[Neurological prognosis after cardiac arrest and resuscitation]

Following initially successful resuscitation and the achievement of a spontaneous rhythm, patients are mostly comatose and are transferred to the intensive care unit. The brain is particularly vulnerable for injuries under global ischemia or hypoxia and therefore severe brain damage without damage to other organs is a frequent occurrence. This is referred to as hypoxic-ischemic encephalopathy (HIE) and preferentially affects neurons in the cerebral cortex, the basal ganglia and the cerebellum. The brain stem is less vulnerable. The unresponsive wakefulness syndrome (UWS), previously known as apallic syndrome or vegetative state, is a frequent form of HIE and can persist for years in a ventilation nursing home. In many patients multimodal neurological prognostication enables a reliable prediction on whether a relevant recovery of cerebral function is likely or impossible, even during the stay in the intensive care unit. These include the clinical neurological examination after a sufficiently long observational time of mostly at least 72h, cerebral imaging, i.e., cranial computed tomography (cCT), if necessary cranial magnetic resonance imaging (cMRI), electrophysiological examinations (electroencephalography, EEG), median nerve somatosensory evoked potentials (SSEP) and determination of blood biomarkers (neuron-specific enolase, NSE, neurofilament light chains, NFL). Findings that make a severe HIE very likely are a bilateral lack of pupillary light reflex 72h after resuscitation, bilateral absence of cortical median nerve SSEP, highly malignant EEG pattern, NSE levels > 90 ng/ml and a lack of gray-white differentiation of the cerebrum in cCT. A normal NSE or NFL level 48-96h after resuscitation, an early continuous EEG with responses to external stimuli, high amplitudes of the median nerve SSEP and a normal cMRI make a severe HIE improbable. If the short-term clinical course and the prognostic investigations do not provide a clear determination of the extent of the HIE, a time-limited trial of a neurological early rehabilitation can clarify the question whether regaining consciousness with relevant cognitive functions occurs or not.