OBJECTIVE: The pathophysiological mechanisms of cognitive dysfunction and dementia in Parkinson's disease (PD) are still poorly understood. Altered resting state oscillatory brain activity may reflect underlying neuropathological changes. The present study using magneto encephalography (MEG) was set up to study differences in the pattern of resting state oscillatory brain activity in groups of demented and non-demented PD patients and healthy, elderly controls. METHODS: The pattern of MEG background oscillatory activity was studied in 13 demented PD patients, 13 non-demented PD patients and 13 healthy controls. Whole head MEG recordings were obtained in the morning in an eyes closed and an eyes open, resting state condition. Relative spectral power was calculated using Fast Fourier Transformation in delta, theta, alpha, beta and gamma frequency bands. RESULTS: In the non-demented PD patients, relative theta power was diffusely increased and beta power concomitantly decreased relative to controls. gamma Power was decreased in central and parietal channels. In the demented PD patients, a diffuse increase in relative delta and to lesser extent theta power and a decrease in relative alpha, beta and to lesser extent gamma power were found in comparison to the non-demented PD group. In addition, reactivity to eye opening was much reduced in the demented PD group. CONCLUSIONS: Parkinson's disease is characterized by a slowing of resting state brain activity involving theta, beta and gamma frequency bands. Dementia in PD is associated with a further slowing of resting state brain activity, additionally involving delta and alpha bands, as well as a reduction in reactivity to eye-opening. SIGNIFICANCE: The differential patterns of slowing of resting state brain activity in demented and non-demented PD patients suggests that, in conjunction with a progression of the pathological changes already present in non-demented patients, additional mechanisms are involved in the development of dementia in PD.
OBJECTIVE: The pathophysiological mechanisms of cognitive dysfunction and dementia in Parkinson's disease (PD) are still poorly understood. Altered resting state oscillatory brain activity may reflect underlying neuropathological changes. The present study using magneto encephalography (MEG) was set up to study differences in the pattern of resting state oscillatory brain activity in groups of demented and non-demented PDpatients and healthy, elderly controls. METHODS: The pattern of MEG background oscillatory activity was studied in 13 demented PDpatients, 13 non-demented PDpatients and 13 healthy controls. Whole head MEG recordings were obtained in the morning in an eyes closed and an eyes open, resting state condition. Relative spectral power was calculated using Fast Fourier Transformation in delta, theta, alpha, beta and gamma frequency bands. RESULTS: In the non-demented PDpatients, relative theta power was diffusely increased and beta power concomitantly decreased relative to controls. gamma Power was decreased in central and parietal channels. In the demented PDpatients, a diffuse increase in relative delta and to lesser extent theta power and a decrease in relative alpha, beta and to lesser extent gamma power were found in comparison to the non-demented PD group. In addition, reactivity to eye opening was much reduced in the demented PD group. CONCLUSIONS:Parkinson's disease is characterized by a slowing of resting state brain activity involving theta, beta and gamma frequency bands. Dementia in PD is associated with a further slowing of resting state brain activity, additionally involving delta and alpha bands, as well as a reduction in reactivity to eye-opening. SIGNIFICANCE: The differential patterns of slowing of resting state brain activity in demented and non-demented PDpatients suggests that, in conjunction with a progression of the pathological changes already present in non-demented patients, additional mechanisms are involved in the development of dementia in PD.
Authors: Ying Yu; David Escobar Sanabria; Jing Wang; Claudia M Hendrix; Jianyu Zhang; Shane D Nebeck; Alexia M Amundson; Zachary B Busby; Devyn L Bauer; Matthew D Johnson; Luke A Johnson; Jerrold L Vitek Journal: J Neurosci Date: 2021-01-22 Impact factor: 6.167
Authors: Alex I Wiesman; Elizabeth Heinrichs-Graham; Timothy J McDermott; Pamela M Santamaria; Howard E Gendelman; Tony W Wilson Journal: Hum Brain Mapp Date: 2016-05-06 Impact factor: 5.038
Authors: Efstathios D Kondylis; Michael J Randazzo; Ahmad Alhourani; Witold J Lipski; Thomas A Wozny; Yash Pandya; Avniel S Ghuman; Robert S Turner; Donald J Crammond; R M Richardson Journal: Brain Date: 2016-06-21 Impact factor: 13.501
Authors: Lindsay Rutter; Frederick W Carver; Tom Holroyd; Sreenivasan Rajamoni Nadar; Judy Mitchell-Francis; Jose Apud; Daniel R Weinberger; Richard Coppola Journal: Hum Brain Mapp Date: 2009-10 Impact factor: 5.038