Modified Ashworth scale and spasm frequency score in spinal cord injury: reliability and correlation

Abstract

Study design: Intra-and inter-rater reliability study. Objectives: To assess intra-and inter-rater reliability of the Modified Ashworth Scale (MAS) and Spasm Frequency Score (SFS) in lower extremities in a population of spinal cord-injured persons, as well as correlations between the two scales. Setting: Clinic for Spinal Cord Injuries, Rigshospitalet, Hornbaek, Denmark. Methods: Thirty-one persons participated in the study and were tested four times in total with MAS and SFS by three experienced raters. Cohen's kappa (κ), simple and quadratic weighted (nominal and ordinal scale level of measurement), was used as a measure of reliability and Spearman's rank correlation coefficient for correlation between MAS and SFS. Results: Neurological level ranged from C2 to L2 and American Spinal Injury Association impairment scale A to D. Time since injury was (mean ± s.d.) 3.4 ± 6.5 years. Age was 48.3 ± 20.2 years. Cause of injury was traumatic in 55% and non-traumatic for 45% of the participants. Antispastic medication was used by 61%. MAS showed intra-rater κ simple = − 0.11 to 0.46 and κ weighted = − 0.11 to 0.83. Inter-rater κ simple = − 0.06 to 0.32 and κ weighted = 0.08 to 0.74. SFS showed intra-rater κ weighted = 0.94 and inter-rater κ weighted = 0.93. Correlation between MAS and SFS showed non-significant correlation coefficients from − 0.11 to 0.90. Conclusion: Reliability of MAS is highly affected by the weighting scheme. With a weighted-κ it was overall reliable and simple-κ overall unreliability. Repeated tests should always be performed by the same rater and in a very standardized manner. SFS was found reliable. MAS and SFS are poorly correlated, and ratings were inversely distributed and suggest that it assesses different aspects of spasticity.

Characterization of Involuntary Contractions after Spinal Cord Injury Reveals Associations between Physiological and Self-Reported Measures of Spasticity

“…This may explain why significant associations between physiological and self-report measures have not been reported here or previously. Since our self-report data matched published data (83% of our participants experienced muscle spasms, 75% reported increased muscle tone, high spasm frequency strongly associated with severe spasms; Figure 6 ; Kawamura et al, 1989 ; Little et al, 1989 ; Lechner et al, 2006 ; Baunsgaard et al, 2016 ), and many people with SCI describe their muscle spasms when asked about spasticity (Mahoney et al, 2007 ), our EMG results reinforce that individuals with SCI likely use spasms and/or tone to rate their spasticity.…”

“…For example, individuals with spasticity had either pronounced or absent reciprocal inhibition but there was no difference in the degree of their spasticity when it was assessed clinically (tone, tendon reflexes, clonus; Crone et al, 1994 ). Self-reported spasm frequency scores correlated poorly with clinical assessment of perceived resistance against passive movement of the limb (i.e., tone using the modified Ashworth scale) or tendon reflexes (Priebe et al, 1996 ; Baunsgaard et al, 2016 ).…”

Exoskeleton gait training after spinal cord injury: An exploratory study on secondary health conditions

“…Furthermore, its use is recommended by the National Institute of Neurological Disorders and Stroke (NINDS) Common Data Element (CDE) (36). In a previous study, we found the MAS to be reliable, assuming that the scale is considered as an ordinal scale (37). The sum-score of MAS used in the analysis is not validated, but a similar approach with a sum-score of spasticity has been used previously (25).…”

Inherited Ataxia and Intrathecal Baclofen for the Treatment of Spasticity and Painful Spasms

“…The high frequency of painful spasms in patients was an important indication for the ITB pump implantation. The modified Ashworth spasticity scale and PSFS are well known scales for evaluating spasticity and spasm frequency in patients with other chronic neurologic disorders such as spinal cord injury and MS [30, 31]. …”