title: Dynamic oscillatory signatures of central neuropathic pain in spinal cord injury.
abstract: Central neuropathic pain (CNP) is believed to be accompanied by increased activation of the sensorimotor cortex. Our knowledge of this interaction is based mainly on functional magnetic resonance imaging studies, but there is little direct evidence on how these changes manifest in terms of dynamic neuronal activity. This study reports on the presence of transient electroencephalography (EEG)-based measures of brain activity during motor imagery in spinal cord-injured patients with CNP. We analyzed dynamic EEG responses during imaginary movements of arms and legs in 3 groups of 10 volunteers each, comprising able-bodied people, paraplegic patients with CNP (lower abdomen and legs), and paraplegic patients without CNP. Paraplegic patients with CNP had increased event-related desynchronization in the theta, alpha, and beta bands (16-24 Hz) during imagination of movement of both nonpainful (arms) and painful limbs (legs). Compared to patients with CNP, paraplegics with no pain showed a much reduced power in relaxed state and reduced event-related desynchronization during imagination of movement. Understanding these complex dynamic, frequency-specific activations in CNP in the absence of nociceptive stimuli could inform the design of interventional therapies for patients with CNP and possibly further understanding of the mechanisms involved.
  
  
  CONCLUSIONS
  This study compares the EEG activity of spinal cord-injured patients with CNP to that of spinal cord-injured patients with no pain and also to that of able-bodied people. The study shows that the presence of CNP itself leads to frequency-specific EEG signatures that could be used to monitor CNP and inform neuromodulatory treatments of this type of pain.
authors.affiliation: Biomedical Engineering Division, University of Glasgow, Glasgow, United Kingdom. Electronic address: Aleksandra.vuckovic@glasgow.ac.uk.
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Vuckovic
authors.affiliation: Biomedical Engineering Division, University of Glasgow, Glasgow, United Kingdom; Department of Biomedical Engineering, NED University of Engineering and Technology, Karachi, Pakistan.
authors.forename: Muhammad A
authors.initials: MA
authors.lastname: Hasan
authors.affiliation: Queen Elizabeth National Spinal Injuries Unit, Southern General Hospital, Glasgow, United Kingdom.
authors.forename: Matthew
authors.initials: M
authors.lastname: Fraser
authors.affiliation: Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom.
authors.forename: Bernard A
authors.initials: BA
authors.lastname: Conway
authors.affiliation: Department of Biomedical Engineering, University of Strathclyde, Glasgow, United Kingdom; Department of Biology, Northeastern University, Boston, Massachusetts.
authors.forename: Bahman
authors.initials: B
authors.lastname: Nasseroleslami
authors.affiliation: Queen Elizabeth National Spinal Injuries Unit, Southern General Hospital, Glasgow, United Kingdom.
authors.forename: David B
authors.initials: DB
authors.lastname: Allan
mesh_terms: D000293:Adolescent; D000328:Adult; D001921:Brain / Q000503:physiopathology*; D001931:Brain Mapping; D016022:Case-Control Studies; D003463:Cues; D004569:Electroencephalography; D019054:Evoked Potentials, Motor / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D009437:Neuralgia / Q000209:etiology* / Q000473:pathology*; D009460:Neurologic Examination; D017711:Nonlinear Dynamics; D010147:Pain Measurement; D010264:Paraplegia / Q000209:etiology; D013119:Spinal Cord Injuries / Q000150:complications*; D055815:Young Adult
keywords: Central neuropathic pain; electroencephalography; event-related synchronization/desynchronization; motor imagery; spinal cord injury