Although the basal ganglia have traditionally been considered as primarily involved in the regulation of motor functioning, their role in the integration of emotions with cognitive and motor behavior is increasingly recognized. Psychiatric symptoms, including disturbance of affect (anxiety and depression), perception (hallucinations), thought (delusions), as well as behavioral and personality changes (apathy and disinhibition) are commonly observed in most basal ganglia diseases. They produce increased suffering and distress both for the patients themselves as well as for the caregivers, and are associated with increased need for care. Thus, psychiatric symptoms should not be viewed as a secondary or additional feature of the movement disorders, but rather, representing important and inherent aspects of these disorders. Although this is true for Parkinson's disease (PD), it is even more so for several of the atypical parkinsonian disorders, where psychiatric symptoms may represent key features of the clinical syndrome. For instance, in dementia with Lewy bodies, visual hallucinations are among the three cardinal features (1), and in focal lesions of the caudate, neuropsychiatry symptoms occur more commonly than motor disorders (2). Knowledge of the wide variety of psychiatric symptoms and having the diagnostic skills to identify and optimize treatment of these symptoms are thus of major importance in the management of patients with movement disorders. In addition to providing important diagnostic information, they help elucidate the relationship between key brain circuits and psychiatric symptoms.
The studies of patients with various parkinsonian disorders differ markedly with regard to diagnostic criteria used, the number and selection of patients with a high risk for random error and selection bias, the level of cognitive functioning within each diagnostic group and between the groups compared, and the use of instruments to measure neuropsychiatry symptoms. Thus, firm conclusions regarding comparisons of the frequency, severity, and profile of psychiatric symptoms in different parkinsonian disorders are premature.
This chapter will define the most common psychiatric symptoms in parkinsonian disorders and how they can be reliably measured, explore the relationship between basal ganglia structure and functioning with neuropsychiatric symptoms, and review studies of the frequency and characteristics, clinical implications as well as the so far limited data pertaining to treatment.
From: Current Clinical Neurology: Atypical Parkinsonian Disorders Edited by: I. Litvan © Humana Press Inc., Totowa, NJ
Was this article helpful?