Brain functional connectivity during the first day of coma reflects long-term outcome.

Kustermann, Thomas; Ata Nguepnjo Nguissi, Nathalie; Pfeiffer, Christian; Haenggi, Matthias; Kurmann, Rebekka; Zubler, Frédéric; Oddo, Mauro; Rossetti, Andrea O.; De Lucia, Marzia (2020). Brain functional connectivity during the first day of coma reflects long-term outcome. NeuroImage: Clinical, 27, p. 102295. Elsevier 10.1016/j.nicl.2020.102295

2020 - Kustermann - NeuroImage. Clinical - PMID 32563037.pdf - Published Version
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In patients with disorders of consciousness (DOC), properties of functional brain networks at rest are informative of the degree of consciousness impairment and of long-term outcome. Here we investigate whether connectivity differences between patients with favorable and unfavorable outcome are already present within 24 h of coma onset.


We prospectively recorded 63-channel electroencephalography (EEG) at rest during the first day of coma after cardiac arrest. We analyzed 98 adults, of whom 57 survived beyond unresponsive wakefulness. Functional connectivity was estimated by computing the 'debiased weighted phase lag index' over epochs of five seconds duration. We evaluated the network's topological features, including clustering coefficient, path length, modularity and participation coefficient and computed their variance over time. Finally, we estimated the predictive value of these topological features for patients' outcomes by splitting the patient sample in training and test datasets.


Group-level analysis revealed lower clustering coefficient, higher modularity and path length variance in patients with favorable compared to those with unfavorable outcomes (p < 0.01). Within all features, the path length variance in the network provided the best positive predictive value (PPV) for favorable outcome and specificity for unfavorable outcome in the test dataset (PPV: 0.83, p < 0.01; specificity: 0.86, p < 0.01) with above-chance negative predictive value and accuracy. Of note, the exclusion of patients with epileptiform activity (20 in total) eliminates all false positive predictions (n = 6) for path length variance.


Topological features of functional connectivity differ as a function of long-term outcome in patients on the first day of coma. These differences are not interpretable in terms of consciousness levels as all patients were in a deep unconscious state. The time variance of path length is informative of comatose patients' outcome, as patients with favorable outcome exhibit a richer repertoire of path length than those with unfavorable outcomes.

Item Type:

Journal Article (Original Article)


04 Faculty of Medicine > Department of Head Organs and Neurology (DKNS) > Clinic of Neurology
04 Faculty of Medicine > Department of Intensive Care, Emergency Medicine and Anaesthesiology (DINA) > Clinic of Intensive Care

UniBE Contributor:

Hänggi, Matthias; Kurmann, Rebekka and Zubler, Frédéric


600 Technology > 610 Medicine & health








Jsabelle Arni

Date Deposited:

11 Sep 2020 13:32

Last Modified:

13 Mar 2021 12:51

Publisher DOI:


PubMed ID:


Uncontrolled Keywords:

Cardiac arrest Coma EEG Functional connectivity Resting state




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