Increased intracranial pressure
Sustained intracranial pressure above 20-22 mmHg from mass effect, edema, hydrocephalus, or venous outflow obstruction, diagnosed by clinical signs plus invasive monitoring and treated stepwise with head elevation, hyperosmolar therapy (mannitol or hypertonic saline), CSF diversion, and decompressive surgery when refractory.
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What this article covers
- Overview
Definition: increased intracranial pressure (ICP) is sustained pressure elevation within the closed cranial vault above normal, defined as ICP greater than 20 to 22 mmHg on an invasive monitor…
- Epidemiology
Trauma-driven burden: severe traumatic brain injury is the leading cause of acutely elevated ICP requiring neurocritical care, present in most patients with a Glasgow Coma Scale (GCS) score of 8 or less.
- Risk factors
Traumatic brain injury: GCS 8 or less, an abnormal head CT, or hypotension and hypoxia at presentation.
- Pathophysiology
Compensatory phase: early volume increases are buffered by CSF displacement into the spinal subarachnoid space and compression of venous structures, so ICP initially rises little.
- Clinical features
Headache: worse in the morning or lying flat (postural), aggravated by coughing, straining, or Valsalva maneuvers, from stretching of pain-sensitive meninges.
- Differential diagnosis
Idiopathic intracranial hypertension (pseudotumor cerebri): chronic papilledema and headache but a normal or small-ventricle MRI and no mass, confirmed by elevated lumbar puncture opening pressure with normal CSF composition.
- Diagnosis
Clinical suspicion establishes the diagnosis: a compatible picture (headache, vomiting, papilledema, declining GCS, or Cushing triad) in a patient with a known or suspected intracranial process…
- Management
First, stabilize and optimize general physiology: secure the airway if GCS is 8 or less, correct hypotension and hypoxemia (keep systolic blood pressure above 90 mmHg and PaO2 above 60 mmHg), elevate…
- Complications
Brain herniation: uncal, central, subfalcine, or tonsillar herniation with brainstem compression, which can rapidly progress to respiratory arrest and death.
- Prognosis
Response to treatment is the strongest predictor: ICP that normalizes with first-tier measures carries a better outcome than ICP requiring barbiturate coma or craniectomy.
- Prevention
Early recognition and monitoring in any patient with GCS 8 or less and an abnormal head CT prevents delayed diagnosis of a treatable rise in ICP.
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Related articles
- Traumatic brain injury
Traumatic brain injury is structural or functional brain damage from biomechanical force, graded moderate (Glasgow Coma Scale 9-12) or severe (Glasgow Coma Scale 3-8) when imaging shows contusion, edema, or hemorrhage; management centers on preventing hypotension and hypoxia, controlling intracranial pressure with hyperosmolar therapy and, when refractory, decompressive craniectomy.
- Subarachnoid hemorrhage
Subarachnoid hemorrhage is sudden bleeding into the subarachnoid space, most often from a ruptured saccular (berry) aneurysm, presenting as the worst headache of a patient's life. Diagnosis is noncontrast head CT, then lumbar puncture if CT is negative, then catheter angiography to define the aneurysm; management is early aneurysm securement, blood pressure control, and nimodipine to reduce delayed cerebral ischemia from vasospasm.
- Intracerebral hemorrhage
Spontaneous bleeding into brain parenchyma, most often from chronic hypertension affecting deep penetrating vessels or from cerebral amyloid angiopathy in lobar locations, diagnosed by noncontrast CT and managed with acute blood pressure lowering, reversal of anticoagulation, and surgical evacuation for select cerebellar or deteriorating hemorrhages.
- Idiopathic intracranial hypertension (pseudotumor cerebri)
Idiopathic intracranial hypertension (formerly pseudotumor cerebri) is raised intracranial pressure of unclear cause, without a mass lesion or hydrocephalus, occurring mainly in obese women of childbearing age and presenting with headache, papilledema, and visual symptoms. Diagnosis requires an elevated lumbar puncture opening pressure with normal CSF and normal or empty-sella imaging; treatment centers on weight loss and acetazolamide to protect vision, with surgery reserved for medically refractory disease.