Increased Intracranial Pressure

Continuing Education Activity

• Normal Cranial Pressure: < 20 mm Hg
• Cranium Structure: Contains brain, cerebrospinal fluid (CSF), and blood
• Clinical Implication of Volume Change: Decreased cerebral blood flow or brain herniation
• Activity Overview: Causes, pathophysiology, and management of increased intracranial pressure (ICP)

Objectives

• Describe causes of increased ICP
• Review clinical presentation
• Summarize treatment options
• Improve interprofessional care coordination

Introduction

Definition and Components

• Intracranial Hypertension (IH): Elevated pressure in the cranium
• Components: Brain, CSF, and blood
• Monroe-Kellie Doctrine: Constant volume state

CSF Flow

• Produced by: Choroid plexus
• Flow Path: Lateral ventricles → 3rd ventricle → 4th ventricle → subarachnoid space → reabsorbed into dural venous sinuses

Etiology

Causes of Increased ICP

• Brain Volume Increase:

  • Generalized swelling (cerebral edema)
  • Mass effect (hematoma, tumor, abscess, infarct)

• CSF Increase:

  • Increased production (choroid plexus tumor)
  • Decreased reabsorption (hydrocephalus, meningitis)

• Blood Volume Increase:

  • Increased cerebral blood flow (hypercarbia, aneurysms)
  • Venous stasis (thromboses, heart failure)

• Other Causes: Idiopathic hypertension, skull deformities, drug side effects

Epidemiology

• TBI linked with increased ICP
• Incidence of idiopathic intracranial hypertension varies, more common in overweight women

Pathophysiology

• Cerebral Ischemia: Decreased brain perfusion due to increased ICP
• Cerebral Perfusion Pressure (CPP): CPP = MAP - ICP; critical to maintain for brain health

History and Physical

• Symptoms: Headaches, vomiting, altered mental status, visual changes
• Cushing Triad: Hypertension, bradycardia, irregular respiration

Evaluation

• Importance: Early identification critical to prevent herniation
• Methods: History, physical exam, CT scans, fundoscopic exams

Monitoring Techniques

• Lumbar Puncture: Measures CSF pressure
• ICP Monitoring Devices: Fiber optic catheters, external ventricular drains
• Optic Nerve Sheath Diameter (ONSD): Ultrasound measurement

Treatment / Management

• Priorities: Maintain cerebral perfusion, treat causes, lower ICP
• Strategies:
  • Elevate head, midline neck position
  • Hyperventilation, osmotic agents (mannitol, hypertonic saline)
  • Carbonic anhydrase inhibitors, lumbar punctures
  • Surgical options: Craniectomy, shunts, optic nerve fenestration

Differential Diagnosis

• Acute nerve injury, stroke, hydrocephalus, migraines

Prognosis

• Depends on etiology and severity
• Benign intracranial hypertension not directly fatal, but associated with obesity-related risks

Deterrence and Patient Education

• Educate on warning symptoms: headaches, vomiting

Pearls and Other Issues

• Evaluate for neurologic deficits with suggestive symptoms
• Follow TBI management guidelines for severe cases

Enhancing Healthcare Team Outcomes

• Importance of interdisciplinary communication and management
• Educate patients on post-discharge safety and follow-up care

References

• Cited literature supporting various aspects of ICP management and guidelines.