Deep brain stimulation of globus pallidus internus in a 16-year-old boy with severe tourette syndrome and mental retardation.

A 16- year-old boy with long-standing severe Tourette syndrome (TS) and mental retardation, non-responsive to complex pharmocological and behavioural treatment was selected for bilateral deep brain stimulation (DBS) of the globus pallidus internus (GPi). Pre-operative and post-operative Yale Tourette syndrome scale (YTSS) scores and several other scores were used to quantify the effect of DBS up to one year follow-up. Although subscores of the YTSS improved, the overall outcome of chronic GPi-DBS showed no substantial therapeutic effect. This finding is in contrast to markedly improved TS of the only two adolescent TS patients in whom DBS has been performed so far. In this article we discuss possible reasons for the poor therapeutic effect of GPi-DBS in our patient contributing to the on-going debate on DBS inclusion criteria for adolescent TS patients.