A colleague reports a similar experience
Nissenkorn A, Hassin-Baer S, Lerman SF, Levi YB, Tzadok M, Ben-Zeev B. Movement disorder in ataxia-telangiectasia: treatment with amantadine sulfate. J Child Neurol. 2013 Feb;28(2):155-60.
Ataxia-telangiectasia is a cerebellar neurodegenerative disorder presenting with ataxia, chorea, myoclonus, and bradykinesia. Literature on treatment of movement disorders is scarce. We treated 17 children (aged 11.2 ± 3.9 years) for 8 weeks with the dopaminergic and anti-N-methyl-d-aspartate (NMDA) agent amantadine sulfate 6.3 ± 0.87 mg/kg/d. Ataxia was assessed by using the International Cooperative Ataxia Scale, parkinsonism by the Unified Parkinson Disease Rating Scale, and chorea/myoclonus by the Abnormal Involuntary Movement Scale. Responders were considered those patients who had at least 20% improvement in the summation of the 3 scales. Overall, 76.5% of patients were responders, with a mean 29.3% improvement. Ataxia, involuntary movements, and parkinsonism improved significantly (25.3%, 32.5%, and 29.5%, respectively); (P < .001, t test). Side effects were mild and transient, and they did not lead to drug discontinuation. Amantadine is a well-tolerated and effective treatment for motor symptoms in ataxia telangiectasia. Assessment of long-term effects and a double-blind study should follow.