Digital Image Speckle Correlation (DISC): Facial Muscle Tracking for Neurological and Psychiatric Disorders

Area of Science:

• Biomedical Engineering
• Clinical Diagnostics
• Neurology

Background:

• Quantitative assessment of facial muscle function and cognitive responses is crucial for diagnosing and monitoring neuromuscular and psychiatric disorders.
• Traditional clinical evaluations can be subjective; objective, quantitative methods are needed to enhance diagnostic accuracy and treatment monitoring.
• Digital Image Speckle Correlation (DISC) offers a potential non-invasive technique for analyzing facial biomechanics and response times.

Purpose of the Study:

• To explore the application of Digital Image Speckle Correlation (DISC) for detecting facial muscle enervation and assessing cognitive responses.
• To evaluate DISC's utility in monitoring recovery in a patient with Bell's palsy.
• To assess DISC's ability to correlate facial motion dynamics with psychiatric conditions and treatment response in a patient with depression and anxiety.

Main Methods:

• Facial movements were captured using a consistent video recording setup in response to visual stimuli.
• The DISC method was employed, analyzing the displacement of natural skin pores to map underlying muscular movement and quantify facial asymmetry and reaction times.
• The technique was applied to a patient with Bell's palsy and a patient with refractory depression and anxiety disorders undergoing ketamine treatment.

Main Results:

• DISC provided high spatial and temporal resolution of facial muscle activity, accurately mapping biomechanical properties.
• The Bell's palsy patient showed a decrease in facial asymmetry from nearly 100% to 20% over one month, indicating recovery.
• The patient with depression and anxiety exhibited prolonged reaction times (518 ms vs. 275 ms control) and reduced response rates, correlating with self-reported symptom severity.

Conclusions:

• Digital Image Speckle Correlation (DISC) is a valuable tool for quantitative assessment of facial muscle function and cognitive responses.
• DISC enhances clinical monitoring of neuromuscular disorders like Bell's palsy and psychiatric conditions such as depression and anxiety.
• The findings suggest DISC can complement traditional clinical examinations and subjective self-reported measures, offering objective data for improved patient management.