Cerebellar Cortex Stimulation for Acquired Dystonia: A Case Report and Review of Its Role in Modern Surgical Practice

Abstract

Background: Cerebral palsy (CP) is a common cause of acquired dystonia, which can lead to significant interference with quality of life and societal participation. In the last two decades, the surgical treatment of dystonia has primarily focused on deep brain stimulation targeting the basal ganglia and thalamic circuits. However, stimulation of the basal ganglia has generally been less effective in acquired combined forms of dystonia, including dystonic CP. These limitations, along with growing evidence for the role of the cerebellum in the pathophysiology of dystonia, have led to renewed interest in the cerebellum as a target for therapeutic stimulation in dystonia. Nevertheless, there are very few contemporary studies demonstrating its use. We present the case of a patient with generalized dystonia due to dyskinetic CP who was successfully treated with stimulation of the cerebellar cortex in the modern era. We also review the evidence underpinning targeting of the cerebellum in surgical therapy for dystonia and examine the latest reports of this approach in the surgical literature.

Summary: The patient derived significant improvement in the control of her dystonic symptoms, with a reduction in her BFMDRS score from 83 to 25. No complications were observed during more than 3 years of postoperative follow-up. Since the turn of the 21st century, there have been only 7 reports of cerebellar stimulation for dystonia, recruiting a total of 18 patients. These studies have exclusively targeted deep brain structures, making the present report of cortical cerebellar stimulation particularly unique.

Key messages: In the 21st century, cerebellar stimulation has predominantly been a second-line treatment for dystonia, after the failure of DBS targeting more mainstream loci within the thalamus and globus pallidus. However, there is increasing recognition of the role of the cerebellum in movement disorders, with multiple convergent lines of evidence supporting its involvement in dystonia pathophysiology. The cerebellum is worthy of greater consideration as a target for neurostimulation in dystonia, particularly in cases of acquired etiology.

Keywords: Cerebellum; Cerebral palsy; Dystonia; Electrical stimulation; Functional neurosurgery; Movement disorders.