A radioactive compound commonly used for imaging neuroblastomas may also help kill these tumors, said Gregory Yanik, MD, at the annual meeting of the American Society of Hematology. 131-I meta-iodobenzylguanidine (MIBG) "can act as a tumor bullet, specifically targeting the neuroblastoma itself, sparing other parts of the body from complications or side effects," he said. The long-term efficacy of MIBG, however, is unknown. Although the therapy was linked to partial remission in three children and complete remission in eight during a phase 1 trial, some children have since relapsed and died.

Bone marrow may be a source of neural cells with potential for treating neurodegenerative diseases or central nervous system injury, suggested two studies in the December 1 Science. In the studies, bone marrow cells transplanted into mice migrated to the central nervous system or brain and developed into cells that expressed neuronal proteins. Research has yet to show whether such marrow-derived cells function as neurons or what prompts bone marrow cells to develop into specific neurons.

Constraint-induced movement therapy, or forced-use therapy, was associated with less arm impairment in post-stroke patients at two weeks than was traditional therapy, according to a pilot study in the December Stroke. Patients receiving constraint-induced movement therapy demonstrated more overall arm strength and coordination improvement than did the patients receiving traditional therapy. "People who received the experimental treatment were certainly as independent as the other patients, and there were some indications that the group as a whole was more independent," reported lead author Alexander W. Dromerick, MD. He and colleagues hope to study a larger patient group to investigate this effect further and to find out how long the positive effect lasts.

No long-term central nervous system sequelae were associated with compressed-air diving under controlled conditions, according to a study in the December 12 Neurology. However, another study in the same issue suggested that neurologic injury subsequent to decompression might be due to paradoxical arterialization of venous gas emboli. The latter study linked the risk of arterialization to the presence of a patent foramen ovale (PFO). Divers should be screened for PFO, as it is present in almost one third of the general population, said lead author Tibo Gerriets, MD.

Abbreviated forms of the dystrophin gene (minidystrophin) delivered by adeno-associated virus (AAV) vectors are a "promising avenue" of gene therapy for Duchenne muscular dystrophy, according to a University of Pittsburgh, Pennsylvania, study. The study, in the December 5 Proceedings of the National Academy of Sciences,showed that the dystrophin gene could be reduced to one third of its 11-kb coding to allow AAV delivery. In a mouse model, intramuscular injections of AAV-delivered minidystrophin genes showed therapeutic efficacy. However, H. Lee Sweeney, PhD, and Elisabeth R. Barton, PhD, noted, in an accompanying commentary, that it is unclear to what extent truncated dystrophin can prevent muscle degeneration or generate dystrophin capable of withstanding and transmitting the forces developed in skeletal muscle in humans.

The number of seizures within the first six months after presentation with epilepsy is the single most important predictive factor for both early and long-term remission of seizures, according to a British study reported in the December Annals of Neurology. Among a prospective community-based cohort of 792 patients, the chance of entering one year of remission by six years for a patient who had two seizures during the first six months was 95%; for five years of remission, it was 47% as opposed to 75% for one year of remission and 24% for five years of remission if there had been 10 or more seizures during this period.

Chronic alcoholism was linked to extensive, but selective, reprogramming of myelin gene expression, indicated the results of a University of Texas, Austin, study. In addition to downregulation of myelin-related genes, cell cycle genes and several neuronal genes were changed in expression, said the authors in the December Alcoholism: Clinical and Experimental Research. The study findings, achieved through microarray analysis, "may provide a molecular basis for the susceptibility of alcoholics to white-matter loss and demyelinating diseases," concluded the authors.

Kalkitoxin, a neurotoxin derived from cyanobacteria ("blue-green algae"), may lead to a better understanding of neurochemical pathways and how pharmacotherapies affect them, according to a report from the 2000 International Chemical Congress of Pacific Basin Societies. The neurotoxin appears to block sodium-ion channels in animals. Therapies such as topiramate and lidocaine are also sodium-channel blockers, noted lead researcher William Gerwick, PhD, of Oregon State University in Corvallis.

Methionine residue 35 may play a role in amyloid ß-peptide (1-42) [Aß(1-42)]-induced oxidative stress and neurotoxicity in Alzheimer's disease, according to a study presented at the 2000 International Chemical Congress of Pacific Basin Societies. Substitution of norleucine for the structurally similar methionine at position 35 in Aß(1-42) "was not toxic to hippocampal neurons, did not induce reactive oxygen species, and did not cause neuronal protein oxidation," said the authors. The study also indicated that vitamin E blocks neurotoxicity by inhibiting Aß(1-42)-induced oxidative stress.

