Effect of therapeutic exercise on pain intensity in individuals with diseases of the central nervous system: integrative review

Silva, Alanna Letícia Santos; Abner, Thiago dos Santos Sousa; Azevedo-Santos, Isabela Freire

doi:10.63231/2595-0118.20250004-pt

home Sumário navigate_before Anterior Atual Seguinte navigate_next

home Sumário

REVIEW ARTICLE • BrJP 8 • 2025 • https://doi.org/10.63231/2595-0118.20250004-en linkcopy

Effect of therapeutic exercise on pain intensity in individuals with diseases of the central nervous system: integrative review

Authorship SCIMAGO INSTITUTIONS RANKINGS

ABSTRACT

BACKGROUND AND OBJECTIVES Pain is a common condition in people with diseases of the central nervous system and affects up to two thirds of patients with spinal cord injury, amyotrophic lateral sclerosis, cerebral palsy and, less frequently, stroke. The search for therapeutic methods, such as physical exercise, that can identify and mitigate pain in this population is essential. In order to integrate therapeutic planning and, consequently, improve treatment, the aim of this study was to analyze the effectiveness of physical exercise in reducing pain in people with diseases of the central nervous system.

METHODS The search was carried out by a reviewer in the databases: Cochrane Library, Google Scholar (first 100 results), LILACS, PeDro, Pubmed Scielo, Scopus and Web of Science. Clinical trials published up to September 2023 were included, with no language restrictions. Selection of studies and data extraction were carried out by a reviewer using a spreadsheet with the relevant variables for preparing the review.

RESULTS After analysis, 16 articles were eligible. The studies in this review recruited 966 individuals. Most of them showed a significant reduction in pain intensity when global muscle training (strengthening and stretching) was carried out compared to control groups.

CONCLUSION Various modalities of physical exercise can be an effective intervention method for the treatment of pain in patients with central nervous system diseases. However, studies investigating this outcome are currently still limited.

Keywords:
Central nervous system diseases; Pain; Physical exercise

HIGHLIGHTS

Pain is a common condition in people with central nervous system diseases and affects up to two thirds of individuals with spinal cord injury, amyotrophic lateral sclerosis, cerebral palsy and, less frequently, stroke

The search for a resolution to the pain, often neglected, even though is frequent, is essential, especially in people with neurological diseases

Physical exercise can be an effective intervention method for the treatment of pain in patients with central nervous system diseases

Authors	Objectives	Sample	Variables	Evaluation tools	Intervention	Main results
Atan et al.¹¹	Evaluate the effects of different percentages of treadmill training with body weight support on gait, balance, quality of life and fatigue in PD.	30 patients divided into 3 groups: conventional treadmill training (n=10), treadmill training with 10% support (n=10) and with 20% support (n=10).	Gait: assessment of PD, balance; quality of life (including the pain variable); fatigue.	6-minute walking test: Berg balance scale; UPDRS I, II and III; Turkish version of the Nottingham health profile (including items referring to pain); fatigue impact scale; fatigue severity scale.	All participants received 30 min of conventional rehabilitation, including ROM, stretching, strengthening and balance exercises, followed by 30 min of treadmill training with body weight support, 5 days/week, for 6 weeks.	UPDRS III scores were significantly lower in the groups with 10% to 20% body weight support. Nottingham Health Profile pain scores at week 6 increased significantly in the group with no support (p=0.019), while they decreased in the 10% and 20% supported groups (p=0.003 and p=0.002, respectively) compared to baseline.
Drory et al.¹²	To determine the effect of moderate regular exercise under guidance on parameters of motor deficit, disability, fatigue, musculoskeletal pain and perceived QoL.	25 patients with ALS or probability of ALS, divided into two groups: one was instructed to exercise (n=14) and the other was instructed not to perform any physical activity beyond the usual needs of daily life (n=11).	Muscle strength; spasticity; disability; fatigue; pain; QoL.	Manual muscle strength test; Ashworth spasticity scale; functional classification scale; fatigue severity scale; VAS; SF-36. The evaluation was carried out at the beginning and after 3, 6, 9 and 12 months.	Exercise Group: list of exercises involving most of the muscle groups of the 4 limbs and trunks. The program was developed for each patient individually, considering their general state of health and level of fitness, lasting 15 minutes, 2x/day at home.	All patients in both groups presented a marked worsening during the follow-up period and the drop-out rate was high, hindering statistical analysis. In patients in both groups, reported pain intensity increased over time. There was no effect of exercise on pain complaints.
Gandolfi et al.¹³	Main: compare the effects of a trunk rehabilitation program on the severity of forward trunk flexion in patients with PD. Secondary: compare the effects of training on the Unified Classification of PD.	37 patients randomly assigned to the experimental group - EG (n = 19) or control group - CG (n=18). Two patients in the EG and one in the CG discontinued the interventions.	Change in degrees of forward trunk flexion, changes in UPDRS III, static and dynamic balance, pain and QoL; assessed before treatment (T0), two days after completion (T1) and one month after completion (T2).	Measurement of degrees of forward trunk flexion; UPDRS III; Numerical Pain Scale (NPS); number of falls; Parkinson's Disease Questionnaire-8 (PDQ-8); Single-axis electronic platform; Mini BESTest.	EG: active self-correction exercises with visual exercises, proprioceptive feedback and no feedback; trunk stabilization exercises and functional tasks. CG: joint mobilization, muscle strengthening and stretching, gait and balance exercises (duration 4 weeks, 60 min/day, 2x/week). Three sessions were carried out as “self-practice” at the patients' homes and monitored by the physiotherapist via phone calls.	The reduction in forward trunk flexion and improvement in dynamic and static balance were significantly greater in the EG than in the CG. Overall, both groups showed a significant reduction in pain from T0 to T2 (EG: p=0.001; CG: p<0.001).
	· Motor subscale of the scale (UPDRS III), dynamic and static balance, pain, falls and QoL.

