Dlugos discusses selection criteria for the early identification of candidates for epilepsy surgery. Issues including prognosis, medical intractability, and the benefits and risks of early surgery are reviewed. The effectiveness of epilepsy surgery is clear, as he points out, but challenging work remains to be done to clarify and optimize the timing of surgery for epilepsy, especially in children and adolescents.
Faden reviews clinical and pharmacological studies in experimental animals and patients, defining the issues and therapies that protect against traumatic brain injury. Issues including the therapeutic window, pharmacokinetics, and brain drug penetration will become increasingly more important in future studies.
Hisanaga and colleagues describe patients with Parkinson with possible abnormalities in the peripheral lymphocytes. Specifically, immune mediators were examined in the peripheral lymphocytes of patients using flow cytometry. Patients with Parkinson disease displayed a significantly greater population of circulating CD3+ CD4 bright+ CD8 dull+ lymphocytes than age-matched control subjects and patients with cerebrovascular disease. These cell-mediated differences in patients with Parkinson disease may reflect immunologic differences, which may contribute to disease causation.
Louis and colleagues review the issue of mild tremor occurring in relatives of patients with essential tremor. They found a considerable number of healthy patient relatives having a genetic predisposition for tremor. Essential tremor may be a genetic disorder with variable penetrance, and theseclinical studies may be a prelude to a population-based linkage analysis.
Sencakova and colleagues have correlated hippocampal volume and the clinical features of Alzheimer disease in a cohort of African American patients. Significant correlations were present between hippocampal volume and specific neuropsychological test score reductions. These data indicate that hippocampal volume measurement do represent a measure of the structural substrate of functional impairment, due to the presence of Alzheimer pathology in African American patients.
Amato and colleagues describe a rigorous assessment of the cognitive performance of patients with multiple sclerosis over time. They found that only 20 of 37 patients who were mentally intact on initial testing remain so by the end of the follow-up period. The proportion of cognitively impaired subjects reached 56%. These are important numbers to keep in mind in assessing functional and cognitive status.
Tomimoto and colleagues describe hypercoagulability in a subgroup of patients with Binswanger disease who had more severe cognitive impairment and brain atrophy. It remains unclear whether coagulation-fibrinolyisis system activation exacerbates neurological dysfunction in these patients. The initial observations are of some interest and justify further studies.
Stockton and colleagues evaluated 50 patients with idiopathic carpal tunnel syndrome for hereditary neuropathy with liability to pressure palsies (HNPP). No HNPP deletions were detected, meaning that the contribution of HNPP to isolated carpal HNPP to isolated carpal tunnel syndrome is likely to be quite small. Thus, continued screening for HNPP deletions in the absence of other clinical signs is not justified. This study is of considerable interest in view of recent emphasis on the need for genetic testing in occupational settings.
Figueroa and colleagues have evaluated expansions in the hSKCa3 polyglutamine domain as a causative factor for ataxia, and have studied the association between the length of the polyglutamine repeat and the presence of ataxia. The small-conductance calcium-activated potassium channel gene (hSKCa3) contains 2 CAG repeats, one of which is highly polymorphic. They analyze this repeat in 122 patients with autosomal-dominant cerebellar ataxia or sporadic ataxia as compared with control subjects. Polyglutamine tracts greater than 22 are more common in patients with ataxia than in control subjects. They conclude that longer stretches of polyglutamine in a human potassium channel are not causative for ataxia but are associated with the presence of ataxia. These studies strongly suggest that is necessary to define the effects of long polyglutamine tracts on channel function and the involvement of this channel in neurodegenerative diseases.
This Month in Archives of Neurology. Arch Neurol. 2001;58(10):1530-1531. doi:10.1001/archneur.58.10.1530