Magnetic resonance imaging (MRI) can be used to detect subacute and acute subarachnoid hemorrhage, according to findings in the February Journal of Neurology, Neurosurgery, and Psychiatry. The study measured the sensitivity and specificity of five MRI sequences to subarachnoid hemorrhage in 41 patients. There was a great deal of variation in the sensitivity to subarachnoid hemorrhage in the five neuroimaging sequences studied, 50% to 94% in acute and 33% to 100% in subacute subarachnoid hemorrhage. The gradient echo T2* was the most sensitive sequence, 94% in the acute phase and 100% in the subacute phase.

The American College of Chest Physicians released guidelines for the prevention of thrombosis in a special supplement to the January Chest. Patients with noncardioembolic stroke should receive an antiplatelet agent regularly to reduce the risk of recurrent stroke. This should be 50 to 325 mg of aspirin; a combination of 25 mg of aspirin and 250 mg of extended-release dipyridamole twice a day, or 75 mg of clopidogrel daily. For treatment of acute ischemia, within three hours of symptom onset the administration of intravenous recombinant tissue plasminogen activator in a dose of 0.9 mg/kg with 10% of the dose given as an initial bolus and the remainder infused over one hour is recommended.

Striatal dopamine D2 receptor availability was significantly lower in 10 obese individuals than in controls, thus showing that dopamine may play an important role in obesity, according to the findings in the February 3 Lancet. The body mass index in obese patients correlated negatively with the measures of D2 receptors. "The results from this study suggest that strategies aimed at improving dopamine function might be beneficial in the treatment of obese individuals," said lead author Gene-Jack Wang, MD.

Transplantation of human Schwann cells results in functional remyelination of a dorsal column lesion in an animal model, according to the findings in the February Journal of Neuroscience. The Schwann cells were taken from amputated limbs of human patients and frozen. Within a few weeks of injection in the rat spinal cords, the human Schwann cells started to form extensive myelin, and nerve impulse conduction was improved. "Such cells could potentially be used in humans for a clinical trial in demyelinating disorders, such as multiple sclerosis," said researcher Jeffrey Kocsis, PhD. The scientists warn, however, that this technique may not work as well if transplanted into a large lesion as seen in multiple sclerosis patients.

Cyclooxygenase-2 (COX-2) is involved in pathogenic events occurring in both the early and late stages of cerebral ischemia, according to a study in the January 30 Proceedings of the National Academy of Sciences. This protein was attributed to the lessening of glutamate neurotoxicity and the nullification of negative effects of postischemic inflammation. "This is a breakthrough in stroke treatment because this is the first time COX-2 has been implicated in the mechanisms of stroke and because it suggests that COX-2 inhibitors, which are known to be well tolerated and safe, can also be used to treat stroke," said lead author Costantino Iadecola, MD.

Frontal lobe lesions impair the ability to infer mental states in others, according to a study in the February Brain. Thirty-two adults with lesions in frontal and non-frontal brain regions and 14 healthy adults were given tests evaluating visual perspective and deception identification. The results show that lesions throughout the frontal lobe, especially in the right frontal lobe, were associated with impaired visual perception. Right ventral medial frontal lesions impaired a patient's ability to detect deception.

Hormone therapy with estrogen and progestin has no significant effect on stroke risk among postmenopausal women with coronary disease, according to a study in the February Circulation. The randomized, placebo-controlled experiment followed 2,763 women postmenopausal over 4.1 years as part of the larger Heart & Estrogen-progestin Replacement Study (HERS). "HERS is the first clinical trial of postmenopausal hormone therapy to examine whether such therapy affects the risk of transient ischemic attacks and stroke," according to lead author, Joel A. Simon, MD. Hormone therapy was not significantly associated with risk of nonfatal stroke, fatal stroke, or transient ischemic attack.

Brain abnormalities are seen in alcoholic women, according to a study in the February Journal of Alcoholism: Clinical and Experimental Research. Functional magnetic resonance imaging of young women 18 to 25 years of age with a history of alcohol abuse since adolescence showed damage mostly on the brain's right side and in the frontal lobe and parietal lobe.

A Phase I study has shown that an autologous peptide-pulsed dendritic cell vaccine has positive effects for sufferers of malignant glioma, according to a study in February Cancer Research. Three biweekly intradermal vaccinations were administered to seven patients with glioblastoma and two patients with anaplastic astrocytoma. The median survival times for the study group were 455 days and 257 days for the control group. "Malignant gliomas are very deadly tumors. Even with aggressive therapy, including surgical resection followed by radiation therapy and chemotherapy, the median length of survival is less than one year. But the median survival for patients who were given the dendritic cell vaccine was extended significantly," said researcher Keith L. Black, MD.

Individual differences in the brain's responses to emotional stimuli are associated with specific personality traits, according to a study in the February Behavioral Neuroscience. Functional magnetic resonance imaging performed on 14 women, 19 to 42 years of age, showed that extroverts compared to introverts have greater brain reactivity to positive stimuli than to negative stimuli. These changes were seen in the frontal cortex, amygdala, and anterior cingulate regions of the brain.

Choline acetyltransferase mutations cause myasthenic syndrome associated with episodic apnea in children, according to the February 13 Proceedings of the National Academy of Sciences. These mutations affect the synthesis of acetylcholine from acetyl CoA and choline at cholinergic synapses. Myasthenic syndrome is a hereditary condition, which is rarely fatal after the age of 15. "What we have developed is a way at the molecular level to confirm a diagnosis that a child has this condition," said researcher Andrew Engel, MD.

A study in the February Neurosurgery provides information which may help predict which patients with Parkinson's disease would benefit from pallidotomy. Twenty-five patients were followed for one year after a unilateral, large-volume, microelectrode-guided, posteroventral pallidotomy. Age younger than 60, tremor, unilateral predominance, levodopa responsiveness, motor fluctuations with dyskinesia, and good lesion placement predicted a good response to pallidotomy. Advanced age, absence of tremor, increased duration of disease, reduced levodopa responsiveness, frontal behavioral changes, prominent apraxic phenomena, and improper lesion placement predicted a poor response.

A new testing system may allow custom-made therapies for patients with Parkinson's disease, according to the February Annals of Neurology. Six patients who recently had deep brain stimulators implanted were monitored using positron emission tomography. Differences in how patients responded to the deep brain stimulators might give clues on how to customize patient-specific treatments. "What is novel here is to use the behavioral test online with the brain imaging, so that we can actually see how the brain is performing the movement," said researcher David Eidelberg, MD. "People actually improved in their motor performance in a reversible way."

Familial dysautonomia is caused by mutations of the IKAP gene and is specifically caused by the tissue-specific expression of a splicing mutation in the IKBKAP gene, according to two studies in the March American Journal of Human Genetics. Familial dysautonomia is almost exclusively found in individuals of Ashkenazi Jewish descent and is an autosomal recessive disorder affecting development and survival of sensory, sympathetic, and some parasympathetic neurons. These findings are significant because they will allow for the identification of carriers of this disorder as well as the development of effective therapies.

Fear behavior can be the main feature in certain epileptic seizures, according to a study in the February Journal of Neurology, Neurosurgery, and Psychiatry. Patients may be misdiagnosed for years as having panic attacks and thereby not receive appropriate therapy. In intense ictal fear, with behavioral and autonomic features, the orbitoprefrontal, anterior cingulate, and the temporal limbic cortices may be involved and their proper functioning may be impeded.

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