APATHY AS THE NON-MOTOR SYMPTOM OF PARKINSON DISEASE AND HUNTINGTON DISEASE

Apathy is one of the most frequent, disabling and difficult to treat non-motor symptoms manifesting in many neurodegenerative diseases, particularly in Parkinson disease and Huntington disease. Aim is to evaluate and compare the clinical profile of apathy in patients with Parkinson disease (PD) and Huntington disease (HD). Materials and methods. The individual registration card was filled in for each patient containing demographic data, clinical features of the disease, the results of validated scales and questionnaires evaluating motor activity (The Movement Disorder Society-Unified Parkinson's Disease Rating Scale - MDS-UPDRS, the Unified Huntington's Disease Rating Scale - UHDRS), cognitive functions (MoCA-test), anxiety-depressive symptoms (hospital scale for evaluating anxiety and depression, Beck's depression scale-II), apathy (apathy rating scale). Patients with dementia or severe depression were excluded from the study. Results. The study included 265 patients: 250 with PD and 15 with HD. Apathy was diagnosed in 57.8% of cases in patients with neurodegenerative diseases (139 out of 250 patients with PD and 9 out of 15 patients with HD). In both groups of patients apathy was associated with the severity of motor manifestations. Patients with PD showed a positive correlation of apathy with more severe depression (r=0.488; p<0.0001), anxiety (r=0.300; p<0.0001) and drowsiness (r=0.254; p<0.0001); a negative correlation with a short duration of the disease (r=-0.160; p=0.021), a lower dose of dopaminergic drugs, LEDD (r=-0.203; p=0.03). In patients with HD, apathy was associated with disease duration (8 (4; 11) years in patients without apathy and 5 (3;9) years in patients with apathy, U =3791.5; p=0.020) and cognitive impairment (26 (19;37) points, without apathy - 18 (12;26), U =3548.5; p=0.003). Conclusions. Similar frequency of apathy was found in patients with PD and HD, but with different clinical correlations due to the involvement of different brain regions in the pathological process, which requires further research to develop targeted therapy.