Is tactile acuity altered in individuals with acute mechanical neck pain?

Abstract

Background: Tactile acuity measured by point discrimination (TPD) refers to the precision by which we can sense touch. An increase in TPD threshold (loss of tactile acuity) is considered suggestive of disruptions to S1 cortical maps of that specific body part. In some chronically painful conditions, reduced tactile acuity is a manifestation of Central sensitization (CS). The other symptoms include hyperalgesia and allodynia due to repeated activation of spinal nociceptors. A recent study has shown that tactile acuity is affected in individuals with chronic neck pain. While there seems to be adequate evidence stating that tactile acuity is reduced in individuals with chronic pain, CS may not be limited to chronic pain states. There is a paucity of literature with respect to the tactile acuity of a person with acute neck pain. A measurement of tactile acuity of the affected body area in acute pain, may suggest the extent of the altered threshold of sensory discriminative aspect of pain experience. Objectives: To compare the two-point discrimination over C7 spinous process between the symptomatic individuals with mechanical neck pain and age matched healthy controls. Methods: 30 individuals with mechanical neck pain & 30 age matched normals were assessed for two point discrimination using mechanical calipers, The two sharp points of the caliper were vertically placed against the skin surface over C7 spinous process, commencing with 5mm, which was stretched out till the subject appreciated the two points. Values were noted down in millimeters. Results: An independent t – test showed a significant difference in the two point discrimination between the 2 groups (P < 0.000). Conclusion: It can be concluded that individuals with acute mechanical neck pain demonstrated a change in tactile acuity.