Simultaneous EEG–PET–fMRI measurements in disorders of consciousness: an exploratory study on diagnosis and prognosis

Abstract

Previous studies could demonstrate that functional magnetic resonance imaging (fMRI), fludeoxyglucose positron emission tomography (FDG-PET), and electroencephalography (EEG) measures contain information about patients suffering from disorders of consciousness (DOC) and thus improve the clinical diagnosis. Additionally, the technical modalities were able to predict the outcome of patients. However, most studies lack proven reproducibility in a clinical setting. We here applied a standardized combined EEG/fMRI/FDG-PET measurement to a cohort of 20 patients suffering from DOC and focused on parameters that have been demonstrated to contain information about diagnosis and prognosis of these patients. We evaluated EEG band power, fMRI connectivity in networks associated with consciousness and sensory networks, as well as absolute glucose uptake in the brain as potential markers of preserved consciousness or favorable outcome. Acquired data were analyzed by a principal component analysis to identify the most important markers in a hypothesis-free manner. These were then analyzed with statistical group comparisons. Absolute FDG-PET could prove that glucose metabolism in the occipital lobe is significantly higher in minimally conscious than in vegetative state patients. Delta band power showed to be prognostic marker for a favorable outcome. We conclude that absolute FDG-PET is a suitable tool to evaluate the level consciousness in DOC patients. Additionally, we propose delta band power as marker of a favorable outcome in DOC patients. We suggest that these findings promote a standardized technical evaluation of DOC patients to improve diagnosis and prognosis.

European Academy of Neurology guideline on the diagnosis of coma and other disorders of consciousness

“…PICO questions 1–3 refer to resting state PET and fMRI, PICO questions 4–6 to passive and active fMRI paradigms. Forty‐four publications were included for final analysis . PICO 1 Should resting state PET be used to diagnose signs of covert consciousness in patients with DoC? …”

From simultaneous to synergistic MR‐PET brain imaging: A review of hybrid MR‐PET imaging methodologies

“…Golkowski et al (2017) acquired BOLD-fMRI, FDG-PET and EEG in people with disorders of consciousness (minimally conscious/comatose). Golkowski et al (2017) acquired BOLD-fMRI, FDG-PET and EEG in people with disorders of consciousness (minimally conscious/comatose).…”

“…Trimodal neuroimaging is also possible on commercially available simultaneous MR-PET scanners. Golkowski et al (2017) acquired BOLD-fMRI, FDG-PET and EEG in people with disorders of consciousness (minimally conscious/comatose). They found that FDG-PET but not EEG or BOLD-fMRI was significantly higher in minimally-conscious people compared to people with unresponsive wakefulness syndrome, and FDG-PET was related to the clinical rating of consciousness.…”

Comparison of EEG microstates with resting state fMRI and FDG‐PET measures in the default mode network via simultaneously recorded trimodal (PET/MR/EEG) data

“…The relationship between simultaneously recorded bimodalities, such as fMRI/PET (Aiello et al, 2015; Riedl et al, 2014, 2015), fMRI/EEG (Goldman, Stern, Engel, & Cohen, 2000; Huster, Debener, Eichele, & Herrmann, 2012; Ritter & Villringer, 2006) and PET/EEG (Hur, Lee, Lee, Yun, & Kim, 2013), has already been reported by a number of groups. Furthermore, other research has shown the feasibility and application (Golkowski et al, 2017; Del Guerra et al, 2017; Shah et al, 2017) of simultaneous trimodal (MR/PET/EEG) measurements. Even though various functional relationships between simultaneously recorded bimodal and trimodal data have already been investigated and reported on, an exploratory analysis on the neuroelectric (electrophysiology as measured by EEG) metrics and its relationship with neurovascular (hemodynamic response as measured by BOLD fMRI) and neurometabolic (metabolic activity as measured by PET) metrics on a simultaneously recorded resting state (rs) trimodal data set has not yet been reported.…”