Cognitive Processing in Patients Surviving Delirium. Neuropsychological, EEG and Structural Brain Correlates.

The overall aim is to understand the pathophysiological mechanism in delirium and septic encephalopathy and its consequences.

For this purpose we will:

1. Provide extensive cognitive testing. These results provide the basis for categorization of patients surviving septic encephalopathy and delirious patients.
2. First, the investigators will examine if the differences in cognitive function is reflected in the ability of the brain to generate high-frequency electrical oscillations that accompany and underlie perception, attention, cognition, memory formation and retrieval. It will be performed by carrying out continuous EEG (cEEG) and by examination of steady-state evoked cognitive EEG responses.
3. Second, the investigations will examine MRI, structural and diffusion tensor imaging sequences. Hippocampal, thalamic, amygdala, lentiform nucleus and cingulate cortex volumes will be determined bilaterally and will be compared between individuals with healthy brain aging and patients that survived delirium.
4. Third, the investigators will assess plasma markers of free radical production.