Quantitative test for sensory hand symptoms based on mechanoreceptor-specific vibrotactile thresholds

Area of Science:

• Neuroscience
• Biomedical Engineering
• Sensory Physiology

Background:

• Fingertip sensory perception relies on mechanoreceptors like Merkel disks and Meissner corpuscles.
• Assessing subtle sensory changes in the hand is crucial for diagnosing neurological and peripheral conditions.
• Existing methods for evaluating fingertip sensation may lack sensitivity or standardization.

Purpose of the Study:

• To develop and validate a novel vibrotactile test for detecting sensory symptoms in the hand.
• To correlate objective vibrotactile threshold measurements with subjective reports of pain and numbness.
• To establish statistically significant criteria for classifying vibrotactile thresholds as abnormal.

Main Methods:

• Developed a vibrotactile test based on fingertip thresholds mediated by Merkel disks and Meissner corpuscles.
• Calculated the summed normalized threshold shift (TS(Sum(SD))) by comparing individual thresholds to healthy subject means.
• Employed three statistical tests on 2x2 contingency tables to assess the association between TS(Sum(SD)) and reported symptoms.

Main Results:

• The TS(Sum(SD)) demonstrated a significant relationship with reported numbness and pain.
• Identified specific ranges of the TS(Sum(SD)) value (t) that are statistically significant for numbness (3.3≤t<3.9) and pain (3.6≤t<4.1).
• These significant ranges align with the established boundary (p≈0.05) for normal versus abnormal vibrotactile thresholds in healthy individuals.

Conclusions:

• The developed vibrotactile test provides a quantifiable and objective measure for sensory symptoms in the hand.
• The test effectively differentiates between normal and abnormal vibrotactile perception, correlating with subjective symptom reports.
• This method offers a promising tool for early detection and assessment of hand sensory dysfunction.