Median Nerve Stimulation Facilitates the Identification of Somatotopy of the Subthalamic Nucleus in Parkinson’s Disease Patients under Inhalational Anesthesia

Abstract

Deep brain stimulation (DBS) improves Parkinson’s disease (PD) symptoms by suppressing neuropathological oscillations. These oscillations are also modulated by inhalational anesthetics used during DBS surgery in some patients, influencing electrode placement accuracy. We sought to evaluate a method that could avoid these effects. We recorded subthalamic nucleus (STN) neuronal firings in 11 PD patients undergoing DBS under inhalational anesthesia. Microelectrode recording (MER) during DBS was collected under median nerve stimulation (MNS) delivered at 5, 20, and 90 Hz frequencies and without MNS. We analyzed the spike firing rate and neuronal activity with power spectral density (PSD), and assessed correlations between the neuronal oscillation parameters and clinical motor outcomes. No patient experienced adverse effects during or after DBS surgery. PSD analysis revealed that peripheral 20 Hz MNS produced significant differences in the dorsal and ventral subthalamic nucleus (STN) between the beta band oscillation (16.9 ± 7.0% versus 13.5 ± 4.8%, respectively) and gamma band oscillation (56.0 ± 13.7% versus 66.3 ± 9.4%, respectively) (p < 0.05). Moreover, 20-Hz MNS entrained neural oscillation over the dorsal STN, which correlated positively with motor disabilities. MNS allowed localization of the sensorimotor STN and identified neural characteristics under inhalational anesthesia. This paradigm may help identify an alternative method to facilitate STN identification and DBS surgery under inhalational anesthesia.

Long-Term Effects of Subthalamic Stimulation on Motor Symptoms and Quality of Life in Patients with Parkinson’s Disease

“…After one week, the electrode cables were connected to the implantable pulse generator. Detailed surgical procedures are described in our previous studies [ 27 , 28 , 29 , 30 ].…”

Subthalamic nucleus single-unit activity in humans with Parkinson's Disease encodes both the rate of change and the magnitude of force during a sustained grip-force task

“…The STN receives inputs from several frontal motor areas, including the primary motor cortex, and the supplementary motor area, as well as lesser inputs from the primary sensory cortex [19][20][21][22] . Sensory responses to light touch, passive movements [23][24][25][26][27][28][29][30] , and median nerve stimulation [31][32][33][34][35][36][37] have been noted with single unit recordings from subthalamic nucleus and other basal ganglia structures. Anatomical studies of the STN and its connectivity suggest a functional compartmentalization of the STN into motor and non-motor regions, and a more fine-grain division of the motor inputs from a variety of cortical source regions 38 .…”