For example, malignant brain edema was present in roughly 31% of people with ischemic strokes within 30 days after onset. Signs and symptoms
The extent and severity of the symptoms of cerebral edema depend on the exact etiology but are generally related to an acute increase of the pressure within the skull. As the skull is a fixed and inelastic space, the accumulation of cerebral edema can displace and compress vital brain tissue, cerebral spinal fluid, and blood vessels, according to the Monro-Kellie doctrine.Increased intracranial pressure (ICP) is a life-threatening surgical emergency marked by symptoms of headache, nausea, vomiting, decreased consciousness. Symptoms are frequently accompanied by visual disturbances such as gaze paresis, reduced vision, and dizziness. Increased pressures within the skull can cause a compensatory elevation of blood pressure to maintain cerebral blood flow, which, when associated with irregular breathing and a decreased heart rate, is called the Cushing reflex. The Cushing reflex often indicates compression of the brain on brain tissue and blood vessels, leading to decreased blood flow to the brain and eventually death. Causes
Cerebral edema is frequently encountered in acute brain injuries from a variety of origins, including but not limited to:
Traumatic brain injury
Stroke
Tumors
Infections (such as a brain abscess or meningitis)
Hepatic encephalopathy
Posterior reversible encephalopathy syndrome
Radiation-induced brain edema
Post-surgical changes
Amyloid-related imaging abnormalities associated with edema (ARIA-E)
Hyponatremia
High-altitude cerebral edema

Risk factors
Cerebral edema is present with many common cerebral pathologies and risk factors for development of cerebral edema will depend on the cause. The following were reliable predictors for development of early cerebral edema in ischemic strokes.
Conversely, therapeutic hyperventilation can be used to lower the carbon dioxide content in the blood and reduce ICP through vasoconstriction. The effects of hyperventilation, although effective, are short-lived and once removed, can often lead to a rebound elevation of ICP. Furthermore, overaggressive hyperventilation and vasoconstriction and lead to severe reduction in CBF and cause cerebral ischemia, or strokes. As a result, standard practice is to slowly reverse hyperventilation while more definitive treatments aimed at the primary cause are instituted.It is important to note that prolonged hyperventilation in those with traumatic brain injuries has been shown to worsen outcomes. Barbiturates
Induction of a coma via the use of barbiturates, most notably pentobarbital and thiopental, after brain injury is used for secondary treatment of refractory ICP. Yet their use is not without controversy and it is not clear whether barbiturates are favored over surgical decompression. In patients with traumatic brain injuries, barbiturates are effective in reducing ICP but have failed to show benefit to clinical outcomes. Evidence is limited for their use in cerebral disease that include tumor, intracranial hypertension, and ischemic stroke. There are several adverse effects of barbiturates that limit their use, such as lowering of systemic blood pressure and cerebral perfusion pressure, cardiodepression, immunosuppression, and systemic hypothermia. Hypothermia
As discussed previously in the treatment of fever, temperature control has been shown to decrease metabolic demand and reduce further ischemic injury. In traumatic brain injury, induced hypothermia may reduce the risks of mortality, poor neurologic outcome in adults.