Gait In Parkinson's Disease Patients Research Articles

Transient effects of 80 Hz stimulation on gait in STN DBS treated PD patients: A 15 months follow-up study

Subthalamic nucleus deep brain stimulation (STN DBS) is an effective therapeutic option for advanced Parkinson's disease (PD). Nevertheless, some patients develop gait disturbances despite a persistent improvement of PD segmental symptoms. Recent studies reported that stimulation of STN with low frequencies produced a positive effect on gait disorders and freezing episodes. To evaluate the effects of 80 Hz stimulation frequency on gait in PD patients undergoing STN DBS and to determine whether such effects are maintained over time. We evaluated 11 STN DBS treated PD patients who had developed gait impairment several years after surgery. Gait was assessed by means of the Stand-Walk-Sit (SWS) test. Motor symptoms and activities of daily living were evaluated through the Unified PD Rating Scale (UPDRS). The stimulation frequency was switched from 130 Hz to 80 Hz, adapting the voltage to maintain the same total delivered energy. Patients were assessed at baseline and 3 hours after switching the stimulation frequency to 80 Hz. Follow-up evaluations were carried out after 1, 5, and 15 months. The clinical global improvement scale was rated at every follow-up visit. A significant improvement of gait (SWS test) was evident immediately after switching the stimulation frequency to 80 Hz, with no deterioration of PD segmental symptoms. However, gait improvement was no longer detectable by the SWS test at follow-up evaluations 1, 5, and 15 months later. Three patients were switched back to 130 Hz because of unsatisfactory control of motor symptoms. Of the eight patients maintained at 80 Hz up to 15 months, five showed a global improvement and three showed no change. Stimulation frequency at 80 Hz has an immediate positive effect on gait in STN DBS treated patients; however, the objective gait improvement is not maintained over time, limiting the use of this frequency modulation strategy in the clinical setting.

Validation of 24-hour ambulatory gait assessment in Parkinson's disease with simultaneous video observation

BackgroundParkinson's disease (PD) is a neurodegenerative disorder resulting in motor disturbances that can impact normal gait. Although PD initially responds well to pharmacological treatment, as the disease progresses efficacy often fluctuates over the course of the day, and clinical management would benefit from long-term objective measures of gait. We have previously described a small device worn on the shank that uses acceleration and angular velocity sensors to calculate stride length and identify freezing of gait in PD patients. In this study we extend validation of the gait monitor to 24-h using simultaneous video observation of PD patients.MethodsA sleep laboratory was adapted to perform 24-hr video monitoring of patients while wearing the device. Continuous video monitoring of a sleep lab, hallway, kitchen and conference room was performed using a 4-camera security system and recorded to hard disk. Subjects (3) wore the gait monitor on the left shank (just above the ankle) for a 24-h period beginning around 5 pm in the evening. Accuracy of stride length measures were assessed at the beginning and end of the 24-h epoch. Two independent observers rated the video logs to identify when subjects were walking or lying down.ResultsThe mean error in stride length at the start of recording was 0.05 m (SD 0) and at the conclusion of the 24 h epoch was 0.06 m (SD 0.026). There was full agreement between observer coding of the video logs and the output from the gait monitor software; that is, for every video observation of the subject walking there was a corresponding pulse in the monitor data that indicated gait.ConclusionsThe accuracy of ambulatory stride length measurement was maintained over the 24-h period, and there was 100% agreement between the autonomous detection of locomotion by the gait monitor and video observation.

High-frequency electrical stimulation of the subthalamic nucleus in Parkinson's disease: kinetic and kinematic gait analysis.

In the advanced phase of Parkinson's disease (PD), gait disturbances represent one of the main causes of disability. Several studies demonstrated that high-frequency electrical stimulation (HFS) of the subthalamic nucleus (STN) significantly improves the motor symptoms of PD. This study was finalised to quantitatively analyze the effect of STN HFS on gait of PD patients, through a three-dimensional gait analysis system. Ten PD patients were studied, with and without STN HFS. The results demonstrated that STN HFS significantly improves all the main gait parameters in PD patients.