Study design: Case report of a 42-year-old woman with non-evoked pain diagnosed with a cavernous C7-Th6 spinal haemangioma.
Objectives: To assess the effect of intramedullary haemorrhage (IH) on nociception and neuropathic pain (NP) at and below an incomplete spinal cord injury (SCI).
Setting: Sensorimotor Function Group, Hospital Nacional de Parapléjicos de Toledo (HNPT).
Methods: T2*-susceptibility weighted image (SWI) magnetic resonance imaging (MRI) of spinal haemosiderin and a complete pain history were performed 8 months following initial dysaesthesia complaint. Thermal pain thresholds were assessed with short 1 s stimuli, while evidence for central sensitization was obtained with psychophysical electronic Visual Analogue Scale rating of tonic 10 s 3 °C and 48 °C stimuli, applied at and below the IH. Control data were obtained from 10 healthy volunteers recruited from the HNPT.
Results: Non-evoked pain was present within the Th6 dermatome and lower legs. T2*-SWI MRI imaging detected extensive haemosiderin-rich IH (C7-Th5/6 spinal level). Cold allodynia was detected below the IH (left L5 dermatome) with short thermal stimuli. Tonic thermal stimuli applied to the Th6, Th10 and C7 dermatomes revealed widespread heat and cold allodynia.
Conclusion: NP was diagnosed following IH, corroborated by an increase in below-level cold pain threshold with at- and below-level cold and heat allodynia. Psychophysical evidence for at- and below-level SCI central sensitization was obtained with tonic thermal stimuli. Early detection of IH could lead to better management of specific NP symptoms, an appreciation of the role of haemorrhage as an aggravating SCI physical factor, and the identification of specific spinal pathophysiological pain mechanisms.