Imepitoin for treatment of idiopathic head tremor syndrome indogs: A randomize d, blinded, placebo-controlled study
Imepitoin para tratamento dos tremores de cabeça idiopáticos em cães: estudo randomizado, duplo cego com placebo controle.
Nina Schneider, Heidrun Potschka, Sven Reese, Franziska Wielaender, Andrea Fischer
Background: Idiopathic head tremor syndrome is a paroxysmal movement disorder
of unknown etiology. Spontaneous remission may occur, but owners may request
treatment in severely affected dogs with continued episodes. Controlled studies of
the disease are not available.
Hypothesis/Objectives: A drug with gamma amino butyric acid-ergic and anxiolytic
effects will decrease head tremor episodes.
Animals: Twenty-four dogs with severe nonremitting head tremor and presumptive
clinical diagnosis of idiopathic head tremor syndrome.
Methods: Prospective, blinded, placebo-controlled clinical trial to compare imepitoin
with placebo in dogs with frequent episodes of idiopathic head tremor. Evaluation of
efficacy used the quotient T2/T1 that represented prolongation of the head tremorfree period compared to a 3-month baseline. A dog was considered a responder if
tremors subsided or if the head tremor-free period was 3× longer than the longest
period during baseline (T2/T1 ≥ 3). Sample size calculations considered a large effect
of imepitoin on T2/T1 (Cohen's d = 0.8).
Results: There were no responders in the placebo group (0/12). In the imepitoin
group, the responder rate was 17% (2/12; P = .18) with T2/T1 3.8 and 4.0. Mean T2/
T1 was 1.0 ± 1.4 in the imepitoin and 0.4 ± 0.4 in the placebo group (P = .37).
Conclusion and Clinical Importance: Imepitoin did not result in a significant overall
benefit. Future studies should focus on treatment of subgroups with a common pathophysiology and similar comorbidities.
Canine, dyskinesia, epilepsy, head bobbing, medical treatment, movement disorders