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This Month in Archives of Neurology
Arch Neurol. 2002;59:1228-1229.
The Sleep-Deprived Electroencephalogram
Thomas H. Glick, MD, (SEE ARTICLE) reappraises the value and utility of the sleep-deprived electroencephalogram
(EEG). He has surveyed the knowledge and practice of nonneurologists in a
community teaching hospital, local and national neurologists and epileptologists,
and EEG laboratory protocols, as well as textbook accounts and recommendations
related to the value of the sleep-deprived EEG. This review offers insights
and recommendations for the clinical use of the sleep and sleep-deprived EEG
with a new perspective.
Brain Development in Healthy, Hyperactive, and Psychotic Children
Gogtay et al (SEE ARTICLE) describe
recent advances in magnetic resonance imaging for measuring brain development
in healthy, hyperactive, and psychotic children. Specific and characteristic
developmental defects are described in the brains of children with attention-deficit/hyperactivity
disorder and in child-onset schizophrenia. Advances in magnetic brain imaging
thus have the potential to supplement preclinical and postmortem data on normal
and abnormal brain development.
Visual Deficits in Parkinson Disease
Diederich et al (SEE ARTICLE) have
determined whether there is progressive, longitudinal deterioration of color
discrimination and contrast sensitivity in patients with Parkinson disease.
Of great interest, they found deterioration of both color discrimination and
contrast sensitivity, and that both deficits correlated with age; the chromatic
deficit additionally correlated with greater impairment of motor functions.
These observations expand considerably our understanding of visual deficits
in Parkinson disease.
Editorial perspective is provided by Ivan Bodis-Wollner,
MD, DSc. (SEE ARTICLE)
Caloric Intake and Alzheimer Disease
Luchsinger et al (SEE ARTICLE) have
examined the association between caloric intake and the occurrence of Alzheimer
disease (AD). In a thorough and precise study, they found that a higher intake
of calories and fats may be associated with a higher risk of AD in individuals
carrying the APOE 4 allele. These findings
support the theory that caloric restriction modifies age-related conditions
in humans and suggests caloric restriction and low-fat diets in individuals
carrying APOE 4.
Cerebrospinal Fluid Levels of Tau Protein and Alzheimer Disease
Buerger et al (SEE ARTICLE) have studied
to what extent cerebrospinal fluid (CSF) levels of phosphorylated tau protein
at threonine 231 (p-tau231) distinguish Alzheimer disease (AD)
from control subjects and from patients with other dementias. They find that
mean CSF levels of p-tau231 are significantly elevated in patients
with AD compared with all other groups. p-tau231 discriminated
with a sensitivity of 90.2% at a specificity of 80% between subjects with
AD and those without AD. This study shows that increased CSF levels of p-tau231 may be a useful, clinically applicable biological marker for the
differential diagnosis of AD, particularly for distinguishing AD from frontotemporal
dementia.
Body Mass in Essential Tremor
Louis et al (SEE ARTICLE) have compared
body mass index (calculated as weight in kilograms divided by the square of
height in meters) in patients with essential tremor with controls and found,
in general, that body mass index was lower in patients with essential tremor
than in controls. It is of interest that these data support the view that
lower body mass index may be due to increased energy expenditure in patients
with essential tremor.
Improving Hand Function in Chronic Stroke
Muellbacher et al (SEE ARTICLE) describe
deafferentation produced by a new technique of regional anesthesia of the
upper arm during hand motor practice, which dramatically improved hand motor
function, including some activities of daily living, in patients recovering
from stroke. The improvement was associated with an increase of transcranial
magnetic stimulationevoked motor output to the practice hand muscles.
This is a novel therapeutic strategy that improves hand function in patients
with chronic weakness after stroke and may develop into a practical new clinical
therapy.
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Effects of regional anesthesia on sensory threshold (A) and muscle
strength in different body parts (B). Changes (during [first bar] and after
[second bar] anesthesia) were expressed as difference in monofilament diameter
size (A) and as difference in muscle strength (Medical Research Council Scale)
(B). Ches indicates upper chest; Shou, shoulder; Uarm, upper arm; Farm, forearm;
Hdors, dorsal side of the hand; Hvol, volar surface of the hand; Tvol, volar
surface of the thumb; Ivol, volar surface of the index finger; Uabd, upper
arm abduction; Fflex, forearm flexion; Fext, forearm extension; Hgrip, handgrip;
Fiext, finger extension; Wext, wrist extension; asterisks, P<.05; and error bar, SEM.
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Repeat DNA in Spinocerebellar Ataxia Type 10
Grewal and colleagues (SEE ARTICLE) have described their experience with spinocerebellar ataxia (SCA) type 10
caused by a large expansion of an unstable ATTCT pentanucleotide DNA repeat.
Ataxia was the initial symptom in 21 of 22 patients studied, and seizure disorders
developed in 11. Although anticipation was apparent in both families, only
family 1 showed a strong inverse correlation between age of onset and pentanucleotide
repeat expansion. Thus, seizures represent an integral part of the SCA10 phenotype,
but family-dependent factors may alter the frequency of the seizures' phenotype
and the pattern of intergenerational DNA repeat size expansion. Here is an
interesting example of a unique and complex genotype-phenotype correlation
study.
A New Spinocerebellar Ataxia at Chromosome 19q13.4-qter
Brkanac et al (SEE ARTICLE) have mapped
the gene for a new autosomal dominant spinocerebellar ataxia to chromosome
19q13.4-qter in a single family. This is a 4-generation American family of
Dutch and English ethnicity with a "pure" cerebellar ataxia.
Surgery for Trigeminal Neuralgia
Theodosopoulos et al (SEE ARTICLE) describe their extensive experience in patients who underwent posterior exploration
in the treatment of idiopathic trigeminal neuralgia. Postoperatively, trigeminal
pain had lessened in 98% and completely resolved in 88% of patients. This
is an extensive and comprehensive clinical survey demonstrating the effectiveness
of posterior fossa exploration as therapy for idiopathic trigeminal neuralgia.
Patient Dependence in Alzheimer Disease
Brickman and colleagues (SEE ARTICLE) have determined the longitudinal course of dependence in patients with Alzheimer
disease (AD). They demonstrate the validity of their Dependence Scale and
that dependency in AD significantly declines with time, independent of global
cognition of other self-care deficits. Their scale may indeed be of value
for outcomes research, efficacy trials, and behavioral research in AD.
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