Stimulation-Based Modulation of Spinal and Cortical Sensory Pathways

The goal of this study is to assess cervical (neck) reflexes by intra-operatively stimulating the neck nerve roots to evoke motor responses through their connections to spinal motoneurons. This data is critical to reveal changes to the spinal sensory modulating circuitry in neurological disorders like stroke.

Spinal afferents continuously convey sensory information on limb movements to the central nervous system which not only gives people conscious experience of movement, but also plays a major role in shaping motor output through monosynaptic afferent-motoneuronal connections. Stroke induces changes in the spinal circuitry modulating this sensory input, leading to sensorimotor deficits. Specifically, the investigators will 1) activate the dorsal root fibers with single and double electrical stimulation pulses at various frequencies using FDA-cleared devices, 2) quantify the stimulation evoked motor potentials in arm and hand muscles recorded with intramuscular EMGs, 3) quantify stimulation evoked sensory potentials in the cortex with intra-op EEGs.