Brain Swelling

 What is Brain Swelling?

 Swelling is a mechanism in which the body responds to various kinds of injuries. Your brain can swell when it is injured or due to overuse and infection. Body swelling can develop quickly and while at times it is may be simple to treat, when it involves the brain, it can be fatal. The skull that protects the brain provides little space for swelling of brain.  Swelling of brain can also be referred to as brain edema, cerebral edema, or elevated intracranial pressure.

The swelling can develop in specific brain locations or throughout the organ. The kind of brain swelling a person has depends on the cause. When swelling occurs, it increases pressure in a person’s skull, also known as intracranial pressure (ICP). The pressure may prevent the flow of blood to the brain, which results in deprivation of oxygen needed to allow proper functioning of the brain. Swelling can also prevent the flow of other fluids coming from the brain causing the swelling to worsen. If damage or death of the cells occurs, the condition can be very serious.

There are many conditions that can cause the brain to enlarge abnormally. Brain swelling occurs when there is enlargement or expansion of the brain following excessive fluid accumulation in the ventricles or chambers. It can also be as a result of collection of fluid inside the brain tissue; a condition known as cerebral edema. The clinical manifestation of this condition is termed as ‘increased intracranial pressure syndrome’.

Cytotoxic cerebral edema is a subtype of cerebral edema that is most frequently observed in patients suffering from cerebral ischemia. This form of cerebral edema occurs when water from the extracellular space enters the cells, causing the cells to expand.

Hydrocephaly is a condition that results when too much fluid accumulates in the ventricles. The brain tissue then suffers pressure exerted by the collected fluid and as a result is force to press on the skull. In the case of infants and the small children, their skulls are not like the adults’ hardened ones. Their skull have soft areas called the sutures and fontanelles. Therefore, for them, in case of hydrocephaly, the head size increases too.

 Brain Swelling – Symptoms and Signs

 The human brain is embedded within the hard bony skull. In case of edema, compression of the brain as well as the blood vessels results due to lack of room for expansion. Hypoxic state ensues and the metabolic processes in the cells are hindered. The common symptoms of brain swelling are those associated with increased intracranial pressure which manifests when it exceeds 30mmHg.They do include the following depending on the extent of rise in the pressure:

Slight increase in intracranial pressure

• Headache
• Minor paralysis involving half of the body
• Changes in the fundus

Average increase in intracranial pressure

• Headache
• Vomiting
• Nausea
• Drowsiness
• Dilated pupils
• Weakness or numbness

Highly elevated intracranial pressure

• Severe headache
• Lethargy
• Seizures and convulsions
• Loss of balance or coordination
• Memory loss
• Incontinence
• Altered LOC (level of consciousness), coma
• Rare pulse
• Uneven Breathing
• High fever that is associated with neck rigidity or stiffness
• Dilated pupils, diplopia, vision loss
• Cushing Triad: Hypertension, Bradycardia, papilledema
• Herniation syndromes

In infants, the signs and symptoms of brain swelling in include:

• Bulging of the sutures and fontanelles (soft spots)
• Increase in the size of the head
• Shrill or high-pitched cry
• Irritability, fussiness
• Difficulty in feeding
• Sleepiness

Toxic exposures and chemical imbalances may lead to brain swelling. Other symptoms often observed in such cases include;

• Difficulty breathing or increased rate of breathing
• Abdominal pain
• Tachycardia (elevated heart rate) or bradycardia (reduced heart rate)
• Loss of consciousness or confusion
• Changes in the skin color and drying up of the skin
• Excessive thirst
• Difficulty in talking
• Hallucinations
• Fruity breath
• Nausea with or without vomiting
• Muscle weakness

Causes of Brain Swelling

Cerebral edema can occur due to many causes that include:

Ischemic stroke: This is the most common form of stroke and results when there is blockage or blood clot locate in or near the brain. The brain thus gets deprived of oxygen and the brain cells die leading to brain swelling.

