NEUROPATHIC PAIN

Pain arising as a direct consequence of a lesion or disease affecting the somatosensory system

Treede et al. Neurology 2008

Neuropathic pain

Pain usually results from activation of nociceptive afferents by actually or potentially tissue damaging stimuli. Pain may also arise by activity generated within the nervous system without adequate stimulation of its peripheral sensory endings. For this type of pain, the IASP introduced the term neuropathic pain.

Kennedy et al 2007

THE ROLE OF SKIN BIOPSIES IN THE DIAGNOSIS OF PERIPHERAL PAINFUL NEUROPATHIES

C. Sommer, University of Wuerzburg, Wuerzburg, Germany.

(…) the correlation between measures of skin innervation and functional data, including pain, is poor, such that additional factors must play a role.

Some patients with severe burning pain of the extremities have reduced skin innervation, which is normal in others.

Among the factors that may play a role are central sensory pathways, local inflammatory cells and mediators, and further variables on the patient side.

IN PERIPHERAL PAINFUL NEUROPATHIES THE CORRELATION BETWEEN SKIN INNERVATION

AND PAIN IS POOR

Fields 1987

PAINFUL NEUROPATHIES

POSITIVEBIOPSY

Distal axonal damage

Death of sensory ganglion neurons

NEGATIVE BIOPSY

Proximal axonal damage

No axonal damage