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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1998-4-29
pubmed:abstractText
Rett syndrome (RS) is one of the most frequent causes of mental retardation in females. As there are no known biochemical, genetic, or morphological markers, diagnosis is based on clinical phenotype including severe dementia, autism, truncal ataxia/apraxia, loss of purposeful hand movements, breathing abnormalities, stereotypies, seizures, and extrapyramidal signs. Myoclonus, although reported in some series, has never been characterized. We studied 10 RS patients, age 3 to 20 years, and observed myoclonus in 9. Severity of myoclonus did not correlate with that of the other symptoms or with age. Multifocal, arrhythmic, and asynchronous jerks mainly involved distal limbs. Electromyographic bursts lasted 48 +/- 12 msec. Burst-locked electroencephalographic averaging generated a contralateral centroparietal premyoclonus transient preceding the burst by 34 +/- 7.2 msec. Motor evoked potentials showed normal latencies, indicating integrity of the corticospinal pathway. Somatosensory evoked potentials were enlarged. The C-reflex was hyperexcitable and markedly prolonged (62 +/- 4.3 msec), mainly due to increase in cortical relay time (28.4 +/- 4.5 msec). We conclude that RS patients show a distinctive pattern of cortical reflex myoclonus with prolonged intracortical delay of the long-loop reflex.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0364-5134
pubmed:author
pubmed:issnType
Print
pubmed:volume
43
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
472-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed-meshheading:9546328-Adolescent, pubmed-meshheading:9546328-Adult, pubmed-meshheading:9546328-Anticonvulsants, pubmed-meshheading:9546328-Cerebral Cortex, pubmed-meshheading:9546328-Child, pubmed-meshheading:9546328-Child, Preschool, pubmed-meshheading:9546328-Electric Stimulation, pubmed-meshheading:9546328-Electroencephalography, pubmed-meshheading:9546328-Electromyography, pubmed-meshheading:9546328-Evoked Potentials, Motor, pubmed-meshheading:9546328-Evoked Potentials, Somatosensory, pubmed-meshheading:9546328-Female, pubmed-meshheading:9546328-Humans, pubmed-meshheading:9546328-Magnetic Resonance Imaging, pubmed-meshheading:9546328-Magnetics, pubmed-meshheading:9546328-Median Nerve, pubmed-meshheading:9546328-Myoclonus, pubmed-meshheading:9546328-Piracetam, pubmed-meshheading:9546328-Reaction Time, pubmed-meshheading:9546328-Reflex, pubmed-meshheading:9546328-Rett Syndrome, pubmed-meshheading:9546328-Severity of Illness Index, pubmed-meshheading:9546328-Video Recording
pubmed:year
1998
pubmed:articleTitle
Cortical reflex myoclonus in Rett syndrome.
pubmed:affiliation
Institute of Child Neurology and Psychiatry, University of Pisa, Italy.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't