Pallidal Deep Brain Stimulation in Patients With Chorea-Acanthocytosis.

INTRODUCTION: Chorea-acanthocytosis (ChAc) is an autosomal recessive hereditary disorder caused by the mutation of gene VPS13A. Deep brain stimulation of ChAc has made substantial progress in the recent decades. However, the reports were scattered across centers and performed by different neurosurgeons. Here, we report a case series consisting of six patients diagnosed with ChAc, receiving bilateral high-frequency stimulation of globus pallidus internus (GPi) in a single center.

METHODS: We report six consecutive patients diagnosed with ChAc and present a review of the literature. All patients received neurological evaluations using the Unified Huntington's Disease Rating Scale (UHDRS) motor score before surgery and during clinical follow-ups. One patient was observed over six months, while five patients were seen over 12 months.

RESULTS: All patients underwent high-frequency stimulation ranging from 130 Hz to 175 Hz. In the follow-up period, a general trend was found toward higher amplitude and broader pulse widths, with a mean current range of 2.08 mA to 3.06 mA and a mean pulse width range of 75 μsec to 98 μsec. On preoperative evaluation, the mean UHDRS motor score was 35.7 ± 16.3 and the chorea subscore was 11.3 ± 4.7. At the three-month postoperative follow-up, both UHDRS motor score (13.5 ± 5.8) and chorea subscore (3.0 ± 1.2) reached valley values. Thereafter, the UHDRS motor score and chorea subscore showed a gradual rise, reaching 19.2 ± 5.9 and 4.8 ± 1.7, respectively, at the 12-month follow-up. In addition, adverse events were also seen. Patient 1 developed dysarthria six months after surgery, whereas Patient 6 had a generalized tonic-clonic seizure attack one day after surgery CONCLUSION: High frequency stimulation of the GPi is an effective and safe modality for the treatment of ChAc, with both rapid symptomatic improvements and steady chronic outcomes.