Gee et al.¹⁴	Main: compare the effects of an exercise bike for the upper limbs and treadmill training with body weight support on QoL and intermediate variables in individuals with spinal cord injury.	28 participants divided into two groups. Group 1: exercise bike for upper limbs (UL) Group 2: treadmill training with body weight support.	Quality of life; physical activity during leisure-time; pain; affect; self-efficacy to perform aerobic exercise; independence to manage self-care, respiratory and sphincter needs and mobility; participation and autonomy.	LISAT-9; SWLS; LTPAQ-SCI; SF-36 2-item pain subscale; PANAS; 10-item questionnaire; SCIM version III, IPAQ.	Participants were randomized to one of the groups and took part in 3 exercise sessions a week for 6 months, for a total of 72 sessions. All exercise sessions were carried out in hospital research institutes or in a university exercise program. Participants completed either 30 min/session of moderate to vigorous intensity UL cycling or 60 min/session of body weight supported treadmill training, in which participants were suspended above a treadmill using a body weight support system and volunteers assisted with passive locomotion. The 2 protocols were matched for exercise volume, calculated as the product of the duration of each session and the perceived exertion ratings of the session.	There was a significant interaction effect for the pain subscale, in which pain was significantly lower in the UL bicycle exercise group throughout the intervention compared to treadmill training with body weight support (p = 0.022). The analysis showed that after 72 sessions with the UL exercise bike, pain was significantly lower compared to baseline (p = 0.092).
Gee et al.¹⁴	Secondary: examine correlations between initial measurements and changes in physical activity, QoL and intermediate variables.
Hicks et al.¹⁵	Examine the effects of 9 months of physical training on strength, arm ergometry performance and indices of psychological well-being and QoL in people with spinal cord injury.	34 individuals with traumatic spinal cord injury	Arm ergometry performance; muscle strength; perceived stress; depression; physical self-concept; pain; perceived health; QoL.	Workloads on an arm ergometer; Maximum load that could be lifted in one repetition (1RM) on both limbs for the bench press, elbow flexion and shoulder flexion maneuvers; Perceived stress scale; Center for Epidemiological Studies Depression Scale; Body Satisfaction Questionnaire; SF-36 2-item pain subscale; SF-36 self-reported health transition subscale; Perceived Quality of Life Scale.	EG: supervised progressive training, including a warm-up and gentle stretching of the UL and resistance training, using pulley exercises on the wall, free weights and a weight machine (twice a week, lasting 90 to 120 minutes). CG: a bimonthly education session (together with the EG) on topics such as exercise physiology for people with spinal cord injury, osteoporosis after spinal cord injury and relaxation techniques.	The participants in the EG reported significantly less pain (p<0.01), stress and depression after training, and scored higher than the CG in the indices of satisfaction with physical function, level of perceived health and general QoL (p<0.05).
Macêdo et al.¹⁶	Evaluate the impact of a home exercise program on pain intensity and QoL in individuals with tropical spastic paraparesis.	56 people with tropical spastic paraparesis classified as definite or probable. 49 completed the 24 weeks of the study (Supervised Group = 15, Unsupervised Group = 10 and Control Group = 11).	Pain and quality of life.	SF-36 and BPI.	Supervised Group: exercise protocol, supervised by a physiotherapist (2x/week, 45 to 50 min, for 12 weeks). Unsupervised Group: clarification from the physiotherapist on how to carry out the exercise protocol and practice the exercises every other day independently, guided by a booklet (24 weeks, at home); Control Group: maintenance of usual care (diet, pharmacological treatment, physiotherapy treatment) without changes during the study period.	Although no significant changes were shown after the exercise program, when the expression “worst pain experienced in the last 24 hours” was analyzed by the BPI, the Supervised Group showed increased intensity between the first and second evaluations (p=0.25), while the Control Group showed worsening pain between the second and third evaluations (p=0.12) and the Non-Supervised Group maintained the value in all three evaluations (p=0.43). There was also no significant differences in the “average pain” of inflammatory bowel disease between the three groups. From a clinical point of view, however, a 33% difference in pain improvement was observed between the Non-Supervised Group (p=0.69) and the Control Group (p=0.58), while the Supervised Group (p=0.78) showed only a 20% reduction in pain.
