Tremor associated with Klinefelter syndrome--a case series and review of the literature

Background: Previous case series suggested a link between Klinefelter syndrome (KS) and essential tremor (ET) or an ET-like syndrome.

Methods: We investigated three KS-patients with tremor including tremor-analyzes and discuss our data in context to findings from a literature review. The clinical outcome after deep brain stimulation (DBS) is also reviewed.

Results: Tremor in KS is predominantly a postural and kinetic tremor that resembles ET. Our patients were further characterized by absent family history for tremor in first degree relatives, lack of subjective alcohol responsiveness inquired by history, and tremor onset in childhood. One of our patients and two cases from literature improved after DBS of the ventral intermediate nucleus (VIM) of the thalamus.

Conclusions: Tremor in KS shares several features with ET. If other characteristics such as family history, alcohol responsiveness, and age at tremor onset may serve as discriminating factors from ET, needs to be further investigated. First observations suggest that VIM-DBS may be efficacious.