Objective: To report a case of right hemi-choreodystonia successfully treated with deep brain stimulation (DBS) targeting at globus pallidus internus (GPi) and pallidothalamic tract (PTT).
Background: DBS is an effective neuromodulation therapy for movement disorders. PTT is a promising neurosurgical target, originating from GPi. We report a case of secondary right hemi-choreodystonia following COVID-19 infection successfully treated with combined left GPi-PTT-DBS.
Method: This case report describes patient’s clinical features and outcomes following DBS surgery, MRI findings, and treatment details.
Results: A 64-year-old man with hypertension and history of right cerebellar hemorrhage presented with chronic progressive hemi-choreodystonia involving the right extremities. His symptoms developed six months after severe COVID-19 pneumonia complicated by acute respiratory distress syndrome. Brain MRI showed no new intracranial abnormalities, including basal ganglia. Serum autoimmune encephalitis and antineuronal antibody panels were negative. The patient was treated with haloperidol, risperidone, tetrabenazine, clonazepam, trihexyphenidyl and valproate without significant improvement. Dual-target left GPi and left PTT DBS was performed due to disabling symptoms. The preoperative Abnormal Involuntary Movement Scale (AIMS) score was 26. Left GPi target was Y = +2mm from mid-commissure point, with X and Z at the dorsolateral border of optic tract. Left PTT target was Y = -1mm from mid-commissure point, Z = -0.5mm below AC-PC plane, and X = 3.5mm lateral to mammillothalamic tract. Postoperatively, the patient demonstrated marked improvement in abnormal movements with sustained benefit for up to 2 years. Current stimulation parameters are C+1-2- at amplitude of 3.5mA, pulse width 60 µsec and frequency of 145Hz, and C+1- at amplitude of 3.6mA with the same pulse width and frequency. Three stimulation conditions were evaluated, including ON-GPi/OFF-PTT, OFF-GPi/ON-PTT, and ON-PTT/ON-GPi, which yielded AIMS scores of 14, 13 and 13, respectively.
Conclusion: This case demonstrated significant improvement of secondary choreodystonia following COVID-19 infection with combined GPi-PTT-DBS. In addition to GPi, PTT stimulation showed promising results in mitigating chorea and dystonia and may represent a potential alternative target for treatment of these movement disorders.
References: 1. Rozanski VE, da Silva NM, Ahmadi SA, et al. The role of the pallidothalamic fibre tracts in deep brain stimulation for dystonia: A diffusion MRI tractography study. Hum Brain Mapp. 2017;38(3):1224-1232. doi:10.1002/hbm.23450
2. Baik K, Lee S, Lee CN, Park KW, Chang JW. MRgFUS pallidothalamic tractotomy following GPi DBS in a patient with refractory hemichorea: A case report. Brain Stimul. 2025;18(3):730-732.
To cite this abstract in AMA style:
W. Saengphatrachai, P. Srivanitchapoom, Y. Pitakpatapee, S. Nanta-Aree. Dual Globus Pallidus Internus and Pallidothalamic Tract Deep Brain Stimulation for Hemichoreodystonia Secondary to Severe COVID-19 Infection: A Case Report [abstract]. Mov Disord. 2026; 41 (suppl 1). https://www.mdsabstracts.org/abstract/dual-globus-pallidus-internus-and-pallidothalamic-tract-deep-brain-stimulation-for-hemichoreodystonia-secondary-to-severe-covid-19-infection-a-case-report/. Accessed October 1, 2026.« Back to 2026 International Congress
MDS Abstracts - https://www.mdsabstracts.org/abstract/dual-globus-pallidus-internus-and-pallidothalamic-tract-deep-brain-stimulation-for-hemichoreodystonia-secondary-to-severe-covid-19-infection-a-case-report/