A case of 18F-FDG PET/MR facilitates early diagnosis of anti-GFAP encephalitis disease.

BACKGROUND

Glial fibrillary acidic protein (GFAP) astrocytosis is a rare autoimmune encephalitis discovered in the last decade. The diagnosis depends on clinical symptoms, imaging, and antibody testing. However, most cases require several months or even longer to make a definite diagnosis. Early-stage diagnosis of this condition poses significant challenges.

CASE DESCRIPTION: A 54-year-old female patient presented high fever and headache as the initial symptoms, accompanied by persistent hyponatremia. Antiviral therapy and dexamethasone anti-inflammatory therapy did not yield satisfactory effects. The patient subsequently developed confusion, lethargy, polyuria, bladder dysfunction, and movement disorder, accompanied by intractable hyponatremia, which was slightly relieved by intravenous immunoglobulin (IVIG). With the help of 18F-FDG PET/MR imaging combined with antibody testing, we diagnosed the patient with anti-GFAP encephalitis approximately one month after symptom onset. Following a course of high-dose methylprednisolone therapy, the patient's symptoms gradually improved. During the one-year follow-up period, the use of methylprednisolone was gradually tapered and the patient remained asymptomatic.

CONCLUSION

This case presented a rare disease with atypical manifestations, highlighting the importance of utilizing 18F-FDG PET/MR imaging as a valuable adjunct tool for patients with unclear lesions on conventional MRI scans. Early diagnosis and timely treatment are crucial for ensuring a favorable prognosis for patients.