OBJECTIVES

Huntington’s disease (HD) diagnosis is typically given when a clinician identifies unequivocal HD motor symptoms. This study aimed to understand the prevalence of motor symptom diagnoses in individuals with HD on or before their first recorded HD diagnosis in UK electronic medical records.

METHODS

This retrospective study used data from the UK Clinical Practice Research Datalink (CPRD). All individuals were aged ≥18 years with first recorded HD diagnosis between 2000 and 2018. HD diagnosis was defined as the first record of HD (read codes F134.00 [Huntington's chorea] and Eu02200 [dementia in HD]). Prevalence of motor symptoms on or prior to HD diagnosis and first motor symptoms were described, including the duration between first motor symptom and HD diagnosis. First motor symptom was defined as a motor symptom code following ≥365 days without another motor symptom code on record.

RESULTS

Overall, 264 adult HD cases were identified; median (interquartile range) age at index was 56 (44–67) years and 53% were female. Of these, 262 had ≥1 recorded motor symptom. Chorea was the most prevalent motor symptom at diagnosis (257/264, 97%). Chorea was also the most common first reported motor symptom (60%), followed by symptoms requiring care involving physical therapy (17%) and abnormal involuntary movements (5%). Most HD cases (156/264; 59%) had their first motor symptom record at the time of HD diagnosis. Overall, 74% (194/262) of individuals displayed motor symptoms within 365 days of diagnosis. No HD cases had their first motor symptom after diagnosis.

CONCLUSIONS

High prevalence of chorea on or before HD diagnosis was observed, which was often the first motor symptom recorded. Low prevalence of other motor symptoms may reflect heterogeneity in motor symptom manifestation, less clinical awareness of other motor symptoms or logistical issues regarding recording of other motor symptoms in CPRD primary care data.