Mechanical and thermal hyperalgesia in patients with poliomyelitis

ObjectiveParalytic poliomyelitis (pPM) is clinically suspected in individuals experiencing a non-progressive syndrome of flaccid paralysis and atrophy as a sequel of an acute infection. Despite normal sensory perception, patients with pPM complain of pain more than matched siblings. Here, we studied the characteristics of evoked pain in a cohort of pPM patients using contact heat evoked potentials and psychophysical tests.MethodsFifteen patients with pPM and 15 controls were studied. Inclusion criteria were unilateral or asymmetric involvement of lower extremities. Mechanical, warm and heat pain perception thresholds and evoked pain were measured in both thighs. Contact heat evoked potentials were recorded from the vertex.ResultsMechanical and heat pain thresholds were significantly lower in the affected than in the less-affected leg or in the legs of controls. Evoked pain ratings were significantly higher in the affected leg than in either the less-affected leg or in controls. Evoked potentials were significantly higher in the affected than in the less-affected leg.ConclusionPatients with pPM have mechanical and thermal hyperalgesia, which suggests abnormalities in processing of somatosensory inputs in these patients.SignificanceThis phenomenon should be taken into account in the routine clinical evaluation and management of pPM patients.

► Evoked pain perception and contact heat evoked potentials are abnormal in some patients with paralytic poliomyelitis. ► Alteration in the processing of somatosensory inputs in pPM may contribute to further understanding the mechanisms underlying pain in clinical practice. ► Hyperalgesia should be taken into account in the routine clinical evaluation and management of patients with pPM.