Parameters of Surface Electromyogram Suggest That Dry Immersion Relieves Motor Symptoms in Patients With Parkinsonism

Abstract

Dry immersion (DI) is acknowledged as a reliable space flight analog condition. At DI, subject is immersed in water being wrapped in a waterproof film to imitate microgravity (μG). Microgravity is known to decrease muscle tone due to deprivation of the sensory stimuli that activate the reflexes that keep up the muscle tone. In contrary, parkinsonian patients are characterized by elevated muscle tone, or rigidity, along with rest tremor and akinesia. We hypothesized that DI can diminish the elevated muscle tone and/or the tremor in parkinsonian patients. Fourteen patients with Parkinson's disease (PD, 10 males, 4 females, 47–73 years) and 5 patients with vascular parkinsonism (VP, 1 male, 4 females, 65–72 years) participated in the study. To evaluate the effect of DI on muscles' functioning, we compared parameters of surface electromyogram (sEMG) measured before and after a single 45-min long immersion session. The sEMG recordings were made from the biceps brachii muscle, bilaterally. Each recording was repeated with the following loading conditions: with arms hanging freely down, and with 0, 1, and 2 kg loading on each hand with elbows flexed to 90°. The sEMG parameters comprised of amplitude, median frequency, time of decay of mutual information, sample entropy, correlation dimension, recurrence rate, and determinism of sEMG. These parameters have earlier been proved to be sensitive to PD severity. We used the Wilcoxon test to decide which parameters were statistically significantly different before and after the dry immersion. Accepting the p < 0.05 significance level, amplitude, time of decay of mutual information, recurrence rate, and determinism tended to decrease, while median frequency and sample entropy of sEMG tended to increase after the DI. The most statistically significant change was for the determinism of sEMG from the left biceps with 1 kg loading, which decreased for 84% of the patients. The results suggest that DI can promptly relieve motor symptoms of parkinsonism. We conclude that DI has strong potential as a rehabilitation method for parkinsonian patients.

Autonomic Function in Parkinson's Disease Subjects Across Repeated Short-Term Dry Immersion: Evidence From Linear and Non-linear HRV Parameters

“…The study enrolled 20 subjects with PD, 13 men and seven women. These subjects have participated in our previously published studies (Meigal et al, 2018(Meigal et al, , 2021aMiroshnichenko et al, 2018), where one can find their individual clinical and anthropological characteristics and medication. General characteristic of the subjects is presented in Table 1.…”

“…The condition of DI was induced by means of the "Medical Facility of Artificial Weightlessness" (MEDSIM, Center for Aerospace Medicine and Technologies, State Scientific Center of Russian Federation "Institute of Biomedical Problems, " Moscow, Russia) housed in Petrozavodsk State University (Petrozavodsk, Russia). A detailed description of the procedure of DI applied to the group of PD subjects is available in our earlier papers (Meigal et al, 2018(Meigal et al, , 2021aMiroshnichenko et al, 2018). The short-term DI session lasted 45-min.…”

“…Earlier we have shown that ground-based microgravity modeled with a short-term session of DI diminished tremor and muscle rigidity in Parkinson's disease (PD; Meigal et al, 2018Meigal et al, , 2021aMiroshnichenko et al, 2018), which can be attributed to the well-established atonia-inducing effect of DI on the skeletal muscle of healthy subjects (Navasiolava et al, 2011;Amirova et al, 2020). Additionally, the performance of the visual-motor reaction time tasks with higher cognition demand has improved after a program of DI sessions (Meigal et al, 2021b).…”

The Ventral Intermediate Nucleus Differently Modulates Subtype-Related Networks in Parkinson’s Disease

“…Before a magnetic resonance imaging (MRI) scan and clinical assessments, the PD patients were asked to withdraw from all anti-Parkinson medications for approximately 12 h. The Unified Parkinson’s Disease Rating Scale (UPDRS), the Hoehn and Yahr disability scale (HY) and the Mini-Mental Sate Examination (MMSE) were obtained from each PD subject. Psychiatric or other neurological illnesses constituted exclusion criteria as Miroshnichenko et al reported ( Miroshnichenko et al, 2018 ). All subjects were free of hypothyroidism, epilepsy, drug/alcohol/nicotine abuse, and free of kidney or liver disease.…”

Program of Seven 45-min Dry Immersion Sessions Improves Choice Reaction Time in Parkinson’s Disease

“…A program of analog microgravity (μG) modeled with “dry” immersion (DI) was recently shown to reduce the scores of muscle rigidity and depression in PD ( Meigal et al, 2018 ). Furthermore, the regularity of the surface electromyogram, indicative of tremor reduction, was decreased after a single short DI session ( Miroshnichenko et al, 2018 ). Programs of common water immersion combined with exercises exerted similar beneficial effect on cognition and motion in elderly people without PD ( Kim et al, 2018 ), presumably due to more efficient cortical processing of somatosensory signals ( Sato et al, 2012 ).…”