Effects of mechanical stimulation of the feet on gait and cardiovascular autonomic control in Parkinson's disease

Abstract

Motor impairment in Parkinson's disease (PD) is partly due to defective central processing of lower limb afferents. Concomitant alterations in cardiovascular autonomic control leading to orthostatic hypotension may worsen motor ability. We evaluated whether mechanical activation of feet sensory afferents could improve gait and modify the response of cardiovascular autonomic control to stressors in 16 patients (age 66 ± 2 yr) with idiopathic PD (Hoehn & Yhar scale 2-3) on their usual therapy. Eight subjects (group A) were randomized to undergo skin pressure (0.58 ± 0.04 kg/mm(2)) stimulation at the hallux tip and first metatarsal joint (effective stimulation; ES) of both feet. Eight remaining patients (group B) underwent sham stimulation (SS) followed by ES. Three-dimensional movement analysis provided quantitative indexes of movement disability before (baseline) and 24 h after ES and SS. Spectral analysis of heart rate and blood pressure variability provided markers of cardiac sympatho-vagal (LF/HF) and vascular sympathetic (LFSAP) modulations. Markers were measured at rest and during 75° head-up tilt, before and 24 h after ES and SS. After ES, step length and gait velocity increased, upright rotation velocity was enhanced, and step number was decreased. After ES, LFSAP declined. The increase in LF/HF and LFSAP induced by tilt was greater than before feet stimulation. No changes in gait and autonomic parameters were observed after SS. Twenty-four hours after ES, patients with PD showed improved gait and increased cardiac and vascular sympathetic modulation during upright position compared with baseline. Conversely, SS was ineffective on both movement and autonomic parameters, indicating a site specificity effect of the stimulation.

Beneficial Effect of Foot Plantar Stimulation in Gait Parameters in Individuals with Parkinson’s Disease

“…A similar improvement in stride length was observed in PD compared to the control group in our study, confirming that plantar stimulation may improve postural instability seen in PD [14,36]. Recent studies have shown that punctual pressure in two specific areas of each foot (bottom-up rehabilitation) is sufficient to improve gait and stability in PD patients [19][20][21][22].…”

“…Likewise, a descriptive analysis was also performed for the qualitative variables, based on frequency distributions. The Kolmogorov-Smirnov test revealed non-normal data distribution for Previous studies investigated the responsiveness of mechanical peripheral stimulation on specific areas of the foot (first metatarsal head, plantar surface of big toe); thus, reducing motor symptoms by stimulating the somatosensory system [19][20][21][22]31]. In such studies, results were compared with age-matched control groups in order to identify differences in gait pattern between PD patients and healthy subjects.…”

“…By enhancing the sensory feedbacks coming from the feet, bottom-up stimulation allows patients to better integrate peripheral inputs with motor control response during gait, producing a stimulating effect of central nervous system areas involved in human movement [18]. Recent studies have shown the effectiveness of plantar mechanical stimulation in PD patients by applying punctual pressure in two specific areas of each foot (bottom-up rehabilitation) [19][20][21][22]. Furthermore, a pilot study by Quattrocchi and co-workers demonstrated the effectiveness of a device for the motor rehabilitation in PD, based on non-invasive stimulations given via controlled mechanical impulses in specific areas of both feet [18].…”

Acute Modulation of Brain Connectivity in Parkinson Disease after Automatic Mechanical Peripheral Stimulation: A Pilot Study

“…The treatment consists in 4 cycles, whereas cycle means the sequential stimulation of the 4 target areas for the duration of 6 seconds each, with no intervals in between; consequently a single cycle has duration of 24 seconds, while the overall treatment including four cycles lasts 96 seconds. The trials were conducted in an isolated room to keep the treatment blind to the clinicians and neuro-radiologists involved in the study [ 32 ].…”

“…It has been reported that mechanical stimulation of the soles of the feet improves gait performance in PD [ 30 – 31 ]. Quantitative measures of gait analysis parameters have shown to increase step length and gait velocity together with autonomic sympathetic modulation in PD patients 24h after automatic mechanical peripheral stimulation (AMPS) [ 32 ]. More recently, PD patients have shown improvement of their ability to perform the Timed Up and Go Test after AMPS [ 33 ] and clinical benefits are maintained up to 10 days after the last treatment [ 34 ].…”