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

German G Miroshnichenko; Alexander Yu Meigal; Irina V Saenko; Liudmila I Gerasimova-Meigal; Liudmila A Chernikova; Natalia S Subbotina; Saara M Rissanen; Pasi A Karjalainen

doi:10.3389/fnins.2018.00667

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

Front Neurosci. 2018 Sep 26:12:667. doi: 10.3389/fnins.2018.00667. eCollection 2018.

Authors

German G Miroshnichenko¹, Alexander Yu Meigal², Irina V Saenko³, Liudmila I Gerasimova-Meigal⁴, Liudmila A Chernikova⁵, Natalia S Subbotina⁶, Saara M Rissanen¹, Pasi A Karjalainen¹

Affiliations

¹ Biosignal Analysis and Medical Imaging Group, Department of Applied Physics, Faculty of Science and Forestry, University of Eastern Finland, Kuopio, Finland.
² Laboratory for Novel Methods in Physiology, Institute of High-Tech Biomedical Solutions, Petrozavodsk State University, Petrozavodsk, Russia.
³ Laboratory of Gravitational Physiology of Sensorimotor System, Department of Sensorimotor Physiology and Countermeasure, Institute of BioMedical Problems, Russian Academy of Sciences, Moscow, Russia.
⁴ Department of Human and Animal Physiology, Physiopathology, Histology, Petrozavodsk State University, Petrozavodsk, Russia.
⁵ Department of Neurorehabilitation and Physiotherapy, Research Center of Neurology, Russian Academy of Medical Sciences, Moscow, Russia.
⁶ Department of Neurology, Psychiatry, and Microbiology, Petrozavodsk State University, Petrozavodsk, Russia.

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.

Keywords: auto-mutual information; determinism; dry immersion; electromyogram; microgravity; nonlinear dynamics; parkinsonism; rehabilitation.