Venous Drainage of the CNS Flashcards
Where are the dural venous sinuses located?
Where do they ultimately drain into?
They are between the peri-osteal dura and the meningeal dura mater.
The internal jugular vein.
Why are the dural venous sinuses not considered to be veins?
No muscular layer.
No valves.
How many venous sinuses are there?
11
Which sinuses are found in the falx cerebri?
1) Superior
2) Inferior
3) Straight
Where do the superior, inferior and straight sinuses meet?
The confluence of sinuses, overlying the internal occipital protuberance.
What is the straight sinus a continuation of?
1) Great cerebral vein
2) Inferior saggital sinus
What sinus extends from the confluence of sinuses?
Transverse sinus and curves into the sigmoid sinus to meet the internal jugular vein.
What does the cavernous sinus drain?
Ophthalmic veins on either side of the sella turcica.
From the cavernoo sinus, blood returns to the internal jugular veins via the superior or inferior petrosal sinuses.
Clinical relevance: cerebral venous sinus thrombosis
Presence of a thrombus within one of the dural venous sinuses.
The thrombus occludes the venous return through the sinuses and causes an accumulation of deoxygenated blood within the brain parenchyma. This can lead to venous infarction. This is further complicated by an accumulation of CSF which can no longer be drained through the thrombosed venous sinus.
Common clinical features are headache, nausea and vomiting, and neurological defects.
Diagnosis is made by CT or MRI scan with contrast.
Treatment is with anticoagulation.
