Countering apathy in patients with Parkinson’s disease
Apathy is a frequent neuropsychiatric disturbance that can precede the onset of motor symptoms in Parkinson’s disease and is most likely to be described, by the patient, as fatigue.
It is defined as reduced motivation with a decrease in goal-directed behaviours and lack of emotion that is not related to cognitive impairment or depression. Normal motivation depends on the integrity of subcortical structures that link the prefrontal cortex with the limbic system.
Dysfunction makes it difficult to redirect attention to novel stimuli, enjoy previous interests or make plans for the future. The person with apathy has ‘nothing to say’ and ‘nothing matters to them’. They may also have difficulty recognising facial emotions in others.
In Parkinson’s disease, apathy decreases after introduction of levodopa but its frequency increases again after five to ten years of disease. The authors report a case of a man having subthalamic stimulation which improved the motor symptoms to such an extent that dopaminergic treatment could be stopped. Five months later apathy had become a severe problem. Restarting levodopa rapidly restored his motivation.