Falls in demented patients are associated with reduced EEG functional connectivity of the dorsal attention network.

OBJECTIVE: Falls are common in individuals with dementia and pose a significant problem in acute hospital care. Aging and dementia affect functional brain networks including the default mode network (DMN), dorsal attention network (DAN) and salience network (SAN). The DAN and SAN are essential for the rapid detection of responses to unexpected stimuli. We hypothesize that global efficiency within these networks is reduced in patients with dementia who experience falls compared with those who do not. METHODS: We analyzed 347 inpatients with dementia from a neurological clinic in Vienna, Austria. Of 153 available EEGs, only those with normal findings were included. FC was calculated using the phase-locking-value across delts, theta, alpha, and beta bands. The characteristic path length of the DAN, SAN and DMN was computed. RESULTS: Fallers showed reduced global efficiency in the DAN. FC between the right rostral middle frontal gyrus and left middle frontal gyrus was decreased in delta, theta, and alpha bands - regions involved in visual stimulus processing and executive control. CONCLUSIONS: Reduced DAN connectivity may impair the ability to respond to unexpected stimuli, increasing fall risk in individuals with dementia. This supports the role of attention network dysfunction in motoric cognitive risk syndrome. SIGNIFICANCE: Falls are a significant problem in dementia, not well understood so far. Identifying network level dysfunction in dementia related falls offers a novel biomarker for risk stratification and possible targets for future interventions.