Brain Disorders & Therapy

Abstract

Case Series: Deep Brain Stimulation in Patients with FXTAS

Randi J Hagerman, Jamie S Pak, Melina Ortigas, John Olichney, Robert Frysinger, Madeline Harrison, Edmund Cornman, Danuta Z. Loesch, Richard G Bittar, Richard Peppard, Lin Zhang and Kiarash Shahlaie

Objective: We describe 3 carriers of the FMR1 premutation with the 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.
 
Background: 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 Parkinson’s disease and essential tremor.
 
Design/Methods/Results: Three men ages 62, 59 and 70 with FXTAS were treated surgically with bilateral Vim DBS. All patients experienced a significantly beneficial effect on tremor. Ataxia improved in case 1 and temporarily in case 2, but worsened in case 3. All patients experienced mild worsening of dysarthria, although the patients and their families unanimously felt there was a worthwhile benefit overall.
 
Conclusions: These cases provided first hand evidence that bilateral Vim DBS effectively manages tremor in selected patients with FXTAS. DBS may prove to be a viable therapeutic option for treating tremor and/or ataxia with or without other medical therapeutics in patients with FXTAS.