Multimodal Imaging in a Patient with Hemidystonia Responsive to GPi Deep Brain Stimulation

Abstract

Background Dystonia is a syndrome with varied phenomenology but our understanding of its mechanisms is deficient. With neuroimaging techniques, such as fiber tractography (FT) and magnetoencephalography (MEG), pathway connectivity can be studied to that end. We present a hemidystonia patient treated with deep brain stimulation (DBS). Methods After 10 years of left axial hemidystonia, a 45-year-old male underwent unilateral right globus pallidus internus (GPi) DBS. Whole brain MEG before and after anticholinergic medication was performed prior to surgery. 26-direction diffusion tensor imaging (DTI) was obtained in a 3 T MRI machine along with FT. The patient was assessed before and one year after surgery by using the Burke-Fahn-Marsden Dystonia Rating Scale (BFMDRS). Results In the eyes-closed MEG study there was an increase in brain coherence in the gamma band after medication in the middle and inferior frontal region. FT demonstrated over 50% more intense ipsilateral connectivity in the right hemisphere compared to the left. After DBS, BFMDRS motor and disability scores both dropped by 71%. Conclusion Multimodal neuroimaging techniques can offer insights into the pathophysiology of dystonia and can direct choices for developing therapeutics. Unilateral pallidal DBS can provide significant symptom control in axial hemidystonia poorly responsive to medication.

The HIV protease inhibitor, ritonavir, corrects diverse brain phenotypes across development in mouse model of DYT-TOR1A dystonia

“…Lower FA (a measure of microstructural integrity in DTI MRI sequences) has now been reported in many forms of dystonia including familial and sporadic disease ( 46 , 69 – 74 ) and five mouse models involving the Tor1a gene ( 42 , 43 , 75 – 77 ). A few studies further suggest correlations between FA values and dystonia symptomatology ( 71 , 78 , 79 ). Collectively, these studies support the potential predictive value of the brain readouts tested in this study.…”

“…This is an important area for future study. In human studies within and outside of dystonia, the capacity for plasticity of DTI signals has been established (78)(79)(80).…”