Abnormal flow void signs and gadolinium enhancement of vascular lesions for the early diagnosis of angiographically occult dural arteriovenous fistulas at the craniocervical junction: A case report

Abstract

Background: Patients with clinical presentations suggestive of craniocervical junction dural arteriovenous fistulas (CCJ DAVFs) need to be diagnosed as early as possible because delayed treatment worsens patient outcomes. However, the early diagnosis for CCJ DAVFs is often challenging due to their various neurological and radiological presentations, which may be affected by vascular factors, such as slow flow in fistulas.Case descriptionA 69-year-old man presented with acute brainstem dysfunction in our hospital. Brain magnetic resonance imaging (MRI) at admission demonstrated a hemorrhage in the left dorsal medulla oblongata, swelling of the entire lower brainstem, and severe edema around the hematoma. Abnormal flow void signs on T2-weighted and susceptibility-weighted imaging, as well as gadolinium enhancement of vascular lesions on contrast-enhanced MRI, helped in the early diagnosis of CCJ DAVF. The slow flow in fistulas contributed to an MR angiography and conventional cerebral angiography that showed no abnormalities. Endovascular embolization was performed immediately, allowing favorable patient outcomes. Conclusions: Abnormal flow void signs and linear gadolinium enhancement on brain MRI were useful for the early diagnosis of the patient’s condition. These findings may be characteristic of the CCJ DAVFs, especially in those with brainstem dysfunction, allowing differentiation from other neurological diseases.

Keywords

• Dural arteriovenous fistulas
• Craniocervical junction
• Angiographically occult
• Brainstem dysfunction
• Abnormal flow void sign
• Gadolinium enhancement