Intracranial Pressure and Regulation

Intracranial Pressure and Regulation

Brain Anatomy Reminder

• Cerebrum: Brain tissue.
• Thalamus and Hypothalamus:
  • Responsible for hormones (pituitary gland).
  • Temperature regulation.
  • Growth.
• Brain Stem (Medulla):
  • Parasympathetic functions.
  • Balance and coordination.
  • Breathing (autonomic).

Intracranial Pressure (ICP) Basics

• Skull: Bone structure protecting the brain.
• Dura Mater: Layers between the skull and brain tissue for shock absorption.
• Brain swelling can occur due to:
  • Viral infections.
  • Injuries.
  • Bacterial infections.
• Swelling within the skull leads to increased intracranial pressure.

Coupe Contra Coupe

• Brain injury where the brain hits one side of the skull and then bounces to hit the opposite side.
  • Example: Car accident where the head is impacted from behind causing the brain to hit the front then back of the skull
• Can cause bruising of the brain.
• Effects can include temporary amnesia and other neurological issues.

Skull and Cranial Vault

• Cranial Vault: Another name for the skull.
• Soft Spot (Fontanelle):
  • In infants, the skull is not fully formed, leaving a soft spot.
  • Sutures gradually close as the child grows, typically by age 12.
  • Sunken soft spot indicates dehydration in infants.
  • Bulging indicates a cranial injury.

Blood-Brain Barrier

• Protects the brain by limiting what can pass through.
• Substances that CAN break through:
  • Alcohol.
  • Some illegal substances.
  • Certain medications.
  • Some viruses.
  • Glucose.
  • Spinal fluid.

Spinal Fluid Leakage

• Testing for spinal fluid: If clear drainage is suspected from the nose, test it.
• Halo Test: Place the fluid on a clear piece of paper or tissue.
  • If it's spinal fluid, a halo (ring) will form around the fluid as it dries due to the presence of glucose.

Increased Intracranial Pressure (ICP) & Cerebral Edema

• Cerebral Edema: Swelling of the brain.
• Cerebral Edema leads to increased intracranial pressure due to the brain pushing against the skull.

Symptoms of Increased ICP

• Headache: Often described as the worst headache ever experienced.
• Hypertension: High blood pressure.
• Vision Disturbances: Blurred or lost vision.
• Speech Changes: Slurred speech.
• Balance Issues: Loss of balance.
• Comprehension Difficulties
• Changes in Level of Consciousness (LOC)

Diagnoses related to Increased ICP

• Hemorrhagic Bleed: Bleeding in the brain, can lead to hemorrhagic stroke
• Brain Tumor: Growth in the brain resulting in increased pressure

Populations at Risk for Increased ICP

• Elderly: Due to falls.
• Young Children: Also due to falls.
• Adolescents and Young Adults: Due to traumatic injury.
• People with Pre-existing conditions: Such as High Blood Pressure / Diabetes

Risk Factors & Assessment

• Falls (number one cause).
• Car accidents (number three cause).
• History of diabetes or high blood pressure.
• Changes in mental or motor function (numbness, vision changes, slurring, difficulty swallowing).
• Glasgow Coma Scale.
• Neurological assessment (arm drift, hand grip strength, foot push/pull).

Glasgow Coma Scale

• Assesses:
  • Eye response (scored 1-4).
    • 4: Spontaneous opening
    • 3: Open to verbal command
    • 2: Open to pain
    • 1: No eye opening.
  • Verbal response (scored 1-5).
    • 5: Oriented conversation
    • 4: Confused conversation
    • 3: Inappropriate words
    • 2: Incomprehensible sounds
    • 1: No verbal response.
  • Motor response (scored 1-6).
    • 6: Obeys commands
    • 5: Localizes to pain
    • 4: Withdraws from pain
    • 3: Abnormal flexion (decorticate)
    • 2: Abnormal extension (decerebrate)
    • 1: No motor response.
      Eye Response + Verbal Response + Motor Response = Total Score
• Total score: 3-15 (higher is better).

Symptoms of Increased ICP

• Adults:
  • Headache.
  • Changes in consciousness.
  • Vision changes.
  • Possible hypertension.
• Infants:
  • Extreme tiredness.
  • Vomiting.
  • Bulging fontanelle.

Measuring ICP

• Invasive monitoring involves inserting a shunt to measure pressure directly.

Cushing's Triad

• Indicates possible imminent death.
• Consists of:
  • Irregular respirations.
  • Bradycardia (decreased heart rate).
  • Hypertension (high blood pressure).
• Widened pulse pressure (large difference between systolic and diastolic).
• Periorbital edema: Raccoon eyes.

Stroke Types

• Hemorrhagic Stroke: Brain bleed.
• Ischemic Stroke: Blockage or lack of oxygen to the brain.

Treatment for Increased ICP

• Mannitol:
  • Number one drug for ICP. Osmotic diuretic to dehydrate the brain.
• Hyperventilation: reduces blood pressure.
• Head Elevation: At least 30 degrees to use gravity to help, do not lay the patient flat.
• Avoid activities that increase pressure (straining, constipation).
  • Stool softeners (Colace) to prevent straining.

Diagnostic Tests

• MRI vs. CT Scan
  • CT Scan: General, can see skeletal structure and some Muscle.
  • MRI: Very detailed, see tendons, ligaments, and other, fine structures
• Skull Radiography: Use some Radiation to find the blockage.
• Brain Biopsy: Examination of brain tissue.
• Lumbar Puncture: Puncturing of the lumbar to obtain cerebrospinal fluid.

Lumbar Puncture

• Patient Positioning:
  • Sitting, hunched over a table.
  • Lying on their side with knees to chest.
• A needle is inserted between vertebrae to extract fluid.
• Post-Procedure:
  • Patient lies on their back for a couple of hours.
  • May experience a slight headache due to fluid loss.
• Contraindications: Intracranial Hypertension, Parkinson's

Patient Education

• Cerebral Artery Disease: High-protein diet and regular exercise.
• Exercise Importance: Increases blood flow and oxygen to the brain.
• Injury Prevention: Protection measures to prevent further injury
• Avoid Tobacco: Causes vasoconstriction, leading to hypertension and low oxygen.

Goals of Treatment

• Prevent secondary injury to the brain.
• Improve and maintain cerebral perfusion.
  • Pharmacotherapy.
  • Surgical interventions.
  • Patient education and rehab.

Pharmacotherapy

• Osmotic Diuretics: (Mannitol) Remove excess fluid from the brain.
• Sedatives (Ativan): Calm the body and reduce overactivity.
• Morphine: promote calmness.
• Antipyretics: Reduce fever.
• Antiparkinsonian (Levodopa): Counteract tremors.
• Antihypertensives: Lower blood pressure.

Surgical Interventions

• Craniectomy: Removal of a piece of the skull to relieve pressure.

Conditions Leading to Increased ICP

• Meningitis: Viral or bacterial.
  • Viral Meningitis: Very common among Adolescents that are in communal housing
  • Bacterial Meningitis: Is more dangerous, need to watch out for.
• Stroke TBI or any Damage to the Brain.
• Epilepsy: Seizures.
• Alzheimer's Disease: Deterioration of brain tissue, starts with holes then more damage.