These findings also show that Parkinson’s patients with low back pain have a greater disability correlated with the severity of motor impairments.
Pain is a typical non-motor symptom of Parkinson’s disease, and has been regarded as one of the most troublesome. Skeletal and joint deformities are possible causes of pain in Parkinson’s patients. In particular, the lumbar region is more involved in musculoskeletal pain in these individuals.
Back pain seems to be a common and early symptom in Parkinson’s disease, and patients appear to be more often troubled by chronic low back pain, possibly due to a combination of altered posture, abnormal muscle tone, and truncal dystonia — uncontrollable muscle contractions in the trunk.
German researchers conducted an observational study to explore the association between low back pain and Parkinson’s by analyzing its prevalence, its underlying skeletal changes in the spine, and the relationship between spinal deformities and Parkinson’s-specific symptoms.
A total of 97 Parkinson’s patients at a mean age of 67.7 years, including 60 men, and 97 individuals used as controls at a mean age of 67.5 years, including six men, without the disorder or other neuromuscular diseases, filled out a questionnaire on the intensity of local lumbar back pain. The intensity of leg radicular pain — caused by inflammation and/or injury to a spinal nerve root – was quantified by the visual analogue scale (VAS) — a continuous scale used to measure pain intensity.
In addition, the participants’ permanent functional disability was assessed via the Oswestry Low Back Pain Disability Questionnaire (ODI) — a self-completed questionnaire that includes 10 different topics: intensity of pain, lifting, ability to care for oneself, ability to walk, ability to sit, sexual function, ability to stand, social life, sleep quality, and ability to travel.
Patients were further asked to describe the painful sensation they experience as pricking, tingling, burning, paresthesia — often described as feelings of pins and needles, or numbness — or other.
The team also assessed Parkinson’s duration, medications being used, severity of motor symptoms — as assessed by the Unified Parkinson’s disease rating scale part III (UPDRS III) — and the Hoehn and Yahr (H&Y) stage, which is a system used to assess symptom progression.
Low back pain was significantly more frequent (87.6%) and lasted longer (16 years) in Parkinson’s patients than in controls (64.9%, 11.8 years). Additionally, in patients with low back pain, the pain was more frequently (87.3%) located in the lumbar region compared with controls with low back pain. Lumbar pain intensity was also higher in Parkinson’s patients.
No differences were found on radicular leg pain frequency and intensity. The distribution of participants describing the sensation they felt as pain, pricking, tingling, burning, paresthesia or other was also not different between Parkinson’s patients and controls. Functional disability was also not different between the two groups.
According to the ODI results, minimal disability was reported by 43.8% of Parkinson’s patients, moderate disability by 27.5%, severe disability by 22.5%, and “crippled” by 6.3%.
Parkinson’s patients with or without low back pain did not differ in disease duration, H&Y stage, UPDRS III motor score, or medications. Higher ODI scores correlated with higher (worse) H&Y stages and UPDRS motor scores.
Patients with hypokinetic Parkinson’s — slow or reduced movement — experienced higher intensities of lumbar and radicular pain than those with tremor.
Fifty-four patients with low back pain had an X-ray of the lumbar spine. Of these, 43 (79.6%) showed arthritic changes, 21 (38.8%) had scoliosis — curvature of the spine — and 13 (24.1%) had spondylolisthesis, which refers to slippage or displacement of one vertebra.
Of the 85 Parkinson’s patients with low back pain, 20 (23.5%) were being treated by an orthopedic specialist, nine of whom had lumbar spine surgery, four received local injections or infiltrations, and seven were continuously treated with oral pain medications. The low number of patients undergoing surgery reflects the difficult surgical management of Parkinson’s patients with spinal deformities, according to the researchers.
Of the 63 controls with low back pain, 24 (38%) received orthopedic treatment. This greater percentage of treated controls compared with Parkinson’s patients supports the previous characterization of low back pain as an underestimated issue in the disease, the scientists observed.
“[Low back pain] and lumbar degeneration are common in [Parkinson’s disease]. Both are related to movement disorder symptoms. The knowledge about musculoskeletal conditions in Parkinson’s disease is important for an interdisciplinary conservative or operative treatment decision of [low back pain],” the researchers concluded.