 |
 |

Movement Disorders 2001
Arch Neurol. 2001;58:169-170.
A Fatal Attraction to Synuclein
Galvin and colleagues (SEE ARTICLE) describe a new set of molecular pathologies involving -, ß-, and -synuclein
proteins and neurodegenerative diseases. Efforts to elucidate the pathobiology
of synuclein proteins will lead to improved strategies for diagnosis and future
therapies for this diverse group of emerging neurodegenerative diseases.
Genomic Ataxia
Tan and Ashizawa (SEE ARTICLE) bring
us up to date with a genomic classification of the inherited ataxias. Diagnosing
by genotype and not phenotype is reinforced once more.
Portuguese Ataxia
Barbot and colleagues (SEE ARTICLE) describe the diagnostic clinical criteria of Portuguese patients affected
with ataxia and ocular apraxia as an autosomal recessive disorder. Ataxia
with occular apraxia is more common than previously suggested. Critical editorial
comment is provided by David Dawson, MD (SEE ARTICLE) .
Genes, Hallucinations, and Parkinson Disease
Goetz and colleagues
(SEE ARTICLE) have studied dopamine receptor gene polymorphisms in Parkinson disease (PD)
patients with and without hallucinations. There was no clear correlation between
dopamine receptor gene polymorphism type and PD with hallucinations. The DRD3 allele 2 showed a borderline increased frequency among
cases compared with controls. Further study is required.
Unilateral vs Bilateral Deep Brain Stimulation
Ondo and colleagues (SEE ARTICLE) have studied patients with PD and essential tremor with unilateral or bilateral
deep brain stimulation. Bilateral thalamic deep brain stimulation was more
effective than unilateral stimulation at controlling bilateral appendicular
and midline tremors in patients with essential tremor and PD. Overall functional
disability improved only in patients with essential tremor. Bilateral deep
brain stimulation should be considered if unilateral stimulation does not
offer a satisfactory benefit.
Antibodies and Cerebellar Ataxia
Honnorat and colleagues (SEE ARTICLE) find evidence suggesting a link between high levels of glutamic acid decarboxylase
antibodies and cerebellar ataxia, particularly in women with insulin-dependent
diabetes mellitus. Glutamic acid decarboxylase antibodies are emerging as
an important diagnostic marker for sporadic cerebellar ataxia and may provide
insight into the biology of this serious disorder.
Parkinsonism and Neck Extensor Myopathy
Askmark and colleagues (SEE ARTICLE) describe a series of patients with parkinsonism with neck extensor weakness
resulting in head drop. Electrophysiologic studies suggest that the process
is a myopathy, and several patients in this study had an autonomic disorder
as well, suggesting that the spectrum may include multiple system atrophy
(MSA).
Growth Hormone Response to Apomorphine and Movement Disorders
Friess and colleagues (SEE ARTICLE) describe patients with PD and MSA and their differential response to growth
hormone released by apomorphine. They found that after a low dose of apomorphine,
the increase in the plasma growth hormone concentration was significantly
greater in patients with PD than in those with MSA or control subjects. Apomorphine
appears to be a useful tool in identifying PD vs MSA, and also a differential
specific deficit of central dopamine synthesis and release in the two patient
groups.
Agonist- and Dopamine-Induced Dyskinesia in PD
Rascol and colleagues (SEE ARTICLE) have compared the use of a selective D1-receptor agonist with levodopa
in their study of patients with PD. Their data provide evidence that, in patients
with PD, a D1 agonist induces the same antiparkinsonian and dyskinetic
effects as levodopa.
Dysarthria and Dysphagia in Parkinsonian Disorders
Müller et al (SEE ARTICLE) studied
differences in the evolution of dysarthria and dysphagia in autopsy-confirmed
parkinsonian disorders. The latency periods until onset of dysarthria and
dysphagia clearly differentiated PD from atypical parkinsonian disorder, but
failed to differentiate the various atypical parkinsonian disorders; survival
after onset of dysphagia was similarly poor across all parkinsonian disorders.
This study helps to define important clinical features in relation to specific
pathologic processes. These findings will be useful in planning practical
patient management.
Dysarthria in Progressive Supranuclear Palsy
Kluin and colleagues (SEE ARTICLE) have correlated the types of dysarthria with neuropathologic features in patients
with progressive supranuclear palsy. They find that the hypokinetic dysarthria
of progressive supranuclear palsy results from degenerative changes in the
substantia nigra and not in other basal ganglia structures.
Staging Huntington Disease
Kirkwood et al (SEE ARTICLE) have
delineated the progression of symptoms in patients with Huntington disease
(HD) in the early and middle stages of disease. In order to evaluate the efficacy
of future therapeutic agents designed to delay or prevent HD progression,
measures sensitive to cognitive function and behavioral abnormalities specific
to HD are necessary. This detailed study is useful in that regard.
Brain Shape in Williams Syndrome
Schmitt and colleagues (SEE ARTICLE) find that subjects with Williams syndrome have cerebral and cerebellar shapes
significantly different from those of normal controls. Decreased volume of
the corpus callosum may be associated with a decreased size of the splenium.
Clinical and morphological evidence of myopathy in this syndrome, giving rise
to hypotonia in infancy, delayed walking, joint contractures, scoliosis, and
increased exhaustion on exertion, has been reported in some patients. Thus,
patients may have a motor syndrome associated with a movement disorder. More
commonly, patients have enhanced language ability and enhanced auditory memory
as well as considerable social use of language in the presence of mental retardation.
Abilities in playing musical instruments, loquaciousness, and engaging personality
characteristics are well known. Thus, the finding of major changes in brain
shape in this syndrome with behaviorial and motor alterations makes the structural
brain observations provided by Schmitt and colleagues most interesting and
insightful.
Ataxia and Calcium Channels
Denier and colleagues (SEE ARTICLE) describe the Glu 1757 Lys missense mutation associated with episodic ataxia
type 2 (EA2) in a family. Most mutations in the 1A subunit of CACNA1A in EA2 patients are caused by a truncated protein,
whereas missense mutations have been associated with familial hemiplegic migraine.
Here we find a missense mutation associated with EA2. These data strongly
suggest that additional work is needed to fully establish the phenotype-genotype
correlations for CACNA1A mutations. Jen and Geschwind provide critical editorial comment (SEE ARTICLE) .
Parkinsonism and Machado-Joseph Disease in a Black Family
Gwinn-Hardy and colleagues (SEE ARTICLE) describe parkinsonism in a large African American pedigree with autosomal
dominant neurologic disease, members of which were shown to possess pathogenic
CAG expansions in the MJD/SCA3 gene. Autosomal dominant
parkinsonism should be evaluated for this mutation.
Spinocerebellar Ataxia Type 6 in Taiwan
Soong et al (SEE ARTICLE) studied
patients with spinocerebellar ataxia type 6 using fluorine-18labeled
deoxyglucose and found significant hypometabolism in the cortex and basal
ganglia as well as the cerebellar hemispheres and brainstem in patients with
expanded CAG repeats in the spinocerebellar ataxia type 6 gene. These studies
extend observations concerning altered glucose metabolism in this dominant
ataxia.
|