Pallidal Deep Brain Stimulation Reduces Sensorimotor Cortex Activation in Focal/Segmental Dystonia

Abstract

Background Although deep brain stimulation of the globus pallidus internus (GPi‐DBS) is an established treatment for many forms of dystonia, including generalized as well as focal forms, its effects on brain (dys‐)function remain to be elucidated, particularly for focal and segmental dystonia. Clinical response to GPi‐DBS typically comes with some delay and lasts up to several days, sometimes even weeks, once stimulation is discontinued. Objective This study investigated how neural activity during rest and motor activation is affected by GPi‐DBS while excluding the potential confound of altered feedback as a result of therapy‐induced differences in dystonic muscle contractions. Methods Two groups of patients with focal or segmental dystonia were included in the study: 6 patients with GPi‐DBS and 8 without DBS (control group). All 14 patients had cervical dystonia. Using H215O PET, regional cerebral blood flow was measured at rest and during a motor task performed with a nondystonic hand. Results In patients with GPi‐DBS (stimulation ON and OFF), activity at rest was reduced in a prefrontal network, and during the motor task, sensorimotor cortex activity was lower than in patients without DBS. Within‐group contrasts (tapping > rest) showed less extensive task‐induced motor network activation in GPi‐DBS patients than in non‐DBS controls. Reduced sensorimotor activation amounted to a significant group‐by‐task interaction only in the stimulation ON state. Conclusions These findings support previous observations in generalized dystonia that suggested that GPi‐DBS normalizes dystonia‐associated sensorimotor and prefrontal hyperactivity, indicating similar mechanisms in generalized and focal or segmental dystonia. Evidence is provided that these effects extend into the OFF state, which was not previously demonstrated by neuroimaging. © 2020 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

A Population Model of Deep Brain Stimulation in Movement Disorders From Circuits to Cells

“…Deep brain stimulation (DBS) has been used over the last three decades to successfully treat the symptoms of a number of neurological and a few psychological disorders (Benabid et al, 1987;Mayberg et al, 2005). By far the most common disorders treated with DBS are movement disorders such as Parkinson's disease (PD; Deuschl et al, 2006) and essential tremor (ET; Kupsch et al, 2006). PD is a movement disorder, with recognizable symptoms of tremor, slowness of movement and stiffness (Lees et al, 2009).…”

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Functional Neural Changes after Low-Frequency Bilateral Globus Pallidus Internus Deep Brain Stimulation for Post-Hypoxic Cortical Myoclonus: Voxel-Based Subtraction Analysis of Serial Positron Emission

“…EEG performed five years after DBS showed slow-wave discharges, with no evidence of generalized spike or polyspikes from prefrontal or frontal that had been seen in the previous EEG. A study investigating the effect of chronic Gpi-DBS on brain activity in focal and segmental dystonia revealed markedly reduced resting cerebral blood flow (rCBF) in the prefrontal cortex in patients who underwent Gpi-DBS for dystonia [ 49 ]. The mechanism of decreased activity in the prefrontal network in dystonia after Gpi DBS may be different from the decrease in glucose metabolism in the prefrontal cortex in PHM.…”