory when activated in the prefrontal cortex of rats, the researchers reported. Inhibiting protein kinase A in the prefrontal cortex improved working memory, they noted.

Children with heart conditions who require surgery as infants may be more vulnerable to neurologic problems if they have a particular variety of gene that may decrease the ability of neurons to repair themselves following open heart surgery, according to a report at the Scientific Sessions of the American Heart Association. Based on a one-year evaluation of 329 children who underwent surgery to repair a congenital heart defect at younger than 6 months, the researchers found that children carrying the apolipoprotein E epsilon2 (APOE2) allele were significantly more likely to have worse outcomes in terms of cognitive and motor skills compared with children who underwent the surgery but did not have the APOE2 gene. The association of APOE2 and lower neurodevelopmental scores was consistent even after controlling for variables including gestational age, age at surgery, ethnicity, socioeconomic status, type of cardiac defect, and surgical technique. APOE4, however, had no effect on neurodevelopment, they noted.

NR

Return to table of contents