Tremor in X-linked recessive spinal and bulbar muscular atrophy (Kennedy's disease)

OBJECTIVE To study tremor in patients with X-linked recessive spinobulbar muscular atrophy or Kennedy's disease. METHODS Ten patients (from 7 families) with a genetic diagnosis of Kennedy's disease were screened for the presence of tremor using a standardized clinical protocol and followed up at a neurology outpatient clinic. All index patients were genotyped and showed an expanded allele in the androgen receptor gene. RESULTS Mean patient age was 37.6 years and mean number of CAG repeats 47 (44-53). Tremor was present in 8 (80%) patients and was predominantly postural hand tremor. Alcohol responsiveness was detected in 7 (88%) patients with tremor, who all responded well to treatment with a β-blocker (propranolol). CONCLUSION Tremor is a common feature in patients with Kennedy's disease and has characteristics similar to those of essential tremor.