Central neuropathic pain in paraplegia alters movement related potentials

Abstract

Objectives: Spinal Cord Injured (SCI) persons with and without Central Neuropathic Pain (CNP) show different oscillatory brain activities during imagination of movement. This study investigates whether they also show differences in movement related cortical potentials (MRCP).

Methods: SCI paraplegic patients with no CNP (n = 8), with CNP in their lower limbs (n = 8), and healthy control subjects (n = 10) took part in the study. EEG clustering involved independent component analysis, equivalent current dipole fitting, and Measure Projection to define cortical domains that have functional modularity during the motor imagery task.

Results: Three domains were identified: limbic system, sensory-motor cortex and visual cortex. The MRCP difference between the groups of SCI with and without CNP was reflected in a domain located in the limbic system, while the difference between SCI patients and control subjects was in the sensorimotor domain. Differences in MRCP morphology between patients and healthy controls were visible for both paralysed and non paralysed limbs.

Conclusion: SCI but not CNP affects the movement preparation, and both SCI and CNP affect sensory processes.

Significance: Rehabilitation strategies of SCI patients based on MRCP should take into account the presence of CNP.

Keywords: Central neuropathic pain; Event related potentials; Measure projection analysis; Motor imagery; Movement related cortical potentials; Spinal cord injury.