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This Month in Archives of Neurology
Arch Neurol. 2002;59:516-517.
Updating Cerebrotendinous Xanthomatosis
Moghadasian and colleagues (SEE ARTICLE) critically assess the clinical and genetic knowledge of cerebrotendinous xanthomatosis (CTX). It is a rare disease with diverse manifestations, including cataracts, Achilles tendon xanthomas, diarrhea, atherosclerotic vascular disease, and diverse neurologic manifestations that include severe mental retardation. Excess production and consequent accumulation of cholestanol in tissues is an important feature and chenodeoxycholic acid is an effective therapy. Early detection and treatment of CTX significantly reduces the impact of the disease. This review alerts the physician to key diagnostic features.
Axonal Polyneuropathy and Successful Aging of the Peripheral Nervous System
Vrancken and colleagues (SEE ARTICLE) describe their experience with chronic idiopathic axonal polyneuropathy (CIAP) by comparing 127 patients with CIAP and 108 age-matched control subjects. Clinical and electrophysiological differences were found between patients with CIAP and normal controls, comparing and contrasting normal aging from axonal disease. Editorial comment is provided by Gil I. Wolfe, MD. (SEE ARTICLE)
Femoral Neuropathy After Renal Transplantation
Sharma and colleagues (SEE ARTICLE) describe the natural history of acute femoral neuropathy (AFN) following renal transplantation. In a prospective manner, 184 renal transplantations were carried out and 4 patients (2.2%) developed AFN postoperatively. All patients had excellent recovery of motor function in 3 to 6 months. These findings provide an important perspective and reassurance for a favorable outcome.
Thrombolysis in Acute Stroke Caused by Cervical Artery Dissection
Arnold et al (SEE ARTICLE) describe 9 patients with acute stroke caused by cervical artery dissection (CAD). Patients were treated with intravenous thrombolysis or local intra-arterial thrombolysis. The responses to thrombolytic therapy were variable, but the authors' data and review of the literature indicate that thrombolysis is a feasible approach in acute stroke caused by CAD.
Carotid Artery Dissection
Milhaud et al (SEE ARTICLE) studied the characteristics and outcomes of acute ischemic stroke in patients with internal carotid artery occlusion caused by either dissection or atherothrombosis. Internal carotid artery occlusion caused by dissection was found in younger patients and had fewer risk factors than occlusion caused by atherothrombosis. However, patients with dissection had more significant clinical features and a less favorable prognosis. These points are of value in considering care and outcome of this select group of patients with stroke.
Basilar Artery Stenosis or Occlusion
Devuyst and colleagues (SEE ARTICLE) describe their extensive experience with basilar artery occlusion and stenosis. Eighty-eight patients were studied and specific clinical syndromes were identified. The prognosis of basilar artery stenosis greater than 50% or occlusion provides a complex analysis, and some clinical patterns result in a lower risk of poor outcome. This study, by a group with great experience, refines and updates specific features of basilar artery disease and will serve to provide guidance during acute patient care management.
Dopaminergic Function and Transport in Parkinson Disease
Ribeiro and colleagues (SEE ARTICLE) compared striatal uptake of 18F-dopa and 76Br-FE-CBT, a dopamine transporter ligand, in patients with Parkinson disease (PD). 18F-dopa is up-regulated in early PD, suggesting an increase of dopamine synthesis in the surviving terminals. Positron emission tomography with dopamine transport ligands and 18F-dopa give complementary information on the presynaptic status of the nigral striatal dopaminergic system. Dopamine transporter ligands might measure dopaminergic neuronal degeneration more accurately than 18F-dopa uptake, and might support methods to evaluate neuroprotective strategies of PD in the future.
Extrapyramidal Signs, Lewy Bodies, and Survival in Alzheimer Disease
Haan et al (SEE ARTICLE) examine whether the association between Lewy bodies and age at death were modified by the presence of extrapyramidal signs and also by hallucinations or delusions. Clinical features of 379 patients with Alzheimer disease (AD), who were subsequently autopsied, were studied. They found that extrapyramidal signs indicated worse prognosis in patients with AD and that these signs may be related to underlying Lewy body pathology. The presence of extrapyramidal signs is a strong predictor of Lewy bodies in this series of cases.
Apolipoprotein E Genotype and Alzheimer Disease in African Americans
Graff-Radford and colleagues (SEE ARTICLE) have investigated the association of apolipoprotein E (APOE) genotypes and Alzheimer disease (AD) in elderly African Americans. In this carefully designed neuroepidemiologic study, APOE- 4 seems to be a potent risk factor and 2 has a protective effect against AD in African Americans. The age-related decline in 4 risk and the apparent protective effect of the 2 allele are similar to the patterns observed in white patients. These findings are of great interest in showing the equivalency of the APOE allele risk status of 4 and 2 across different racial groups.
Predictors of Cognitive Decline in Healthy Elderly Persons
Marquis and colleagues (SEE ARTICLE) have measured memory ability, hippocampal volume, and gait speed to independently predict cognitive decline in healthy elderly people. Logical memory performance and hippocampal volume each predicted the onset of early dementia independent of age and sex. Time to walk 30 ft additionally contributed to the prediction of time of onset to cognitive impairment. These clinical features may be of practical value in assisting in the early detection of cognitive impairment.
Frontotemporal Degeneration: Tau and Apolipoprotein E Polymorphisms
Short and colleagues (SEE ARTICLE) found that clinical subtypes of frontotemporal lobar degeneration have different tau and apolipoprotein E genotype frequencies, suggesting that these genes may influence the clinical presentation. It is a convincing clinical-molecular correlation study that offers new molecular insights.
Planum Temporale and Planum Parietale in Neurofibromatosis Type 1
Billingsley and colleagues (SEE ARTICLE) have determined whether planum temporale (PT) and planum parietale (PP) morphology are associated with learning disabilities in neurofibromatosis type 1 (NF-1). The left PTs in boys with NF-1 were significantly smaller in both surface area and gray matter volume compared with girls with NF-1 and with controls. Boys with NF-1 also showed greater symmetry between the left and right hemispheres in this region compared with girls with NF-1 and controls. Learning disabilities in NF-1 seemed to be significantly related to PT symmetry in the NF group as a whole. Thus, the susceptibility of individuals with NF-1 to develop reading and other learning disabilities seems to be related to the development of the sylvian fissure.
DNA Repeats With Ataxia
Silveira and colleagues (SEE ARTICLE) studied 110 unrelated families from Portugal or Brazil with dominantly inherited ataxia for trinucleotide repeat (TNR) expansions at the known genetic loci. The degree of disease due to (CAG)n expansions was: 63% Machado-Joseph disease (MJD1), 3% spinocerebellar ataxia (SCA2), 2% dentatorubropallidoluysian atrophy, 1% SCA6, and 1% SCA1. (CTG)n expansions at the SCA8 gene were found in 2%, and (GAA)n expansions in the FRDA gene for Friedreich ataxia (FA) were found in 64% of families with recessive ataxia. Isolated patients also had TNR expansions. An expanded allele at the TATA-binding protein gene, with 43 CAGs, was present in 1 patient with SCA17. The SCAs, especially MJD1 and FA, are common causes of inherited progressive ataxia and can be identified early for genetic counseling and family planning. Of considerable interest, an association between the frequencies of SCA2 and SCA6 and the frequency of large normal alleles was found in this population, suggesting a genetic predisposition for expansion and clinical disease.
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