Bilateral Ventral Intermediate Nucleus Thalamic Deep Brain Stimulation in Orthostatic Tremor

• Published in: Stereotactic and functional neurosurgery Vol. 94; no. 2; p. 69
• Main Authors: Coleman, Robert R, Starr, Philip A, Katz, Maya, Glass, Graham A, Volz, Monica, Khandhar, Suketu M, Ostrem, Jill L
• Format: Journal Article
• Language: English
• Published: Switzerland 01.01.2016
• Subjects: Aged; Deep Brain Stimulation - methods; Dizziness - diagnostic imaging; Dizziness - physiopathology; Dizziness - surgery; Electromyography - methods; Female; Humans; Middle Aged; Tremor - diagnostic imaging; Tremor - physiopathology; Tremor - surgery; Ventral Thalamic Nuclei - physiology; Ventral Thalamic Nuclei - surgery
• ISSN: 1423-0372
• DOI: 10.1159/000444127

Orthostatic tremor (OT) is characterized by high-frequency leg tremor when standing still, resulting in a sense of imbalance, with limited treatment options. Ventral intermediate (Vim) nucleus thalamic deep brain stimulation (DBS) has been reported as beneficial in a few cases. To report clinical outcomes, lead locations, and stimulation parameters in 2 patients with severe medication-refractory OT treated with Vim DBS. The patients underwent surface electromyography (EMG) to confirm the OT diagnosis. Outcomes were measured as change in tolerated standing time at the last follow-up. Lead locations were quantified using postoperative MRI. Vim DBS was well tolerated and resulted in improvement in standing time (patient 1: 50 s at baseline to 15 min 16 months after surgery; patient 2: 34 s at baseline to 4.2 min 7 months after surgery). Postoperative surface EMG for patient 1 demonstrated a delayed onset of tremor, lower-amplitude tremor, and periods of quiescence, but an unchanged tremor frequency. These cases provide further support for Vim DBS to improve standing time in severe medication-refractory OT. The location of the effective thalamic target for OT does not differ from the effective target for essential tremor.