Estrogen users are less cognitively impaired and more independent in their activities of daily living than are nonusers, according to data from a study of 10,145 elderly women with Parkinson's disease. While 45% of estrogen users and 33.5% of nonusers had minimal or no cognitive impairment, 13.3% of estrogen users and 26.4% of nonusers had severe cognitive impairment, said the authors in the November Movement Disorders. However, although this inverse relationship remained after adjusting for age, race, and motor impairment, more estrogen users were depressed and more likely to be taking an antidepressant than were nonusers, the authors noted.

The US Food and Drug Administration approved Myobloc™ (botulinum toxin type B) Injectable Solution for the treatment of pain associated with abnormal head and neck position in patients with cervical dystonia (CD). Myobloc significantly reduced the severity of CD pain for between 12 and 16 weeks, in patients who responded to the therapy, during two phase 3 trials. Adverse events associated with Myobloc include dry mouth, dysphagia, dyspepsia, and injection site pain. Caution should be exercised when administering Myobloc to patients with peripheral motor neuropathic diseases or neuromuscular joint disorders, according to Elan Corporation.

The use of handheld cellular telephones is not associated with risk of brain cancer, according to a study in the December 20 JAMA. Between 1994 and 1998, 469 people with primary brain cancer and 422 matched controls were evaluated. The mean frequency of use was 2.5 monthly hours for cases and 2.2 hours for controls; the mean duration of use was 2.8 years for cases and 2.7 years for controls.

Transient ischemic attack (TIA) increases the short-term risk of stroke or adverse events, according to a University of California at San Francisco study. During the 90 days after index TIA, 10.5% of the 1,707-patient cohort presented to the emergency department with stroke—half of whom presented in the first two days. Five independent risk factors for subsequent stroke or adverse events included age greater than 60, diabetes mellitus, symptom duration longer than 10 minutes, weakness, and speech impairment, said the authors in the December 13 JAMA.

Calcium channel blockers (CCBs) are inferior to angiotensin-converting enzyme (ACE) inhibitors, ß-blockers, and diuretics in reducing the risk of several major complications of hypertension, according to a report in the December 9 Lancet. "In an analysis of more than 27,000 patients with high blood pressure, we found that those treated with CCBs had a 26% higher risk of heart attack and a 25% higher risk of heart failure than those treated with other drugs," said lead researcher Marco Pahor, MD. He added that "these data reinforce the view that use of CCBs should be limited to patients who do not tolerate, or who have failed on diuretics, ß-blockers, and ACE inhibitors."

A modified antioxidant enzyme significantly delayed the onset and increased the survival of mice affected with familial amyotrophic lateral sclerosis in a Mayo Clinic study. "This study shows for the first time that the antioxidant enzyme called catalase, when modified by the naturally-occurring polyamine, putrescine, can better penetrate the blood-brain barrier and delay the progression of the disease," said Joseph Poduslo, PhD, a molecular neurobiologist and senior author of the December Annals of Neurologyreport. This is the greatest increase in survival for any systemically administered drug thus far achieved in mice with the disease, the researchers reported.

There is no increased death rate for patients with Parkinson's disease who use the drug selegiline in combination with levodopa, reported researchers from the University of Dundee, Scotland, in the December 26 Neurology. The study, which compared 97 newly diagnosed patients receiving drugs for Parkinson's disease to 902 controls who did not have the disease, showed that although those with Parkinson's disease were twice as likely to die during the study period as their healthy counterparts, those who were taking selegiline in combination with levadopa were no more likely to die than the people without Parkinson's disease.

A spinal cord fluid leak may cause headaches initially attributed to brain tumor, according to researchers from the Hospital General de Mostoles in Madrid, Spain. The researchers identified enlarged pituitary glands in the brains of 11 patients with intracranial hypotension syndrome. Magnetic resonance imaging exams of the study participants revealed pituitary glands an average of 50% larger than normal; it is believed that the gland enlargement results from the sinuses surrounding the pituitary gland becoming engorged with blood to compensate for the low fluid pressure. Before advances in MRI technology, intracranial hypotension might have been inaccurately diagnosed as tumorous growth, said the authors in the December 26 Neurology.

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