Apathy in Parkinson's disease. Impairment in quality of life

Apathy is one of the most prominent non-motor symptoms in Parkinson Disease (PD). Its range of prevalence in PD has been estimated in 20 to 45%. The objective of this work is to assess the prevalence of apathy in PD patients, and its relation with depression and executive function impairment. Fifty seven PD patients (54% women), mean age of 68.7 years, and a disease duration of 7.5 years from diagnosis were included. We used the following scales: UPDRS, Hoehn & Yahr, Mini Mental State Examination, the 14-item Apathy Scale (AS), the Beck Depression Inventory, and Trail Making Test versions A and B (TMT), and Parkinson's Disease Quality of Life Questionnaire (PDQL). Apathy was identified in 31.6%; apathy without depression was present in 33.3% of patients. The TMT A and B were abnormal in 66.7% and 83.3% respectively of the apathetic patients vs. 46.2% and 61.5% in non-apathetic patients. Quality of life was impaired in apathetic patients. In our PD sample apathy is highly prevalent, has a great impact on quality of life and it may occur in the absence of depression. The alterations of TMT in apathetic patients contributes to suggest a positive relationship between apathy and the impairment of executive function secondary to the involvement of frontal-subcortical circuits.