DBS for Essential Tremor: Research Clinical Trial

The symptoms of Essential Tremor (ET), the most common movement disorder in adults, are seriously disabling and are only marginally improved by medication alone. Tremor control has improved greatly with the use of deep brain stimulation (DBS) to the ventrointermediate nucleus (Vim) of the thalamus, a node along a circuit of abnormal rhythmic output in ET that travels from the cerebellar dentate nucleus to the contralateral red nucleus and cortex via the dentato-rubro-thalamic tract (DRTt). Recent advances in diffusion imaging have led to the development of tractography techniques where the structural connectivity of fiber tracts such as the DRTt can be illustrated and then, as we have shown, directly targeted during DBS surgery for excellent clinical effect.

Despite such novel targeting methodology and initial tremor improvement, however, the development of side effects such as progressive gait ataxia and waning efficacy after years of chronic stimulation points to the fact that the pathology of essential tremor is poorly understood. Such incomplete knowledge of the network effects of chronic stimulation in ET is a major barrier that needs to be overcome through understanding the dysfunction and modulation of the connectivity of the cerebellar-thalamic-cortical (CTC) network over time.