Blinded placebo crossover study of gabapentin in primary orthostatic tremor.
Primary orthostatic tremor (OT) is a rare but disabling condition characterized by leg tremor and feelings of instability during stance. Previous studies have reported a reduction in OT symptoms with gabapentin treatment. In this study, we report on the benefits of gabapentin treatment in a double-blind placebo-controlled crossover study of 6 OT patients. First, the maximally effective gabapentin dosage (600-2,700 mg/day) for each patient was determined during an initial dose-titration phase. Patients were then studied 7 days after drug withdrawal and again after two 2-week periods of treatment with either gabapentin or placebo, using force platform posturography to quantify postural sway and tremor. Other medications for OT were continued unchanged. Symptomatic response was assessed by a patient-rated severity scale and quality of life (QOL) questionnaire. All patients reported an increase in symptoms during the washout phase and symptom reduction (50%-75%) during gabapentin treatment. Tremor amplitude was reduced to 79% +/- 11% and sway area to 71% +/- 11% of the placebo state. QOL improved in all patients, no adverse drug effects were noted, and symptomatic benefit was maintained at follow-up (mean = 19 months). The findings confirm that gabapentin is an effective treatment for OT, reducing both tremor and postural instability and improving quality of life, and support its use as add-on or first-line therapy for OT.
Movement Disorders Clinic, Australian Neuromuscular Research Institute, Western Australia, Australia. jrod@cyllene.uwa.edu.au
Julian P
JP
Rodrigues
Dylan J
DJ
Edwards
Susan E
SE
Walters
Michelle L
ML
Byrnes
Gary W
GW
Thickbroom
Rick
R
Stell
Frank L
FL
Mastaglia
D000368:Aged; D000588:Amines / Q000009:adverse effects / Q000627:therapeutic use*; D000978:Antiparkinson Agents / Q000009:adverse effects / Q000627:therapeutic use*; D018592:Cross-Over Studies; D003509:Cyclohexanecarboxylic Acids / Q000009:adverse effects / Q000627:therapeutic use*; D004244:Dizziness / Q000175:diagnosis / Q000188:drug therapy*; D004311:Double-Blind Method; D005260:Female; D005500:Follow-Up Studies; D000077206:Gabapentin; D006801:Humans; D008297:Male; D008875:Middle Aged; D009460:Neurologic Examination; D004856:Postural Balance / Q000187:drug effects*; D011788:Quality of Life; D012008:Recurrence; D013375:Substance Withdrawal Syndrome / Q000175:diagnosis; D014202:Tremor / Q000175:diagnosis / Q000188:drug therapy*; D005680:gamma-Aminobutyric Acid / Q000009:adverse effects / Q000627:therapeutic use*
D000588:Amines; D000978:Antiparkinson Agents; D003509:Cyclohexanecarboxylic Acids; D005680:gamma-Aminobutyric Acid; D000077206:Gabapentin