Tentorial dural arteriovenous fistula presenting symptoms due to mass effect on the dilated draining vein: case report.

Background: Tentorial dural arteriovenous fistula (AVF) presented symptoms due to mass effect on the dilated draining vein. We report a patient presenting left hemisensory disturbance because of compression of the midbrain by a dilated draining vein of the AVF. The AVF has disappeared completely by drainer clipping after feeder embolization.
Case Description: A 66-year-old woman presented with left hemisensory disturbance due to compression of the midbrain by a dilated draining vein with tentorial dural AVF. On admission, she complained of left hemisensory disturbance. Enhanced computed tomography (CT), magnetic resonance imaging, and magnetic resonance angiogram revealed the midbrain compressed by a mass lesion, which was a draining vein with AVF fed by numerous feeding arteries neighboring the right tentorial edge. The single-photon emission CT (SPECT) did not depict any laterality.
Conclusion: This is a rare case of a tentorial dural AVF which caused left hemisensory disturbance not by venous congestion, but by a compression of the midbrain by the dilated draining vein, because SPECT showed no laterality. In this case, magnetic resonance angiogram, 3-dimensional CT angiography, and SPECT were useful in the diagnosis and planning the strategy for treatment.