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 DSMs
- DSM involving the confluence of sinuses and adjacent sinuses
- appears as giant dural sinus lake with mural 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
- DSM 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 AVF which preserves the cerebral venous drainage
- these malformations represent dysmaturation of jugular bulb with occlusion of distal sigmoid sinus
DSMs involving the jugular bulb and sigmoid sinus present with minimal symptoms (due to preserved cerebral venous drainage) whereas DSMs involving the torcular and adjacent sinuses are mostly symptomatic which includes microcrania, mental retardation and symptoms associated with venous infarct and parenchymal haemorrhage.
DSM's can 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
DSMs involving the jugular bulb carry excellent prognosis with occlusion of AVF and thrombosis of sigmoid sinus distal to the superior petrosal sinus.
Prognosis of DSMs of torcular and adjacent sinuses is less favourable. The aim of treatment is to preserve the cerebral venous drainage and occlusion of mural AV shunts.
Imaging differentials include