Clinical and neuropsychological features and changes to regional cerebral blood flow in ‍patients with Parkinson's disease dementia

Abstract

This study aimed to clarify associations of clinical and neuropsychological features and change in regional cerebral blood flow (rCBF) on 123I-IMP-SPECT in patients with Parkinson's disease (PD) who developed dementia. Sixty-one PD patients (mean age, 65.9 ± 8.6 years; mean disease duration, 11.0 ± 11.0 years) were recruited and followed-up for two years. Clinical and neuropsychological characteristics, and rCBF from SPECT were compared between PD patients who developed dementia (PDD+) and those who remained undemented (PDD-). Thirty-eight PD patients (62.3%) were diagnosed with PD-MCI at baseline. During follow-up, 22 PD patients (36%) developed dementia (PDD+). Univariate logistic regression models showed that Hoehn and Yahr scale 4 (odds ratio [OR] 5.85; 95% confidence interval [CI] 1.35-30.75]), visual hallucination (OR 5.95; 95%CI 1.67-25.4]), and PD-MCI (OR 6.47; 95%CI 1.57-39.63]) represented a significant risk factor for PDD+. Among neuropsychological parameters, WAIS (Wechsler Adult Intelligence Scale)-III block design (OR 6.55; 95%CI 1.66-29.84), letter number sequencing (OR 7.01; 95%CI 1.65-36.64), digit-symbol coding (OR 3.90; 95%CI 1.13-14.2), Wechsler Memory Scale, revised (WMS-R) visual paired associates II (delayed recall) (OR 4.68; 95%CI 1.36-17.36), Logical memory I (immediate recall) (OR 8.30; 95%CI 1.37-90.89), Logical memory II (delayed recall) (OR 6.61; 95%CI 1.35-44.33), Visual reproduction I (immediate recall) (OR 7.67; 95%CI 2.11-31.40), and Visual reproduction II (delayed recall) (OR 5.64; 95%CI 1.62-21.47) were significant risk factors. Decreased rCBF assessed using the general linear model (two-sample t-test) by SPM8 was observed in the left precuneus (0, -66, 16), right cuneus (6, -76, 30), and left angular gyrus (-46, -74, 32) in PDD+ compared with PDD- patients. Collectively, we have here shown that clinical and neuropsychological characteristics as well as changes to rCBF in PD patients who converted to PDD+. These features should be carefully monitored to detect the development of dementia in PD patients.