CCRN Metabolic Encephalopathy

CCRN Metabolic Encephalopathy Overview

Metabolic encephalopathy is defined as a potentially reversible abnormality of brain function caused by processes of extra cerebral origin. These processes usually involve some metabolic upset (electrolytes, serum osmolarity, renal function or hepatic dysfunction); some deficiency (metabolic substrates, thyroid hormone, vitamin B12, etc.); some toxic exposure (drugs, alcohol, medicines, etc.) or systemic toxic states (sepsis, for example). Therefore, in metabolic encephalopathy, there is diffuse cerebral dysfunction. Of course, the degenerative diseases of the brain that result in dementia also produce diffuse dysfunction of the brain.

Signs and Symptoms

• Muscle weakness in one area
• Poor decision-making or concentration
• Involuntary twitching
• Trembling
• Difficulty speaking or swallowing
• Seizures
• Lethargy
• Dementia
• Tremors
• Muscle twitching and myalgia
• Cheyne-Stokes respirations (an altered breathing pattern seen with brain damage and coma)

Causes

Causes of metabolic encephalopathy include carbon monoxide or cyanide poisoning; which prevents hemoglobin from carrying oxygen in the bloodstream and results in tissue anoxia. In addition to liver and kidney waste products; it may include abnormally high or low blood sugar, thyroid problems, and high or low sodium levels in the blood.

Treatment

Metabolic encephalopathy treatment is directed toward reversal or control of the underlying process, supportive care, and prevention of complications such as infection, electrolyte imbalance, and cerebral edema. Successful treatment of metabolic encephalopathy depends upon early recognition of the symptoms and intervention to reverse the conditions that could lead to hypoxia or accumulation of toxins in the bloodstream. Delayed treatment could result in permanent or residual damage to the brain. Patients are maintained on a low-protein diet to lower blood ammonia levels since ammonia is a by-product of protein metabolism. Comatose patients may require special tube feedings and life support systems. Liver transplantation may be considered in patients with chronic liver cirrhosis.