Rhythmic cortical myoclonus in a case of HIV-related encephalopathy.
We describe a 66-year-old, HIV-seropositive patient presenting with ataxia and upper limb rhythmic myoclonus activated by postural maintenance. Electromyograph (EMG) recordings of the forearm muscles showed 50-msec bursts, with a frequency of 10 Hz, concurring with frontocentral electroencephalograph (EEG) rhythmic activity. Autoregressive spectral analysis applied to the EEG-EMG traces made it possible to detect significant coherence between the rhythmic EEG discharges and EMG bursts. The amplitude of the middle-latency somatosensory evoked potentials was increased. Long-latency reflexes were enhanced. On the basis of the electrophysiological findings, the movement disorder should be considered a rhythmic variant of cortical myoclonus. In our patient, HIV infection may have caused a dysfunction in the central nervous system pathways involving the cerebellum and sensorimotor cortex, similar to that occurring in genetically determined conditions characterised by cortical myoclonus.
Canafoglia
Laura
L
Department of Clinical Neurophysiology; Istituto Nazionale Neurologico Carlo Besta, Milan, Italy.
Panzica
Ferruccio
F
Franceschetti
Silvana
S
Carriero
M Rita
MR
Ciano
Claudia
C
Scaioli
Vidmer
V
Chiapparini
Luisa
L
Visani
Elisa
E
Avanzini
Giuliano
G
D015526:AIDS Dementia Complex / Q000150:complications*; D000368:Aged; D001284:Atrophy / Q000473:pathology; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D004569:Electroencephalography; D004576:Electromyography; D006801:Humans; D008297:Male; D009207:Myoclonus / Q000175:diagnosis / Q000209:etiology* / Q000503:physiopathology*; D010507:Periodicity