Fragile X-associated Tremor Ataxia Syndrome (FXTAS) whose tremor was significantly improved by bilateral Deep Brain Stimulation (DBS) to Ventral Intermediate nucleus (Vim) of the thalamus. FXTAS is a recently described neurodegenerative disorder caused by CGG expansions of the FMR1 gene within the premutation range (55 to 200 CGG repeats). Individuals with FXTAS typically develop an intention tremor followed by gait ataxia within two years. Vim DBS has been shown to effectively treat tremor in a variety of disorders, including Parkinsonâs disease and essential tremor. The MRI of patients with FXTAS typically demonstrates brain atrophy and white matter hyperintensities, with 60% of males and 13% of females showing involvement of the middle cerebellar peduncles. Neuropathology demonstrates eosinophilic intranuclear inclusions in neurons and astrocytes throughout the brain with the highest counts in the hippocampus and certain areas of the limbic system. Stimulation at 130 Hz and 60 microseconds produced good tremor control at deeper contacts at amplitudes of 2 to 3.5 volts with transient paresthesias at higher amplitudes. The tips of the leads were left at VIM of the thalamus. A post-operative MR series was taken about 12 hours after the implant operation to confirm placement and rule out hemorrhagic complications.
Last date updated on June, 2014