From the Guidelines
The narrowing of the rural venous transverse sinus in the brain is most commonly caused by idiopathic intracranial hypertension (IIH), thrombosis, anatomical variations, arachnoid granulations, external compression from tumors, inflammatory conditions, and iatrogenic causes. According to the most recent study 1, the causes of narrowing of the rural venous transverse sinus can be identified using neuroimaging such as MR venography or CT venography. Some of the key causes include:
- Idiopathic intracranial hypertension (IIH) which creates increased pressure that compresses the sinus
- Thrombosis or blood clots that partially obstruct blood flow
- Anatomical variations that some people are born with
- Arachnoid granulations that protrude into the sinus
- External compression from tumors, particularly meningiomas
- Inflammatory conditions like cerebral venous sinus vasculitis
- Iatrogenic causes from previous surgeries or procedures The study also highlights that transverse sinus stenosis could be a cause or result of IIH or sigmoid sinus wall abnormalities (SSWAs) 1. Treatment depends on the underlying cause, with options including anticoagulation for thrombosis, acetazolamide or other pressure-lowering medications for IIH, or in severe cases, stenting procedures to maintain sinus patency. It is essential to note that the transverse sinus is critical for draining blood from the brain, and narrowing can lead to increased intracranial pressure and symptoms like headaches, visual disturbances, and pulsatile tinnitus if left untreated, as supported by previous studies 1.
From the Research
Causes of Narrowing of the Rural Venous Transverse Sinus in the Brain
- The narrowing of the transverse sinus, also known as transverse sinus stenosis (TSS), can be caused by various factors, including cerebral venous thrombosis 2, hypoplasia of the transverse sinus 3, and idiopathic intracranial hypertension 4.
- Cerebral venous thrombosis is a rare and potentially fatal condition that can cause narrowing of the transverse sinus, and its diagnosis is often overlooked due to its nonspecific presentation 2.
- Hypoplasia of the transverse sinus is a common anatomical variation that can increase the risk of ipsilateral thrombosis, and it is more frequently found in cases with transverse sinus thrombosis than in controls 3.
- Idiopathic intracranial hypertension is a complex neurological condition characterized by symptoms of increased intracranial pressure, and transverse sinus stenosis is often present in patients with this condition 4.
- The severity of transverse sinus stenosis has been found to be associated with the total brain volume, suggesting that extramural venous compression due to enlarged brain and/or venous hypertension with associated cerebral congestion/swelling may play a role in the narrowing of the transverse sinus 4.
Risk Factors
- Cerebral venous thrombosis is a multifactorial disease, and its major forms of clinical presentation include isolated intracranial hypertension syndrome, focal neurological deficits, and cavernous sinus syndrome 2.
- Transverse sinus stenosis is more frequently found in patients with chronic headaches of unclear cause, particularly those that remain unexplained after initial evaluation or those that are refractory to medical treatment 5.
- Cerebral arterial stenosis can also be a comorbidity with cerebral venous sinus stenosis, and the symptoms caused by the latter are often mistakenly thought of being attributed to the former 6.
Diagnosis and Treatment
- MRI with magnetic resonance venogram (MRV) is considered the gold standard for diagnosis of cerebral venous thrombosis and transverse sinus stenosis 2, 5, 6.
- Anticoagulation with heparin or low-molecular-weight heparin is the mainstay of treatment for cerebral venous thrombosis, while endovascular management is indicated for those cases with severe symptoms or worsening of symptoms despite anticoagulation therapy 2.
- Intravenous stenting may be a feasible and effective way for symptoms relieving in patients with cerebral venous sinus stenosis comorbid with cerebral arterial stenosis 6.