Brief overview
- Description: partial or complete occlusion of a vein in the brain by a blood clot. Cerebral venous thrombosis is rare.
- Symptoms: e.g. headaches, epileptic seizures, neurological deficits (e.g. motor disorders), impaired consciousness.
- Diagnosis: Imaging of the brain (CT, MRI) with contrast medium.
- Treatment: administration of anticoagulants (heparin, vitamin K antagonists), treatment of the underlying disease in septic cerebral venous thrombosis (antibiotics, surgery if necessary), further measures as required, e.g. medication against epileptic seizures, reduction of intracranial pressure (elevation of the upper body, surgery if necessary), administration of painkillers
What is cerebral venous thrombosis?
Blood congestion often occurs at the same time elsewhere – cerebral venous thrombosis often occurs together with sinus thrombosis. This is a clot-related occlusion (thrombosis) of one or more of the so-called cerebral sinuses (cerebral blood vessels): These are cavities between two sheets of the hard meninges (dura mater) that carry venous blood from the brain, meninges, and orbits to the internal jugular vein (which also receives blood from various cerebral veins).
The combination of cerebral venous thrombosis and sinus thrombosis is called sinus vein thrombosis. The current guideline on cerebral sinus and cerebral vein thrombosis refers to cerebral venous sinus thrombosis (CVST).
Possible consequences of disturbed venous outflow
The blood stasis caused by the disturbed outflow of venous blood in cerebral venous thrombosis or sinus vein thrombosis can have serious consequences:
In addition, the congestion of blood and the resulting increase in pressure can cause fluid to spill out of the vessels into the surrounding tissue, resulting in brain swelling (cerebral edema).
Last but not least, the accumulated blood can also cause hemorrhage (stasis hemorrhage) (in a sense, blood is squeezed out of the smallest venous vessels by the blood stasis).
Cerebral venous thrombosis: Frequency is low
Regardless of the exact figures, cerebral venous thrombosis or sinus vein thrombosis are rare events. A higher incidence is observed among children, young adults, women of fertile age, and in low-income countries.
Cerebral vein thrombosis: symptoms
The symptoms of cerebral venous thrombosis usually present themselves gradually. They include, for example:
- Headache of variable severity or location (most common symptom)
- epileptic seizures (convulsions)
- neurological deficits depending on the location of the thrombosis, e.g. motor disorders (such as hemiparesis, i.e. paralysis of one half of the body, or monoparesis, i.e. weakness/paralysis in one limb or part of the limb), speech disorder (aphasia)
- Nausea
- Vomiting
- Impaired consciousness
The symptoms of cerebral vein thrombosis or sinus vein thrombosis can vary greatly – not only in the type, but also in the severity of the symptoms.
If you notice such symptoms in yourself or another person, you should consult a doctor or clinic immediately. The condition can be life-threatening!
Cerebral venous thrombosis: Causes and risk factors
Aseptic (bland) cerebral venous thrombosis
Most often, cerebral venous thrombosis (sinus vein thrombosis) is not caused by infection. Doctors then refer to it as aseptic or bland.
In most cases, hormonal factors play a causal or facilitating role in the development of the disease: Women who take oral contraceptives (“the pill”), are pregnant or in childbed, or are receiving hormone replacement therapy due to menopausal symptoms are often affected.
More frequently, aseptic sinus or cerebral venous thrombosis also occurs in the presence of a congenital or acquired tendency to blood clot formation (thrombophilia). For example, patients with the hereditary disease Factor V Leiden (APC resistance) are affected.
Sometimes blood disorders (hematologic disorders such as sickle cell disease and polycythaemia vera) or malignant tissue neoplasms (malignancies) contribute to aseptic sinus or cerebral venous thrombosis.
In about one quarter of patients, no reason for aseptic sinus or cerebral venous thrombosis can be found. This is then referred to as idiopathic.
Very rarely, sinus or cerebral venous thrombosis occurs after corona vaccination (see below).
Septic cerebral venous thrombosis
Septic (infectious) cerebral venous thrombosis or sinus vein thrombosis is caused by infection, as the name implies. Sometimes a local infection in the head is the cause such as:
- Tonsillitis (inflammation of the tonsils)
- Inflammation of the mastoid process of the temporal bone (mastoiditis)
- Sinusitis (inflammation of the paranasal sinuses)
- Inflammation of the oral mucosa (stomatitis)
- Inflammation and/or abscess in the area of the jaw and teeth
- Cerebral abscess
- Meningitis (inflammation of the brain)
In addition, infections affecting the whole body (systemic) can also cause cerebral venous thrombosis or sinus vein thrombosis, such as:
- “blood poisoning” (sepsis)
- Typhoid fever
- Tuberculosis
- Malaria
- measles
- infection-related liver inflammation (hepatitis)
- infections with herpes simplex viruses
- Cytomegaly
- covid-19
- aspergillosis (a fungal disease)
- Trichinosis (a worm disease)
Cerebral venous thrombosis as a vaccine side effect
According to studies, individual patients develop a so-called thrombosis-with-thrombocytopenia syndrome (TTS), i.e. thrombosis in combination with platelet deficiency, after administration of one of these vaccines: the body increasingly produces special antibodies that dock onto the blood platelets (thrombocytes). These are activated as a result and clump together. These “clumps” can then clog the fine vessels – brain veins, for example.
Cerebral venous thrombosis: Diagnosis
Taking the patient’s medical history (anamnesis) can give the physician valuable clues as to what is causing complaints such as severe headaches and motor weakness. If the patient is unable to provide information, for example, because of impaired consciousness, the physician will ask the family member for necessary information, if possible. Important questions include:
- How long have you (or the patient) had symptoms? What exactly are the complaints?
