This Month in Archives of Neurology

Emilien and colleaguesArticle provide a superb review of transgenic mouse models with human gene mutations that cause Alzheimer disease. Specific strategies for using these elegant experimental approaches are presented and provide the clinician with insights into the molecular mechanisms involved in Alzheimer disease.

Funnell and colleaguesArticle are pioneers and leaders in the field of split-brain patient studies and review the current state of knowledge comparing patients with callosotomy with localized lesions involving different portions of the corpus callosum. Their review provides a succinct analysis of clinical phenomena in patients with these lesions.

Chui and colleaguesArticle describe specific clinical criteria for diagnosing vascular dementia. Criteria must be specific and defined, and the authors review and clarify this challenging literature. The subject is put into perspective in an accompanying editorial by Bowler and HachinskiArticle. Their comments are of great interest in view of their pioneering contributions to our understanding of vascular dementia in its several forms.

Siegel and VerhagenArticle provide an admirable study of patients with Parkinson disease who are treated with pallidotomy and their subsequent gait improvement. This is a model of clinical research and will be widely cited.

Schwarz and colleaguesArticle explore the specific binding of ligands to dopamine transporters as a tool to detect the early loss of nigra striatal neurons in patients with Parkinson disease. They find early and specific changes with definite clinical correlations that will be useful in following the natural history of the disease.

Farrer et alArticle have studied the interrelationships between apolipoprotein E and angiotensin-converting enzyme genotypes as risk factors for late-onset Alzheimer disease. Angiotensin-converting enzyme does present a restricted risk factor that will be the subject of intense future investigations.

Fernández et alArticle describe a novel missense mutation (W797R) in the myophosphorylase gene in patients with McArdle disease. It is a unique mutation among Spanish patients and needs to be included in future gene analyses.

Jenkins and colleaguesArticle have assessed total intracranial volume as an independent predictive factor for Alzheimer disease. Premorbid brain size does not differ between patients with familial and sporadic Alzheimer disease and controls and does not delay disease onset. These data provide interesting evidence against the cerebral-reserve hypothesis and clearly will be the subject of future debates.

Binetti and colleaguesArticle conclude that there is a characteristic cognitive profile in the course of dementia in Pick disease compared with Alzheimer disease, but specific cognitive test performance does not clearly distinguish these two entities. Interesting data are provided that are of considerable clinical value.

Maruyama and colleaguesArticle report no association between estrogen receptor α gene polymorphisms and Alzheimer disease. These data do not support a selective estrogen receptor response in some patients but serve to focus current discussion concerning estrogen protection against Alzheimer disease.

Bidichandani and colleaguesArticle describe a unique case of very late Friedreich ataxia with large GAA triplet repeat expansions in both X25 genes that were estimated to contain 835 and 1200 repeats, respectively. This is the first instance of a patient with Friedreich disease with over 800 GAA repeats in both alleles who presented with late onset and a generally milder disease than that seen in typical patients. Clearly, other genetic and environmental factors can modify disease severity that thus far have escaped attention.