Reye Syndrome is a group of syndromes characterized by brain edema and liver dysfunction caused by fatty infiltration of internal organs, also known as encephalopathy with fatty degeneration of viscera. It was first reported by Reye in 1963. It mostly occurs in infants or children aged 6 months to 15 years, with an average age of 6, and is rare in adults.

bubble_chart Etiology

The cause of the disease is unknown, but it is often associated with viral infections such as influenza virus, coxsackievirus, herpes virus, and Epstein-Barr virus. It may also be linked to aflatoxin, salicylate preparations, or environmental and genetic factors. After viral infection, structural and metabolic abnormalities in mitochondria lead to a series of generation and transformation changes, which are the primary basis for liver and brain lesions. The main pathological changes occur in the brain and liver, where significant fat deposition is observed. The cytoplasm is filled with fat droplets, and under electron microscopy, mitochondria appear swollen with polymorphic changes, disappearance of cristae, stretched matrix forming small strands, coarsened granules, and reduced glycogen. Additionally, fat infiltration is also observed in organs such as renal tubules, myocardium, pancreas, gastrointestinal tract, lungs, spleen, and lymph nodes.

bubble_chart Clinical Manifestations

The disease has a rapid onset, with its main clinical manifestations as follows: ① Prodromal symptoms of viral infections in the upper respiratory tract and digestive tract often appear within 2 weeks before the illness. ② Brain damage is the most prominent manifestation of this disease. When the prodromal symptoms improve, frequent vomiting and severe headache may suddenly occur, initially presenting with excitement, irritability, mental confusion, and drowsiness, followed by convulsions, unconsciousness, and even decerebrate rigidity, which can lead to death due to respiratory failure. ③ Liver damage manifests as hepatomegaly accompanied by liver dysfunction, mostly without jaundice or bleeding tendencies. ④ Most cases are accompanied by hypoglycemia, while a few may present with dehydration and metabolic acidosis.

1. Elevated serum transaminases, prolonged prothrombin time, and increased blood ammonia, plasma free fatty acids, and short-chain fatty acids.

2. Cerebrospinal fluid examination shows increased pressure, but the cell count and protein are mostly within the normal range.

3. Electroencephalogram (EEG) reveals moderate, grade III diffuse abnormalities.

4. CT examination helps exclude space-occupying lesions in the brain. {|103|}

bubble_chart Diagnosis

Given a history of mild upper respiratory and digestive tract infections prior to the onset of pediatric illness, followed by progressively worsening neuropsychiatric symptoms, liver signs, and manifestations of hypoglycemia, this disease should be considered. The definitive diagnosis relies on liver biopsy, which reveals characteristic changes such as numerous fat droplets within hepatocytes, mitochondrial swelling, and reduction or disappearance of dense bodies under electron microscopy.

bubble_chart Treatment Measures

The key to treating this disease and improving prognosis lies in eliminating cerebral edema. It is essential to protect liver function and enhance supportive therapy. Some have adopted exchange transfusion to remove toxins, reduce blood ammonia, and correct coagulation disorders, achieving certain therapeutic effects.

bubble_chart Differentiation

Attention should be paid to differentiate it from epidemic cerebrospinal meningitis, Japanese encephalitis, purulent meningitis, and sepsis.