What are the signs of increased Intracranial Pressure (ICP)?

Signs of Increased Intracranial Pressure (ICP)

The most common signs of increased intracranial pressure include headache, papilledema, nausea, vomiting, and altered mental status, which may progress to more severe neurological deterioration if left untreated. 1

Primary Clinical Manifestations

Early Signs

• Headache
  • Typically diffuse, progressive in severity over days to weeks
  • Often worse in the morning or when lying flat
  • Exacerbated by Valsalva maneuvers (coughing, straining)
  • May present as thunderclap headache in some cases 1, 2
• Nausea and vomiting
  • Often projectile vomiting without preceding nausea
  • May occur particularly in the morning 1, 2
• Visual disturbances
  • Transient visual obscurations
  • Blurred vision
  • Double vision (diplopia from sixth nerve palsy) 1
• Papilledema
  • Swelling of the optic disc visible on fundoscopic examination
  • Present in approximately 60% of cases 1

Late Signs

• Declining level of consciousness
  • Progressing from drowsiness to stupor and coma 3
• Pupillary abnormalities
  • Unequal pupils
  • Dilated, poorly reactive pupils
  • Sluggish or absent pupillary responses (most reliable sign) 1
• Cushing's triad (late finding)
  • Hypertension
  • Bradycardia
  • Irregular respiratory pattern 1, 3
• Abnormal posturing
  • Decorticate or decerebrate posturing 1, 3
• Focal neurological deficits
  • Hemiparesis or quadriparesis
  • Cranial nerve palsies 1, 3

Age-Specific Presentations

In Infants

• Increasing head circumference (before fontanelle closure)
• Bulging fontanelle
• Loss of developmental milestones 1
• Irritability
• Poor feeding

In Children

• Headache and vomiting (most common)
• Poor school performance
• Fatigue
• Personality changes 1
• Seizures (may be subtle or subclinical in 25% of cases) 1

In Adolescents and Adults

• Similar to adult presentation with headache, visual changes, and nausea/vomiting
• May present with isolated headache without focal neurological findings in up to 25% of cases 1

Imaging Findings of Increased ICP

• Empty sella
• Flattening of the posterior aspect of the globes
• Distention of the perioptic subarachnoid space
• Transverse sinus stenosis 1
• Dilated optic sheaths 1

Common Pitfalls and Caveats

1. Isolated headache without focal neurological findings occurs in up to 25% of patients with increased ICP and presents a significant diagnostic challenge 1

2. Papilledema may be absent in acute onset of increased ICP, making diagnosis more difficult 1, 2

3. Post-ictal states can mimic signs of increased ICP, with altered pupillary responses and consciousness that may be misleading 1

4. Secondary causes of increased ICP should be considered in males, young children, older patients, and those not overweight 4

5. Certain medications can cause increased ICP, particularly tetracycline-class antibiotics and some fluoroquinolones 5

6. Imaging may be normal despite elevated ICP, particularly in idiopathic intracranial hypertension 2

The recognition of these signs is essential for timely diagnosis and treatment to prevent cerebral hypoperfusion and possible brain death. When increased ICP is suspected, prompt neuroimaging and consideration of invasive ICP monitoring may be necessary, particularly in cases with progressive neurological deterioration 3, 6.