Cognitive functions in Parkinson's disease: relation to disease severity and hallucination.
OBJECTIVE
We wished to relate severity of Parkinson's disease (PD) with cognitive function in relation to cerebral blood flow (CBF).


METHODS
Eighty-one consecutive PD patients were enrolled in this study. We used Mini-Mental State Examination (MMSE) and Wechsler Adult Intelligence Scale-Third edition (WAIS-III) to evaluate cognitive functions, and three-dimensional stereotactic ROI template (3DSRT) and Statistical Parametric Mapping (SPM) 8 to evaluate single photon emission CT (SPECT) recordings of regional CBF.


RESULTS
The mean MMSE score of PD patients was 27.4 ± 2.4. The scores of most patients were higher than 23/30. On the other hand, the mean Full-scale IQ of PD patients was 88.4 ± 17.3 in WAIS-III, which was lower than that of normal controls. In particular, visuospatial function score of most patients was lower. There was significant correlation between cognitive scores and Hoehn & Yahr stage and hallucinatory episodes. PD Patients with stage III and IV showed significant deterioration in cognitive functions compared to stage II patients. Analysis of CBF revealed relative reductions in perfusion in the cerebral cortex relative to that in normal control. SPM 8 showed that cognitive functions in PD patients were positively correlated with rCBF in the thalamus and cingulate gyrus.


CONCLUSIONS
This is the study to demonstrate the cognitive impairments in PD patients using WAIS-III. Visuospatial dysfunction might be caused by decrease in rCBF in the parietal and occipital lobes and dorsolateral prefrontal cortex. The severity of cognitive impairments in PD patients was correlated with disease severity and hallucinatory episodes.
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Takaaki
T
Wakamori
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan. Electronic address: agarit@cc.okayama-u.ac.jp.
Takashi
T
Agari
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Takao
T
Yasuhara
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Masahiro
M
Kameda
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Akihiko
A
Kondo
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Aiko
A
Shinko
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Susumu
S
Sasada
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Tatsuya
T
Sasaki
Department of Psychology, Kibi International University, Japan.
Tomohisa
T
Furuta
Department of Neurological Surgery, Okayama University Graduate School of Medicine, Dentistry and Pharmaceutical Sciences, Japan.
Isao
I
Date
D000368:Aged; D001921:Brain / Q000098:blood supply* / Q000503:physiopathology; D002560:Cerebrovascular Circulation / Q000502:physiology; D003072:Cognition Disorders / Q000209:etiology* / Q000503:physiopathology; D005260:Female; D006212:Hallucinations / Q000209:etiology* / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000150:complications* / Q000503:physiopathology / Q000523:psychology*; D015899:Tomography, Emission-Computed, Single-Photon
Cognitive functions; Disease severity; Hallucinations; Parkinson's disease; SPECT