Failed DBS for palliation of visual problems in a case of oculopalatal tremor

Wang, David; Sanchez, Justin; Foote, Kelly D.; Sudhyadhom, Atchar; Bhatti, M. Tariq; Lewis, Steven; Okun, Michael S.

doi:10.1016/j.parkreldis.2008.01.020

« Previous Next »Parkinsonism & Related Disorders
Volume 15, Issue 1 , Pages 71-73, January 2009

Failed DBS for palliation of visual problems in a case of oculopalatal tremor

David Wang
- Department of Neurology, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
Justin Sanchez
- Department of Pediatrics, University of Florida, Gainesville, FL, USA
Kelly D. Foote
- Department of Neurosurgery, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
Atchar Sudhyadhom
- Department of Neurosurgery, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
M. Tariq Bhatti
- Department of Ophthalmology, University of Florida, Gainesville, FL, USA
Steven Lewis
- Department of Neurosurgery, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
Michael S. Okun
- Department of Neurology, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
- Department of Neurosurgery, University of Florida Movement Disorders Center, McKnight Brain Institute, Gainesville, FL, USA
- Corresponding author. Department of Neurology, University of Florida Movement Disorders Center, McKnight Brain Institute, 100S Newell Drive, L3-100, Gainesville, FL 32610, USA. Tel.: +1 352 273 5550; fax: +1 352 273 5575.

Received 22 January 2008; received in revised form 28 January 2008; accepted 29 January 2008.

Abstract

Objective

To report the results of attempted bilateral red nucleus (RN) deep brain stimulation (DBS) for the palliative treatment of visual problems associated with oculopalatal tremor (OPT).

Background

It is hypothesized that OPT results from a defect in the Guillain–Mollaret triangle, a circuit that includes connections with the dentate nucleus, the contralateral red nucleus, and the inferior olive. We present a high functioning patient (an accountant) who underwent a palliative trial of RN region DBS in an approach targeted through the subthalamic nucleus region. The aim was to reduce eye tremor and improve vision through interruption of the pathologically oscillating circuit in the Guillain–Mollaret triangle.

Methods

Following informed consent, a patient with OPT (and failure of multiple classes of medication and botulinum toxin therapy) underwent placement of bilateral DBS electrodes within the region of the RN. He underwent preoperative testing and testing after 12 months of continuous stimulation with the device in monopolar, bipolar, low frequency, and high frequency settings.

Results

The patient did not demonstrate significant changes in the neurological examination following the procedure and postoperative programming sessions. Eye tremor was monitored pre- and postoperatively by ocular EMG and did not change in frequency. Following the one-year trial, stimulation was discontinued as there were no improvements in vision.

Conclusion

DBS for OPT was not clinically effective. There were many potential reasons for failed efficacy including a failure to implant the electrodes deep and medial enough into the target region because of stimulation induced side effects. Other targets within the Guillain–Mollaret circuit (and outside of the circuit) may be more useful, though they may prove to be less safe and even more difficult to access. Better custom designed DBS leads may be needed for such small targets in critical brain regions.

Key words: DBS, Red nucleus, Physiology, Microelectrode recordings, Oculopalatal