Endarterectomy for patients with 70% to 99% stenosis and recent symptoms is efficacious in the long term, according to a report in the September Stroke.The study compared risks and causes of ipsilateral stroke in patients who either underwent delayed endarterectomy or continued on medical therapy during the North American Symptomatic Carotid Endarterectomy Trial (NASCET). The risk of ipsilateral stroke at three years was 28.3% for medically randomized and 8.9% for surgically randomized patients, the authors reported.

Hypothermia may reduce mortality and neuronal damage after stroke, according to a Danish research team. Within 12 hours of stroke onset, 17 patients were given hypothermic treatment for six hours. They were covered with a cooling blanket through which air cooled to 10°C was forced, thus reducing their body temperature from 36.8°C to 35.5°C. They were also given pethidine (meperidine) for shivering. At six months after stroke, the mortality was 12% for the hypothermic group and 23% for the control group, while neurologic impairment (as ranked on the Scandinavian Stroke Scale) was 42.4 and 47.9, respectively. According to the report in the September Stroke,the authors recommend a large, randomized, clinical trial of unselected patients.

A deficient hypocretin system may cause narcolepsy in humans, according to a study in the September Nature Medicine.An HCRT mutation, which impaired peptide trafficking and processing, was found in only one person with early-onset narcolepsy, although the cells that make hypocretin were either completely missing in the brains of narcolepsy patients, or the few cells that remained were not producing the peptide. "We think that there's something that specifically kills the cells that make hypocretin," said lead author Emmanuel Mignot, MD, Director of the Stanford Center for Narcolepsy, in California. "We don't know how or why, but it's most likely an autoimmune disease."

The brain may be as involved as the stomach in nausea, according to research in the September American Journal of Physiology: Gastrointestinal and Liver Physiology.The authors found that the immune system responds to any threat by releasing tumor necrosis factor (TNF). This chemical causes the neurons of the nucleus of the solitary tract in the brainstem to stop digestion by relaxing the stomach muscles. Cessation of stomach movement is perceived as nausea, said the authors.

Almost 15% of the 5% of football players who are concussed each year will have a second—usually more serious—concussion within that year, indicated data from a University of North Carolina at Chapel Hill study. Between 1995 and 1997, researchers surveyed 242 randomly selected, certified athletic trainers who represented 17,500 football players on high school and college teams in the United States. According to the study, in the September/October American Journal of Sports Medicine,31% of players who experienced a second concussion within the year returned to play the day of the injury. "Many clinicians are not following the medical guidelines that players should be symptom-free for several days before returning," said lead author Kevin M. Guskiewicz, MD.

Episodic memory failure may be pathogenically different in cerebrovascular disease and in Alzheimer's disease, report the authors of a study in the September Annals of Neurology.A comparison of patients with cognitive impairment following stroke and patients with Alzheimer's disease indicated that memory in the patients with stroke correlates with prefrontal lobe metabolism, while memory in Alzheimer's disease correlates with left hippocampal and temporal lobe metabolism. The authors suggested that if the pathogenesis of memory deficit is identified as cerebrovascular disease, it can more easily be treated.

Exposure to hydrocarbon solvents is associated with an increased severity and a younger age of onset of Parkinson's disease, indicate data from a study of 990 patients with Parkinson's disease. The authors of the study, in the September 12 Neurology,suggest that hydrocarbon solvents—found in petroleum-based products such as paints and glues—may be involved in the etiopathogenesis of Parkinson's disease. Nine occupations were identified as the source of 91.1% of hydrocarbon exposure in this cohort. Petroleum, plastic, and rubber workers; painters; engine mechanics; and lithographers are at particular risk of exposure, said the authors.

Unawareness of olfactory deficits could be an early clinical marker of Alzheimer's disease, report the authors of a study in the September American Journal of Psychiatry.Patients who scored low on the University of Pennsylvania Smell Identification Test but who were oblivious to their impairment were more likely to be diagnosed with Alzheimer's disease two years later. "Other recent, promising studies have shown that brain wave imaging can provide clinicians with an early warning sign of Alzheimer's disease. However, the results of our olfaction deficit study could lead us to a prediction method that is a lot less expensive than brain scans," said lead author D. P. Devanand, MD.