Traumatic brain Injury: This also referred to as head or cerebral injury. In this case sudden occurrence of events leads to brain damage. The physical contact as wells the acceleration and deceleration in a quick sequence cause head injury. The most common Traumatic Head Injuries (TBIs) involve vehicle accidents, falls, assaults and crashing into or being hit with an object. The initial injury itself can cause brain damage and hence swelling occurs. Broken bones due to fractures in the skull can rapture the blood vessels leading to bleeding into the brain ventricles and subsequent accumulation of fluids causing swelling. The body’s response to the injury may result in swelling too. The out flow of fluids from the brain is hindered by too much swelling.

Intracerebral hemorrhages and strokes: The most common form of brain hemorrhage is the hemorrhagic strokes which occur due to rapture of blood vessels in any location in the brain. Blood leaks into the brain leading to pressure build up. The hemorrhagic stokes are associated mainly with high blood pressures. Hemorrhages in the brain can also be due to unknown inherited malformations, certain medications and head injuries.

Acute infectious diseases that are viral or bacterial in nature such as:

• Encephalitis: This refers to a condition involving inflammation of the brain tissue itself. It is mainly viral infections that are spread commonly through insect bites. Encephalopathy is similar to this condition and is a result of Reyes Syndrome

• Meningitis: This refers to the infection that attacks the meninges (the outer brain’s cover) leading to inflammation. It can be due to viruses, bacteria, other organisms, and the use of certain medications.

• Subdural Empyema: Refers to the condition whereby some part of the brain tissue becomes filled with pus or abscessed, usually following another ailment such as sinus infection or meningitis. Quick spread of infection results in swelling and subsequent blockage of fluid from flowing out of the brain.

• Toxoplasmosis: It’s a caused by a parasite and often affects the unborn fetuses, the young infants as well as individuals whose immune systems have been damaged.

Other Infections

Other infections in addition to the discussed above are influenza and in the children – scarlet fever, parotitis and chicken pox

• Complications of diabetes such as diabetic coma
• Brain tumors

These can lead to brain swelling in various ways. As the tumor gets bigger in size, it exerts pressure on the various areas of the brain in contact with it. In some situations, the tumor may cause blockage of cerebrospinal fluid flow out of the brain. The new blood vessels that grow in and near the brain tumor also do cause brain swelling.

Brain Swelling – Other Causes

Other causes of brain in addition to the above are;

• Chemical imbalances in the brain
• Abuse of opioids
• Intake of certain toxic substances for example poisonous drugs and chemicals
• High altitude sickness: Also referred to as acute mountain sickness. It is not common and usually manifest when one travels to altitudes at 5000ft and above.
• Malignant hypertension (blood pressure that is persistently extremely high)
• Poisonous animal or insect bites
• Large epileptic seizures.
• Eclampsia (convulsions)
• Severe nephrotic syndrome
• Heavy liver disease
• Anaphylactic shock
• Renal insufficiency
• Vitamin B12 deficiency.

 Causes of brain swelling that are related to hydrocephaly are:

• Birth defects
• Genetic abnormalities
• Cysts
• Infection
• Normal pressure hydrochepalus
• Injuries to the brain or spinal cord
• Complications of birth
• Tumors in the brain or spinal cord

 Brain swelling is a medical emergency due to the fact that the process leads to ongoing brain tissue damage thus the need for treatment as soon as possible. One is required to seek immediate medical attention in case of severe headache, head trauma, high fever that is associated with neck rigidity or stiffness, high altitude sickness, poisonous insect or animal bites, ingestion of toxins (known), or signs and symptoms that suggest brain swelling.

 Diagnosis

 For diagnostic purposes, the following procedures are usually performed:

• Examination of the head and neck
• Neurologic exam
• Laboratory tests of blood and urine samples
• Computed Tomography scan to aid in identifying the location and extent of the swelling
• Angiography
• Lumbar Puncture
• MRI

Treatment of Brain Swelling

 Treatment is dependent on the cause and the extent of brain swelling. The minor cases such as those cased by mild concussion and moderate altitude sickness do resolve after a short period of time. However, brain swelling warrants immediate medical attention. Delays result in brain damage due to the hypoxic state and other associated serious complications.

