A Simplified Version of the Psychogenic Movement Disorders Rating Scale: The Simplified Functional Movement Disorders Rating Scale (S‐FMDRS)

Abstract

Background The Psychogenic Movement Disorders Rating Scale (PMDRS) has potential as a useful objective assessment in clinical research, but the current scale has limitations. We developed a simplified version (S‐FMDRS) and assessed inter‐rater reliability, concurrent validity, and sensitivity. Methods Fifty‐two videos of subjects with functional (psychogenic) movement disorders (FMD) were rated according to the PMDRS and S‐FMDRS by three neurologists. Inter‐rater reliability was assessed using intraclass correlation coefficient (ICC). Agreement of symptomatic body regions and movement disorder classification was assessed using Light's kappa. Spearman's correlation coefficient was used to assess concurrent validity. A physiotherapist also rated videos on the S‐FMDRS. The simplified scale was piloted in a feasibility study of physiotherapy for FMD to assess sensitivity. Results ICC of total scores was 0.84 for the original scale and 0.85 for the simplified scale. Light's kappa for agreement of symptomatic body regions and movement disorder classification was moderate to low. Concurrent validity was demonstrated by Spearman's correlation between the two scales ranging from 0.84 to 0.95. The simplified scale was sensitive to change, with an effect size in the feasibility study of 0.79. Inter‐rater reliability between physiotherapist and neurologist was high (ICC 0.85). Discussion Both versions of the scale had good inter‐rater reliability for the total score. Low agreement on movement disorder classification and identification of symptomatic body regions support our argument for a simplified scale. Conclusions The S‐FMDRS has high inter‐rater reliability and good sensitivity to change. Further psychometric evaluation is warranted.

Speech, language and swallowing impairments in functional neurological disorder: a scoping review

“…() and Nielsen et al . (), however, do not comment on what ‘speech’ means or which parameters should be rated. Nielsen et al .…”

“…Nielsen et al . () tested their scale with physiotherapists as raters because they highlight that these healthcare professionals are those who treat the patients, as opposed to the diagnosing neurologist. It is these professionals, therefore, who will require the rating scales in order to measure outcomes of treatment.…”

“…The inclusion of a speech section on standardized rating scales for FND suggests that speech is considered an important and common enough factor in the presentation of functional disorders to warrant rating. The scales developed by Hinson et al (2005) and Nielsen et al (2017a), however, do not comment on what 'speech' means or which parameters should be rated. Nielsen et al (2017a) tested their scale with physiotherapists as raters because they highlight that these healthcare professionals are those who treat the patients, as opposed to the diagnosing neurologist.…”

“…The scales developed by Hinson et al (2005) and Nielsen et al (2017a), however, do not comment on what 'speech' means or which parameters should be rated. Nielsen et al (2017a) tested their scale with physiotherapists as raters because they highlight that these healthcare professionals are those who treat the patients, as opposed to the diagnosing neurologist. It is these professionals, therefore, who will require the rating scales in order to measure outcomes of treatment.…”

Prepulse inhibition of the blink reflex is abnormal in functional movement disorders

“…We recorded the predominant motor symptom type and all additional motor symptoms. The Simplified Functional Movement Disorders Rating Scale (s‐FMDRS) was used to assess functional motor disorder severity of both abnormal movements and weakness . Seventeen patients reported presence of sensory symptoms (hyperesthesia, dysesthesia, or paresthesia) in some body part; however, no patient had sensory deficits (hypoesthesia) in the right upper limb where the prepulse stimulus was applied.…”