Demographic and clinical characteristics of patients with functional motor disorders: the prospective Salpêtrière cohort

Abstract

Functional motor disorders (FMD) are common and disabling. They are known to affect predominantly women and to start at young or middle age but to date, large case series are lacking, and demographic and clinical characteristics of patients with FMD rely on data from small cohorts. The aim of the current study was to describe demographic and clinical characteristics of these patients. Methods: We prospectively collected data from FMD patients who were referred to the Neurophysiology Department of the Pitie-Salpetriere University Hospital between 2008 and 2016 for treatment with repeated transcranial magnetic stimulation. Results: 482 patients were included. There was a majority of women (73.7%) with a median age of 40 years old at TMS treatment. Median age at the onset of the symptoms was 35.5 years old and symptoms were mostly characterized by an acute (47.3%) or subacute (46%) onset. Only 23% of patients were active workers while 58.3% were unemployed for medical reasons. Half of the patients referred for TMS treatment suffered from functional motor weakness (n= 241) and the other half suffered from movement disorders (n=241), mainly represented by tremor (21.15%) and dystonia (20.5%). Regarding psychiatric comorbidities, 33.6% had no psychiatric comorbidity and 17.4% reported no history of trauma. No significant differences were found according to clinical phenotypes. Conclusion: We present the largest cohort of patients with FMD published to date. This cohort will contribute to a better understanding of FMD risk factors.

Functional movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases

“…Despite its prevalence, the basic epidemiology of FMD is unclear. With some exceptions,3–6 large-scale epidemiological data are limited due to presentation heterogeneity, as most studies are smaller case series describing specific phenotypes. It is unknown whether different FMD phenotypes are associated with differences in age at onset (eg, whether functional parkinsonism is more common in older individuals) or if certain phenotypes exhibit gender differences (eg, the reported higher incidence of functional axial myoclonus in men) 7.…”