Cervical spinal arteriovenous fistula with ventral perimedullary venous drainage.

[BACKGROUND] Spinal arteriovenous fistula (AVF) represents the most common type of spinal vascular lesions and is often associated with progressive neurological dysfunction.

[METHOD] Here, we present a unique case of a spinal vascular malformation that does not fit the traditional classification schemes. The patient presented with progressive neurologic deficits resembling partial Brown-Sequard syndrome and was subsequently found to have a lesion resembling type I spinal AVF. However, this intradural fistula drained into the ventral venous plexus rather than dorsal.

[CONCLUSION] Recognizing these rare anatomical variants is paramount in achieving successful obliteration and improved functional outcome for patients.