Mulroy et al.¹⁷	Main: investigate the effect of a home exercise program + instructions to optimize the performance of UL tasks on shoulder pain in people with spinal cord injury. Secondary: determine the impact of the intervention on physical activity and participation and to identify whether the improvement in pain or function was maintained 4 weeks after the end of the intervention.	80 individuals with paraplegia due to spinal cord injury and shoulder pain, divided into two groups. Group 1 (n=40): movement/exercise optimization. Group 2 (n=40): attention control intervention.	Shoulder pain, muscle strength (ability to generate force), activity and quality of life.	Wheelchair user shoulder pain index; VAS; dynamometer; propulsion speed over a distance of 25 meters; physical activity scale for individuals with physical disabilities; social interaction inventory; QoL questionnaire, SF-36 and QoL scale.	Home-based program of shoulder strengthening and stretching exercises, with recommendations on how to optimize the movement technique of transfers, lifts and wheelchair propulsion (12-week duration). The attention Control Group watched a 1-hour educational video emphasizing shoulder anatomy, injury mechanisms and general concepts of shoulder pain management.	Shoulder pain intensity was reduced in the immediate post-intervention assessment in Group 1 to approximately one third of the baseline values (from 51.2±33.0 to 14.9±14.0, p<.001), but remained unchanged in the Control Group (from 45.4±38.8 to 45.6±38.2). According to the VAS, shoulder pain intensity was also reduced to a third of baseline values in Group 1 (from 5.1±2.8 to 1.4±1.6, p<.001), but was not significantly reduced in the Control Group (from 4.7±2.7 to 4.2±27).
Nightingale et al.¹⁸	Assess the influence of a home exercise intervention on health-related QoL in people with spinal cord injuries.	24 individuals with chronic (>1 year) spinal cord injury below the second thoracic level, divided into two groups: Control Group (n=8) and Exercise Group (n=16).	Physical QoL; emotional QoL; number of years with QoL; fatigue severity; global fatigue; shoulder pain; exercise self-efficacy.	SF-36 physical and mental index; Quality of Life Adjusted in Years (QALY); Fatigue Severity Scale (FSS); Wheelchair User's Shoulder Pain Index (WUSPI); Exercise Self-Efficacy Scale (ESES).	IG: moderate-intensity exercise on a portable tabletop ergometer set up in their own home (4x/week for 6 weeks). CG: instructed to maintain their usual physical activity behavior.	The intervention improved health-related quality of life scores in individuals with spinal cord injury. Although there was a small negative effect of the intervention on shoulder pain, there was no significant interaction (p= 0.386) and the mechanistic inference was unclear, suggesting that the intervention had no significant effect on pain perceptions.
Pérez-de la Cruz¹⁹	To apply 2 physiotherapy protocols to test the effect on the intensity of pain in the lower limbs (LL), balance and quality of life in patients with PD.	30 individuals diagnosed with PD, divided into 2 groups: Experimental Group (n=15) and Control Group (n=15).	Pain intensity, balance, gait and PD assessment.	VAS; BERG: Berg Balance Scale; FTSTS: 5x sit and stand test; Tinetti scale; TGUG: Timed Get Up and Go test; UPDRS: Unified PD Rating Scale.	Ground therapy (Control Group): supervised group training; aquatic Ai Chi: group intervention carried out by a physiotherapist specializing in clinical Ai Chi. Twenty sessions were held 2x/week for 10 weeks.	EG: significant differences in the reduction of post-treatment pain intensity (p<0.001), as well as in the variables related to static and dynamic balance, with the exception of FTSTS. CG: improvements were observed only in the reduction of pain intensity, and were less significant than the changes found in the Experimental Group (p=0.006).
Pérez-de la Cruz²⁰	Determine the 12-week effect of 3 treatment proposals on pain, gait and balance in patients with chronic stroke.	40 patients diagnosed with CVA, divided into 3 groups: ground therapy (n=14), aquatic therapy (n=13) and combined therapy (n=13).	Pain intensity, balance, gait and LL strength.	VAS; Tinetti test; 360° turn test; balance test in unipodal support; sit and stand test for 30 seconds.	Ground therapy (Control Group): supervised group training, lasting 45 minutes, twice a week, for a period of 12 weeks; aquatic Ai Chi (Experimental Group): therapy carried out by a physiotherapist with experience in neurological rehabilitation and certified in Ai Chi, lasting 45 minutes, twice a week, for a period of 12 weeks; Combined therapy: alternating joint sessions of floor therapy (Monday and Wednesday, totaling 12 sessions) and aquatic Ai Chi therapy (Tuesday and Thursday, totaling 12 sessions).	The aquatic therapy and combined therapy groups showed significant improvements at the end of treatment in the variables of pain, balance, gait and LL strength (p<0.001), and these improvements were maintained over time in the VAS (reduction in mean score), Tinetti scale (increase in mean score), 360° turn test (reduction in mean score) and the 30-second sit and stand test (increase in mean score). No differences were found between the values obtained in the Control Group (ground therapy) throughout the measurements.
