Cerebral edema - high brain pressure

Cerebral edema occurs when fluid builds up around the brain, which increases brain pressure. The brain pressure is also called intracranial pressure or ICP.

swelling due to fluid that has nowhere to go.
Cerebral edema can have serious consequences.

The brain needs good blood flow to supply oxygen and food, such as glucose. This is necessary in order to function.

 

Cerebral edema can restrict the flow of blood to the brain. As a result, a lack of oxygen in the brain can occur and the brain cells can be damaged or even die. Because the hard skull cannot expand, the brain can be pushed towards the brain stem.

Important parts of the brain stem can become trapped. The brainstem is responsible for respiration, circulation and consciousness.

Cerebral edema can cause irreversible damage and in some cases can be fatal.

 

Complaints

The following complaints can occur

  • Headache
  • Nausea and vomiting
  • Trouble speaking
  • Trouble moving
  • Trouble seeing
    • double vision
    • blurred vision
  • Loss of feeling
  • Dizziness
  • Pain in the neck
  • Epileptic attacks
  • Disturbances in consciousness, unconsciousness

 

Treatment

Because increased brain pressure can cause serious damage to the brain and brainstem, medical intervention will be necessary. Possible treatment methods or combinations are listed below.

  • Medication depending on the cause:
    • Diuretics, usually corticosteroids, mannitol or glycerol by infusion
    • Anticoagulant medications to dissolve blood clots and help blood to clot less quickly
  • Pain relief, because pain can influence the pressure in the brain
  • Installing a pressure sensor, a tube with a small pressure sensitive device,  ICP measurement. (This is done in the operating room or ICU and takes about 30 minutes. The tube is attached to the skull with a screw.)
  • Keeping the patient asleep / artificial coma
  • Ventilation
  • Surgery
    • Constructing a brain drain / shunt
    • Opening the skull to release the pressure from the brain.
    • Surgery on the damaged brain areas
  • Hypothermia / cooling the body

 

Causes of cerebral edema / high brain pressure

 

By an accident brain tissue can tear and swell, partly due to blood leakage. The bleeding takes up space within the skull and causes an increase in brain pressure. The walls of the brain capillaries can leak blood plasma, and this plasma then leaks into the brain tissue

- Severe concussion

- Brain contusion

Cerebral hemorrhage occurs when a blood vessel in the brain ruptures and starts leaking. The bleeding takes up space within the skull and causes an increase in brain pressure.

Lack of oxygen can damage brain cells and cause swelling and pressure.

  • Sinus thrombosis

When a large vein in the brain becomes blocked, the blood cannot be drained, but the arteries supply more blood. Then increased brain pressure can arise.

This can put pressure on other brain areas or prevent brain fluid / liquor from being drained.

  • Brain cyst
  • High blood pressure pinching surrounding blood vessels
  • Pregnancy complications
  • Birth defects
  • Hydranencephaly or hydroenencephaly; (partly) missing large brains, causing the skull to fill with fluid
  • Hydrocephalus
  • Narrowing of the connection between the third and fourth brain chamber
  • Disruption in the development of the fourth brain chamber.

  • Cerebral hemorrhage in the first days of a baby born prematurely

  • Increased production of cerebrospinal fluid

  • Inadequate drainage of cerebrospinal fluid with congestion of the brain chambers (ventricles) - ventriculoma

  • Disturbance in the balance between production and drainage of cerebrospinal fluid - idiopathic intracranial hypertension - benign intracranial hypertension - pseudotumor cerebri

  • Tumor in the organ of production of cerebrospinal fluid (plexus papilloma)
  • Enlarged brain chambers, enlarged ventricles after traumatic brain injury (post traumatic ventriculomegaly)
  • Normal Pressure Hydrocephalus due to age, resembles dementia. Also called NPH; Normal Pressure Hydrocephalus (see the hydrocephalus page).
  • Untreated or long-term diabetes that can make the blood vessel wall brittle
  • Kawasaki disease; vascular wall inflammation, which causes blood vessels to build up and impedes the drainage of fluid
  • Stay at a high altitude above 4000 meters

 

Midline shift


Midline shift literally means the shift of the center line of the brain. It is closely related to intracranial pressure (ICP) explained above.
It describes the situation where the midline of the brain anatomy is no longer centered. The center has moved.
This can occur when the pressure exerted by the pooling of blood and swelling around the damaged brain tissues is so forceful that it pushes the brain away from its center.
It can be a result of traumatic brain injury, stroke, bruising (hematoma) or birth defect in which the brain pressure is increased.

 

There are three brain structures that serve as reference points. If any of these three are misaligned, it indicates that pressure on one side of the brain is pushing the brain out of position.
Being:

  1. the septum pellucidum: a thin membrane that runs directly through the center of the brain.
  2. the third ventricle: a space filled with cerebrospinal fluid located deep in the center of the brain.
  3. the pineal gland (epiphysis): a small gland located just behind the third ventricle.

 

The image below shows a midline shift due to a subdural hematoma

By James Heilman, MD Own work, CC BY-SA 3.0 https://commons.wikimedia.org/w/index.php?curid=16263158

Brain pressure fact

  • Normal brain pressure / intracranial pressure (ICP) is between 5 and 15 mmHG (mercury pressure), but should remain below 20 mmHg (mercury pressure). ICP should be less than 20 mmHg.
  • Another value is cerebral perfusion pressure (CPP), which is also measured to detect and treat cerebral edema. Cerebral perfusion pressure (CPP) is determined by the mean pressure in the arteries (arterial blood pressure, mean arterial pressure (MAP)) and intracranial pressure (ICP) Cerebral perfusion pressure must be between 50 and 70 mmHg.

 

 

Sources
Bratton SL et al. J Neurotrauma 24 (S1): S55-S58, S59-S64 2007,
Lang EW, Chesnut RM. Intracranial pressure and cerebral perfusion pressure in severe head injury. New Horizons 3:400-409, 1995
Robertson CS et al. Crit Care Med 27: 2086, 1999

Eisenberg H, Frankowski R, Contant C et al. Comprehensive central nervous system trauma centers: High dose barbiturate control of elevated intracranial pressure in patients with severe head injury. J Neurosurg 1988;69:15-23

Marmarou A, Anderson RL, Ward JD et al. Impact of ICP instability and hypotension on outcome in patients with severe head trauma. J Neurosurg 75:S59-S66, 1991
Ghajar JB, Hairiri RJ, Paterson RH. Improved outcome from traumatic coma using only ventricular CSF drainage for ICP control. Adv in Neurosurg 21:173-177, 1993

https://www.openanesthesiaintracranial_pressure_manual/