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.