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

Abstract

The study hypothesis held that in subjects with Parkinson’s disease (PD), the reaction time (RT) tests of the higher cognition demand would have more readily improved under the program of analog microgravity (μG) modeled with “dry” immersion (DI). To test this hypothesis, 10 subjects with PD have passed through a program of seven DI sessions (each 45 min long) within 25–30 days, with overall μG dose 5 1/4 h. Five patients were enrolled as controls, without DI (noDI group). Simple RT (SRT), disjunctive RT (DRT), and choice RT (CRT) were assessed in four study points: before the DI program (preDI), 1 day after the DI program (postDI), 2 weeks after the DI program (DI2w), and 2 months after the DI program (DI2m). The motor time (MT) was assessed with the tapping test (TT). Additionally, signal detection time (SDT) and central processing time (CPT) were extracted from the data. Before the program of DI, the RT tests are in accordance with their cognition load: SRT (284 ± 37 ms), DRT (338 ± 38 ms), and CRT (540 ± 156 ms). In accordance with the hypothesis, CRT and DRT have improved under DI by, respectively, 20 and 8% at the study point “DI2w,” whereas SRT, SDT, and MT did not change (<5% in the preDI point, p > 0.05). Thus, the program of DI provoked RT improvement specifically in the cognitively loaded tasks, in a “dose of cognition-reaction” manner. The accuracy of reaction has changed in none of the RT tests. The neurophysiologic, hormonal/neuroendocrine, behavioral, neural plasticity, and acclimation mechanisms may have contributed to such a result.

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

“…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). However, these positive effects do not translate to quality of life and activity of daily living, or body balance (Meigal et al, 2018(Meigal et al, , 2021a).…”

Gait Characteristics Analyzed with Smartphone IMU Sensors in Subjects with Parkinsonism under the Conditions of “Dry” Immersion

“…Their anthropometric and clinical data and the medication they use is presented in Table 1 . All of them are from the same cohort of subjects who participated in our earlier studies [ 7 , 8 , 9 , 10 ]. The data on gait characteristics presented in this article were obtained from these studies.…”

“…The on-Earth microgravity was modeled using the conditions of a “dry” immersion (DI). This method of DI has already been presented in detail in our earlier papers [ 7 , 8 , 9 , 10 ]. In brief, the condition of DI was created with the help of MEDSIM (Medical simulator of weightlessness, Center for Aerospace Medicine and Technology, IMBP, Moscow, Russia), which is housed in the Laboratory of Novel Methods in Physiology (Petrozavodsk State University).…”

“…Earlier, we have shown that in subjects with PD that both single session of Earth-based microgravity—modeled with “dry” immersion conditions (DI) [ 7 ]—and a program of repeated DI sessions [ 8 ] attenuates muscle rigidity and tremors and improves some aspects of activity of daily living. Additionally, some motor-cognition tests [ 9 ] and characteristics of hemodynamics and heart rate variability were improved after a program of DI sessions [ 10 ]. On the other hand, the function of a patient’s spatial orientation in a vertical stance and the function of postural transition proved non-responsive to the condition of DI [ 7 ].…”

“…Among them are optical motion trackers, biopotential devices, audio and video recording, and, especially, wearable sensors, such as smart glasses, hats, insole sensors of ground-reaction force and smartphones [ 22 ]. Previously, we evaluated the effect of DI on PD subjects with conventional laboratory tools (EMG, reaction time, tapping test, posturography) [ 7 , 8 , 9 , 10 ].…”