eMedicine Specialties > Neurology > Neuro-vascular Diseases

Cerebral Venous Thrombosis

Author: W Alvin McElveen, MD, Medical Director of Stroke Center, Department of Neurology, Blake Medical Center
Coauthor(s): Ralph F Gonzalez, MD, Private Practice, Bradenton Neurology, Inc; Consulting Staff, Department of Neurology, Blake Hospital, Lakewood Ranch Medical Center, Manatee Memorial Hospital; Andrew P Keegan, MD, Private Practice, Bradenton Neurology, Inc; Consulting Staff, Department of Neurology, Manatee Memorial Hospital, Lakewood Ranch Medical Center, Blake Medical Center
Contributor Information and Disclosures

Updated: Nov 5, 2008

Introduction

Background

Thrombosis of the venous channels in the brain is an uncommon cause of cerebral infarction relative to arterial disease but is an important consideration because of its potential morbidity. Venous thrombosis may occur with headache and cranial nerve palsies. Newer imaging procedures have led to easier recognition of venous sinus thrombosis, offering the opportunity for early therapeutic measures. Venous thrombosis also may be associated with other medical complications that require therapeutic intervention.

Pathophysiology

Knowledge of the anatomy of the venous system is essential in evaluating patients with venous thrombosis, since symptoms associated with the condition are related to the area of thrombosis. Cerebral infarction may occur with cortical vein or sagittal sinus thrombosis secondary to tissue congestion with obstruction. Lateral sinus thrombosis may be associated with headache and a pseudotumor cerebri–like picture. Extension into the jugular bulb may cause jugular foramen syndrome; cranial nerve palsies may be seen in cavernous sinus thrombosis as a compressive phenomenon. Cerebral hemorrhage also may be a presenting feature in patients with venous sinus thrombosis.

Frequency

International

Incidence of cerebral venous thrombosis (CVT) is difficult to determine. Generally, it is believed to be an uncommon cause of stroke. However, with the advent of newer imaging techniques, the reported incidence is likely to increase as less severe cases are found. In 1973, Towbin reported CVT in 9% of 182 autopsies.¹ In 1995, Daif reported a frequency in Saudi Arabia of 7 cases per 100,000 hospital patients.² The ratio of venous to arterial strokes has been found to be 1:62.5.

Mortality/Morbidity

Mortality in untreated cases of venous thrombosis has been reported to range from 13.8-48%; this high mortality rate may be a reflection of clinical severity at entrance into the study. Between 25% and 30% of patients have full recovery.

More recently, a Portuguese study group prospectively analyzed 91 consecutively admitted patients from 1995 to 1998 over a mean 1-year follow-up interval.³ Of the patients analyzed, 7% died in the acute phase, 1% died during the one year follow-up, 82% recovered completely, and 1% were dependent; 59% developed thrombotic events during the follow-up, 10% had seizures, 11% complained of severe headaches, and 1 patient experienced severe visual loss.

In 2003, Buccino et al found a good overall outcome in their reinvestigation of a series of 34 patients with confirmed cerebral venous thrombosis.⁴ However, 10 patients (30%) had episodic headaches, 3 patients (8.8%) had seizures, 4 patients (11.7%) had pyramidal signs, and 2 (5.9%) had visual deficits. Mild nonfluent aphasia was seen in 3 patients. Working memory deficit and depression of mood were seen in 6 patients (17.6%).

Race

No racial predilection has been observed.

Sex

Cerebral venous thrombosis is believed to be more common in women than men. In a series of 110 cases, Ameri and Bousser found a female-to-male ratio of 1.29:1.⁵

Age

In 1992, Ameri and Bousser reported a uniform age distribution in men with cerebral venous thrombosis, while 61% of women with CVT were aged 20-35 years.⁵ This may be related to pregnancy or the use of oral contraceptives.

