Các nghiên cứu trước đây cho thấy sự thờ ơ, được định nghĩa như là một trạng thái của động cơ giảm, xảy ra trong PD như là một hội chứng độc lập trong khoảng 12% bệnh nhân và đồng tồn tại với các rối loạn trầm cảm trong ít nhất 25% bệnh nhân. Không có dự báo rõ ràng của sự thờ ơ | 168 Marsh and Friedman APATHY Epidemiology Previous studies show that apathy defined as a state of diminished motivation occurs in PD as an independent syndrome in about 12 of patients and co-exists with depressive disorders in at least 25 of patients. There are no clear predictors of apathy. The data are contradictory as to whether patients with independent apathetic syndromes have greater cognitive impairment. Certainly apathy is a common component of dementia delirium or demoralization. Signs and Symptoms Apathy is manifest as a lack of motivation or initiative along with indifference about the degree of inactivity 8 . There is usually diminished perseverance interest in new things and concerns over one s health. Such patients generally enjoy themselves at arranged or structured activities but they return to their usual inert state once the event is over. Patients fail to take an active interest in others and may be less conversational. They do not exhibit negativism active social withdrawal or anhedonia as seen with depressive disorders. Apathy is usually not distressing to the patient but their inactivity and lack of spontaneous effort are frustrating to family members and caregivers who tend to initiate complaints and wonder if the patient has a depressive disorder. Etiopathological Factors Goal-directed activity is associated with intact dopaminergic and prefrontal cortical activity but apathetic syndromes commonly involve basal ganglia pathology. Evidence for neuronal loss in the locus coeruleus implicates a role for noradrenergic dysfunction. A role for abnormalities in frontal-subcortical circuitry is thus suggested. Parallels between features of apathy and those of PD especially bradyphrenia and bradykinesia suggest shared pathophysiological processes among these cognitive behavioral and motor aspects of the disease. One study showed strong associations between apathy executive dysfunction impairments in instrumental activities of daily living and higher
