Somatosensory Disturbance and Long-Term Exposure to Methylmercury: A Comprehensive Review

Chronic exposure to methylmercury remains a significant public health concern, particularly in populations with high fish consumption. Somatosensory disturbances are among the most frequently reported neurological manifestations, even at exposure levels below internationally established safety thresholds. This review aims to synthesize current evidence on somatosensory disturbances associated with long-term methylmercury exposure in human populations. This comprehensive review findings from human studies investigating clinical, psychophysical, and neurophysiological aspects of somatosensory function in populations chronically exposed to methylmercury. Relevant literature was identified through searches in major scientific databases, and studies were selected based on their relevance to the topic. The reviewed studies consistently report distal, symmetrical somatosensory impairments, commonly described as a glove-and-stocking pattern. Psychophysical assessments demonstrate altered tactile, vibration, and thermal perception, while neurophysiological investigations reveal cortical and peripheral sensory dysfunctions. The evidence indicates that chronic methylmercury exposure is associated with clinically relevant somatosensory disturbances. These findings highlight the importance of incorporating somatosensory assessment into the clinical evaluation and surveillance of populations at risk.