Abnormal Gait Spatiotemporal Parameters During Regular Walking And Improvement Of Freezing Gait To Alternating Electrical Stimulation On Bilateral Common Peroneal Nerves In Patients With PPFG

BackgroundPrimary progressive freezing gait (PPFG) is characterized by early freezing of gait (FOG). For PPFG patients are presented with mild parkinsonian symptoms, whether gait spatiotemporal parameters in PPFG are altered or similar to that of Parkinson’s disease (PD) is unknown. No definite pharmaceutical treatment is available. External visual and auditory cues are well known for advantage on episodes of FOG, employed in limited situations. Increased freezing behavior occurs when patients are denied adequate proprioceptive feedback.ObjectiveWhether the gait spatiotemporal parameters and foot plantar pressure during regular walking for PPFG are disturbed similarly as idiopathic PD has not been addressed. We test if increasing proprioceptive inputs by means of alternating electrical stimulation on bilateral common peroneal nerves could alleviate the attack of FOG and improve walking performance.MethodsWe included 7 patients diagnosed as PPFG,10 patients with PD-FOG and 20 healthy volunteers. Gait spatiotemporal parameters and plantar pressures were measured by computer assisted force plate system. A portable dual-channel electrical stimulator was used to deliver alternating electrical stimuli to bilateral common peroneal nerves. The effects of electrical stimulation on gait performance of subjects were evaluated by a modified 12 meters timed walking trail. The total walking time (Tt) and durations of three walking sub-stages (T1=initiating, T2=turning and T3=maintaining) as well as the FOG scores in the trail were collected and analyzed.ResultsPPFG patients had reduced step length, increased step width, shorter swing phase and single support duration, longer double support duration and decreased walking speed. Tt, T1, T2 and T3 as well as FOG scores were significantly reduced by the electrical stimulation for patients with PPFG, with T1 being most prominent. The improvement percentages of time durations of the total walking and sub-stage walking under stimulator "on" over "off"(ToffTon)/Toff% in the 12 m timed walking trail for PPFG group on T1, T2, T3 and Tt were (83.67±14.49)%, (39.14± 10.42)%, (25.56±17.32)% and (51.03±9.57)% respectively, while the corresponding data for PD-FOG group were (16.98±14.42)%, (13.07±20.42)%, (12.57±8.24)% and (14.05±9.74)% respectively. Statistical differences of improvement percentage between the two groups were detected for Ti, T2 and Tt, but not for T3.ConclusionsThe gait spatiotemporal characteristics of PPFG during regular walking without freezing were altered. Proprioceptive sensory cueing provided by alternating electrical stimulation is helpful in alleviating FOG of PPFG patients, especially on the initiating and turning. The improvement percentage of Ti is the most prominent in both PPFG and PD-FOG groups.