Multimodal Artificial Intelligence Based Fall Risk Prediction in Parkinson's Disease

The Mini-BESTest is a 14-item balance assessment tool designed to evaluate dynamic balance, including postural responses, sensory orientation, and dynamic gait. The final section allows for assessment of dual-task performance within the context of a mobility test involving cognitive load. Each item is scored on a scale from 0 to 2, where 0 indicates inability to complete the task and 2 indicates normal performance. The maximum total score is 28. It is a unidimensional measure that takes approximately 15 minutes to complete and is considered valid and reliable for use in individuals with Parkinson's disease.

This test evaluates the ability to step over obstacles in multiple directions. At the start, the participant stands in the top left square (Square 1) and faces Square 2. The stepping sequence begins clockwise through Squares 2, 4, and 3, and then continues counterclockwise through Squares 3, 4, 2, and back to 1. The clinician demonstrates the sequence, and the participant is allowed to practice. If the participant fails to complete the sequence correctly, loses balance, or touches the aid, the test is repeated. Two trials are performed, and the best time is recorded. Timing begins when the leading foot contacts Square 2 and ends when the trailing foot returns to Square 1.

During this test, participants' stepping and changing direction movements will be recorded on video.

This test consists of two components: forward and backward digit span. Each section begins with short sequences of numbers that gradually increase in length. Numbers are read aloud at a consistent pace, and the participant repeats them in order. If the participant fails two consecutive trials in either direction, the test is discontinued. The total number of correctly repeated digits in the last successful trial is recorded as the span score.

This task measures phonemic verbal fluency. Participants are instructed to generate as many words as possible beginning with specific letters (e.g., F, A, S) within one minute per letter. Proper nouns and derivatives are excluded. The total score is the sum of all valid words generated across the letters.

Mental flexibility is evaluated through a serial subtraction task involving backward counting from 100 in sevens, stopping at 65. For individuals with limited education who are unable to perform this task, an alternative version involving reciting the days of the week in reverse order is used. One point is awarded for each correct response in both formats.

This 10-item questionnaire assesses the frequency of difficulties experienced during daily dual-task activities. Participants respond on a 5-point scale ranging from "never" to "very often" or "not applicable." The final score is calculated by summing the individual item scores and dividing by ten, yielding an average difficulty score.

Gait parameters are evaluated using Kinovea® motion analysis software. The system provides quantitative analysis of spatiotemporal and kinematic aspects of walking. A camera positioned in the sagittal plane records a 3-meter walk, with colored markers placed on both heels to facilitate tracking. Parameters such as step length and stride length are analyzed based on heel strike sequences extracted from the recorded video.

This simple and widely used test assesses mobility, balance, and fall risk. The participant is instructed to rise from a standard chair, walk three meters, turn around, return to the chair, and sit down. The total time to complete the sequence is recorded using a stopwatch. TUG is performed under both single-task and dual-task conditions. Cognitive dual-tasks include counting backwards by threes or reciting the days of the week in reverse. Motor dual-tasks include passing a ball between hands or carrying a glass of water. Dual-task cost will be calculated using the following formula:

(Single-task time - Dual-task time) / Single-task time × 100

Quality of life is assessed using a disease-specific self-report scale. It consists of multiple domains including mobility, daily activities, emotional well-being, social support, cognition, and communication. Each item is scored using a five-point Likert scale. The total score ranges from 0 to 100, with higher scores indicating lower perceived quality of life.