PAIN-MODULATION (ASCENDING PATHWAYS)

SUMMARY

FUNCTION
1. Lateral spinothalamic (neospinothalamic) system: sensory-discriminative dimensions.
2. Medial spinothalamic (paleospinothalamic) system: motivational- affective & cognitive-evaluative dimensions of the pain experience.

PROJECTION
3. Lateral spinothalamic: projects to the ventral posterolateral (VPL) and ventral posteromedial (VPML) thalamic nuclei before projecting to the somatosensory and premotor cortices.
4. Medial spinothalamic: medial thalamic nuclei & limbic cortices, which include the anterior cingulate gyrus, orbito-frontal cortex, and amygdala.

TARGET AREAS
5. The medial system involves important connections with periaqueductal gray: modulates nociceptive inhibition & behavioral responses to potentially threatening stimuli.
6. Anterior cingulate gyrus: regulates avoidance behaviors & the perception of pain unpleasantness.

Reference(s)

Cifu, D.X. (2020). Braddom’s physical medicine and rehabilitation. Elsevier. Get it on Amazon.
Cuccurullo, S. (2019). Physical medicine and rehabilitation board review. New York: Demosmedical. Get it on Amazon.
O’Young, B., Young, M.A. and Stiens, S.A. (2008). Physical Medicine and Rehabilitation Secrets. Mosby. Get it on Amazon.