Multicenter cross-sectional study of the clinical features and types of treatment of spinal cord-related pain syndrome

Background: We termed chronic neuropathic pain (NeP) in patients with diseases associated with spinal cord damage as "spinal cord-related pain syndrome". We conducted a survey of patients with the syndrome to assess the type and severity of NeP and its effect on QOL, and treatment modalities.

Methods: This cross-sectional study was conducted in 185 patients recruited from 15 medical institutions. We analyzed the questionnaires sent to clinicians (basic information, magnetic resonance imaging (MRI) findings, type and effectiveness of medications) and patients [modified Neuropathic Pain Symptom Inventory (NPSI) and short form (SF)-36 healthy survey].

Results: The incidence of spinal cord-related pain syndrome was highest in patients with cervical spondylotic myelopathy, ossification of posterior longitudinal ligament (OPLL) and spinal cord injury. The number of patients with at-level pain was higher than those with below-level pain; dysesthesia/paresthesia, spontaneous and evoked pain types were mainly seen in patients with at-level pain and dysesthesia/paresthesia was common among those with below-level pain. NPSI score was higher than 10 in the majority of patients, and the subscore for dysesthesia/paresthesia was significantly the highest. The NPSI score was the highest in patients with severe hyperintense signal increase on MRI. The scores of all SF-36 sub-items were significantly lower than the national average. The majority of patients used non-steroid anti-inflammatory drugs and gabapentin/pregabalin; the latter was significantly effective for allodynia, compared with other medications, regardless of the pain level.

Conclusions: The majority of patients with spinal cord-related pain syndrome suffered from severe NeP, which affected physical activity. The pain phenotype varied according to the level of the lesion and dysesthesia/paresthesia was the most intense. Compared with other medications, gabapentin/pregabalin was significantly effective especially for dysesthesia/paresthesia and evoked pain regardless of the pain level.