Inner Ear Conductive Hearing Loss and Unilateral Pulsatile Tinnitus Associated with a Dural Arteriovenous Fistula: Case Based Review and Analysis of Relationship between Intracranial Vascular Abnormalities and Inner Ear Fluids
Table 1
Cognard classification of dural arteriovenous fistulas (1995).
Cognard type
Venous drainage pattern
I
Venous drainage into dural venous sinus with antegrade flow
IIa
Venous drainage into dural venous sinus with retrograde flow
IIb
Venous drainage into dural venous sinus with antegrade flow and CVR
IIa + b
Venous drainage into dural venous sinus with retrograde flow and CVR
III
Venous drainage directly into subarachnoid veins (CVR only)
IV
Type III with venous ectasias of the draining subarachnoid veins
