Segmental Myoclonus Post-Herpes Zoster Is Not Always Subcortical in Origin.
Abstract number :
1.182
Submission category :
Year :
2001
Submission ID :
3135
Source :
www.aesnet.org
Presentation date :
12/1/2001 12:00:00 AM
Published date :
Dec 1, 2001, 06:00 AM
Authors :
P.A. Hwang, MD, FRCPC, Bloorview Epilepsy Program, University of Toronto, Toronto, ON, Canada; L. Chen, MD, MSc., Neurophysiology, Bloorview Epilepsy Program, Toronto, ON, Canada; J. Porepa, MD, FRCPC, Paediatrics, Hospital for Sick Children, Toronto, ON,
RATIONALE: To determine whether segmental myoclonus following herpes zoster is cortical or subcortical in origin.
METHODS: A retrospective search of 4,500 EEGs and evoked potentials over 5 years from a single community-based neurophysiology laboratory, using Microsoft Access database (MS Office 97). All EEGs used electrodes in the 10-20 system with zygomatic leads and sleep, hyperventilation and intermittent photic stimulation at 2-20 Hz. SEP studies used C3[ssquote], C4[ssquote]electrodes referenced to FPz, averaged over 50 ms following median nerve stimulation. Antibody titres to VZ, EB virus and HSV were obtained at the Ontario Provincial Labs.
RESULTS: Case 1: A 9-year old boy developed myoclonic jerking of the right arm and hand, 3 months after herpes zoster appeared in the same limb, with positive VZ titres in serum. A L.frontal slow wave disturbance was recorded on EEG, but no epileptiform abnormality.
Case 2: A 69-year old man presented with myoclonic jerking of the Right arm, 3 years after herpes zoster involved the Left arm (C5-6). A left temporal focus was found on the EEG with zygomatic electrodes. Median nerve-SEP and neuroimaging studies were normal in both. The myoclonus responded to benzodiazepines partially.
CONCLUSIONS: Segmental myoclonus post-zoster may be subcortical in origin (case 1), but may also be associated with EEG activity suggesting a cortical disturbance (case 2), although somatosensory pathways appear to be spared. The relevance to myoclonus epilepsy or corticoreticular myoclonus is debatable.
Support: Bloorview Children[ssquote]s Hospital Foundation through a grant-in-aid to the University of Toronto Bloorview Epilepsy Program. PAH is a speaker for Draxis Health (Canada) and Janssen-Ortho (Canada).