A Case of Acute Necrotic Encephalopathy Associated with Influenza A Virus in Adults

Acute necrotizing encephalopathy is a rare acute, explosive, and severe form of encephalopathy that predominantly occurs in children; however, it is infrequent in adults. The patient is typically caused by viral infection, with rapid onset of fever, convulsion, disturbance of consciousness, and other symptoms. It presents symmetrical, multifocal, involving bilateral thalamic damage and other typical imaging features. This disease has a poor prognosis and can lead to severe neurological symptom sequelae such as epilepsy, coma and even necrotic encephalopathy [1], and its fatality rate can be as high as 52% [2]. Early identification and timely treatment are the key to reducing the fatality rate.

Laboratory routine examinations, encompassing blood routine, biochemistry, influenza PCR, cytokines, and blood gas, were carried out for the patient. Moreover, imaging examinations such as skull CT were also conducted. Based on the combination of clinical symptoms, the patient was diagnosed and treated.

Auxiliary examination: The white blood cell count was 2.33 x 109/L, the lymphocyte percentage was 62.3%, the platelet count was 83.0 x 109/L, the CRP was 7.4 mg/L, the PCR was positive, the partial pressure of oxygen was 59.3 mmHg, the partial pressure of carbon dioxide was 26.6 mmHg, the lactic acid was 6.98 mmol/L, the ALT was 1,892 U/L, the AST was 6,804 U/L, the IL6 was > 1,1836 pg/mL, the plasma D-dimer determination was > 35.20 mg/L, the 3P test was positive, the PT was > 180 sec, and the fibrinogen was 0.1 g/L. Skull CT revealed a small number of low-density changes in the bilateral thalamus.

Oral tube intubation, ventilator-assisted ventilation, cranial pressure reduction, pressure enhancement, methylprednisolone injection for anti-inflammation, plasma and platelet transfusion, and oseltamivir capsule for antiviral purposes. After MDT consultation, acute necrotic encephalopathy was considered, and intravenous shock therapy with immunoglobulin and methylprednisolone needle was added. Forty-eight hours after admission, the patient's condition deteriorated, multiple organ failure occurred, and the family gave up treatment.

Acute necrotizing encephalopathy is infrequent in adults, prone to being overlooked and misdiagnos-ed, and the disease progresses rapidly with a high fatality rate. Clinicians should enhance the early recognition ability of the disease and actively administer glucocorticoid treatment combined with immunoglobulin, which is conducive to a better prognosis for patients.