Functional movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases. Issue 6 (25th February 2022)

• Record Type: Journal Article
• Authors: Lidstone, Sarah C.; Costa-Parke, Michael; Robinson, Emily J.; Ercoli, Tommaso; Stone, Jon
• Other Names: author non-byline.; Ahmad Omar author non-byline.; Akbaripanahi Sepideh author non-byline.; Albanese Alberto author non-byline.; Aybek Selma author non-byline.; Baizabal-Carvallo José Fidel author non-byline.; Beek Peter J. author non-byline.; Bhatia Kailash P. author non-byline.; Cabreira Verónica author non-byline.; Carson Alan J. author non-byline.; Castagna Anna author non-byline.; Dale Russell C. author non-byline.; Dallocchio Carlo author non-byline.; Defazio Giovanni author non-byline.; Degos Bertrand author non-byline.; Demartini Benedetta author non-byline.; Deuschl Günther author non-byline.; Diukova Galina author non-byline.; Duque Kevin R. author non-byline.; Edwards Mark J. author non-byline.; Epstein Steven A. author non-byline.; Espay Alberto J. author non-byline.; Factor Stewart A. author non-byline.; Garcin Beatrice author non-byline.; Geroin Christian author non-byline.; Hagenaars Muriel author non-byline.; Hallett Mark author non-byline.; Hassa Thomas author non-byline.; Hassan Anhar author non-byline.; Herbert Lorena D. author non-byline.; Holden Samantha K. author non-byline.; Jankovic Joseph author non-byline.; Kanaan Richard A. author non-byline.; Kempe Lianne author non-byline.; Kojovic Maja author non-byline.; Kompoliti Katie author non-byline.; Kostić Vladimir S. author non-byline.; Kyle Kevin author non-byline.; LaFaver Kathrin author non-byline.; Lang Anthony E. author non-byline.; MacGillivray Lindsey author non-byline.; Martino Davide author non-byline.; Massano João author non-byline.; Maurer Carine W. author non-byline.; McWhirter Laura author non-byline.; Mehanna Raja author non-byline.; Mesrati Francine author non-byline.; Morris John C. author non-byline.; Nielsen Glenn author non-byline.; Obukhova Anastasia author non-byline.; Pandey Sanjay author non-byline.; Perez David L. author non-byline.; Petrović Igor author non-byline.; Pullman Seth L. author non-byline.; Quartarone Angelo author non-byline.; Roelofs Karin author non-byline.; Schrag Anette author non-byline.; Seliverstov Yury author non-byline.; Serranová Tereza author non-byline.; Søgaard Ulf author non-byline.; Sojka Petr author non-byline.; Stamelou Maria author non-byline.; Stephen Christopher D. author non-byline.; Stins John F. author non-byline.; Tinazzi Michele author non-byline.; Tomić Aleksandra author non-byline.; Valadas Anabela author non-byline.; Voon Valerie author non-byline.; Waugh Jeff L. author non-byline.; Wu Allan D. author non-byline.;
• Is Part Of: Journal of neurology, neurosurgery and psychiatry. Volume 93:Issue 6(2022)
• Page Start: 609
• Page End: 616
• Publication Date: 2022-02-25
• Subjects: functional neurological disorder -- meta-analysis -- systematic reviews; Neurology -- Periodicals; Nervous system -- Surgery -- Periodicals; Psychiatry -- Periodicals; 616.8
• DOI: 10.1136/jnnp-2021-328462
• Languages: English
• ISSNs: 0022-3050

Abstract

Abstract : Functional movement disorder (FMD) is a common manifestation of functional neurological disorder presenting with diverse phenotypes such as tremor, weakness and gait disorder. Our current understanding of the basic epidemiological features of this condition is unclear. We aimed to describe and examine the relationship between age at onset, phenotype and gender in FMD in a large meta-analysis of published and unpublished individual patient cases. An electronic search of PubMed was conducted for studies from 1968 to 2019 according to Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Individual patient data were collected through a research network. We described the distribution of age of onset and how this varied by gender and motor phenotype. A one-stage meta-analysis was performed using multilevel mixed-effects linear regression, including random intercepts for country and data source. A total of 4905 individual cases were analysed (72.6% woman). The mean age at onset was 39.6 years (SD 16.1). Women had a significantly earlier age of onset than men (39.1 years vs 41.0 years). Mixed FMD (23.1%), tremor (21.6%) and weakness (18.1%) were the most common phenotypes. Compared with tremor (40.7 years), the mean ages at onset of dystonia (34.5 years) and weakness (36.4 years) were significantly younger, while gait disorders (43.2 years) had a significantly later age at onset. The interaction between gender and phenotype was not significant. FMD peaks in midlife with varying effects of gender on age at onset and phenotype. The data gives some support to 'lumping' FMD as a unitary disorder but also highlights the value in 'splitting' into individual phenotypes where relevant.