A Computer-Assisted Tool for Objective Assessment of Extrapyramidal Symptoms

This prospective, single-center observational study aims to develop and validate a computer-assisted tool for the objective quantitative assessment of extrapyramidal symptoms (EPS). The study will enroll 180 participants, including 90 healthy controls and 90 participants with clinically confirmed antipsychotic-induced EPS. The healthy control group will provide reference data on normal movement, while the EPS disease group will provide data on abnormal movements associated with drug-induced parkinsonism, akathisia, or tardive dyskinesia. Each participant will complete one study visit lasting approximately 60 minutes. During the visit, a trained psychiatrist will assess EPS using the Simpson-Angus Scale (SAS), Barnes Akathisia Rating Scale (BARS), and Abnormal Involuntary Movement Scale (AIMS). Participants will also complete standardized movement tasks while a non-contact computer vision system records and analyzes movement features. The device-based assessment will be repeated after a short rest to evaluate the stability of the measurements. Data collected earlier in the study will be used to develop and optimize the assessment tool. After the algorithm is finalized and locked, data from subsequently enrolled participants will be used for independent validation. The study will evaluate how closely the tool's results agree with clinician assessments, as well as its ability to identify EPS, produce stable repeated measurements, and operate feasibly and safely in a clinical setting. This is an observational study. The study does not assign treatment, change participants' medications, or use the investigational tool to make treatment decisions.

Inclusion Criteria A. Control Group 1. Aged 18 to 80 years, with no restriction on sex. 2. No current or past history of a psychiatric disorder meeting ICD-10 or DSM-5 criteria. 3. No current or past history of central nervous system disease, such as primary Parkinson's disease or epilepsy, and no severe physical illness. 4. No use within the 3 months before screening of medications that may cause extrapyramidal symptoms, such as antipsychotics or certain antiemetic medications. 5. Sufficient visual, auditory, and cognitive ability to understand and cooperate with the standardized device-side assessment task sequence. 6. Full understanding of the purpose and exploratory research nature of the study, voluntary participation, and provision of written informed consent. B. EPS Disease Group 1. Aged 18 to 80 years, with no restriction on sex. 2. Diagnosis of schizophrenia or a related psychotic disorder according to ICD-10 criteria. 3. Regular treatment with one or more antipsychotic medications for at least 4 weeks. 4. Clinically confirmed antipsychotic-induced extrapyramidal symptoms meeting at least one of the following criteria: 1. Drug-induced parkinsonism: a total score of 2 or higher on Items 1, 2, 3, 4, 5, and 9 of the Simpson-Angus Scale (SAS). 2. Akathisia: a score of 2 or higher on the Global Clinical Assessment item of the Barnes Akathisia Rating Scale (BARS). 3. Tardive dyskinesia: a score of 3 or higher on any one of Items 1 through 7 of the Abnormal Involuntary Movement Scale (AIMS), or a score of 2 or higher on any two of these items. 5. Sufficient visual, auditory, and cognitive ability to understand and cooperate with the standardized device-side assessment task sequence. 6. Full understanding of the purpose and exploratory research nature of the study, voluntary participation, and provision of written informed consent by the participant or, where applicable, the participant's legal guardian. Exclusion Criteria The following exclusion criteria apply to both groups: 1. Primary neurological or organic movement disorders that may affect the assessment results, such as primary Parkinson's disease, Huntington's disease, Wilson's disease, or sequelae of stroke. 2. Severe musculoskeletal disease, recent fracture, limb disability, or other physical conditions that prevent completion of the required assessment tasks. 3. Acute exacerbation of psychiatric symptoms with severe agitation, impulsivity, stupor, or severe cognitive impairment that prevents safe and adequate cooperation with the assessment. 4. Severe deformity of the face or tested limbs, large dark-colored tattoos, or severe non-removable occlusion that may substantially interfere with computer-vision-based assessment. 5. Poorly fitting removable dentures or frequent compensatory oral movements that may interfere with objective assessment of orofacial movements. 6. Any condition that, in the investigator's judgment, may affect participant safety, substantially compromise data quality, or make the individual unsuitable for participation.