Author(s): Syrimi Z.J.; Mills R.J.; Young C.A.
Source: Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration; 2018; vol. 19 ; p. 194-195
Publication Date: 2018
Publication Type(s): Conference Abstract
Abstract:Background: Although pain worsens quality of life for patients with ALS/MND, it is an under explored aspect of the disease (1). Objective(s): To investigate in ALS/MND: 1) the prevalence and severity of neuropathic pain (NP) and whether the severity of NP was associated with age, gender or disease duration; 2) whether NP is due to confounding comorbidities that may also cause NP; and 3) which characteristics of pain contribute to overall pain severity. Method(s): 636 participants in the Trajectories of Outcomes in Neurological Conditions (TONiC) study completed a questionnaire pack, including the Neuropathic Pain Scale (NPS) and a co-morbidity inventory. Summed raw score scale data were converted to parametric data by Rasch analysis. Comparisons were made by t-test or chi-square and linear regression sought by Pearson’s rho (alpha 0.05). Result(s): Mean age was 65.1 years (SD 10.7) with mean disease duration 24.9 months (SD 34.8). 67.1% reported some element of NP (ie NPS 40), corresponding to 68.2% of males and 65.4% of females; mean NPS score was 44.9 (SD 10.5). There was no statistically significant difference in NP severity between genders or correlation with age or disease duration. There was no statistically significant difference in prevalence of NP (NPS 40) between diabetics (n=22) and non-diabetics (n=328), between B242 deficient (n=314) and non B242 deficient participants (n=17), and those with (n=18) and without thyroid disease (n=327). There was no statistically significant difference in NP severity between diabetics and non-diabetics and between those with and without thyroid disease. However, the severity of reported NP was higher in the B242 deficient population (mean difference =5.61, 95% confidence intervals=2.18-8.23, p=0.01). The highest average scores came from the “unpleasant”, “deep” and “dull” pain domains and the lowest from the “itchy”, “hot” and “sensitive” domains. Although all NPS domain scores correlated positively with total NPS score, the strongest predictors of overall NP severity were unpleasantness (R=0.73, p50.001), deep nature of pain (R=0.67, p50.001) and dullness (R=0.61, p50.001). Discussion and conclusions: NP in ALS/MND is not determined by co-morbidities, disease duration, age or gender. High scores came from deep and dull pain, which could be a manifestation of muscular pain secondary to spasticity. In a recent study 63.7% of the US general population (n=24,925) reported pain, of which 15.7% had probable neuropathic features based on PainDetect (2). In order to assess whether NP is a direct product of ALS/MND, case-control studies would be needed.