Apathy Antedating and Evolving With Dementia: A Case Report and Insights Into Apathy as a Network Dysfunction

Apathy is a motivational disorder characterized by a lack of drive or indifference to salient endogenous or exogenous influences or stimuli. In the classical literature, it was referred to as a lack of mental energy or vitality and attributed to dysfunction of the ergotropic sympathetic pathway involving the posterior hypothalamus, thalamus, cingulate cortex, and hippocampal formation. Recent advanced imaging studies have expanded the ambit of network dysfunction to include the dopaminergic mesolimbic system and the salience network that gauges the valence or energy of the mesolimbic system. The classic Papez circuit also has a role in the pathogenesis of apathy. In order to understand the mechanisms of apathy seen with a wide range of diseases including neurodegenerative disorders, trauma, and strokes, one needs to think of apathy as a network disorder. In this report, we present a case of apathy antedating and evolving with Alzheimer’s disease and delve into the network theory of apathy and explore potential pharmacological therapies.