Sensory function in spinal cord injury patients with and without central pain

• Published in: Brain (London, England : 1878) Vol. 126; no. 1; pp. 57 - 70
• Main Authors: Finnerup, N. B., Johannesen, I. L., Fuglsang‐Frederiksen, A., Bach, F. W., Jensen, T. S.
• Format: Journal Article
• Language: English
• Published: Oxford Oxford University Press 01-01-2003; Oxford Publishing Limited (England)
• Subjects: Adult; allodynia; ASIA = American Spinal Injury Association; Biological and medical sciences; Case-Control Studies; central pain; dorsal column function; Evoked Potentials, Somatosensory; Female; Humans; Hyperesthesia - etiology; Injuries of the nervous system and the skull. Diseases due to physical agents; Male; Medical sciences; neuronal hyperexcitability; Neurons - physiology; NRS = numeric rating scales; Pain - etiology; Pain - physiopathology; Pain - psychology; Pain Threshold; QST = quantitative sensory testing; SCI = spinal cord injury; Sensory Thresholds; SEP = sensory evoked potential; Spinal Cord Injuries - complications; Spinal Cord Injuries - physiopathology; Spinal Cord Injuries - psychology; spinothalamic function; Temperature; Traumas. Diseases due to physical agents; VAS = visual analogue scales; Vibration; Human; Nervous system diseases; Spinal cord; central pain; Pathophysiology; dorsal column function; Trauma; allodynia; Pain; neuronal hyperexcitability; Central nervous system disease; spinothalamic function; Spinothalamic bundle; Spinal cord disease
• ISSN: 0006-8950; 1460-2156
• DOI: 10.1093/brain/awg007

Spinal cord injury (SCI) frequently results in neuropathic pain. However, the pathophysiology underlying this pain is unclear. In this study, we compared clinical examination, quantitative sensory testing (QST) and somatosensory evoked potentials (SEPs) in SCI patients with and without pain below spinal lesion level, with a control group of 20 subjects without injury. All patients had a traumatic SCI with a lesion above T10; 20 patients presented with spontaneous central neuropathic pain below lesion level, and 20 patients had no neuropathic pain or dysaesthesia. Patients with and without pain had a similar reduction of mechanical and thermal detection and pain thresholds, and SEPs. SCI patients with central pain more frequently had sensory hypersensitivity (brush‐ or cold‐evoked pain, dysaesthesia or pinprick hyperalgesia) in dermatomes corresponding to lesion level than SCI patients without pain. There was no difference in intensity of pain evoked by repetitive pinprick at lesion level between patient groups. There was a significant correlation between intensity of brush‐evoked dysaesthesia at lesion level and spontaneous pain below lesion level of SCI. These data suggest that lesion of the spinothalamic pathway alone cannot account for central pain in SCI patients, and that neuronal hyperexcitability at injury or higher level may be an important mechanism for pain below injury level.