Supplementary Material for: Post-Stroke Apathy: An Exploratory Longitudinal Study

Introduction: Post-stroke apathy is a disturbance of motivation evidenced by low initiative, difficulties in starting, sustaining or finishing any goal-directed activity, low self-activation or self-initiated behavior and emotional indifference. Apathy is a common behavioral disturbance in stroke survivors. We aimed to analyze the relationship between post-stroke apathy at 1 year after stroke and (1) apathy in acute phase; (2) demographic, pre-stroke predisposing conditions (previous mild cognitive impairment, alcohol abuse, mood/anxiety disorder) and clinical features (stroke type and location, neurological symptoms); (3) post-stroke depression and post-stroke cognitive impairment, and (4) post-stroke functional outcome, quality of life and the perception of health. Methods: Consecutive stroke (infarct/intracerebral hemorrhage) patients without aphasia or consciousness disturbances were included in the acute phase of stroke and assessed at 1 year after stroke. We assessed apathy with the clinically rated version of the Apathy Evaluation Scale. We also assessed post-stroke depression (Montgomery Asberg Depression Rating Scale) and post-stroke cognitive impairment (attention, mental flexibility, verbal, motor and graphomotor initiative, and non-verbal and verbal abstract reasoning, and Mini-Mental State Examination), functional outcome (Barthel Index), quality of life and perception of health (EuroQol). Data were analyzed using bivariate associations (χ² and t test) and stepwise multivariate analysis. Results: We included 76 stroke patients [32.9% women, mean age 62.9 years (SD = 10.9) and a mean of 6.9 (SD = 4.3) years of education]. Apathy was present in 17 patients in the acute phase and in 18 (23.7%) patients at 1 year after stroke. At 1 year after stroke, 41% of the acute apathetic patients remained apathetic. Sixty-one percent of new cases of post-stroke apathy were detected. Post-stroke apathy was associated only with previous cognitive impairment, apathy in acute stroke, post-stroke cognitive impairment, verbal abstract reasoning and with worse Barthel Index scale scores. In the multivariate logistic regression model, verbal abstract reasoning (odds ratio, OR = 7.03) and apathy in acute stroke (OR = 3.8) were identified as independent factors for post-stroke apathy at 1 year. Apathetic patients did not report worse quality of life or health. Conclusion: Apathy in acute stroke phase was a reliable indicator of post-stroke apathy. Apathy should be assessed in both phases. Verbal abstract reasoning impairment was also an independent factor for post-stroke apathy impairing patients' ability to reason about goal-directed activity. Even though apathetic patients had worse post-stroke functional outcome, they did not report losing quality of life or having worse health.