Background: Spasticity is a common symptom in multiple sclerosis (MS) that increases the burden of disease. This study investigated the relationship between the degree of spasticity and patients' health-related quality of life (QoL).

Methods: Epidemiological, multicentre, cross-sectional study in patients with MS spasticity. The SF-12 questionnaire was used to assess QoL. The modified Ashworth scale and a 0-10 Numerical Rating Scale (NRS) were used to assess spasticity severity.

Results: Data were analysed for 409 MS patients with spasticity from 53 neurology clinics in Spain. Mean age was 46.4 (±11.0) years; 62.4% were women. Most patients had relapsing-remitting MS (42.1%) or secondary progressive MS (43.9%). Mean time since MS diagnosis was 12.5 (±7.4) years and mean time since first spasticity symptoms was 6.1 (±4.8) years. A total of 71.3% of patients were being treated pharmacologically for spasticity. Moderate to severe spasticity was measured in 59.2% of patients according to the modified Ashworth scale and in 83.4% according to the NRS. Mean scores for the 0-100 Physical Component Summary and Mental Component Summary subscales of the SF-12 questionnaire were 31.0 (±9.3) and 45.4 (±12.0), respectively. Scores on the SF-12 correlated significantly with scores on both spasticity scales ( p ≤ 0.002) but the correlation was stronger with the NRS across all domains.

Conclusions: The results confirm an association between spasticity severity and QoL in patients with MS. The correlation between 0-10 NRS scores and QoL was stronger than that between modified Ashworth scale scores and QoL.