Article

Post-stroke shoulder pain (PSSP), traditionally regarded as purely nociceptive
pain, is often persistent and the mechanisms underlying the pain complaints are
not well understood. This explorative study is the first to address the possible
changes in cortical somatosensory processing in patients with PSSP. Cortical
potentials were recorded following intracutaneous electrostimulaton in stroke
patients with chronic PSSP (n= 6), pain-free stroke patients (PF, n=14) and
healthy controls (HC, n=20) using EEG. Amplitudes and latencies of both sensory
discriminative (N90) as well as cognitive evaluative (N150, P200, the N150-P200
peak-to-peak difference and P300) evoked potential components were evaluated.
Stroke was associated with reduced N150 and P300 amplitudes and increased N90,
N150 and P300 latencies at both sides. Compared to PF and HC, the P200 and
N150-P200 latencies were increased in PSSP patients after stimulation at both
sides, even when comparing subgroups with similar lesion size and location.
Stroke was associated with reduced sensory-discriminative as well as with reduced
cognitive-evaluative cortical somatosensory processing. This reduction was more
pronounced in patients with PSSP and may be related to the central effects of
persistent nociceptive pain.

Langue : ANGLAIS