Spatiotemporal integration of sensory stimuli in complex regional pain syndrome and dystonia

Abstract

The aetiology of dystonia in complex regional pain syndrome (CRPS-I) is incompletely understood. In primary dystonia, somatosensory-evoked potentials (SSEP) after spatially or temporally separated stimulation revealed impaired central sensory integration. Information on somatosensory processing in dystonia in CRPS-I patients may provide better insight into the underlying pathophysiological mechanism. We studied SSEPs in 33 patients with CRPS-I and dystonia and 19 healthy controls. N9, N14, N20 and N35 amplitudes were recorded after paired stimulation of median and ulnar nerves (''spatial'') and after stimulation of both nerves with single stimuli and with interstimulus intervals of 20 and 40 ms (''temporal'' stimulation). Finally, both methods were integrated resulting in spatiotemporal stimulation. Statistical testing was performed using linear mixed model analysis of variance. SSEP amplitudes were significantly suppressed after spatial and temporal stimulation. No difference was observed between patients and healthy controls. Spatiotemporal stimulation did not show an additional suppressive effect in any group. Central sensory integration of proprioceptive afferent input is normal in patients with CPRS-related dystonia. Other mechanisms may underlie the development of dystonia in this disorder.

Somatosensory Misrepresentation Associated with Chronic Pain: Spatiotemporal Correlates of Sensory Perception in a Patient following a Complex Regional Pain Syndrome Spread

“…However, some MEG studies did show a stronger response in S1 to stimulation of the affected compared to the unaffected hand (16). In comparison to healthy controls, no differences were reported so far (14, 16, 17). In summary, if at all, only small changes in amplitude and topographical representation can be expected in CRPS patient’s sensorimotor cortex when comparing affected and non-affected hemisphere responses to tactile stimulation.…”

“…Contralateral spread is twice as likely as ipsilateral, and diagonal spread is rather rare (17). There is a strong body of evidence showing changed functional organization of the primary sensory cortex associated with CRPS [reviewed in Ref.…”

Spinal cord stimulation for complex regional pain syndrome type 1 with dystonia: a case report and discussion of the literature

“…Indeed, Van Rijn et al 22 found no differences in somatosensory-evoked potentials (SSEP) in CRPS-1 patients with dystonia compared to healthy controls after spatio-temporal stimulation (confirming the integrity of “cortical proprioceptive afferent processing”). In relation to our case report, we would like to highlight the role of small nerve fibers in CRPS (C and Aδ).…”

Imaging and Clinical Evidence of Sensorimotor Problems in CRPS: Utilizing Novel Treatment Approaches

“…Oaklander and colleagues (2009) hypothesised that these dystonias could be caused by small and large fibre neuropathies. However, sensory integration of proprioceptive afferent input has been found to be normal (Van Rijn et al 2009) thus ruling out large nerve fibre involvement. More recent work by Munts and colleagues (2011) suggests that dystonias in CRPS arise from problems in peripheral control of muscle force.…”