Wernicke's encephalopathy

Medical quality assurance by Dr. Albrecht Nonnenmacher, MD at September 23, 2016
StartWernicke's encephalopathy

Wernicke's encephalopathy is a condition with diverse symptoms caused by a deficiency of thiamine or vitamin B1. This rare but serious condition requires immediate medical attention to avoid risk of death.

Contents

Definition & Facts

Wernicke's encephalopathy is a collection of diverse symptoms caused by biochemical brain lesions that are the result of a thiamine deficiency. The location of the lesions influences which symptoms will manifest. It has widely been considered to be a disease caused by alcoholism.

However, this is not wholly accurate, as it can be caused by a wide variety of other factors. Wernicke's encephalopathy is officially considered a "rare disease", according to the Office of Rare Diseases of the National Institutes of Health. It is also considered to be under-diagnosed.

Symptoms & Complaints

The three major symptoms of Wernicke's encephalopathy are confusion, ophthalmoplegia, and ataxia. Ophthalmoplegia refers to weakness of the muscles that are responsible for eye movement. Ataxia refers to difficulty coordinating voluntary muscle movements. Gait abnormality, or walking in an abnormal way, is a common manifestation of ataxia.

Aside from this symptom triad, many other symptoms can be present in Wernicke's encephalopathy. These can include eye-related symptoms such as lazy eye, changes in the pupil, impaired vision or vision loss, retinal hemorrhage, and papilledema (swelling of the optic disc, a spot in the back of the eye where nerves exit).

Other symptoms include cognitive symptoms like memory loss, slowed thinking, and psychosis. Psychological symptoms may also occur and include irritability, depression, and apathy. Other assorted symptoms can include hearing loss, fatigue, difficulty swallowing (dysphagia), epilepsy, hypothermia, and excessive sweating.

Causes

The core cause of Wernicke's encephalopathy is thiamine deficiency. However, one can still develop this disease despite getting adequate dietary intake of this vitamin, as there are medical conditions that can keep the body from using thiamine correctly. Wernicke's encephalopathy is more common among those who are addicted to alcohol. This is because alcohol adversely affects the uptake and use of thiamine.

There are many other conditions that can interfere with the absorption and metabolism of thiamine. For example, many gastrointestinal diseases can cause malabsorption of nutrients, and these disorders are fairly common in the general population. A couple of examples of such disorders include Crohn's disease and celiac disease. Even chronic diarrhea or chronic vomiting can cause a thiamine deficiency.

A wide variety of other types of medical conditions can lead to Wernicke's encephalopathy, ranging from autoimmune diseases, to neurological disorders, to pregnancy-related conditions. A few of the many other documented causes of Wernicke's encephalopathy include AIDS, Creutzfeldt–Jakob disease, bone marrow transplantation, cancer, chemotherapy, use of diuretics, fasting, febrile infections, gastrointestinal surgery, hyperemesis gravidarum, liver disease, pancreatitis, dialysis, starvation, stem cell transplantation, thyrotoxicosis or hyperthyroidism, and uremia.

Diagnosis & Tests

Diagnosing Wernicke's encephalopathy is not as straightforward of a process as some other conditions. This is partly because thiamine serum levels are not a reliable basis for a diagnosis. It is also because there are such a wide variety of symptoms, most of which can be caused by other medical conditions. Therefore, the presence of Wernicke's encephalopathy is determined by the best judgment of the clinical practitioner. All signs and symptoms will be taken into account when making this decision.

The diagnostic process sometimes also includes psychological evaluations, cognitive tests, and neurological examinations. For example, testing for memory and physical coordination can be useful when making a Wernicke's encephalopathy diagnosis.

Among the three main symptoms (confusion, ophthalmoplegia, and ataxia), only 10% exhibit all three. If Wernicke's encephalopathy is a possibility, it's crucial to immediately seek a diagnosis in order to start treatment and avoid further adverse health complications.

Treatment & Therapy

Wernicke's encephalopathy is considered a medical emergency and must be treated immediately. Generally, the first step in treating this condition is hospitalization. Since the root cause of Wernicke's encephalopathy is thiamine deficiency, the main treatment method for the condition is thiamine supplementation. Most of the time, this treatment is in the form of intramuscular injections or intravenous supplementation.

The patient usually receives two or three doses daily. Administration of thiamine continues until the patient recovers as much as possible. Early-stage lesions on the brain are fully reversed in most people following thiamine supplementation.

In some cases, anti-inflammatory medications are also administered. Depending on the cause of the encephalopathy, the patient may also require additional nutrients. For example, having a co-existing magnesium deficiency can aggravate the thiamine deficiency. If a magnesium deficiency is the case, then the patient also requires magnesium supplementation.

After hospitalization, the patient may continue to receive nutritional supplements on an outpatient basis. Aside from treating the thiamine deficiency itself, it's also important to treat the underlying cause. There are many chronic medical conditions that can lead to Wernicke's encephalopathy, and managing these conditions under the guidance of a physician is necessary for preventing Wernicke's encephalopathy as well as many potential other complications.

Prevention & Prophylaxis

The most basic way to reduce the risk of Wernicke's encephalopathy is to get adequate nutrition. It can be a good idea to get checked for nutrient deficiencies on a regular basis; this can be done with a simple blood test. Most nutritional deficiencies are easily corrected through dietary changes or dietary supplements, unless there's an interfering medical condition present.

Another important aspect of preventing Wernicke's encephalopathy is to avoid excessive alcohol consumption. The Centers for Disease Control and Prevention define moderate alcohol consumption as up to one drink per day for women and up to two drinks per day for men; this is a reliable guideline to follow. This variety of encephalopathy is also prevented by managing the other underlying medical conditions that can cause it.

On a clinical level, there are healthcare protocols for preventing Wernicke's encephalopathy in patients. For example, clinicians often administer preventative thiamine supplements in people with alcoholism, malnutrition, diarrhea, and peripheral neuropathy.