A positionally sensitive spinal cord stimulation apparatus and method using near-infrared (NIR) reflectometry are provided for automatic adjustments of spinal cord stimulation. The system comprises an electrode assembly with an integrated optical fiber sensor for sensing spinal cord position. The integrated optical fiber sensor, comprising a set of optical elements for emitting light from a set of IR emitters and for collecting reflected light into a set of IR photodetectors, determines a set of measured optical intensities. As the spinal cord changes position, the angles of incidence for light from the IR emitter and the measured optical intensities change. Electrode pulse characteristics are adjusted in real time, based on the set of measured optical intensities, to minimize changes in stimulation perceived by the patient during motion.
