Dose-dependent improvement of myoclonic hyperkinesia due to Valproic acid in eight Huntington's Disease patients: a case series.
BACKGROUND
Chorea in Huntington's Disease (HD) is usually treated with antidopaminergic neuroleptics like haloperidol, olanzapine and tiaprid or dopamine depleting drugs like tetrabenazine. Some patients with hyperkinesia, however, react to treatment with antidopaminergic drugs by developing extrapyramidal side effects. In earlier studies valproic acid showed no beneficial effect on involuntary choreatic movements. Myoclonus is rare in HD and is often overseen or misdiagnosed as chorea.


METHODS
In this report, we present eight patients whose main symptom is myoclonic hyperkinesia. All patients were treated with valproic acid and scored by using the Unified Huntington's Disease Rating Scale (UHDRS) motor score before and after treatment. In addition to this, two patients agreed to be videotaped.


RESULTS
In seven patients myoclonus and, therefore the UHDRS motor score improved in a dose dependent manner. In three of these patients antidopaminergic medication could be reduced.


CONCLUSIONS
In the rare subgroup of HD patients suffering from myoclonic hyperkinesia, valproic acid is a possible alternative treatment.
Saft
Carsten
C
Department of Neurology, Huntington-Center NRW, St, Josef Hospital, Bochum, Germany. carsten.saft@ruhr-uni-bochum.de
Lauter
Thorsten
T
Kraus
Peter H
PH
Przuntek
Horst
H
Andrich
Juergen E
JE
D000328:Adult; D000927:Anticonvulsants / Q000627:therapeutic use*; D004305:Dose-Response Relationship, Drug; D005260:Female; D006801:Humans; D006816:Huntington Disease / Q000150:complications / Q000188:drug therapy; D006948:Hyperkinesis / Q000188:drug therapy* / Q000209:etiology; D008297:Male; D008875:Middle Aged; D012720:Severity of Illness Index; D016896:Treatment Outcome; D014635:Valproic Acid / Q000627:therapeutic use*
D000927:Anticonvulsants; D014635:Valproic Acid