Ward and Cohen describe the development of new, noninvasive, and innovative techniques to study how the brain responds to focal injury and possible strategies to enhance the response to injury. One way that is explored to enhance motor function in a paretic hand is the down-regulation of activity in the ipsilateral, intact motor cortex with the purpose of reducing abnormal inhibition from the intact to the affected hemisphere, a hypothesis they have under investigation. They present a compelling and intriguing concept of potential therapy for motor impairment.
Schott and Schott describe a high prevalence of left-handed mirror writing among those whose native languages are traditionally written in a leftward direction, including Chinese, Japanese, and Hebrew. Their findings have important implications for understanding hemisphere specialization in relation to handedness.
Seltzer and colleagues have studied the effectiveness of donepezil in patients with early Alzheimer disease in a multicenter, randomized, double-blind, 24-week, placebo-controlled study. Improvements favoring donepezil on the Alzheimer Disease Assessment Scale–cognitive subscale were found at weeks 12 and 24 and at the end point. Other cognitive tests gave similar positive results for donepezil. This study suggests that donepezil provides benefits in early-stage Alzheimer disease for preserving cognitive functioning.
Mean ± SE change from baseline through 24 weeks of treatment on the Alzheimer Disease Assessment Scale–cognitive subscale (ADAS-cog) total score for the donepezil and placebo groups. The difference between groups was as follows: P = .02 at week 12, P = .008 at week 24, and P = .001 at the end point. LOCF indicates last observation carried forward.
Qu and colleagues have shown that gene gun–administered genetic immunization with the Aβ42 gene in wild-type BALB/cand transgenic mice with Alzheimer disease can effectively elicit humoral immune responses without significant T-cell–mediated immune response to the amyloid-β peptide. This immunotherapeutic approach could provide an alternative active immunization method for therapy and prevention of Alzheimer disease. Editorial perspective is provided by Shoji Tsuji, MD, PhD.
Dürr and colleagues have provided data on the frequency, phenotype, and mutation spectrum of SPG3A in patients with pure autosomal dominant spastic paraplegia and onset before age 20 years. They find the frequency of the SPG3A mutations in France to be 39% in families with young-onset autosomal dominant spastic paraplegia after exclusion of SPG4 cases. They provide a definitive and scholarly description of the phenotype-genotype correlations with mutations in this gene. Editorial perspective is provided by Jeffrey L. Elliott, MD.
Josephs and colleagues analyzed 12 specific regions of interest on head magnetic resonance imaging in 17 patients with corticobasal syndrome who had an autopsy-confirmed diagnosis of corticobasal degeneration (CBD) or other neurodegenerative diseases. Of note, similar patterns of regional atrophy and subcortical and periventricular white matter signal changes were found in the patients with autopsy-proven CBD as well as in the patients with other neurodegenerative diseases. Thus, of considerable interest, the authors show that neither cortical or corpus callosum atrophy nor subcortical and periventricular white matter signal changes on head magnetic resonance imaging are specific to CBD.
Morris and colleagues in this comprehensive genomic analysis have not identified a single gene locus for the Parkinsonism-dementia complex of Guam, confirming the impression of a geographical disease isolate with a complex genetic or a genetic/environmental etiology.
Rogaeva and colleagues assessed the prevalence of PINK1 mutations within a series of patients with early- and late-onset Parkinson disease in North America. They identified 27 variants, including the first reported compound heterozygous mutation (Glu240Lys and Leu489Pro) and a homozygous Leu347Pro mutation in 2 unrelated young-onset patients.
Aarsland and colleagues studied the rate and predictors of change on the Mini-Mental State Examination (MMSE) in patients with Parkinson disease (PD). The mean annual decline on the MMSE for patients with PD was 1 point with some variation. For patients with PD and dementia, the mean annual decline was 2.3, which was similar to the decline observed in patients with Alzheimer disease.
Popescu and colleagues have characterized the spectrum of diseases associated with Lewy body (LB) formation in the amygdala in neurodegenerative disease and control cases. Lewy bodies were abundant in classic Pick disease, argyrophilic grain disease, Alzheimer disease, and dementia with LBs, but not in cases with amygdala degeneration lacking tau-based inclusions, control cases, preclinical disease carriers, or degenerative diseases lacking pathologic involvement of the amygdala. Thus, the authors believe that these data support the view that tau aggregates predispose neurons to develop secondary LBs. Future studies should attempt to definitively explain why 2 types of pathology, LBs and tau inclusions, overlap in certain brain regions. Why does the abnormal processing and/or deposition of one central nervous system protein relate to the deposition of other central nervous system proteins?
Lee and colleagues have investigated the regional selectivity of dopamine terminal loss during the progression of Parkinson disease (PD). They studied 67 patients with PD and 20 control subjects using positron emission tomography with a ligand for the monoamine transporter. Their findings suggest that the mechanisms responsible for the progression of PD may not be the same as those responsible for its onset.
Huang and colleagues have studied whether the risk of dementia and Alzheimer disease due to a positive family history is explained by apolipoprotein E (APOE) genotypes. They find that family history of dementia is associated with an increased risk of dementia and Alzheimer disease in this very old population, but only among APOE ε4 carriers. This suggests the existence of other genetic or environmental risk factors that may be active in the presence of the APOE ε4 allele.
Tay and colleagues have studied whether cytochrome-c oxidase (COX) assembly genes, such as COX16, COX19, and PET191, are implicated in human COX deficiency. They conclude in this molecular genetic analysis that these genes are either not involved or very rarely involved in human COX deficiency.
George and colleagues write that patients with myotonic dystrophy type 2 (DM2), unlike patients with other chronic noninflammatory muscle disorders, have pain that is exercise related, temperature modulated, and palpation induced, whereas cramps are rare. Thus, patients with DM2 have musculoskeletal pain that shows features distinct from other noninflammatory muscle disorders.
Modoni and colleagues assessed the cognitive performance in a group of 70 patients with myotonic dystrophy type 1 (DM1). They find a cognitive pattern characteristic of mental retardation in congenital cases, whereas in adult forms there is an age-related decline of frontal and temporal cognitive functions.
This Month in Archives of Neurology. Arch Neurol. 2004;61(12):1830-1831. doi:10.1001/archneur.61.12.1830