The treatment entails combination of both medical and surgical interventions. All the sought interventions aimed at ensuring that the brain gets enough oxygen by promoting blood circulation in and out of the brain while relieving the swelling. To achieve proper treatment, the root cause of the cerebral edema needs to be determined and treated too. The following can be done dependent on the underlying condition:

• Oxygen therapy -The oxygen can provided with the aid of a respirator or ventilator to ensure adequate supply of oxygen to the brain.
• Infusion of appropriate intravenous fluids – This can cause a reduction in the blood pressure as well as it ensures adequate blood supply to the brain.
• In case of brain tumors surgical intervention may be executed to excise the tumor.
• Brain abscess warrants surgical intervention to drain the abscess.
• Ventriculostomy – A hole is made and a plastic drain tube insert to aid in drainage of the excess fluid in case of hydrocephaly. Draining the CSF relieves the pressure.
• Lumbar puncture to withdraw excess fluid
• Decompressive craniotomy – in this case, the surgeon opens the skull surgically in order to reduce brain swelling by relieving it of causes of increased pressure.
• Burr holes – These refer to the small openings that are made into the individual’s skull to aid in the removal of any blood clots.
• Bone flap removal –  This entails the removal of a piece of bone from the skull to help relieving any pressure that is caused by the brain swelling.
• To lower the intracranial pressure, skull trepanation can be performed in order to free up space to accommodate the swollen brain.
• Ensure the airway is patent to ensure adequate blood oxygen levels are achieved.
• Medication –  Use antidiuretic medication to help in relieving the swelling  ensuring that the brain has reduced fluid access. The use of anticonvulsants help in preventing or stopping seizures that usually occur as a result of increased electrical activity. Barbiturates are prescribed and administered when ones’ intracranial pressure cannot be easily controlled and elevates to extremely high levels. It makes the person have a very deep sleep known as barbiturate coma and this aids in prevention of any further damage to the brain.
• Limit the intake of fluids – The brain has a sponge-like property of absorbing fluid therefore restriction of the fluid intake might be helpful in managing the swelling.
• Positioning –  Entails slight elevation of the head with the neck straight. This aids in the drainage of cerebrospinal spinal fluid from the head thus lowering the intracranial pressure.
• Brain swelling due to high altitude requires descent to lower altitudes (at least 3000 feet) – Other treatment adjuncts include; use of hyperbaric bag, avoiding exertion while one is descending, hyperventilating and use of medications such as benzodiazepines if seizures occur.

Effects of Brain Swelling

 The long term effects are dependent on the severity as well as the area in which the injury is located. Symptoms may be noticed with cognitive function impairment, for example memory and attention skills; affected motor function: weakness in the extremities, alteration in balance and coordination; affected emotional response:  depression, anxiety, aggression, personality changes;  loss of sensation: vision, hearing, impaired perception.

Prevention of Head Injuries to Avoid Brain Swelling

 Prevention entails protecting the brain from injuries through practice of the following in the day to day activities:

• Using of the helmets when skating, biking, batting, playing games involving contact like boxing, football and ice hockey, snowboarding or any other activity that can lead to falling.
• Avoid smoking
• Wearing the seat safety belts properly when riding in or driving a vehicle
• Slow speed to allow bodily adjusts to occur when travelling to higher altitudes
• Proper control of elevated blood pressure and any other heart disease
• Making the environment safe by removing any tripping hazards, ensuring stairways have hand rails, use of non-slip mats on wet floors, installing window guards and proper lighting among others
• Avoid driving when under influence of drugs or alcohol.

Authoritative Clinical References

Pathophysiology of Ischemic Brain Swelling →
https://link.springer.com/chapter/10.1007/978-3-642-70696-7_56