Atypical antipsychotic therapy in Parkinson's disease psychosis: A retrospective study.

OBJECTIVE: Parkinson's disease psychosis (PDP) is a frequent complication of idiopathic Parkinson's disease (iPD) with significant impact on quality of life and association with poorer outcomes. Atypical antipsychotic drugs (APDs) are often used for the treatment of PDP; however, their use is often complicated by adverse drug reactions (ADRs). In this study, we present patients with PDP who were treated with the most commonly used atypical antipsychotic agents and review their respective ADRs. METHODS: A retrospective study was carried out to include a total of 45 patients with iPD who visited a movement disorders clinic between 2006 and 2015. All PDP patients treated with atypical APDs were included in the analysis for their specific ADRs. RESULTS: Forty-five iPD patients (mean age of onset: 62.67 ± 9.86 years) were included, of those 10 patients had psychosis (mean age of onset: 76.80 ± 4.61 years). Of the 45 patients, 22.2% were found to have psychotic symptoms, of whom 70% had hallucinations, 20% had delusions, and 10% illusions. Seventy percent of psychotic symptoms occurred after ten or more years from diagnosis of iPD. PDP patients were treated with quetiapine, olanzapine, and risperidone separately or in combination, all of which were found to have certain ADRs. LIMITATIONS: This study was limited by its retrospective study design and small sample size and with likely selection bias. CONCLUSIONS: The prevalence of PDP is relatively high in older patients with iPD. The uses of the currently available atypical APDs in this patient population are often complicated by ADRs. The selective 5-HT 2A inverse agonist, pimavanserin, could be a better alternative in the treatment of PDP.

Perceived and performance-based executive dysfunction in Parkinson's disease.

Executive dysfunction is common in early stage Parkinson's disease (PD). We evaluated the relationship between self- and informant-report measurement of real-world executive functions as well as performance-based neuropsychological measures in mildly cognitively impaired individuals with PD and healthy controls. The PD group reported more difficulty with initiation of complex tasks compared to caregiver ratings, and processing speed was a strong predictor of self-reported executive dysfunction for the PD group, followed by depression. Processing speed and semantic verbal fluency predicted informant-reported executive dysfunction in PD. These findings highlight the contribution of speeded processing for performance of everyday executive tasks in PD.

Movement activation and inhibition in Parkinson's disease: a functional imaging study.

BACKGROUND: Parkinson's disease (PD), traditionally considered a movement disorder, has been shown to affect executive function such as the ability to adapt behavior in response to new environmental situations. OBJECTIVE: to identify the impact of PD on neural substrates subserving two specific components of normal movement which we refer to as activation (initiating an un-cued response) and inhibition (suppressing a cued response). METHODS: We used fMRI to measure pre-movement processes associated with activating an un-cued response and inhibiting a cued response plan in 13 PD (ON anti-parkinsonian medications) and 13 control subjects. Subjects were shown a visual arrow cue followed by a matched or mismatched response target that instructed them to respond with a right, left, or bilateral button press. In mismatched trials, an un-cued (new) response was initiated, or the previously cued response was suppressed. RESULTS: We were able to isolate pre-movement responses in dorsolateral prefrontal cortex, specifically in the right hemisphere. During the activation of an un-cued movement, PD subjects showed decreased activity in the putamen and increased cortical activity in bilateral DLPFC, SMA, subcentral gyrus and inferior frontal operculum. During inhibition of a previously cued movement, the PD group showed increased activation in SMA, S1/M1, premotor and superior parietal areas. CONCLUSION: Right DLPFC plays a role in pre-movement processes, and DLPFC activity is abnormal in PD. Decreased specificity of responses was observed in multiple ROI's. The basal ganglia are involved in circuits that coordinate activation and inhibition involved in action selection as well as execution.