Levetiracetam improves intention tremor in fragile x-associated tremor/ataxia syndrome.

Fragile X-associated tremor/ataxia syndrome is a recently discovered disorder affecting more of one third of older adult male carriers of premutation alleles of fragile X mental retardation 1 (FMR1 gene). There is no established treatment.The 66-year-old right-handed grandfather of a boy with fragile X syndrome, a carrier of premutation alleles of FMR1 gene, developed an action tremor in his right hand when writing. His writing became large and completely illegible. Administration of levetiracetam was associated with subjective and objective improvement, and handwriting became possible again. Levetiracetam was well tolerated, and no adverse effects were reported.