RESUMEN
Aim: To assess the changes in frequency parameters of STN-DBS stimulation over 6 months required to optimize gait in PD patients. Methods: It's a single center, open label longitudinal study of PD patients after STN-DBS with gait disorders. Gait assessment using stand-walk-sit (SWS) test and freezing of gait (FOG) scores were done at baseline and after 6 months. Gait was assessed in five frequencies settings, that is, 60 Hz, 90 Hz, 130 Hz, 180 Hz and stimulation "OFF" during medication ON state. Voltage was maintained. Results: Fifteen post-deep brain stimulation (DBS) patients were included. Mean duration after surgery was 3.73 ± 2.82 years. In SWS and FOG at baseline, five patients have good response at 180 Hz frequency, five at 130 Hz, one at 90 Hz, two patients at 60 Hz, one both 60 and 90 Hz, and one at both 90 and 180 HZ. And after 6 months out of the 13 patients who were able to perform the test, four patients had good response at 180 Hz frequency, four at 130 Hz, two at 90 Hz, one each for 60 Hz and battery OFF state, and one for both 130 Hz and 180 Hz. At 6 months, four patients had good response at the same frequency as baseline, while 11 patients have change in frequency from baseline. Conclusion: Optimal frequency for gait varies in patients-both low and high frequency may be useful. Optimal frequency for improving gait changes over period of time. Regular assessment and changing frequency may improve gait after DBS.
RESUMEN
Background: Movement abnormalities pertaining to balance, posture, and gait are observed in Parkinson's disease patients. Gait characteristics vary widely and their analysis has been performed traditionally in gait labs. Freezing and festination usually occur at an advanced stage of the disease and are associated with reduced quality of life. Therapeutic strategies and surgical interventions are often modulated by the physician depending upon the clinical manifestations. Introduction of accelerometers and wireless data transmission systems made quantitative gait analysis possible and cost-effective. Objective: To assess spatiotemporal gait parameters (step height, length (spatial), and swing support time of each foot and double support time (temporal)) in subjects who underwent deep brain stimulation surgery using a purpose-built instrument-Mobishoe. Methods: A simple footwear-based gait sensing device-Mobishoe was built in-house. Thirty-six participants were included in the study after obtaining consent. Participants were made to wear Mobishoe and walk an empty corridor of 30m before Deep Brain Stimulation (DBS) in the drug on and off stated and post DBS in DBS stimulation on and medication off state (B1M0), DBS stimulation off-medication off state (B0M0), DBS stimulation off-medication on (B0M1), and DBS stimulation on and on medication (B1M1). Data was electronically captured and analyzed offline in MATrix LABoratory (MATLAB). Various gait parameters were extracted and analyzed. Results: Improvement in gait parameters was observed when the subject was on medication, on stimulation, or on both when compared to baseline. Improvement was similar with both medication and stimulation and was synergistic when both were used. Significant improvement was noted in spatial characteristics when the subjects were on both the treatments, which is the ideal treatment modality. Conclusion: Mobishoe is an affordable device which can measure spatiotemporal characteristics of gait. The best improvement was seen when the subjects were on both the treatment groups and the improvement can be justified as a synergistic effect of stimulation and medication.
