Symptom-based characteristics and treatment efficacy of neuropathic pain related to spinal disorders.

ABSTRACT

BACKGROUND: Symptom-based therapeutic management is required for neuropathic pain (NeP) to achieve higher treatment efficacy. In spinal disorders, which have a high prevalence of NeP, neurological symptoms are classified into myelopathy, radiculopathy, and cauda equina syndrome. The characteristics of pain and the treatment efficacy for each of these symptoms require clarification. METHODS: A retrospective patient-based outcome study was conducted in 265 outpatients with chronic NeP (≥3 months) related to spinal disorders. The patients were classified into three groups according to their neurological symptoms spinal cord-related pain, radicular pain, and cauda equina syndrome. Data were obtained from patient-based questionnaires using the Neuropathic Pain Symptom Inventory (NPSI) and the Brief Scale for Psychiatric Problems in Orthopaedic Patients (BS-POP), and from clinical information. RESULTS: Most of the patients with NeP had a NPSI score >10 (moderate to severe pain) and 40% had psychiatric problems. The common subtype of NeP was spontaneous pain and paresthesia/dysesthesia in patients with radicular pain and cauda equina syndrome, whereas more severe paresthesia/dysesthesia was particularly prominent in patients with spinal cord-related pain. The pain reduction rate was significantly lower in these latter patients, especially in association with residual paresthesia/dysesthesia. CONCLUSIONS: The characteristics and treatment efficacy of NeP in patients with spinal disorders varied according to neurological symptoms. Effective treatment was difficult, especially for paresthesia/dysesthesia in patients with spinal cord-related pain. These findings enhance the understanding of the underlying mechanisms of pain and could help in design of symptom-based therapeutic management.