Changes in theta activities in the left posterior temporal region, left occipital region and right frontal region related to mild cognitive impairment in Parkinson's disease patients

Abstract

The aim of this study was to investigate changes in brain activity associated with mild cognitive impairment (MCI) in a large sample of nondemented Parkinson's disease (PD) patients and its relationship with specific neuropsychological deficits. Electroencephalography (EEG) and neuropsychological assessment were performed in a sample of 135 nondemented PD patients and 44 healthy controls. All patients underwent a neuropsychological battery to assess global cognitive function. Patients were classified according to their cognitive status as PD patients with MCI (n = 61) and without MCI (n = 74). EEG data were used to analyze the relative band power parameters for the following frequency bands: delta (0.5–4 Hz), theta (4–8 Hz), alpha (8–13 Hz) and beta (13–30 Hz). In addition, relative band power parameters were compared between groups and examined for correlations with neuropsychological performance. The relative theta band powers in three regions (O1, T5 and F4) exhibited statistically significant increases in PD patients with MCI. Beta band powers also exhibited obvious decreases in five regions (T5, T6, P3, P4 and C3) in the PD-MCI group compared with the normal control group. Furthermore, correlation analyses revealed that attention, visuospatial and executive functions were associated with theta power in local regions, mainly in the frontal region (F4). The present study demonstrated that changes in brain activities limited to distinct cognitive domains, especially the theta power in the frontal region, could serve as an electrophysiological marker of cognitive impairment in nondemented PD patients.

KEYWORDS:

• Parkinson's disease
• electroencephalography
• mild cognitive impairment

Acknowledgements

We thank the participating subjects and caregivers.

Declaration of Interest

The authors declare that no conflict of interest exists. This work was supported by grants from the National Natural Science Foundation of China (No. 81371401), the Science and Technology Planning Project of Guangdong (No. 2013B021800199), the Natural Science Foundation of Guangdong (No. S2013010014033), the Science and Technology Program of Guangzhou (Nos. 2014J4100083 and 2013J4100068) and the Medical Scientific Research Foundation of Guangdong Province (A2014015).

Additional information

Funding

National Natural Science Foundation of China (No. 81371401), the Science and Technology Planning Project of Guangdong (No. 2013B021800199), the Natural Science Foundation of Guangdong (No. S2013010014033), the Science and Technology Program of Guangzhou (Nos. 2014J4100083 and 2013J4100068) and the Medical Scientific Research Foundation of Guangdong Province (A2014015)