BACKGROUND: Postural instability and gait abnormalities are cardinal features in Parkinson's disease (PD). It represents one of the most disabling symptoms in the advanced stages of the disease.

The purpose of this study was to evaluate the immediate and long-term effects of adding computer-based cognitive training to physical therapy interventions on postural stability, locomotion, and cognitive performance in Parkinson's disease patients.

Study design: A randomized control clinical trial among sixty-eight Egyptian Parkinson's Disease patients of both sexes participated in the study; their ages ranged from 55 to 70 years. They were selected from the Neurology Clinics and from the Movement Disorder Clinic, Neurology Department, Faculty of Medicine, Cairo University, in the period from May 2024 to March 2025.

The patients will be divided into two equal groups: the control group (GA) and the study group (GB). Patients in GA will be treated by a designed physiotherapy program consisting of aerobic exercise on a treadmill, stretching exercises, proprioceptive neuromuscular facilitation (PNF) techniques, graduated active exercises, gait training, reciprocal, and weight-shifting exercises for 60 minutes. Patients in (GB) will be treated with computer-based cognitive training using REHACOM (30 minutes) in addition to the same physiotherapy program as GA (30 minutes). Rehacom software will be used for cognitive training targeting four main cognitive domains; attention/concentration, figural memory, auditory response control, and visual response control. . The treatment session for all patients in both groups will be 60minutes/session. The whole treatment protocol will include 24 sessions, three sessions per week, for two successive months.

Primary Outcomes:

1. Postural stability:

   - Biodex balance system was used to assess dynamic balance indices ( Overall stability index, mediolateral stability & anteroposterior stability)

2. Spatio-temporal gait parameters:

   • Digital video camera and kinovea (video motion analysis software) was used to assess spatiotemporal gait parameters (Stride length, velocity & Cadence).

Secondary Outcome:

a. Overall cognitive functions:

- Parkinson's Disease - Cognitive Rating Scale (PD-CRS).

Inclusion Criteria:

• Egyptian Parkinson's Disease patients of both sex , all patients fulfilled the U.K Parkinson's Disease Brain Bank Criteria for diagnosis of idiopathic PD.
• The patients' age ranged from 58 to 68 years.
• The duration of illness ranged from two to five years.
• The severity of the disease ranged from mild to moderate disability according to UPDRS motor scores (part III) and Modified Hoehn and Yahr staging (stage 2.5&3) .
• Cognitive function ranged from 65 to 81 according to Parkinson's Disease-Cognitive Rating Scale (PD-CRS) that indicates mild cognitive impairment.
• The patients with mild balance and gait impairments
• Medically and psychologically stable patients and of adequate cardiac function to adhere to the protocol.

Exclusion Criteria:

• Patients with secondary parkinsonism (Drug-induced, post traumatic, or post infectious) or atypical parkinsonism.
• Patients with major language disturbance, severe physical, auditory or visual impairment affecting their ability to complete testing.
• Patients with magnetic devices or any other implanted device (e.g., metallic implants such as pacemakers, surgical aneurysm clips…etc).
• Patients with a history of seizure, head injury or brain surgery.
• Complicating or unstable cardiovascular disease (unstable angina, recent myocardial infarction within the last three months, congestive heart failure, significant heart valve dysfunction, or unstable hypertension) or pulmonary disorders.
• Patients with musculoskeletal disorders such as severe arthritis, knee surgery, total hip joint replacement, lower limb fractures or contractures of fixed deformity.
• Patients with evidence from the history, physical examination, or special investigations for any concomitant medical or metabolic illness known to affect cognition e.g. cerebrovascular stroke, thyroid or parathyroid disease, hepatic or renal failure.
• Patients receiving certain drugs known to improve cognition (e.g. rivastigmine, memantine…..etc).
• Patients with current or prior history of major psychiatric disorder and/or current use of anxiolytic, neuroleptic, sedative medication or sleeping aids.
• Uncooperative patients.
• Illiterate patients.

Patients participated will be masked about the type of intervention, where (GA) patients will receive PT program for 60 minutes, while patients in (GB) will receive computer -based REHACOM cognitive training (30 minutes) in addition to the same PT program as (GA)(30 minutes).