What are the signs and management of increased intracranial pressure (ICP) in patients?

Signs of Increased Intracranial Pressure

The key signs of increased ICP include declining consciousness, headache, nausea/vomiting, pupillary abnormalities, and papilledema, with late signs including Cushing's triad (hypertension with widened pulse pressure, bradycardia, and irregular respirations) indicating severe intracranial hypertension requiring emergent intervention. 1

Early Clinical Signs

Neurological Symptoms

• Headache is typically severe and worsens with Valsalva maneuvers, representing one of the earliest symptoms 1
• Altered mental status ranges from mild confusion to progressive decline in consciousness, with behavioral changes occurring even with minimal consciousness impairment 1, 2
• Nausea and vomiting are common, with projectile vomiting occurring without preceding nausea being particularly characteristic 1

Visual Disturbances

• Papilledema (optic disc swelling on fundoscopic examination) is a notable sign, though it may be absent in acute onset despite significantly elevated ICP 1
• Blurred vision, diplopia, and visual field defects can occur 1
• Sixth nerve palsy causing incomitant esotropia (typically greater at distance) can indicate elevated ICP 1

Progressive Signs by Severity Grade

Grade I-II Encephalopathy

• Behavioral changes with minimal consciousness change, gross disorientation, drowsiness, and possibly asterixis 2

Grade III Encephalopathy

• Marked confusion, incoherent speech, sleeping most of the time but arousable to vocal stimuli 2

Grade IV Encephalopathy

• Comatose state, unresponsive to pain, indicating severe intracranial hypertension 2

Late and Critical Signs

Cushing's Triad (Late Finding)

• Hypertension with widened pulse pressure, bradycardia, and irregular respirations represent a late sign of elevated ICP 2
• Waiting for the full Cushing's triad before intervention results in delayed treatment, as these signs manifest late in the disease course 2
• Cushing's reflex indicates severe intracranial hypertension with ICP typically >40 mmHg, associated with 6.9-fold increased mortality 3

Pupillary Changes

• Anisocoria (unequal pupils) or bilateral mydriasis (dilated pupils) are associated with elevated ICP 2

Abnormal Posturing

• Decorticate or decerebrate posturing indicates severe brain dysfunction from elevated ICP 1

Pediatric-Specific Signs

• Bulging fontanelle, increased head circumference, and separation of cranial sutures in infants with open fontanelles 1
• Brain swelling is a major feature in fatal pediatric malaria cases 1

Diagnostic Thresholds

ICP Measurements

• ICP >20-25 mmHg is generally considered elevated and requires aggressive therapy 1, 3
• Lumbar puncture opening pressure >200 mm H₂O (approximately 15 mmHg) indicates elevated ICP 1

Severity and Mortality Risk

• ICP 20-40 mmHg is associated with 3.95-fold higher risk of mortality and poor neurological outcome 2, 3
• ICP >40 mmHg increases mortality risk 6.9-fold and is almost universally associated with severe consciousness impairment or coma 2, 3

Neuroimaging Findings

• Disappearance of cerebral ventricles, brain midline shift >5 mm, intracerebral hematoma volume >25 mL, and compression of basal cisterns confirm elevated ICP 1, 2
• Absence of basal cisterns is associated with ICP >30 mmHg in more than 70% of cases 2

Critical Pitfalls to Avoid

• Relying solely on CT findings can be misleading, as visible basal cisterns do not completely exclude intracranial hypertension 2
• Papilledema may be absent despite significantly elevated ICP, especially in acute onset 1
• Transcranial Doppler findings (increased pulsatility index) require confirmation by other means to reliably indicate intracranial hypertension 2
• Daily interruption of sedation may be deleterious to cerebral hemodynamics in patients with signs of high ICP 3

Immediate Management Priorities

• Neurosurgical consultation is mandatory when Cushing's reflex is present, as it indicates severe intracranial hypertension requiring emergent evaluation 3
• Consider neurology consultation if grade 1 CRES develops and for specialized screening for papilledema 4
• Patients should be closely monitored for signs and symptoms of cerebral edema, with intensive-care management and osmotherapy required for ICP ≥20 mmHg or clinical signs of increased ICP 4