The loss of neural synchrony in the post septic brain

Abstract

Objective: Survivors of sepsis often develop long-term neuropsychological malfunctions, which can be reversible to a certain extent. The following study aimed to investigate whether this recovery is due to a loss in neural synchrony by regarding the response to a given frequency.

Methods: Magnetoencephalography measurements were conducted in 36 survivors of severe sepsis and septic shock three times within a time range of 12months after discharge from intensive care unit. We analyzed steady state visual evoked responses using a set of familiar vs. unfamiliar pictures.

Results: Sepsis survivors exhibit oscillatory deficits in terms of an impaired response to periodic visual stimulation. Oscillatory deficits and neuropsychological impairments obtained by the DemTect questionnaire were strongly linked. Impaired responses were equally found during the presentation of familiar and unfamiliar stimuli. Compared to familiar stimuli however, the response to unfamiliar stimuli was significantly lower in the follow up but not in the post-acute stage.

Conclusions: We assume that the processing of unfamiliar pictures requires a higher amount of networking. In case of a disrupted network, complex networking might not be maintained.

Significance: Results indicate that neural synchrony might be restored to a certain level while more complex networking remains impaired.

Keywords: Long-term cognitive impairments; Magnetoencephalography; Neuronal oscillations; Sepsis.