bubble_chart Overview

Reye's syndrome, also known as acute encephalopathy with fatty degeneration of the viscera syndrome, was first reported by Reye in 1963. It primarily occurs during infancy and early childhood. The pathological characteristics include cerebral edema combined with fatty degeneration of the liver, kidneys, heart, and other internal organs. The clinical features involve onset within a few days after a viral infection, presenting with vomiting, fever, impaired consciousness, convulsions, unconsciousness, and a high mortality rate.

bubble_chart Clinical Manifestations

1. Prodromal stage 90% of cases have a prodromal stage, most commonly presenting as a viral common cold, followed by chickenpox and gastroenteritis. The child may experience fever, vomiting, and diarrhea. After a stable period of 3–7 days, the condition progresses to the encephalopathy stage.
2. Early encephalopathy stage Sudden onset of vomiting, fever, headache, and drowsiness, followed by convulsions, mild unconsciousness, bulging fontanelle, deep breathing, hepatomegaly, and positive pathological reflexes.
3. Advanced stage of encephalopathy Unconsciousness deepens, with flexion of the arms and extension of the lower limbs, presenting as a decorticate posture. Pupils dilate, followed by deep unconsciousness, with limbs stiffening into a decerebrate state. The pupils become extremely dilated and fixed, accompanied by manifestations of brainstem dysfunction such as central respiratory and circulatory failure.
4. Stage of convalescence Mild cases regain consciousness within 1–2 days and recover fully within a week. Moderate cases gradually recover within a month, with either grade I or no sequelae. Severe cases often leave significant sequelae. Liver function may return to normal completely.

The entire course of the disease varies from several days to weeks. In some cases, mild conditions may suddenly worsen, and fulminant cases can lead to death within hours.

5. Other manifestations Some children may develop chickenpox-like rashes or red macules and papules on the skin. Cardiac involvement may lead to arrhythmias.

bubble_chart Auxiliary Examination

1. The blood picture shows an increase in white blood cells up to 20-40×10⁹/L, with elevated neutrophils, and a few cases may present with thrombocytopenia.
2. Liver function tests reveal characteristic abnormalities. Alanine aminotransferase, aspartate aminotransferase, creatine phosphokinase, and lactate dehydrogenase are all elevated.
3. Blood tests indicate increased blood ammonia (up to 29–174 µmol/L). Prothrombin time is prolonged. Blood sodium is low, with most cases showing metabolic acidosis and respiratory alkalosis. Blood glucose decreases. Blood lipids (short- to medium-chain fatty acids) increase.
4. Cerebrospinal fluid pressure is elevated, with white blood cells increasing to 20-40×10⁶/L, mostly lymphocytes. Protein and chloride levels are normal, glucose may decrease to grade I, and ammonia increases.
5. Electroencephalography mostly shows diffuse high-voltage б waves.
6. Liver biopsy, if necessary, should be performed after correcting coagulation abnormalities. Microscopic examination reveals diffuse fatty degeneration of the liver lobules.

bubble_chart Diagnosis

The youngest age of onset was 40 hours after birth, and the oldest was 28 years old, with the majority occurring between 4 months and 5 years.

bubble_chart Treatment Measures

﹝Treatment﹞

The principle is to prevent and treat cerebral edema, brain herniation, and hepatic failure.

(1) General supportive therapy: A low-protein, high-carbohydrate diet is used to reduce endogenous protein breakdown. Attention should be paid to correcting acidosis and preventing hypokalemia. Prevent and correct hypoglycemia. Initial intravenous infusion can use 50% glucose (20–40 ml), followed by 10% glucose solution. To promote glucose utilization and inhibit fat breakdown, insulin-glucose solution can be administered. The total daily fluid intake should be two-thirds of the normal maintenance volume or 50 ml/(kg•d). At the same time, a urinary catheter and nasogastric tube should be placed to accurately calculate intake and output. Strengthen monitoring. Use a ventilator to control hyperventilation.

(2) Management of encephalopathy

1. Control of convulsions: Seizures require emergency treatment. Intravenous anticonvulsants such as diazepam, amobarbital, or phenytoin sodium can be used. For example, diazepam (0.3 mg/kg per dose) acts quickly and effectively but should not be used concurrently with barbiturates to avoid respiratory failure.
2. Reduce fever using sub-hibernation therapy to maintain body temperature between 35–37°C.

3. Reduce intracranial pressure: Apply an ice cap to lower head temperature, and administer intravenous 20% mannitol, furosemide, and dexamethasone.

(3) Management of hepatic failure: To reduce blood ammonia, enemas with normal saline or neomycin can be used. In severe cases, peritoneal dialysis or exchange transfusion may be performed. When prothrombin time is prolonged, fresh plasma or partial exchange transfusion can be administered. Intravenous arginine and infusion of 10–15% glucose solution can also help lower blood ammonia and raise blood sugar.

bubble_chart Differentiation

It should be differentiated from toxic encephalopathy complicated by bacterial infection, viral meningoencephalitis, post-pestilence encephalitis, purulent meningitis, fulminant hepatitis, etc.