Mild Cognitive Impairment in newly diagnosed Parkinson's disease: A longitudinal prospective study.

INTRODUCTION: In PD, Mild Cognitive Impairment (PD-MCI) occurs since early stages of disease. The aims were to assess presence of PD-MCI in untreated, drug-naive PD patients, and to follow-up the sample over 4 years to ascertain evolution of neurocognitive profile. METHODS: Seventy-six patients underwent neuropsychological testing at baseline (T0), and after 2 (T1:n = 62) and 4 years (T2:n = 55). Diagnosis of PD-MCI and PD-associated dementia (PDD) was made according to current consensus criteria. RESULTS: PD-MCI occurred in 25/76 patients (32.9%) at baseline, and 4 of them reverted from PD-MCI to Normal Cognition (Reverters), 7 remained stable (Non-Reverters) and 2 developed PDD at T2; 12 patients were lost to the follow-up. Among the 51 patients with normal cognition (PD-CN) at T0, 27 had normal cognition at T2 (5 of them were Reverters with respect to diagnosis at T1), 5 had MCI at T1 and T2 (Non-Reverters), 9 had MCI at T2 only, whereas 1 developed PDD; 9 patients were lost to the follow-up. At baseline, Reverters (n = 9) had younger age at onset and better performance on constructional visuospatial task than Non-Reverters (n = 12). Compared to patients without PD-MCI at all evaluations (n = 19), Reverters had poorer performance on verbal immediate recall and attention tasks and higher level of apathy at T0. Reduced performance on the Stroop Test at baseline predicted PD-MCI at T2. CONCLUSION: Executive dysfunctions predicted development of PD-MCI after few years from onset. Reversal from PD-MCI to PD-CN was related to young age at onset and high level of apathy at baseline evaluation.

Apathy and striatal dopamine transporter levels in de-novo, untreated Parkinson's disease patients.

INTRODUCTION: Apathy is a neuropsychiatric symptom in Parkinson's Disease (PD) which has a negative impact on quality of life and might be related in part to damage of presynaptic dopaminergic system. Little is known about relationship between striatal dopamine levels and apathy in PD patients without dementia and/or depression. The aim of the present study was to investigate the relationship between "pure apathy" and striatal dopamine uptake in untreated, drug-naïve PD patients without clinically significant dementia and/or depression. METHODS: Fourteen PD patients with pure apathy and 14 PD patients without apathy, matched for age, side of motor symptoms at onset, motor disability and disease duration, underwent both neuropsychological and behavioral examination including self-rated version of the Apathy Evaluation Scale (AES-S). All patients underwent 123 I-FP-CIT (DaT-SCAN) SPECT to assess dopamine transporter (DAT) striatal uptake. RESULTS: PD patients with apathy showed lower DAT levels in the striatum than non-apathetic patients. After Bonferroni correction the difference between groups was significant in the right caudate. CONCLUSIONS: Apathy is associated with reduced striatal dopamine transporter levels, independent of motor disability and depression in non-demented PD patients. These findings suggest that dysfunction of dopaminergic innervation in the striatum and particularly in the right caudate may contribute to development of apathy in early PD.

Apathy in untreated, de novo patients with Parkinson's disease: validation study of Apathy Evaluation Scale.

Apathy is a behavioural disturbance occurring alone or in concomitance with depression in Parkinson's disease (PD). Here we present a validation study for the self-report version of the Apathy Evaluation Scale (AES-S), carried out in a sample of 60 non-demented, non-depressed untreated, drug-naïve, de novo PD patients; 20 patients of the sample (33.3%) were classified as apathetic according to current clinical criteria. All enrolled patients completed the AES-S and a neurological and cognitive assessment. Mean AES-S score was 34.43. AES-S did not show floor or ceiling effect. Cronbach's alpha was 0.872. Principal component analysis revealed three factors: the first (34.4% of the variance) represented constitutive aspects of the construct of apathy; the second (8.5% of the variance) represented a social dimension; the third factor (7.9% of the variance) represented a dimension related to insight. With respect to clinical criteria for apathy considered as the gold standard, receiver operating characteristics curve analysis showed that a cut-off of 36/37 has the maximum discrimination power. High sensitivity and negative predictive values were obtained with cut-off scores of 33/34 or lower; high specificity and positive predictive values were obtained with cut-off scores of 38/39 or higher. AES-S score correlated with scores on frontal tasks, but not on Beck Depression Inventory, Unified Parkinson's Disease Rating Scale, Hoehn and Yahr scale. The AES-S is a reliable and valid questionnaire for detecting apathy in PD. For screening purposes a 33/34 cut-off score is indicated, but a 38/39 cut-off score is necessary when a high specificity is desired.