NEUROPATHIC PAIN-HYPERALGESIA & ALLODYNIA

SUMMARY

1. Studies have shown that sensory hypersensitivity precedes the development of neuropathic pain conditions, e.g. after spinal cord injury.

2. In peripheral neuropathic pain, early hyperaesthesia has been found to increase the likelihood of persistent pain, e.g. after surgery.

TYPES OF ALLODYNIA & HYPERALGESIA
3. Dynamic mechanical allodynia evoked by light touch, extends beyond the primary hyperalgesic area, may be mediated through through large myelinated (Aβ) or unmyelinated, low-threshold mechanosensitive afferents.

4. Punctate allodynia and hyperalgesia evoked by punctate skin stimulation with a pin or monofilament (400 mN), extends beyond the primary hyperalgesic area,driven by activity in Aδ fibres and a minor input from C fibres.

5. Static allodynia and hyperalgesia provoked by pressure to skin or deep tissue, mediated by sensitised peripheral nociceptors.

Reference(s)

Jensen, T.S. and Finnerup, N.B., 2014. Allodynia and hyperalgesia in neuropathic pain: clinical manifestations and mechanisms. The Lancet Neurology, 13(9), pp.924-935.

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.