Pain in patients with motor neuron disease: Variation of pain and association with disease severity, health-related quality of life and depression - A longitudinal study.

Objectives: To describe levels of pain over time during disease progression in individual patients and for a total sample of patients with motor neuron disease (MND), respectively, and to examine associations between pain, disease severity, health-related quality of life (HRQOL), and depression.
Methods: A prospective cohort study was conducted on 68 patients with MND, including data collected on five occasions over a period of 2 years. Pain was assessed using the Brief Pain Inventory - Short Form. Depression was assessed using the Amyotrophic Lateral Sclerosis (ALS)-Depression-Inventory (ADI-12). Disability progression was measured using the Amyotrophic Lateral Sclerosis Functional Rating Scale - Revised Version (ALSFRS-R). HRQOL was assessed using the Amyotrophic Lateral Sclerosis Assessment Questionnaire (ALSAQ-5).
Results: Participants reported great individual variation over time. The median level of pain was 4 (min 0 and max 10). Higher levels of pain during the last 24 h were associated with higher depression scores (ADI-12), poorer quality of life (ALSAQ-5), and lower reporting of fine and gross motor skills (ALSFRS-R). Baseline pain levels did not predict future values of depression and function. Individuals reporting average pain >3 experienced more hopelessness toward the future and reported higher depression scores compared with participants reporting average pain <3.
Significance of Results: Great within-individual variation of pain intensity was reported. Pain intensity was associated with depression, function and HRQOL cross-sectionally, but it did not have a strong prognostic value for future depression, function, or HRQOL. Patients with MND should be offered frequent assessment of pain and depressive symptoms in person-centered care, allowing for individualization of treatment.