eprintid: 10163062 rev_number: 10 eprint_status: archive userid: 699 dir: disk0/10/16/30/62 datestamp: 2023-01-12 16:52:24 lastmod: 2023-01-12 16:52:24 status_changed: 2023-01-12 16:52:24 type: article metadata_visibility: show sword_depositor: 699 creators_name: Lidstone, Sarah C creators_name: Costa-Parke, Michael creators_name: Robinson, Emily J creators_name: Ercoli, Tommaso creators_name: Stone, Jon creators_name: FMD GAP Study Group, title: Functional movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases ispublished: pub divisions: UCL divisions: B02 divisions: C07 divisions: D07 divisions: F84 keywords: Functional neurological disorder, meta-analysis, systematic reviews, Conversion Disorder, Dystonia, Female, Humans, Movement Disorders, Phenotype, Tremor note: This version is the author accepted manuscript. For information on re-use, please refer to the publisher’s terms and conditions. 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examine the relationship between age at onset, phenotype and gender in FMD in a large meta-analysis of published and unpublished individual patient cases.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. date: 2022-06 date_type: published publisher: BMJ Publishing Group official_url: https://doi.org/10.1136/jnnp-2021-328462 oa_status: green full_text_type: other language: eng primo: open primo_central: open_green verified: verified_manual elements_id: 1983733 doi: 10.1136/jnnp-2021-328462 medium: Print-Electronic pii: jnnp-2021-328462 lyricists_name: Schrag, Anette lyricists_id: AESCH71 actors_name: Schrag, Anette actors_name: Taib, Linda actors_id: AESCH71 actors_id: LTAIB41 actors_role: owner actors_role: impersonator funding_acknowledgements: [NHS Scotland NRS Career Fellowship] full_text_status: public publication: Journal of Neurology, Neurosurgery and Psychiatry volume: 93 number: 6 pagerange: 609-616 event_location: England citation: Lidstone, Sarah C; Costa-Parke, Michael; Robinson, Emily J; Ercoli, Tommaso; Stone, Jon; FMD GAP Study Group; (2022) Functional movement disorder gender, age and phenotype study: a systematic review and individual patient meta-analysis of 4905 cases. Journal of Neurology, Neurosurgery and Psychiatry , 93 (6) pp. 609-616. 10.1136/jnnp-2021-328462 <https://doi.org/10.1136/jnnp-2021-328462>. Green open access document_url: https://discovery.ucl.ac.uk/id/eprint/10163062/2/Schrag_FMD%20GAP%20manuscript_0128_Final%20%28003%29%20-%20AA-KL.pdf