Investigation of the changes in the presynaptic inhibition in association with the subthalamic nucleus stimulation in Parkinson's disease.

BACKGROUND AND PURPOSE

Presynaptic inhibition (PSI) is a critical spinal inhibitory mechanism for modulating muscle coordination by adjusting both supraspinal motor commands and sensory feedback at the spinal level. The literature data regarding the role of PSI in the efficiency of STN-DBS therapy in Parkinson's disease (PD) are limited. We aimed to investigate the possible alteration in this pathway in association with the STN stimulation (STIM) within the very early period after the STIM is off.

METHODS

We performed the H-reflex investigation on 8 PD subjects with STN-DBS who applied to our polyclinic for routine clinical evaluations. The investigations were initially performed at the STIM-on period and repeated after the STIM set is off for 5 min. A

RESULTS

The results of the analyses did not reveal marked changes in the variables of the H-reflex between the STIM-on and -off states.

CONCLUSION

PSI do not alter in the very early period after the STIM is off. Taken together with the related literature data and our study results, it can be hypothesized that the PSI might involve in the DBS efficiency in the later phase of the STIM as a compensatory mechanism. Further prospective studies including a larger number of patients with serial electrophysiological recordings to investigate the temporal course of the underlying dynamics are required to clarify these discussions.