Hypoxic-ischaemic brain injury

Abstract

Hypoxic-ischaemic brain injury is common and usually due to cardiac arrest or profound hypotension. The clinical pattern and outcome depend on the severity of the initial insult, the effectiveness of immediate resuscitation and transfer, and the post-resuscitation management on the intensive care unit. Clinical assessment is difficult and so often these days compromised by sedation, neuromuscular blockade, ventilation, hypothermia and inotropic management. Investigations can add valuable information, in particular brain MRI shows characteristic patterns depending on the severity of the injury and the timing of imaging. EEG patterns may also suggest the possibility of a good outcome. There is no entirely reliable algorithm of clinical signs or investigations which allow a definitive prognosis but the combination of careful repeated observations and appropriate ancillary investigations allows the neurologist to give an informed and accurate opinion of the likely outcome, and to advise on management. Overall, the prognosis is extremely poor and only a quarter of patients survive to hospital discharge, and often even then with severe neurological or cognitive deficits.

RYR1-related malignant hyperthermia with marked cerebellar involvement – A paradigm of heat-induced CNS injury?

“…Although a hypoxic ischaemic contribution to the CNS insult in our patient is likely, the pattern of brain injury, in particular the prominent posterior involvement, is not the pattern seen in typical hypoxic ischaemic brain injury (for review see [7,8]), and it is tempting to hypothesize a direct impact of the RYR1 mutation identified in him. There are several lines of evidence to suggest that the specific genetic background may explain the predominant cerebellar involvement in our patient and possibly in other, genetically unresolved individuals with a similar pattern of heat-induced CNS injury: RyR1 is one of three ryanodine receptor isoforms expressed in the brain, with strong preference for the hippocampus and cerebellar Purkinje cells [9].…”

Hypoxia after stroke: a review of experimental and clinical evidence

“…Seizures occur in up to a third of individuals within a day of exposure to hypoxia, and are commonly partial complex or myoclonic in nature. Intractable forms of either of these types of seizure are associated with a poor prognosis [20]. Cognitive impairment domains include amnesia, visuospatial deficits, frontal lobe symptoms, impairment of executive function, and impairments in language [21].…”

“…These are covered in more detailed reviews on the subject [22, 23]. Involvement of the basal ganglia, a region particularly susceptible to hypoxic injury, can result in delayed Parkinsonism in older subjects, dystonia mainly in younger people, choreo-athetosis, and tremors [20]. Varying degrees of unilateral or bilateral motor impairment may be observed depending on both the anatomical level and extent of corticospinal tract involvement.…”

Medial Occipital Lobe Hyperperfusion Identified by Arterial Spin-Labeling: A Poor Prognostic Sign in Patients with Hypoxic-Ischemic Encephalopathy

“…1 Despite advances in its treatment, patients with HIE have high rates of morbidity and mortality. 2 Given that the severity of HIE varies widely, a wealth of predictive prognostic tools exist, ranging from clinical markers, including level of consciousness and motor response to central noxious stimulation, to neurophysiologic testing, such as electroencephalogram, laboratory markers, and somatosensory-evoked potentials.…”