Burn Encephalopathy - Symptoms and Management

What Is Burn Encephalopathy?

Encephalopathy is the term for any disease that alters brain function or structure. If the alteration occurs from severe burns, it is called burn encephalopathy.

Burns are dynamic and complex injuries; damage depends on the severity and the cause of the burn. Based on the severity, the burns can range from a first-degree burn affecting the outer layer of the skin to a fourth-degree burn that destroys the two layers of the skin, underlying tissue, and sometimes the muscle and the bone.

The different causes of burns are-

• Fire.

• Electrical currents.

• Chemical burns.

• Radiation from X-rays.

• Hot liquids and metals.

• Abuse.

The reason behind knowing the cause is to understand the degree of damage that is caused by each injury. For example, if a fire causes a third or fourth-degree burn, the extent of external injury that it will cause is already mentioned, but the internal damage, especially to the brain, is not visible. But after examining different victims over a period of time, it is evident that cerebral hypoxia, cerebral edema, septic encephalopathy, etc. are a few complications caused due to fire-related burns.

Another example is encephalopathy caused due to electrical burns; it causes brain damage by two different mechanisms- direct injury due to blast effect and tissue exposure to the current through thermal injury. This can cause damage to the brain tissue and vascular endothelium (also known as blood-brain barriers).

After the injury, the immune responses become disproportionate, and inflammatory cells readily cross the blood-brain barrier and release copious amounts of harmful chemicals that will cause neuronal damage and life-threatening cerebral edema. Both short-term and long-term neurological complications that follow after burns are one of the leading causes of mortality in burn victims.

What Are the Neurological Complications of Burn Victims?

Burn victims suffer a myriad of symptoms, some of which are discussed below-

Short-Term or Acute Complication-

1. Cerebral Hypoxia - Cerebral hypoxia is a condition where the brain tissue is deprived of oxygen, leading to loss of brain functions. Fire consumes oxygen from the atmosphere to continue burning; as a result, patients trapped in the fire often have less oxygen in the air to breathe. The longer the brain lacks oxygen, the more damage occurs.

2. Cerebral Stroke - Under normal conditions, the blood-brain barrier (present in the blood vessels supplying the brain) regulates the substances that enter and out of the brain. When the body is subjected to severe burns, the immune system gets triggered and releases a plethora of inflammatory substances in an attempt to restore equilibrium in the body. These substances also disable the selective permeability of the blood-brain barrier and enter the brain in large amounts, thereby increasing intracranial pressure. This increased pressure will compress the narrow blood vessels that supply blood to the brain, causing a cerebral stroke.

3. Carbon Monoxide Intoxication - During a fire, the atmosphere has higher concentrations of carbon monoxide (also known as a silent killer), which will enter the patient's respiratory system. Carbon monoxide readily binds with hemoglobin and reduces the oxygen-carrying capacity of the red blood cells, which in turn will cause cerebral hypoxia in burn victims.

4. Toxic Shock Syndrome - Burn victims are prone to toxic shock syndrome as they are immunosuppressed, and as a result, they are easily subjected to bacterial infections, which then secretes large amounts of life-threatening toxins into the body, including the brain. The events that follow are fever, vomiting, headaches, confusion, diarrhea, etc., which will eventually lead to shock, renal failure, and death.

Long-Term or Chronic Complications -

1. Pain - This is both a short-term and a long-term complication. In some patients following a burn injury, some nerve endings get completely damaged; this insensates the surrounding area, and as a result, the patient does not experience any pain.

However, in many of the victims, the nerves remain undamaged, resulting in significant pain at the site of the injury. The pain is similar to neuropathic pain, which occurs when the nervous system is damaged or not working properly, and as time progresses, it becomes chronic.

The process of pain in both acute and chronic conditions is multidimensional, comprising nociceptive, cognitive, emotional, and affective components, each of these relating to specific brain structures.

