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

Abstract

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. 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. 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. 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.