Pérez-de la Cruz¹⁹	Evaluate the effects of 12 weeks of treatment with aquatic Ai Chi sessions, dry therapy or combined therapy (aquatic therapy and dry therapy) on pain, depression and quality of life in people diagnosed with CVA.	41 CVA patients, divided into 3 groups: ground therapy (n=15), aquatic therapy (n=13) and combined therapy (n=13).	Pain, resilience and QoL.	VAS; Resilience Scale; SF-36 Quality of Life Scale.	Ground therapy (Control Group): sessions lasting 45 minutes, twice a week, for a period of 12 weeks; aquatic Ai Chi (Experimental Group): therapy carried out by a physiotherapist specializing in clinical Ai Chi, with the same number of sessions as the Control Group and lasting 45 minutes; combined therapy: ground physiotherapy sessions and aquatic Ai Chi were alternated under the same conditions as the participants in the other groups, thus receiving the sum of the therapies from the other two groups.	In the Experimental Group, significant differences were found in terms of reduced pain intensity on the VAS scale and higher scores on the resilience scale (p < 0.001). A greater variation was observed in the groups that received aquatic interventions (Ai Chi and combined therapy). These changes were more significant in the post-intervention measures.
Schmid et al.²¹	Evaluate the change in physical functioning after 8 weeks of yoga-therapy in people with chronic stroke.	People with chronic CVA (n=47) randomized to yoga therapy (n=37) or control care care in a 2:1 ratio (n=10).	Pain; ROM; strength; endurance.	PEG (3-item functional pain measure), derived from the BPI; Goniometer; Arm flexion test; Sit and stand test for 30 sec; 6 min walk (Senior Fitness Test item); Modified 2 min step test.	The therapeutic yoga sessions were held in a group of no more than 10 people, lasting 1 hour, twice a week, for 8 weeks (16 sessions). A standardized and progressive protocol was developed which included modified yoga postures, breathing,	Individuals randomized to yoga had a significant improvement in multiple variables (bilateral neck ROM, passive hamstring ROM, UL strength and increased distance walked in 6 min). Pain improved significantly after 8 weeks of yoga (12.2 vs. 8.9, p = 0.004).
Schmid et al.²¹					and relaxation in the sitting, standing and supine positions. Participants in the waiting list Control Group received no intervention.
Topcuoglu et al.²²	Investigate the clinical, functional and psychosocial effects of upper extremity aerobic exercise (arm ergometry) and to compare the effect of aerobic exercise with that of conventional physiotherapy in patients with complex regional pain syndrome type 1 after CVA.	40 patients with hemiplegia associated with a cerebrovascular event that occurred at least 1 month and 6 months before the study, as well as a diagnosis of complex regional pain syndrome on the hemiplegic side.	Motor level; spasticity; pain; level of independence; depressive mood.	Brunnstrom staging; modified Ashworth scale; VAS; Functional Independence Measure (FIM); Nottingham Health Profile (NHP); Beck Depression Scale.	TENS (100 Hz, 20 min/day, cold compress (20 min/day), retrograde massage and contrast baths. Medical treatment involved standard NSAIDs drugs. 20 of the 40 patients received only the standard conventional physiotherapy program. The other 20, in addition to this program, also performed exercises accompanied by arm ergometry (5 days/week, 30 min/day, for 4 weeks). A physiotherapy program for AVE consisting of therapeutic, neurophysiological, postural, balance and coordination and ADL was applied to all patients.	In the Upper Limb Aerobic Exercise Group, patients reported significant pain relief (89.9%) and a significant decline in CRPS signs and symptoms. The mean change between the groups with regard to a reduction in shoulder pain, hand pain, as well as in the NHP scores and Beck depression scale scores, which indicated a reduction in pain, fatigue and depression were statistically significant (p<0.05).
