Toxic-metabolic encephalopathy (or metabolic encephalopathy) is a broad term that describes brain dysfunction characterized by symptoms of deliriumand/orconfusion. It is not primarily related to any structural brain damage, but may be associated with other systemic illnesses, including infection and organ failure, as well as exposure to toxic substances and other causes of chemical imbalance that may affect brain function. The condition is commonly seen among very ill patients, including elderly patients with underlying dementia, but it may also occur in young people who have been exposed to toxic substances.
What Is Toxic Metabolic Encephalopathy?
Itis a condition characterized by delirium and acute confusion due to brain dysfunction that is not primarily related to any structural brain disorder. It usually occurs in critically ill patients who have systemic illnesses, infections, or organ failure. However, it can also affect previously normal individuals who have been exposed to toxins. Depending on the cause, this condition may be reversible with proper treatment. However, in some cases, if left untreated, permanent brain damage may result, such as in cases of chronic thiamine deficiency.
Symptoms of Toxic Metabolic Encephalopathy
Abnormalities in brain function due to toxic-metabolic encephalopathyusually manifests as a decrease in levels of consciousness, ranging from lethargy to deep coma. Encephalopathy causes confusion, abnormal thought processes, poor memory, hallucinations, and psychotic thinking.
Other symptoms that suggest lack of brain control include incoordination of movements, difficulty walking, problems with vision and speech. The condition may mimic a person having a stroke, because of similar symptoms like muscle weakness, numbness on one side of the body, and facial droop. In some patients, brain dysfunction is so severe that it affects even basic activities like breathing, heartbeat, and body temperature.
Symptomsoftoxic-metabolic encephalopathy may depend on the cause of brain dysfunction. Symptoms may be constant, or they may wax and wane or become progressively severe. For example, confusion due to low blood glucose levels (hypoglycemia) may be reversed by eating, without residual effects on the brain, but a prolonged lack of oxygen in the brain may lead to permanent brain damage or even death.
When to Seek Medical Attention
Any person who displays altered mental function, unexplained confusion, seizure, weakness, or unresponsiveness should receive medical attention immediately. In patients who have recurrent encephalopathy, home treatments may be tried before calling for medical help. These include patients with known diabetes who experience symptoms of confusion due to low blood sugar. Home treatment using oral glucose or glucagon injections may relieve symptoms. However, if home treatments do not help, emergency care may be needed to find another cause for their symptoms.
Diagnosis of Toxic Metabolic Encephalopathy
The diagnosis is usually made after the doctor conducts thorough clinical tests including a physical examination, mental status evaluation, neurologic assessment and other laboratory tests. A review of the patient’s current medications may be done, since any of these may be responsible for the symptoms. Other health problems may also be evaluated since they may be the underlying cause for the brain dysfunction. Laboratory evaluation may include any of the following:
- Complete blood count (CBC)
- Metabolic tests for glucose, electrolytes, oxygen, lactate, ammonia, and liver enzymes)
- Drug or toxin levels (including alcohol, amphetamines, and cocaine)
- Blood or body fluid cultures
- CT scan or MRI
- Doppler ultrasound
- Encephalogram (EEG)
- Autoantibody analysis
These are only some of the possible tests that may be required, but other specific tests may be ordered by the physician according to the medical history and physical evaluation of the patient.
How to Manage Toxic Metabolic Encephalopathy
First, discontinue all drug intakes which could potentially affect the central nervous system. In the hospital, limb restraints, gauze mittens, and Posey belts may be necessary for the patient’s own safety.
1. Supportive Care
To prevent complications, supportive care may be provided, with goals to:
- Protect the airway
- Provide nutrition and fluids
- Assist with movement
- Treat pain
- Treat incontinence
- Limit the use of physical restraints
- Avoid the use of bladder tubes
- Avoid changes in environment
- Use same caregivers when possible
- Encourage involvement of family members or friends
Ask your doctor about limiting the use of drugs that can trigger delirium. Ask about medications to control pain that may be causing symptoms. Certain drugs may also be needed when the patient who is exhibiting confusion and abnormal behaviors has to undergo medical testing or treatment, or is endangering his own life or the safety of others. These medications may include:
- Haloperidol, to treat severe agitation. Doses are reduced for elderly patients. It should be avoided in patients with symptoms of alcohol withdrawal, benzodiazepine withdrawal or anticholinergic toxicity.
- Thiamine, to treat patients with a history of malnutrition, cancer, alcoholism, renal failure, or hyperemesis gravidarum.
3. Other Coping Tips
If you are caring for someone who has symptoms of toxic-metabolic encephalopathy, you can help improve their health and prevent complications by promoting or encouraging:
Good Sleep Habits
- By providing a quiet environment
- By keeping appropriate lighting
- By helping keep a regular scheduleatdaytime
- By encouraging activity and self-care
- By allowing the patient to sleep uninterrupted at night
Calmness and Proper Orientation
- By having a calendar and clock in the room
- By using simple communication about changes in activity
- By avoiding a cluttered environment
- By approaching the person calmly
- By identifying yourself regularly
- By avoiding arguments
- By using appropriate comfort measures
- By keeping noise levels to a minimum
- By providing eyeglasses or hearing aids when necessary
Prevent Complicating Medical Problems
- By giving their proper medication on schedule
- By providing a healthy dietandplenty of fluids
- By encouraging physical activity
- By getting proper treatment for medical problems