Background Cervico-medullary spinal cord lesions are usually inflammatory (or rarely neoplastic). Dural arteriovenous fistula (DAVF) is considered very unlikely in the cervical cord, particularly if the history is of an acute myelopathy.

Method Case note review of five patients with skull base DAVF.

Results All were men aged 60–69 years. Four were symptomatic for a month or less, followed by acute deterioration over hours-7days, mimicking myelitis. MRIs showed extensive T2-hyperintensity and swelling in the cervico-medullary region. Worsening after corticosteroids occurred in 3/4 patients and one needed ventilation. Conspicuous and unambiguous cord-surface vessels were present in only one patient. Clinical suspicion prompted digital subtraction angiography (DSA) in the other four patients. Median time from initial MRI to diagnostic DSA and embolization was 28 days (7–91 days). All patients survived with good clinical recovery.

Systematic retrospective review of MRIs showed lack of gadolinium enhancement in 4/5. CSF examination (n=4) showed normal leucocyte count in all cases and elevated protein concentration in 3/4 (0.6–1.2 g/L).

Conclusion Skull base DAVF can mimic acute cervical myelitis. Steroids may prompt life-threatening clinical deterioration mistaken for ascending myelitis. A low threshold for angiography in the context of non-enhancing lesions and acellular CSF will facilitate earlier diagnosis and improve outcomes.