Tseng et al.²³	Evaluate the effect of a ROM exercise program aimed at improving joint flexibility, activity function, pain perception and depressive symptoms in a sample of stroke survivors.	59 patients with hemiplegia for 6 months or more since the CVA, divided into 3 groups: Special Care Group (n=17), Intervention Group I (n=21) and Intervention Group II (n=21).	Functional independence, joint angle, self-reported pain and depression.	FIM™ ADL subscale; joint angle measurements in 6 joints + self-perceived pain; Chinese version of the FIM™.	G1 intervention: protocol of ROM exercises supervised by a nurse; G2 intervention: same ROM protocol with the presence of a nurse to help them physically achieve maximum ROM; Special Care Group: did not receive any extra ROM exercises beyond the institution's routine. The intervention groups completed the protocol five times per joint (6 in total), 2x/day and 6 days/week, for 4 weeks, with each session lasting approximately 10 to 20 minutes.	The average pre- and post-intervention scores for pain increased by 5.41 in the usual care group and decreased by an average of 7.62 in Intervention Group I, and decreased by 10.00 in Intervention Group II.
Tseng et al.²³				Geriatric Depression Scale - Short Form (GDS-15).		Intervention Group I, and decreased by 10.00 in Intervention Group II. A comparison of the changes in pre- and post-intervention scores between the three groups showed a statistically significant difference (p<0.001).
Wagner et al.²⁴	Evaluate the effectiveness of physiotherapy using a tablet compared to usual care on QoL and other health-related parameters.	230 patients with idiopathic PD who were taking part in a 3-week multimodal treatment (n=93 for IG and n=137 for CG).	QoL, participation restrictions; fear of falling; sleep disorders; anxiety/depression; comorbidity; pain; performance capacity; physical activity.	Parkinson's Disease Questionnaire (PDQ-8 German version); IMET; Falls Efficacy Scale International Version (FES-I); German version of the Parkinson's Disease Sleep Scale (PDSS-2); short version of the Patient Health Questionnaire (PHQ-4); modified version of the Sangha comorbidity questionnaire; 5-point scale; Performance capacity in the domains of work, daily life and leisure was quantified using numerical scales from 0 to 10; Physical activity was measured using the instrument used by Mensink in the 1999 Federal Health Survey; Pain assessment: individual items (Questions on pain in the Federal Health Survey 98 questionnaire).	IG: tablet app with verbal instructional videos and explanations for all the exercises taught in the multimodal treatment for Parkinson's. CG: usual therapy services of the multimodal treatment and, after discharge, the usual outpatient treatment. A The actual nine-month intervention began after discharge from the clinic. Patients were asked to train using the program for up to 3x/week, in addition to their usual outpatient therapy. therapy. These exercises are available in different degrees of difficulty and promote endurance, strength and balance.	Both the IG and CG achieved significant improvements at the end of treatment. There were only significant differences in the group comparisons for the variables FES-I, PHQ-4 total score and PHQ depression (scores decreased, p<0.01). With regard to pain, no significant changes were observed. There was a worsening in both groups in almost all the primary and secondary outcome variables in the anamnesis. However, this worsening was less pronounced in theIG than in the CG.
Zhao et al.²⁵	develop a seated Tai Chi program for subacute stroke survivors and examine its effects.	160 participants divided into two groups.	Upper limb (UL) function; balance control; sitting balance control; depressive symptoms; shoulder ROM; shoulder pain; activities of daily living (ADL; QoL.	Fugl-Meyer assessment of the upper extremity and Wolf motor function test; Berg balance scale; Trunk Impairment Scale; Geriatric Depression Scale Short Form; Shoulder Q; Modified Barthel Index; CVA-specific quality of life scale.	IG: Wheelchair-adapted Tai Chi series offered for stroke survivors with mild weakness (UL muscle strength: 4 or 5). A registered nurse and a qualified Tai Chi master developed the series to meet the needs of stroke survivors with hemiparesis or hemiplegia UL muscle strength: ≤3). The demonstration of the movements was recorded by the Tai Chi master in video form. Caregivers were involved to ensure the safety of the participants and to supervise the practice. Adherence to the treatment protocol between the 2 sites (home and rehabilitation hospitals) was ensured by adherence to the participant handbook and phone call reminders. CG: UL movements recommended by the hospital.	The results revealed significant improvements in UL function in the domains of execution time and functional capacity of the Wolf motor function test (T2, T3 and T4), depression (T2, T3 and T4), balance control (T3 and T4), sitting balance control (T2, T3 and T4), shoulder extension (T2 and T3), shoulder external rotation (T4), internal rotation (T4), ADL (T2, T3 and T4) and QoL (T2, T3 and T4) in the Intervention Group compared to the Control Group (all P<0.05). No significant differences were found between groups at T3 in UL function (Fugl-Meyer assessment of the upper extremity) shoulder flexion, shoulder abduction and shoulder pain (p>0.05).