- Is there currently an infection, for example with bacteria, viruses or parasites?
- Have you (or has the patient) recently had an infection, such as a cold, middle ear infection or sinusitis?
- Have you (or has the patient) recently been vaccinated against coronavirus?
Computed tomography (CT)
Computed tomography (CT) of the skull using contrast medium shows possible thrombosis in the brain.
Magnetic resonance imaging (MRI)
MRI (magnetic resonance imaging) of the skull with the administration of a contrast medium also provides good visualization of the blood vessels in the brain and possible occlusions. During the MRI, the patient is wheeled into the tube-shaped MRI machine on a couch and must lie there as still as possible. The computer then creates precise images of the head – not with the help of X-rays, however, but with magnetic fields and radio waves.
D-dimers possibly supportive
D-dimers are cleavage products of fibrin, a protein involved in blood clotting. They are formed when a blood clot dissolves. The blood level of D-dimers is therefore determined primarily when a clot-related vascular occlusion (thrombosis, embolism) is suspected – and mainly in the case of possible leg vein thrombosis or pulmonary embolism.
Cerebral venous thrombosis: Therapy
Acute treatment of sinus/brain vein thrombosis should be carried out in a “stroke unit” if possible. This is a department in a hospital that specializes in the treatment of stroke. There, patients can be closely monitored. This enables the treating physicians to react in good time if a patient’s condition deteriorates or complications arise.
Anticoagulation (medication to prevent clotting)
In the case of cerebral venous thrombosis or sinus vein thrombosis, doctors administer anticoagulant drugs. These are designed to prevent a blood clot from continuing to grow and to prevent new clots from forming.
Heparin
In the acute phase of sinus/brain vein thrombosis, doctors give heparin for anticoagulation – even if a brain hemorrhage is also present.
However, unfractionated heparin may be beneficial in patients who may require surgery in the short term. After discontinuation of UFH, blood clotting returns to normal more quickly (within one to two hours) than after discontinuation of NMH. This is important to avoid severe bleeding in the event of surgery scheduled at short notice.
Sinus/brain vein thrombosis during pregnancy or in the puerperium is treated with low-molecular-weight heparin. For women in the puerperium, however, the anticoagulant warfarin can be given as an alternative (it passes into breast milk only in very small quantities).
Vitamin K antagonist
This oral anticoagulation is intended to prevent a relapse – i.e., a recurrence of sinus or cerebral vein thrombosis. It can be continued for three to 12 months. In patients with a severe tendency to thrombosis (thrombophilia), long-term use of the tablets may be indicated if necessary (although the benefits and risks must be weighed up regularly).
Further therapeutic measures
Depending on the need, sinus/brain vein thrombosis treatment may include other measures:
Intracranial pressure therapy
As a general measure, elevation of the upper body by about 30 degrees is recommended.
If necessary, removal of the skullcap (craniectomy) may also be necessary for rapid pressure relief. This applies to patients with acute sinus/brain vein thrombosis, damage (lesions) to brain tissue (due to brain swelling as a result of impaired venous outflow and/or brain hemorrhage), and impending entrapment of brain areas. In these patients, the intervention can be life-saving!
If the patient has suffered an epileptic seizure due to the sinus/brain vein thrombosis, the doctor prescribes special antiepileptic drugs. The medications reduce the likelihood of another seizure.
Pain management
Acetylsalicylic acid (ASA) should never be given for pain relief! The active substance also has anticoagulant properties, which is unfavorable if a patient has to undergo surgery at short notice (increased risk of bleeding!).
Measures in septic cerebral venous thrombosis
Cerebral venous thrombosis: Prognosis
Compared to other forms of stroke, the prognosis for cerebral vein thrombosis or sinus thrombosis is relatively favorable:
The chances of recovery are quite good with proper treatment: within several weeks to months, the previously occluded cerebral veins or cerebral sinuses become fully or partially reopened in most patients. However, symptoms occasionally remain, especially headaches and epileptic seizures.
Prognostic factors
The following factors are more likely to predict a more favorable outcome:
- Sinus/brain vein thrombosis in the context of pregnancy, puerperium or taking oral contraceptives
- Headache as the only initial symptom
Prognostic factors suggesting a less favorable course in sinus/brain vein thrombosis are:
- Paralysis (paresis)
- Coma
- male gender
- advanced age
- thrombosis of the internal cerebral veins
- Congestive bleeding
Prevent cerebral vein thrombosis
If someone has already suffered cerebral venous thrombosis once, secondary prophylaxis can be used to reduce the risk of another venous thrombosis in the brain (or elsewhere in the body):
- For women who have already had a sinus/brain vein thrombosis in connection with pregnancy, puerperium or oral contraception (taking the “pill”), the advice is not to continue oral contraception or not to start it again.
- In children and adolescents with a history of sinus/brain vein thrombosis, preventive use of low-molecular-weight heparin is recommended in situations where there is an increased risk of recurrent cerebral venous thrombosis or other clot-related vascular occlusion-such as immobilization (e.g., bedridden) for more than four days, air travel lasting more than four hours, or rheumatic or cancer disease.
In children and adolescents with a history of sinus/brain vein thrombosis, preventive use of low-molecular-weight heparin is recommended in situations where there is an increased risk of recurrent cerebral venous thrombosis or other clot-related vascular occlusion-such as immobilization (e.g., bedridden) for more than four days, air travel lasting more than four hours, or rheumatic or cancer disease.
