Comparison of omnidirectional versus unidirectional STN-DBS - Impact on gait and balance in Parkinson's disease
Related Research units
Abstract
Objective
This study was designed to compare the effects of bilateral omnidirectional and unisegmental directional deep brain stimulation in the subthalamic nucleus (STN-DBS) on axial symptoms in Parkinson’s disease (PD) patients.
Background
In PD, gait disturbances and freezing of gait represent therapeutically demanding symptoms impacting quality of life. The effects of conventional, omnidirectional STN-DBS on gait are limited. To date it is unclear, whether unisegmental DBS might be a beneficial stimulation mode to improve gait and balance.
Methods
The primary outcomes of this prospective, randomised, double-blind, short-term, clinical trial were stimulation induced changes of freezing of gait (FOG-Score [1]) and spatio-temporal gait parameters recorded by the GAITRite® system. Secondary outcome was the 7-item Berg Balance scale [2]. PD patients were tested on two consecutive days in five conditions in pseudo-randomised order (stimulation: OFF, omnidirectional and anterior, postero-lateral, postero-medial segment) in the medication off-state. During unisegmental stimulation, amplitude was reduced by about 30% compared to omnidirectional stimulation (omnidirectional right STN: 2.5 ± 0.5 mA, left STN: 2.5 ± 0.9 mA). For each patient, single segments were compared and classified from best to worst for every score separately. Results are presented as mean ± standard deviation.
Results
Preliminary results of 9 patients (age 63.2 ± 4.3 years; 8 males; 14.9 ± 8.4 months postoperatively) revealed numerical, but non-significant improvements of spatio-temporal gait parameters and balance under best-segment and omnidirectional STN-DBS regime compared to DBS-OFF state, e.g. fast speed velocity: OFF: 1.44 ± 0.35 m/s; unidirectional: 1.60 ± 0.35 m/s, p = 0.35; omnidirectional: 1.61 ± 0.28 m/s, p = 0.29. The best-segment and omnidirectional STN-DBS reduced freezing of gait significantly (OFF: 18.0 ± 11.9 points; unidirectional: 7.3 ± 3.0 points, p = 0.02; omnidirectional: 7.4 ± 3.0 points, p = 0.02). The worst-segment stimulation displayed similar outcomes to the DBS-OFF state.
Conclusion
These first results suggest that unisegmental directional STN-DBS at best direction with reduced stimulation amplitude leads to comparable improvements of freezing of gait equivalent to omnidirectional stimulation.
This study was designed to compare the effects of bilateral omnidirectional and unisegmental directional deep brain stimulation in the subthalamic nucleus (STN-DBS) on axial symptoms in Parkinson’s disease (PD) patients.
Background
In PD, gait disturbances and freezing of gait represent therapeutically demanding symptoms impacting quality of life. The effects of conventional, omnidirectional STN-DBS on gait are limited. To date it is unclear, whether unisegmental DBS might be a beneficial stimulation mode to improve gait and balance.
Methods
The primary outcomes of this prospective, randomised, double-blind, short-term, clinical trial were stimulation induced changes of freezing of gait (FOG-Score [1]) and spatio-temporal gait parameters recorded by the GAITRite® system. Secondary outcome was the 7-item Berg Balance scale [2]. PD patients were tested on two consecutive days in five conditions in pseudo-randomised order (stimulation: OFF, omnidirectional and anterior, postero-lateral, postero-medial segment) in the medication off-state. During unisegmental stimulation, amplitude was reduced by about 30% compared to omnidirectional stimulation (omnidirectional right STN: 2.5 ± 0.5 mA, left STN: 2.5 ± 0.9 mA). For each patient, single segments were compared and classified from best to worst for every score separately. Results are presented as mean ± standard deviation.
Results
Preliminary results of 9 patients (age 63.2 ± 4.3 years; 8 males; 14.9 ± 8.4 months postoperatively) revealed numerical, but non-significant improvements of spatio-temporal gait parameters and balance under best-segment and omnidirectional STN-DBS regime compared to DBS-OFF state, e.g. fast speed velocity: OFF: 1.44 ± 0.35 m/s; unidirectional: 1.60 ± 0.35 m/s, p = 0.35; omnidirectional: 1.61 ± 0.28 m/s, p = 0.29. The best-segment and omnidirectional STN-DBS reduced freezing of gait significantly (OFF: 18.0 ± 11.9 points; unidirectional: 7.3 ± 3.0 points, p = 0.02; omnidirectional: 7.4 ± 3.0 points, p = 0.02). The worst-segment stimulation displayed similar outcomes to the DBS-OFF state.
Conclusion
These first results suggest that unisegmental directional STN-DBS at best direction with reduced stimulation amplitude leads to comparable improvements of freezing of gait equivalent to omnidirectional stimulation.
Bibliographical data
| Original language | English |
|---|---|
| Article number | 1348 |
| ISSN | 0885-3185 |
| Publication status | Published - 09.2020 |