A routine electroencephalogram should be included in the diagnostic evaluation of first nonfebrile seizure in children, recommends the Quality Standards Subcommittee of the American Academy of Neurology. The subcommittee gathered data from multiple searches of relevant literature. The guidelines are published in the September 12 Neurology.

Attempting to regulate emotion affects memory, found psychologists from Stanford University, California. According to the study in the September Journal of Personality and Social Psychology,53 people watched footage of a couple arguing. The people who were asked to suppress their expression of emotion during the scene had a poorer memory of what they had heard and seen than did the control group; the researchers believe that the continual self-monitoring and self-correction required for expressive selection uses cognitive resources thus decreasing the accuracy of the memory of the event. A second experiment showed that people who were asked to look at slides of injuries with the objectivity of medical professionals performed better on nonverbal recall than did the control group or the expression-suppression group.

Particular medical conditions or drug therapies may place older drivers at higher risk of involvement in automobile accidents, indicate data from a University of Alabama at Birmingham study. Male and female drivers with stroke or heart disease and female drivers with arthritis are at greater risk of involvement in at-fault automobile crashes. According to the study in the September American Journal of Epidemiology,nonsteroidal anti-inflammatory drugs, angiotensin converting enzyme inhibitors, anticoagulants, and benzodiazepines are associated with an increased risk of at-fault involvement in accidents; calcium channel blockers and vasodilators, however, are associated with a reduced risk.

Cytoplasmic, not nuclear, polyglutamine aggregates are associated with spinocerebellar ataxia type 2 (SCA2) according to a study in the September Nature Genetics.As the damage is cytoplasmic rather than nuclear, SCA2 is more similar to Parkinson's and to Alzheimer's disease than to other polyglutamine disorders, said the University of California at Los Angeles authors. Thus, the SCA2 animal model will be useful in understanding these diseases as well, they suggested.

Transplantation of cultured neuronal cells is feasible in patients with motor infarction, according to a report in the August 22 Neurology.The authors noted that transplantation was associated with motor improvement in six of the 12 patients who had experienced infarct between six months and six years previously, and that it was not associated with adverse serologic or imaging-defined effects during the one-year follow-up. However, as at least one false positive can be expected in a cohort of this size 50% of the time, it is unlikely that the study detected meaningful improvement, said Justin A. Zivin, MD, in an accompanying editorial. He also noted that a longer follow-up may detect a malignant transformation in this cell line, which is derived from human embryonic carcinoma.

Piracetam may improve language function after stroke, according to German researchers. During the study, 24 stroke patients with aphasia were randomized to 2,400 mg piracetam twice daily or to placebo. Both groups also received intensive speech therapy before and after the treatment period. The piracetam group showed improvement in six measures of language function, while the control group showed improvement in three subtests. The authors noted, in the September Stroke,that the piracetam group also showed increased activation in the left transverse temporal gyrus, the left triangular part of inferior frontal gyrus, and the left posterior superior temporal gyrus, while the placebo group showed increased activation in the left vocalization area.

The magnetic stereotaxis system (MSS) can be used to guide brain catheters more accurately and safely, according to a study in the August Journal of Neurosurgery. The study indicates that magnetic fields can be used to noninvasively direct a probe in planned, nonlinear direction, and that close-to-real-time imaging supplies immediate feedback about the path, to allow timely corrections. Catheter placement was within 1.5 mm of the planned site, registration error averaged 1.7 mm, and tissue disruption was similar to that of standard stereotactic procedures, said the authors.

Replicon vectors might be able to deliver therapeutic proteins to the central nervous system for treatment of disease or trauma, reported University of Alabama at Birmingham researchers. The study of modified poliovirus in a mouse model was described in the September Nature Biotechnology.The delivery system could be used to promote an anti-inflammatory reaction or neuronal regrowth, suggested the authors.

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