F078 Functional neurological disorder in patients with pathogenic mutations for Huntington’s disease: a retrospective cohort study

<h3>Background</h3> Functional neurological disorder (FND) is a common condition that is often associated with concomitant neurological diseases. In 2021 our HD clinic was started with dedicated neurology participation for the first time. In the first 18 months 5/55 (9%) of new referrals involved the presence of FND alongside a positive HD genetic test. <h3>Aims</h3> We aimed to better understand the natural history of FND in patients with a pathogenic mutation for HD. Methods/Techniques: We undertook a case review of the 5 cases of FND and a positive HD test, supported by a wider review of the other 50 HD cases that did not have FND. This included assessment of demography, review of genetics testing, relevant family/social history, neuropsychology profile and FND phenomenology. <h3>Results/Outcome</h3> All 5 FND cases were female (non-FND cohort 58% female) with a mean age of 41 years compared to 45 years in the non-FND group. 4/5 had some form of motor FND presentation. 1 patient had neurological features of HD alongside their FND symptoms. All the FND patients had a mental health diagnosis compared 3/6 from the non-FND stage1/early stage 2 HD group. 4/5 FND patients had chronic pain compared to 1/6 in the non-FND stage1/early stage 2 HD group. An average total functional capacity score of 9 was noted for the FND group and 6 for non-FND HD group. <h3>Conclusions</h3> This project highlights the importance of awareness of functional symptoms in patients with a positive HD genetic test, this is important given modifiable outcomes in FND. <h3>References</h3> Kurtis MM, Pareés I. Functional movement disorder comorbidity in Parkinson’s disease: Unraveling the web. <i>Parkinsonism Relat Disord.</i> 2021;<b>82</b>:138–145. Fekete R, Jankovic J. Psychogenic chorea associated with family history of Huntington disease. <i>Mov Disord.</i> 2010;<b>25</b>(4):503–504 Soltan W, Sitek E, Wichowicz H, Wieczorek D, Slawek J. Abnormal gait and bradykinesia in the preclinical phase of Huntington’s disease - psychogenic movement disorder? <i>Acta Neuropsychiatr.</i> 2011 Dec;<b>23</b>(6):315–7. Rodrigues FB, Wild EJ. Psychogenic non-epileptic seizures in early Huntington’s disease. <i>Pract Neurol.</i> 2016 Dec;<b>16</b>(6):452–4.