Objectives: Pain is common in patients with multiple
sclerosis, but its underlying mechanism is still unclear, thus
limiting the development of effective treatment. In this
prospective clinical and neurophysiological study we sought
information on the clinical characteristics and underlying
mechanism of neuropathic pain related to multiple sclerosis.
Materials and methods: 296 patients with multiple
sclerosis were screened for neuropathic pain. 8 patients had
trigeminal neuralgia, 15 dysesthesic pain and 18 Lhermitte’s
sign. All patients with neuropathic pain underwent clinical
examination and neurophysiological testing. In patients
with dysesthesic pain and Lhermitte’s sign we recorded
somatosensory evoked potentials, mediated by Aβ nonnociceptive
fibres, and laser evoked potentials, mediated by
Aδ nociceptive fibres.
Results: While in patients with dysesthesic pain laser
evoked potentials were more frequently abnormal than
somatosensory evoked potentials we found the opposite in
patients with Lhermitte’s sign (p<0.001, Chi-squared test).
Discussion: Neurophysiological tests show that while
dysesthesic pain is associated to nociceptive pathway
damage, Lhermitte’s sign is related to damage of nonnociceptive
pathways.
Conclusion: These data may be useful in designing a new
therapeutic approach to neuropathic pain related to multiple
sclerosis.
|
||||||||||||||||||||||||||||||||||||||||||
|
|
||||||||||||||||||||||||||||||||||||||||||
