Abstract
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.
| Original language | English |
|---|---|
| Pages (from-to) | 472-479 |
| Number of pages | 8 |
| Journal | Annals of Neurology |
| Volume | 43 |
| Issue number | 4 |
| DOIs | |
| Publication status | Published - Apr 1998 |
Fingerprint
ASJC Scopus subject areas
- Neuroscience(all)
Cite this
Cortical reflex myoclonus in Rett syndrome. / Guerrini, Renzo; Bonanni, Paolo; Parmeggiani, Lucio; Santucci, Margherita; Parmeggiani, Antonia; Sartucci, Ferdinando.
In: Annals of Neurology, Vol. 43, No. 4, 04.1998, p. 472-479.Research output: Contribution to journal › Article
}
TY - JOUR
T1 - Cortical reflex myoclonus in Rett syndrome
AU - Guerrini, Renzo
AU - Bonanni, Paolo
AU - Parmeggiani, Lucio
AU - Santucci, Margherita
AU - Parmeggiani, Antonia
AU - Sartucci, Ferdinando
PY - 1998/4
Y1 - 1998/4
N2 - 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.
AB - 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.
UR - http://www.scopus.com/inward/record.url?scp=0031799988&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0031799988&partnerID=8YFLogxK
U2 - 10.1002/ana.410430410
DO - 10.1002/ana.410430410
M3 - Article
C2 - 9546328
AN - SCOPUS:0031799988
VL - 43
SP - 472
EP - 479
JO - Annals of Neurology
JF - Annals of Neurology
SN - 0364-5134
IS - 4
ER -