From the Guidelines
Metabolic encephalopathy is a clinical syndrome of altered mental status, manifesting as reduced consciousness or altered cognition, personality, or behavior, caused by metabolic derangements, including systemic infection, inherited metabolic encephalopathies, toxins, hypoxia, trauma, vasculitis, or central nervous system infection 1.
Definition and Causes
Metabolic encephalopathy occurs when abnormal chemical changes in the body affect the brain, leading to altered mental status, confusion, and neurological dysfunction. These metabolic disturbances can arise from various conditions, including liver or kidney failure, electrolyte imbalances, hypoglycemia, hyperglycemia, thyroid disorders, vitamin deficiencies, toxin exposure, or oxygen deprivation.
Symptoms and Severity
The symptoms of metabolic encephalopathy typically include:
- Confusion
- Altered consciousness
- Cognitive impairment
- Personality changes
- Seizures or movement disorders The severity can range from mild confusion to coma, depending on the underlying cause and its severity.
Treatment and Prognosis
Treatment focuses on addressing the underlying metabolic disturbance, such as correcting electrolyte imbalances, treating organ failure, removing toxins, or managing blood glucose levels. Prompt identification and treatment are essential, as metabolic encephalopathy can be reversible if the underlying cause is addressed quickly, though prolonged metabolic disturbances may lead to permanent brain damage. In cases of hyperammonaemia, hybrid therapy, such as continuous kidney replacement therapy (CKRT) combined with extracorporeal membrane oxygenation (ECMO), may be recommended for patients with moderate or severe encephalopathy, haemodynamic instability, or rapidly deteriorating neurological status 1.
From the Research
Definition of Metabolic Encephalopathy
Metabolic encephalopathy is a syndrome of temporary or permanent disturbance of brain functions that occurs in different diseases and varies in clinical presentation 2. It is characterized by global cerebral dysfunction induced by systemic stress, ranging from mild executive dysfunction to deep coma with decerebrate posturing 3.
Causes of Metabolic Encephalopathy
The causes of metabolic encephalopathy are numerous and include:
- Hepatic failure 4, 5
- Renal failure 4, 6
- Sepsis 4, 6, 2
- Electrolyte disarray 4
- Wernicke encephalopathy 4
- Hypoxia 6, 2
- Ischemia 6, 2
- Systemic diseases 2
- Toxic agents 2
Clinical Presentation
Metabolic encephalopathy can manifest in a range from very mild mental disorders to deep coma and death 2. Clinically, it is characterized by a variety of psychiatric and neurological symptoms and signs, including:
- Lethargy or mild confusion 6
- Coma 6
- Myoclonus 5
- Movement disorders 5
- Altered brain functioning, going from mild neuropsychological impairment to coma 5
Diagnosis and Treatment
Diagnosis of metabolic encephalopathy involves ruling out differential diagnoses, such as structural brain lesions, infections of the central nervous system, or drug reactions 6. Treatment consists mainly of correcting the underlying cause, with specific treatment options available for certain conditions, such as hepatic encephalopathy and some drug-induced encephalopathies 5. Supportive care and management of the underlying etiology are also crucial in the treatment of metabolic encephalopathy 4.