Actigraphic daytime activity is reduced in patients with cognitive impairment and apathy

Apathy is a neuropsychiatric symptom in mild cognitive impairment (MCI) and dementia. This study examines correlations between Apathy Evaluation Scale (AES) ratings and actigraphic measures of daytime activity. The aim of this study is to determine the value of ambulatory actigraphy in the assessment of locomotor deficits as a correlate of apathy in geriatric patients with cognitive impairment.

In this cross-sectional study a total of 82 participants were recruited, 32 patients with dementia, 21 patients with MCI and 23 elderly controls. Rating scales for apathy (AES) and depression (Beck Depression Inventory, BDI) were completed. To measure daytime activity a wrist-worn actigraph and an established protocol were used. A single measure of mean daytime activity per participant was calculated for further statistical analysis.

In the two groups of patients with MCI and dementia, apathy is associated with reduced daytime activity, independent of diagnosis (no group by apathy interaction). AES scores correlate significantly with daytime activity. Cognitive impairment reduces daytime activity (effect greater in dementia than in MCI). Daytime activity is negatively correlated with memory deficits.

Ambulatory actigraphy is a promising method to evaluate self-initiated action as a correlate of apathy in patients with cognitive impairment.