vertical_align_top show_chart

more_horiz close
- image
- translate
- link
- article
- vertical_align_top
- file_download
- show_chart
- image
- translate
- link
- article

location_on

Sociedade Brasileira para o Estudo da Dor Av. Conselheiro Rodrigues Alves, 937 Cj2 - Vila Mariana, CEP: 04014-012, São Paulo, SP - Brasil, Telefones: , (55) 11 5904-2881/3959 - São Paulo - SP - Brazil
E-mail: dor@dor.org.br

rss_feed Acompanhe os números deste periódico no seu leitor de RSS

[1] PD: Parkinson's disease; QoL: quality of life; ALS: amyotrophic lateral sclerosis; VAS: Visual Analogue Scale; NSAIDs: non-steroidal anti-inflammatory drugs; LL: lower limbs; UL: upper limbs; CVA: cerebral vascular accident; ADL: activities of daily living; LISAT-9: Life-Satisfaction Questionnaire-9; SWLS: Satisfaction with Life Scale; LTPAQ-SCI: Leisure Time Physical Activity Questionnaire for People with Spinal Cord Injury; SF-36: Medical Outcomes Short-Form 36-Item Health Survey; PANAS: Positive and Negative Affects Scale; SCIM: Spinal Cord Independence Measure version III; IPAQ: Impact on Participation and Autonomy Questionnaire; UPDRS: Unified Parkinson's Disease Rating Scale; ROM: range of motion; IG: intervention group; CG: control group; FTSTS: 5x sit and stand test; TGUG: Timed Get Up and Go test; WUSPI: Wheelchair User's Shoulder Pain Index; ESES: exercise self-efficacy scale; FSS: exercise self-efficacy scale; PEG: Patient-Reported Experience of Cancer Pain; CRPS: Complex Regional Pain Syndrome; PDQ-8: Parkinson's Disease Questionnaire; FES-I: Falls Efficacy Scale International Version; PDSS-2: Parkinson's Disease Sleep Scale; PHQ-4: short version of the Patient Health Questionnaire.