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This Month in Archives of Neurology
Arch Neurol. 2001;58:1968-1969.
Chemokines and Multiple Sclerosis
Trebst and Ransohoff (SEE ARTICLE) describe the emerging major roles that chemokines and their receptors have in the pathogenesis of demyelinating disease. Their review emphasizes a general model of leukocyte migration into the central nervous system under normal and inflammatory conditions that are mediated and modified by chemokines and their receptors. Future opportunities and challenges in this area of investigation are identified.
New Concepts in Mild Cognitive Impairment
Petersen and colleagues (SEE ARTICLE) , part of a collaborative international effort, have reviewed our current understanding of mild cognitive impairment and its role and position in the spectrum of disease of cognitive impairment and in normal aging. Mild cognitive impairment is an important concept and its role as a transitional disorder continues to be defined as it emerges more clearly and quantitatively.
Gamma Knife Surgery for Parkinson Disease
Okun and colleagues (SEE ARTICLE) describe their experience using radiosurgery with a gamma knife (GK) for pallidotomy and thalamotomy as a safe and effective alternative to radiofrequency ablative surgery and deep brain stimulation for Parkinson disease. Eight patients are presented who were treated with GK surgery for Parkinson disease and subsequently developed unexpected complications, including dysphagia, hemiplegia, homonymous visual field deficit, hand weakness, dysarthria, hypophonia, aphasia, arm and face numbness, and pseudobulbar laughter. In all cases, the GK-induced lesions were significantly off target. This report calls attention to the potential benefit but also the potential risks. An editorial by Jankovic is included.
Intravenous tPA for Ischemic Stroke
Grotta et al (SEE ARTICLE) describe the Houston experience during 1996-2000 in which a total of 269 patients were treated with tissue plasminogen activator (tPA) therapy for ischemic stroke within the first 3 hours of symptom onset. This large single-center experience shows that up to 15% of patients with ischemic stroke can be treated with intravenous tPA. Clearly, successful experience with intravenous tPA therapy depends on the experience and organization of the treating team and adherence to published guidelines.
Silent Infarcts in Children With Sickle Cell Anemia
Pegelow et al (SEE ARTICLE) point out that in a substantial minority of neurologically normal children with sickle cell disease, magnetic resonance imaging results reveal lesions consistent with cerebral infarction. They have shown that blood transfusion lowers the risk for new silent infarcts or strokes in children having both abnormal transcranial doppler velocity and silent infarcts. This therapeutic approach is an important one and the experience cited here reinforces the importance of early detection and treatment in this subgroup of children at high risk for stroke.
A -Containing Amyloid Plaques and Cognitive Decline
Parvathy et al (SEE ARTICLE) have studied whether A deposition correlates with dementia and whether it occurs at an early stage of cognitive decline. They found that there was a significant deposition of 3 A species that correlated with cognitive decline. Deposition of A occurred very early in the disease process before there could be a diagnosis of Alzheimer disease. These important results support a role of A in mediating the pathogenic events in Alzheimer disease dementia. Therapies directed at the formation, accumulation, or cytotoxic effects of A should be pursued vigorously.
Education and Dementia
Qiu et al (SEE ARTICLE) have explored the relationship between education and Alzheimer disease (AD) by studying a community-based cohort of 1296 persons without dementia aged at least 75 years and following them to detect incident AD. In this cohort of patients in Sweden, less education was related to increased incidence of clinical AD or dementia but not to mortality of subjects with AD or dementia. The findings support the cognitive reserve hypothesis.
Oligoclonal Bands and Multiple Sclerosis Prognosis
Avasarala et al (SEE ARTICLE) studied 1800 patients diagnosed with multiple sclerosis to find a correlation between prognosis of disease progression and oligoclonal bands in cerebrospinal fluid at the time of diagnosis. They found that a low or absent number of oligoclonal bands in cerebrospinal fluid at the time of diagnosis predicted a better prognosis. While it is an interesting observation, the method is not especially sensitive and not to be used to influence therapeutic options. It may evolve into a more practical method in the future.
Imaging and Temporal Lobe Epilepsy
Kuzniecky et al (SEE ARTICLE) have used magnetic resonance spectroscopy (MRS) to study patients with temporal lobe epilepsy. They prospectively performed quantitative hippocampal magnetic resonance imaging (MRI) volumetry and MRS imaging in 33 patients with intractable mesial temporal lobe epilepsy undergoing surgery. In general, their findings support the concept that the metabolic dysfunction measured by MRS imaging and the hippocampal volume loss detected by MRI volumetry did not have the same neuropathologic basis. Results of MRS imaging reflect neuronal and glial dysfunction rather than neuronal loss as has been previously assumed. This findings of this study define more precisely the molecular and cellular events occurring in patients with temporal lobe epilepsy.
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