What are the symptoms and signs of increased intracranial pressure (ICP)?

Signs and Symptoms of Increased Intracranial Pressure

The key signs and symptoms of increased intracranial pressure (ICP) include declining consciousness, focal neurological deficits, abnormal pupillary responses, and abnormal posturing, which typically develop in the later stages of illness and constitute a medical emergency requiring immediate intervention. 1

Early Signs and Symptoms

• Headache - Often severe and may worsen with Valsalva maneuvers 1
• Nausea and vomiting - Particularly projectile vomiting without preceding nausea 1
• Visual disturbances - Including blurred vision, diplopia, and visual field defects 1
• Altered mental status - Ranging from mild confusion to progressive decline in consciousness 1
• Papilledema - Swelling of the optic disc visible on fundoscopic examination 1

Late Signs and Symptoms

• Declining level of consciousness - Progressive deterioration from drowsiness to coma 1
• Focal neurological deficits - Including weakness, sensory changes, or abnormal reflexes 1
• Pupillary abnormalities - Unequal, dilated, or poorly responsive pupils; unilateral sluggish or absent pupillary responses are the most reliable signs 1
• Abnormal posturing - Decorticate or decerebrate posturing indicating severe pressure on brain stem structures 1
• Cushing's triad - Late finding consisting of:
  • Hypertension with widened pulse pressure
  • Relative bradycardia
  • Irregular respiratory pattern 1

Special Considerations

Pediatric Patients

• In infants with open fontanelles: bulging fontanelle, increased head circumference, separation of cranial sutures 1
• In children with malaria: brain swelling is a major feature in fatal cases 1
• Children may develop generalized cerebral hyperemia during the first 24-48 hours post-injury 2

Ophthalmologic Signs

• Papilledema is a late finding in acute raised ICP 1
• Sixth nerve palsy (abducens nerve) causing incomitant esotropia, typically greater at distance 1
• Abduction nystagmus may be present 1

Diagnostic Considerations

• Lumbar puncture - Opening pressure >200 mm H₂O indicates elevated ICP 1
• Neuroimaging findings - CT/MRI may show:
  • Disappearance of cerebral ventricles
  • Brain midline shift over 5 mm
  • Intracerebral hematoma volume over 25 mL
  • Compression of basal cisterns (best radiographic sign of ICP) 1

Important Pitfalls and Caveats

• Pupillary signs and consciousness level may be misleading in the peri-ictal state (after seizures) 1
• Papilledema may be absent despite significantly elevated ICP, especially in acute onset 1
• Symptoms may be subtle or subclinical in up to 25% of cases 1
• Hypoglycemia may precipitate seizures or posturing and should be ruled out 1
• The development of features suggestive of raised ICP should be considered a medical emergency 1

Treatment Considerations

• Rapid induction of anesthesia, tracheal intubation, and mechanical ventilation may be needed 1
• Mannitol (0.5-1 g/kg) infused rapidly over 5-10 minutes can effectively lower ICP but has short-term effects 1, 2
• Maintain cerebral perfusion pressure (CPP) above 50-60 mmHg 1
• Avoid steroids as their effect on raised ICP remains unclear and may adversely affect outcomes 1
• Monitor for potential complications of mannitol including renal failure, fluid and electrolyte imbalances 2

Early recognition of these signs and symptoms is critical for timely intervention to prevent secondary brain injury, herniation, and death.