Comorbidities Of Essential Tremor And Huntington’s Disease

Background and objective: Both Essential Tremor (ET) and Huntington’s disease (HD)are extrapyramidal diseases. ET is a common movement disorder with inheritance,while HD is a rare and an autosomal dominant neurodegenerative disorder. ET or HDwas reported as a single disease in previous studies. However, some comorbidities wererecognized in western countries, which were absent in the domestic studies. To explorethe mechanism, our study will investigate the prevalence of migraine in the patientswith ET and diabetes mellitus(DM) in the HD patients.Methods: A uniform questionnaire was designed in our study. The prevalence and thedetailed clinical characteristics of migraine in ET or DM in HD were obtained bylooking up medical records, face-to-face interview and telephone interview.Furthermore, genetic study was used to explore the underlying mechanism.Results: The prevalence of lifetime migraine in ET patients was significantly higherthan the controls, and the dopamine receptor D3(DRD3) Ser9Gly variant may be lowerin ET with migraine than the ET patients without migraine although there was nosignificant difference. However, both the clinical features of ET and migraine were notaltered when they coexisted. Additionally, the prevalence of DM was higher in thepedigree of HD than that in the general population.Conclusions: Our data suggested that ET patients had a higher risk of migraine than didcontrols and the DRD3Ser9Gly variant might be lower in ET patients with migrainethan the general ET patients. When ET and migraine coexisted, the characteristics oftremor and migraine remained unaltered. Meanwhile, we firstly reported a HD familywith high prevalence of DM, which suggested there was a genetic link between HD andDM.