Effects of Subdural Monopolar Cortical Stimulation Paired With Rehabilitative Training on Behavioral and Neurophysiological Recovery After Cortical Ischemic Stroke in Adult Squirrel Monkeys. (February 2016)

• Record Type: Journal Article
• Authors: Plautz, Erik J.; Barbay, Scott; Frost, Shawn B.; Zoubina, Elena V.; Stowe, Ann M.; Dancause, Numa; Eisner-Janowicz, Ines; Bury, Scott D.; Taylor, Michael D.; Nudo, Randolph J.
• Is Part Of: Neurorehabilitation & neural repair. Volume 30:Number 2(2016)
• Page Start: 159
• Page End: 172
• Publication Date: 2016-02
• Subjects: implanted stimulation electrodes -- primate -- primary motor cortex -- premotor cortex -- neuronal plasticity; Nervous system -- Diseases -- Patients -- Rehabilitation -- Periodicals; Brain damage -- Patients -- Rehabilitation -- Periodicals; Spinal cord -- Wounds and injuries -- Patients -- Rehabilitation -- Periodicals; Nervous system -- Regeneration -- Periodicals; Neuroplasticity -- Periodicals; 616.804305
• DOI: 10.1177/1545968315619701
• Languages: English
• ISSNs: 1545-9683

Abstract

Background . Cortical stimulation (CS) combined with rehabilitative training (RT) has proven effective for enhancing poststroke functional recovery in rats, but human clinical trials have had mixed outcomes. Objective . To assess the efficacy of CS/RT versus RT in a nonhuman primate model of cortical ischemic stroke. Methods . Squirrel monkeys learned a pellet retrieval task, then received an infarct to the distal forelimb (DFL) representation of primary motor cortex. A subdural monopolar electrode was implanted over the spared DFL representation in dorsal premotor cortex (PMD). Seven weeks postinfarct, monkeys underwent 4 to 6 weeks of RT (n = 8) or CS/RT (n = 7; 100 Hz, cathodal current) therapy. Behavioral performance was assessed before and after infarct, prior to therapy, and 1 and 12 weeks posttherapy (follow-up). The primary outcome measure was motor performance at 1 week posttherapy. Secondary outcomes included follow-up performance at 12 weeks and treatment-related changes in neurophysiological maps of spared DFL representations. Results . While postinfarct performance deficits were found in all monkeys, both groups demonstrated similar recovery profiles, with no difference in motor recovery between the RT and CS/RT groups. Posttherapy, PMD DFL area was significantly expanded in the RT group but not the CS/RT group. A significant relationship was found between motor recovery and DFL expansion in premotor cortex. Conclusions . Results suggest that the specific parameters utilized here were not optimal for promoting behavioral recovery in nonhuman primates. Though CS/RT has consistently shown efficacy in rat stroke models, the present finding has cautionary implications for translation of CS/RT therapy to clinical populations.