Background Dysphagia is a common problem in HD, frequently leading to aspiration pneumonia and consecutive mortality. Objective estimates of prevalence using instrumental diagnostics and data on neuronal correlates of dysphagia in HD are scarce. Similarly, its correlation with other clinical markers is unknown. Thus, we aimed at defining clinical risk factors and neural correlated for HD-associated dysphagia more precisely.

Methods/techniques 21 subjects (12 w, 9 m, Shoulson-Fahn stadium I-IV) underwent a full clinical-neurological exam including the UHDRS motor score and cognitive data from neuropsychological tests. A clinical swallowing examination was performed by a trained SLT, as well as videoendoscopic swallow examination (FEES). Patients additionally underwent an MRI scan (T1, 3 Tesla MRI Siemens Prisma). We then correlated validated scores of dysphagia with motor and cognitive scores as well as measures of atrophy from MRI.

Results/outcome Mean UHDRS motor score was 33.6 (SD 15.3), mean UHDRS cognition score 158.6 (SD 64.3). In 20 patients, FEES showed penetration or aspiration in 80%. No significant correlations were found between dysphagia severity and any of the clinical markers (motor score, cognition, functional assessment, age, CAG). Voxel based morphometry confirmed atrophy patterns in known swallowing-network areas rather than motor function, e.g. striatum, when comparing patients with no/mild vs. moderate/severe dysphagia.

Conclusions Our results so far suggest that dysphagia is not predicted sufficiently well by clinical markers, as aspiration can occur even in early stage of HD, thus necessitating early instrumental assessments in the course of the disease. Arguably, dysphagia should not be referred to as a ‘prevalent motor symptom’, but rather as a distinct entity.