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Savica and colleaguesArticle review the convincing evidence that the Parkinson disease neurodegenerative process begins many years before the onset of motor manifestations. Initial estimates based on nigral neuropathology or striatal dopamine imaging suggested a 5- to 6-year preclinical period. Epidemiologic studies of nonmotor manifestations such as constipation, anxiety disorders, rapid eye movement sleep behavior disorder, or anemia suggested that the preclinical period extends at least 20 years before the motor manifestations. Olfactory impairment and depression may also precede the onset of motor manifestations; however, the lag time may be shorter. Recognition of a nonmotor preclinical phase spanning 20 or more years should guide the search for predictive biomarkers and the identification of risk or protective factors for Parkinson disease.
Latov et alArticle investigate the timing, course, and clinical characteristics of the response to intravenous immunoglobulin in chronic inflammatory demyelinating polyradiculoneuropathy. Their data suggest that treatment with 2 doses of immune globulin intravenous, 10% caprylate/chromatography purified, given every 3 weeks may be required for initial improvement, and continued maintenance therapy may be necessary to achieve a maximal therapeutic response.
Responders who reached maximal improvement. Cumulative number of responders in immune globulin intravenous, 10% caprylate/chromatography purified (IGIV-C) and placebo groups reaching maximal adjusted Inflammatory Neuropathy Cause and Treatment (INCAT) score improvement.
Knekt and colleaguesArticle point out that low vitamin D status has been suggested to be related to Parkinson disease risk. They have investigated whether serum vitamin D level predicts the risk of Parkinson disease. Individuals with higher serum vitamin D concentrations showed a reduced risk of Parkinson disease. Their results are consistent with the suggestion that high vitamin D status provides protection against Parkinson disease.
Pitt et alArticle indicate that conventional magnetic resonance imaging has a low sensitivity for cortical demyelination, making it difficult to establish the effect of cortical pathology on the disease course. Ultra–high-field (7-T) magnetic resonance imaging with intrinsically high signal to noise ratio, spatial resolution, and image contrast can visualize previously unattainable morphological details. They report that 3-dimensional, T2*-weighted gradient-echo and white matter–attenuated turbo-field-echo sequences at 7-T field strength detect most cortical lesions in postmortem multiple sclerosis tissue. This study indicates the potential of T2*-weighted gradient-echo and white matter–attenuated turbo-field-echo imaging at ultra–high-field magnetic resonance imaging for cortical lesion detection in patients with multiple sclerosis.
Devore and colleaguesArticle have studied the consumption of major dietary antioxidants in relation to long-term risk of dementia. They conclude that higher intake of foods rich in vitamin E may modestly reduce long-term risk of dementia and Alzheimer disease.
Lillo et alArticle compare the clinical features at presentation in patients with behavioral variant frontotemporal dementia (FTD) who develop amyotrophic lateral sclerosis (ALS) vs those who do not develop ALS. Of note, they find that delusions were particularly common in patients destined to develop FTD/ALS. The occurrence of delusions in the context of behavioral variant FTD should lead to an early search for ALS features.
Burrus and colleaguesArticle find that knowledge is limited related to the neurologic manifestations associated with thrombotic thrombocytopenic purpura (TTP). Of patients who had acute abnormalities on brain magnetic resonance imaging, 13 (48%) were found to have posterior reversible encephalopathy (PRES). The only variable highly associated with PRES on neuroimaging was the glomerular filtration rate (P = .02). The occurrence of PRES in patients with acute TTP is associated with worse renal function.
Reitz et alArticle aim to develop a simple summary risk score for the prediction of Alzheimer disease in elderly persons based on their vascular risk profiles. Risk factors that contributed to the risk score were age, sex, education, ethnic group, apolipoprotein E ε4 genotype, history of diabetes, hypertension, or smoking, high-density lipoprotein levels, and waist to hip ratio. The resulting risk score predicted dementia well.
Kirton and colleaguesArticle indicate that periventricular venous infarction (PVI) has emerged as an important and unique cause of presumed perinatal ischemic stroke (PPIS). They hypothesize that clinical presentations and risk factor profiles differ between PVI and arterial PPIS. They find that PPIS diagnosis is often delayed, and the association of acute perinatal risk factors with arterial PPIS compared with PVI supports distinct timing of these diseases. Prospective, case-control risk factor studies of PPIS subtypes will be required to develop prevention strategies.
Crugnola et alArticle submit that, although defects of the mitochondrial respiratory chain have been described in several patients with amyotropic lateral sclerosis (ALS), their pathogenic significance is unclear. Their data confirm that the histochemical finding of cytochrome c oxidase–negative fibers is common in the skeletal muscle of patients with sporadic ALS. In 7 patients, the oxidative defect was severe enough to support the hypothesis that mitochondrial dysfunction must play a role in the pathogenesis of the disease.
Wilson and colleaguesArticle find that administration of cognitive test batteries by telephone has been shown to be a valid and cost-effective means of assessing cognition but it remains relatively uncommon in epidemiological research. They report that assessment of cognition by telephone has little effect on performance and provides operational flexibility and a means of reducing costs and missing data.
Dreyfus et alArticle appraise the relationship of a task assessing memory for recent autobiographical events and those of 2 commonly used brief memory tasks with the results of a clinical assessment for dementia. The autobiographical recall task and each of the other brief clinical measures correlate significantly with the Clinical Dementia Rating sum of boxes (P < .001). The autobiographical recall task has a significantly higher correlation (P < .001) with the Clinical Dementia Rating sum of boxes than the 2 commonly used clinical memory measures.
Storace and colleaguesArticle report the average plasma levels of β-amyloid 1-42 plasma autoantibodies of patients with mild cognitive impairment who progress to having Alzheimer disease, but not that of the stable cases, is significantly higher than in cognitively normal controls (P < .001). The evaluation of β-amyloid 1-42 autoantibodies, after dissociation of the complexes, is a simple and inexpensive method that may be used to predict the occurrence of Alzheimer disease.
This Month in Archives of Neurology. Arch Neurol. 2010;67(7):793-794. doi:10.1001/archneurol.2010.134