Dural sinus malformations (DSMs) are congenital vascular malformations characterized by massive dilatation of one or more dural venous sinuses. This condition is typically associated with arteriovenous shunts (DAVS).
There are two types of dural sinus malformations (DSM):
- DSMs involving the confluence of sinuses and adjacent sinuses
- appears as giant dural sinus lake with mural arteriovenous (AV) shunts and partial thrombosis
- this giant sinus communicates with other sinuses and normal cerebral veins
- these lesions are often associated with facial or calvarial venous malformations
- DSMs involving the jugular bulb
- malformed jugular bulb with otherwise normal sinuses appears as sigmoid sinus-jugular bulb diaphragm
- these lesions are associated with a petromastoid-sigmoid sinus high flow arteriovenous fistulae which preserves the cerebral venous drainage
- these malformations represent dysmaturation of the jugular bulb with occlusion of the distal sigmoid sinus
Dural sinus malformations involving the jugular bulb and sigmoid sinus present with minimal symptoms (due to preserved cerebral venous drainage) whereas dural sinus malformations involving the torcular and adjacent sinuses are mostly symptomatic which includes microcrania, intellectual disability, and symptoms associated with venous infarct and parenchymal hemorrhage.
Dural sinus malformations may be diagnosed antenatally by ultrasound and/or MRI. It appears as hugely dilated dural venous sinuses with presence or absence of partial or complete thrombosis.
Treatment and prognosis
Dural sinus malformations involving the jugular bulb carry excellent prognosis with occlusion of AVF and thrombosis of sigmoid sinus distal to the superior petrosal sinus.
Prognosis of dural sinus malformations of torcular and adjacent sinuses is less favorable. The aim of treatment is to preserve the cerebral venous drainage and occlusion of mural AV shunts.
Imaging differentials include