Encephalopathy – ICD 10 Coding and Documentation Guidelines

A diagnosis that medical coding companies come across quite often, the term encephalopathy broadly refers to brain disease, damage, or malfunction. The National Institute of Neurological Disorders and Stroke defines encephalopathy as follows:

“Encephalopathy is a term for any diffuse disease of the brain that alters brain function or structure. Encephalopathy may be caused by infectious agent (bacteria, virus, or prion), metabolic or mitochondrial dysfunction, brain tumor or increased pressure in the skull, prolonged exposure to toxic elements (including solvents, drugs, radiation, paints, industrial chemicals, and certain metals), chronic progressive trauma, poor nutrition, or lack of oxygen or blood flow to the brain.”

“Altered Mental Status”

Encephalopathy is characterized by an altered mental state. There are many different types of encephalopathy and the most common types are: toxic encephalopathy, metabolic encephalopathy, anoxic encephalopathy, hepatic encephalopathy, hypertensive encephalopathy, acute encephalopathy and chronic traumatic encephalopathy (CTE).

Encephalopathy is always regarded as the result of another disease or systemic illness. For instance, according to Coding Clinic Fourth Quarter 2003: “Metabolic Encephalopathy: is always due to an underlying condition. There are many causes of metabolic encephalopathy, such as brain tumors, brain metastasis, cerebral infarction or hemorrhage… Metabolic Enceph. may be the first manifestation of a critical systemic illness and may be caused by various reasons-one of the most important being sepsis.”

Encephalopathy ICD-10 Codes

G92 Toxic Encephalopathy

This condition is caused by the interaction of a chemical compound with the brain. It is caused by substances such as solvents, drugs, radiation, paints, industrial chemicals, and certain metals solvents, medications or drug ingestions, radiation, paints, industrial chemicals, and certain metals. Toxic encephalopathy is usually irreversible.

G93.41Metabolic Encephalopathy

This condition is a result of infections, toxins, or organ failure. Imbalances in electrolytes, hormones, or other chemicals in the body can impact the brain’s function. The condition usually resolves when the underlying chemical imbalance is restored or offending infection/toxin is eliminated.

G93.1 Anoxic Encephalopathy

Caused by brain damage due to lack of oxygen, anoxic encephalopathy is also referred to as hypoxic encephalopathy. Anoxic brain damage can occur if blood flow to the brain is blocked or slowed due to blood clot, stroke, or heart attack. It can also occur due to lung disease, prolonged exposure to certain poisons or toxins, or any incident that compromises breathing.

K72.90 Hepatic Encephalopathy/Hepatic failure, unspecified without coma

This is a syndrome observed in patients with cirrhosis or liver disease. Exposure to viruses or harmful chemicals or disease can harm the liver and when this happens, the organ cannot remove toxin from the blood. It is characterized by personality changes, intellectual impairment, and a depressed level of consciousness. Around 30% of patients with end-stage liver disease experience significant encephalopathy. Coma may or may not be present. Appropriate treatment and compliance with protocols could reverse the condition.

I67.4 Hypertensive Encephalopathy

This term is used to refer to encephalopathic findings associated with hypertension. The effects of this condition can usually be reversed by reducing blood pressure levels.

G93.40 Acute and/or Unspecified Encephalopathy

Acute encephalopathy is characterized by an acute or subacute global, functional alteration of mental status due to systemic factors. The 2013 Neurocritical Care Society Practice Update states that “acute encephalopathy is synonymous with acute confusional state, acute organic brain syndrome or delirium…[it] describes the clinical presentation of a global cerebral dysfunction induced by systemic factors.” Correction of these abnormalities can reverse the condition. Acute encephalopathy may be further identified as toxic, metabolic, or toxic-metabolic.

Diagnosis of Encephalopathy

The diagnosis of encephalopathy is based on the following:

• History and physical exam
• Lab findings: CBC, liver function tests, ammonia and blood glucose levels, lactate
  levels, kidney function tests, blood cultures, virology testing, and or ABGs
• Neuroimaging studies
• EEG findings

Documenting Encephalopathy

Encephalopathy is often denied if the documentation does not support it. Clinicians need to document neurological findings consistent with encephalopathy for medical coding service providers to report the condition correctly. ICD-10-CM has many options for documenting its underlying cause, such as due to medications (toxic encephalopathy), metabolic issues (acute hypoglycemia, uremia, or hyponatremia), anoxia, and so on. HCPro expert James S. Kennedy says that if a patient’s altered mental status (dementia, delirium, or psychosis) can be explained by a named brain disease such as Parkinson’s disease or Alzheimer’s disease, then the term “encephalopathy” is integral to these diseases unless it is explicitly documented that the altered mental status differs from that of the underlying brain condition. In other words, the documentation should include terms like “toxic encephalopathy” or “metabolic encephalopathy” and describe what the toxin, poison, or metabolic issue is.

According to idc10online.com, it is critical for providers to document the following details about the encephalopathy to ensure it is coded and reported accurately:

• Type of encephalopathy (metabolic, toxic, hepatic, alcoholic, anoxic/hypoxic, hypertensive)
• Delirium, if appropriate
• Description of symptoms and manifestations of the encephalopathy to support the diagnosis and demonstrate severity and complexity of the patient’s condition
• Underlying cause of encephalopathy
• Additional information as required by instructions in the code book, such as: Vaccination information; Alcohol or substance use, abuse, or dependence; Medications; Organ failure Causative organisms; Type and location of cancer

Any other signs and symptoms that may not be associated routinely with a disease process should be also be coded when present.

Wherever appropriate, the provider should link clinically relevant conditions. Examples of linking:

• Encephalopathy secondary to influenza
• Toxic encephalopathy due to phenytoin, causing delirium
• Hepatic encephalopathy with coma secondary to cirrhosis
• Delirium due to metabolic encephalopathy

Unless physicians incorporate clinical relationships in their documentation, medical coding service providers cannot assign the correct codes.

In an icd10online.com Q&A session on “CDI Issues Related to ICD-10-CM Mental and Behavioral Health Codes” dated March17, 2016, one question was: if a patient has documented delirium and encephalopathy at the same time, both due to the same cause, can we code both?

The answer given is as follows: both can be coded if each required their own diagnostic work up or interventions. Also, according to DSM-5, in order to capture the full spectrum of the disease, both delirium and the specific type of encephalopathy must be documented, along with the underlying cause. In the DSM-5 there is a coding note that states: “Include the name of the other medical condition in the name of the delirium (e.g., 293.0 [F05] delirium due to hepatic encephalopathy). The other medical condition should also be coded and listed separately immediately before the delirium due to another medical condition (e.g., 572.2 [K72.90] hepatic encephalopathy; 293.0 [F05] delirium due to hepatic encephalopathy).”