Can a driving simulator reveal hidden driving risks in Parkinson's and MS?

Copied word for word from the study's registry entry, so the wording is the study team's rather than ours.

Inclusion Criteria: * Age 18 to 85 years. * Ability to understand study instructions and provide written informed consent. * Valid driving license for passenger vehicles (Category B or equivalent). * Active non-professional driving of a motor vehicle. * Ability to understand the instructions and complete the standardized driving simulator assessment. For participants with multiple sclerosis: * Confirmed diagnosis of multiple sclerosis according to applicable diagnostic criteria. * Expanded Disability Status Scale (EDSS) score less than 6.5. * Clinically stable disease at the time of simulator assessment. * At least 6 weeks since the most recent multiple sclerosis relapse and any corticosteroid treatment for relapse. * Previous completion of the psychodiagnostic and screening assessment used in the preceding OP-JAK research framework (NCT07360886) within 6 months before simulator testing, provided that no clinically relevant deterioration has occurred. * Completion of the required neurological, ophthalmological, visual-field, and audiometric assessments before or on the day of simulator testing, as specified by the study protocol. For participants with Parkinson's disease: * Confirmed diagnosis of idiopathic Parkinson's disease. * Hoehn and Yahr less than stage IV in the ON-medication state. * Clinically stable condition at the time of simulator assessment. * Ability to undergo simulator testing during the best practically achievable ON-medication state. * Previous completion of the psychodiagnostic and screening assessment used in the preceding OP-JAK research framework within 6 months before simulator testing, provided that no clinically relevant deterioration has occurred. * Completion of the required neurological, ophthalmological, visual-field, and audiometric assessments before or on the day of simulator testing, as specified by the study protocol. For healthy control participants: * No known neurological disorder expected to substantially affect driving performance. * Self-reported current health status compatible with safe completion of the driving simulator assessment. * Visual and auditory function, with usual correction if applicable, sufficient to safely and validly complete the simulator assessment. Exclusion Criteria: * Acute medical or neurological deterioration that would prevent safe or valid completion of the driving simulator assessment. * Current intoxication with alcohol or other psychoactive substances. * Marked sleep deprivation, excessive fatigue, or another temporary condition that, in the judgment of the responsible study personnel, would substantially impair the ability to complete testing safely and validly. * Severe simulator sickness or current vestibular symptoms that prevent completion of simulator testing. * Clinically significant uncorrected visual or auditory impairment that prevents valid completion of the simulator assessment. Inability to understand study instructions or safely operate the driving simulator. \- Withdrawal of consent or refusal of data recording required for the study when no technically valid alternative method is available. Additional exclusion criteria for participants with multiple sclerosis: * Current multiple sclerosis relapse. * Less than 30 days since the most recent relapse or corticosteroid treatment for relapse. * EDSS score \> 6.5. Additional exclusion criteria for participants with Parkinson's disease: * Atypical parkinsonian syndrome. * Hoehn and Yahr stage \> 4 in the ON-medication state. * Deep brain stimulation in the main Parkinson's disease cohort. * Clinical condition preventing testing during a sufficiently stable ON-medication period. Additional exclusion criteria for healthy control participants: * Self-reported neurological disease or other health condition expected to substantially influence cognitive, sensory, or motor functions relevant to driving. * Current psychiatric or medical condition that would prevent safe or valid completion of the simulator assessment. * Current use of substances or medications producing an acute level of impairment incompatible with safe simulator testing.