2. Pruritus - Also known as itchy skin, is a common symptom affecting almost 90 % of burn survivors. The body releases inflammatory substances like histamine, leukotrienes, cytokines, etc., as a response to burn, which also act as pruritogenic agents instigating the itch mechanism.

In addition to this, burns also reduce peripheral sensitization, which decreases the activation threshold and increases the activity of itch-related receptors and nerve fibers.

Both mechanisms exacerbate the symptomatology of itch, which significantly affects the survivor's quality of life, sleep, psychosocial health, and daily activities.

3. Psychological Disorders - These include anxiety, depression, and post-traumatic stress disorder (PTSD). Anxiety is defined as feelings of excessive fear, worry, and unease caused by external or internal threats that last for more than six months.

Depression is characterized by low mood, often in concordance with low self-esteem, loss of interest in normally enjoyable activities, and loss of energy for at least two weeks.

PTSD is a mental disorder caused due to exposure to either death, serious injury, or sexual violence. Symptoms include disturbing thoughts, feelings, or dreams related to the events, mental or physical distress to trauma-related cues, and attempts to avoid trauma-related cues.

4. Sleep Disturbance - This includes disorders in instigating and maintaining sleep, excessive somnolence, sleep-wake schedule alterations, and dysfunctions associated with actual sleep, sleep stages, and partial arousals. These are caused due to traumatic experiences, psychiatric disorders, and neurological damages caused during burns.

5. Fatigue - It is of two types, myopathic and subjective fatigue. Myopathic fatigue is due to muscle weakness and is seen in peripheral nerve disorders and neuromuscular junction disorders, which are common after severe burns.

Subjective fatigue includes cognitive fatigue caused due to lesions in the neural pathways caused by high levels of inflammatory cytokines released into the body as a response to burns.

6. Impaired Motor Strength - This is a consequence of myopathic fatigue; due to extreme fatigue, the patient is unable to use their muscles which leads to muscle wasting.

During muscle wasting, the fibers in the skeletal muscle are repeatedly broken down, which leads to degeneration of the sensory and motor neuron nerves and subsequent symptoms of motor weakness.

Apart from the above-mentioned symptoms, burns also cause gliomas which are solid tumors of the central nervous system with a poor overall prognosis. Studies have shown that inflammation caused as a result of burn is responsible for gliomagenesis.

How Is Burn Encephalopathy Treated?

Unfortunately, there is no standard treatment plan to treat neurological complications caused due to severe burns. They are often addressed last because the focus is and should be on treating medical emergencies like maintaining a competent airway if the patient is unconscious, inducing a coma in patients who are in shock, 100% oxygen administration, dressing the wounds, etc. Once the patient is stable, the clinician will prescribe pain medication (like Codeine, Morphine, etc.) as part of the maximum medical therapy.

Along with these, a few adjuvant therapies to manage burn-induced encephalopathy are-

• Electrical Stimulation - Known as transcutaneous electrical nerve stimulation (TENS), this treatment uses low voltage electrical impulses to relieve pain.

• Massage Therapy - It has been observed that burn victims experience less itching, pain, anxiety, and depressed mood when they receive massage therapy during the healing of the wounds.

• Physical Therapy - It improves blood circulation to the brain along with restoring the movements and functions of the affected areas.

• Mind-body Medicine - Some clinicians believe that hypnosis and therapeutic touch (TT) reduce pain, and anxiety, enhance relaxation and correct the body’s imbalances in people with burns. However, there is not enough evidence behind this theory.

Conclusion:

Burns are devastating injuries that affect almost every system in the body, but priority is always given to immediate management of the actual burn and vitals. The neurological and musculoskeletal symptoms appear after a few weeks or years and lead to life-altering and sometimes life-threatening conditions. Appropriate management can only be achieved when the critical-care personnel adjusts their treatment modalities in accordance with the systemic and cerebral pathophysiology that follows severe burns.