Deep brain stimulation evoked potentials may relate to clinical benefit in childhood dystonia

Nasir H Bhanpuri; Matteo Bertucco; Diana Ferman; Scott J Young; Mark A Liker; Mark D Krieger; Terence D Sanger

doi:10.1016/j.brs.2014.06.003

Deep brain stimulation evoked potentials may relate to clinical benefit in childhood dystonia

Brain Stimul. 2014 Sep-Oct;7(5):718-26. doi: 10.1016/j.brs.2014.06.003. Epub 2014 Jun 25.

Authors

Nasir H Bhanpuri¹, Matteo Bertucco¹, Diana Ferman², Scott J Young¹, Mark A Liker³, Mark D Krieger³, Terence D Sanger⁴

Affiliations

¹ Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA.
² Department of Neurology, University of Southern California and Children's Hospital Los Angeles, Los Angeles, CA, USA.
³ Department of Neurology, University of Southern California and Children's Hospital Los Angeles, Los Angeles, CA, USA; Department of Neurosurgery, University of Southern California and Children's Hospital Los Angeles, Los Angeles, CA, USA.
⁴ Department of Biomedical Engineering, University of Southern California, Los Angeles, CA, USA; Department of Neurology, University of Southern California and Children's Hospital Los Angeles, Los Angeles, CA, USA; Department of Biokinesiology and Physical Therapy, University of Southern California, Los Angeles, CA, USA. Electronic address: [email protected].

PMID: 25088460
DOI: 10.1016/j.brs.2014.06.003

Abstract

Background: Deep brain stimulation (DBS) of the globus pallidus internus (GPi) is a treatment for severe childhood-onset dystonia. A common challenge for clinicians is determining which contacts of the DBS electrode to stimulate in order to provide maximum future benefit to the patient.

Objective: To characterize how the cortical responses to DBS relate to stimulation parameters (i.e. electrode contacts, voltage, and pulse width) and clinical outcomes.

Methods: We examined 11 patients with dystonia undergoing DBS therapy (9-21 years old when implanted). We varied the active contacts, voltage, and pulse width of the stimulating electrode and analyzed the deep-brain stimulator evoked potentials (DBSEPs) measured with electroencephalogram, and assessed symptoms with the Barry-Albright dystonia scale. Statistical tests included: Repeated measures ANOVA, Mann-Whitney U test and paired t-test.

Results: DBSEPs near sensorimotor areas were larger ipsilaterally than contralaterally (P = 0.007). The rate of DBSEP amplitude increase with respect to stimulator voltage (voltage gain) and pulse width (pulse width gain) varied across subjects and stimulating contacts. Voltage gains were significantly higher among patients who showed larger improvements with DBS (P = 0.038). Additionally, a within-subject comparison of all patients showed that voltage gains were higher for contacts chosen for chronic stimulation as compared to those that were not (P = 0.007).

Conclusions: DBSEPs may be good predictors of therapeutic response to stimulation at different electrode contacts. Furthermore, effective DBS therapy appears to modulate sensorimotor cortex. These findings may help clinicians optimize stimulator programming and may eventually lead to improved targeting during implantation.

Keywords: Cerebral palsy; Deep brain stimulation; Dystonia; Evoked potentials; Globus pallidus internus.

Publication types

Research Support, Non-U.S. Gov't

MeSH terms

Adolescent
Child
Deep Brain Stimulation / methods*
Dystonic Disorders / diagnosis
Dystonic Disorders / physiopathology*
Dystonic Disorders / therapy*
Electrodes, Implanted*
Electroencephalography / methods
Evoked Potentials / physiology*
Female
Globus Pallidus / physiology
Humans
Male
Treatment Outcome
Young Adult