P4‐117: CORRELATION BETWEEN CORTICAL EXCITABILITY AND LOCAL β‐AMYLOID DEPOSITION AS EVALUATED BY MEG AND PIB‐PETстатья из журнала
Аннотация: It has been noticed that patients with Alzheimer's disease (AD) often show seizures [Hause et al, 1986], however the underlying pathomechanisms were not completely understood. Recently, frequent occurrence of seizures were also found in transgenic mice for AD model [Palop et al. 2007], and Bousche et al (2008) have demonstrated that clusters of neurons near amyloid plaques become hyperactive. Therefore, the objective of this study was to investigate relationships between cortical excitability and local amyloid deposition in humans using MEG and PiB-PET. To assess the cortical excitability in noninvasive manner, we measured somatosensory evoked magnetic field recovery (SEF-R) function to paired electric stimuli [Ugawa et al. 1991]. The participants were 7 AD, 12 mild cognitive impairment (MCI) and 33 cognitively normal (NC) volunteers. The study was approved by the Ethic Committee of National Center for Geriatrics and Gerontology and written informed consent was obtained from all of the participants. Five paired stimuli with different inter-stimulus intervals (ISIs = 30, 60, 90, 120, 150 ms) were randomly administered to the left median nerve at the wrist. Magnetic responses were measured using a 306 channel system (Neuromag, Elekta). The paired stimuli elicited two primary responses (R1 and R2), and SEF-R value was calculated by dividing the magnitude of R2 by that of R1 in each ISI. PiB -PET images were taken using a PET-CT scanner (Biograph, Siemens). The standard uptake value ratio (SUVR) images were created using the radioactivity in the cerebellum as a reference. Whole brain regression analysis between SEF-R values and SUVR images were conducted using SPM 8. In NC subjects, the SEF-R value was the smallest at ISI 30 ms, and recovered to around 1.0 at ISI 90 ms. In contrast, AD and MCI subjects showed significantly larger overshoot at ISI 90 and 120 ms indicating cortical hyper-excitability. PiB-PET revealed that 7/7 of AD, 6/12 of MCI, and 7/33 of NC were amyloid positive. The regression analysis demonstrated that the SEF-R values were positively correlated with amyloid deposition in and around the bilateral somatosensory cortices. This study suggested that the local amyloid deposition in the somatosensory cortex causes hyper-excitability in the same area in humans.
Год издания: 2014
Авторы: Akinori Nakamura, Takashi Kato, Misako Yamagishi, Kaori Iwata, Masahiko Bundo, Kimiko Kato, Hideyuki Hattori, Takashi Sakurai, Yutaka Arahata, Maess Burkhard, Kengo Ito, Study Group MULNIAD
Издательство: Wiley
Источник: Alzheimer s & Dementia
Ключевые слова: Functional Brain Connectivity Studies
Открытый доступ: closed
Том: 10
Выпуск: 4S_Part_22