Clinical

History

• Patients with cerebral venous thrombosis (CVT) may present with headache. Although thunderclap headache usually indicates subarachnoid hemorrhage (SAH), it also may be seen in sinus thrombosis.
• SAH has been described as the presenting event with CVT. CVT should be considered in the workup of SAH, especially when the basilar cisterns are not involved.⁶
• Nausea and vomiting may be associated.
• Patients with lateral sinus thrombosis may present with a pseudotumor cerebri–like syndrome. Using a technique called auto-triggered elliptic-centric-ordered 3-dimensional gadolinium-enhanced MR venography, Farb et al found that 27 of 29 patients with idiopathic intracranial hypertension had bilateral sinovenous stenosis; this was seen in only 4 of 59 control subjects.⁷
• Patients may have seizures that can be recurrent. See Medscape's Epilepsy Resource Center.
• Patients with cerebral venous thrombosis may have a decreased level of consciousness that progresses to coma.
• Focal neurologic deficit may occur depending on the area involved.
  • Hemiparesis may occur, and in some cases of sagittal sinus thrombosis, weakness in the lower extremity. This also may develop as bilateral lower extremity involvement.
  • Aphasia, ataxia, dizziness, chorea, and hemianopia all have been described.
• Cranial nerve syndromes are seen with venous sinus thrombosis. These include the following:
  • Vestibular neuronopathy
  • Pulsatile tinnitus
  • Unilateral deafness
  • Double vision
  • Facial weakness
  • Obscuration of vision

Physical

• Mental status may be quite variable, with patients showing no change in alertness, developing mild confusion, or progressing to coma.
• Cranial nerve findings may include papilledema, hemianopia, oculomotor and abducens palsies, facial weakness, and deafness. If the thrombosis extends to the jugular vein, the patient may develop involvement of cranial nerves IX, X, XI, and XII with the jugular foramen syndrome.
• Thrombosis of the superior sagittal (longitudinal) sinus may present with unilateral paralysis that then extends to the other side secondary to extension of the clot into the cerebral veins. Because of the location, this may present as a unilateral lower extremity weakness or paraplegia.
• Cavernous sinus thrombosis with obstruction of the ophthalmic veins may be associated with proptosis and ipsilateral periorbital edema. Retinal hemorrhages and papilledema may be present. Paralysis of extraocular movements, ptosis, and decreased sensation in the first division of the trigeminal nerve often are observed.
• Although unusual, cortical vein thrombosis may be seen in the absence of dural sinus involvement. These cases are associated with varied focal deficits including aphasia, hemiparesis, hemisensory loss, and hemianopia.

Causes

Many causative conditions have been described in cerebral venous thrombosis. These may be seen alone or in combination. For example, the prothrombin gene mutation in association with oral contraceptive use raises the odds ratio for developing cerebral venous thrombosis.

• Infection may occur by extension from the paranasal sinuses. These cases also may be associated with subdural empyema. Bacterial meningitis as a coexistent condition should be considered in these cases. Frontal sinuses are the most common source of infection, with spread through the emissary veins between the posterior sinus mucosa and the meninges. Rarely, sphenoid sinusitis may be associated with cavernous sinus thrombosis. Multiple organisms are to be considered, Staphylococcus aureus being the most common. In chronic infections, gram-negative organisms and fungi such as Aspergillus species may be found.
• Trauma may be an etiologic event. Cerebral sinus thrombosis easily may be overlooked in cases of minor head trauma. Neurosurgical procedures such as dural taps and infusions into the internal jugular vein also have been implicated.
• Many medical conditions have been associated with venous sinus thrombosis.
  • Pregnancy and puerperium are important considerations in women of childbearing age.
  • Inflammatory bowel diseases such as Crohn disease and ulcerative colitis are described as risk factors for venous thrombosis. Corticosteroids used in treatment of these conditions may play a causative role.
  • Hypercoagulable states associated with the antiphospholipid syndrome, protein S and C deficiencies, antithrombin III deficiency, lupus anticoagulant, and the Leiden factor V mutation may result in CVT. Pregnancy also is associated with a hypercoagulable tendency.
  • Hematologic conditions, including paroxysmal nocturnal hemoglobinuria, thrombotic thrombocytopenic purpura, sickle cell disease, and polycythemia, are to be considered. Malignancies may be associated with hypercoagulable states and therefore may be risk factors.
  • Collagen-vascular diseases such as systemic lupus erythematosus, Wegener granulomatosis, and Behçet syndrome have been reported to be associated with CVT.
  • Nephrotic syndrome, dehydration, spontaneous intracranial hypotension, high altitude, hepatic cirrhosis, and sarcoidosis have all been described as increasing the risk of CVT.
  • Hyperhomocysteinemia is a strong and independent risk factor for CVT. It is present in 27-43% of patients and 8-10% of the population. However, whether treatment with folate, pyridoxine, and/or cobalamin reduces the risk of CVT is unclear.
• Several medications are reported to increase the risk of CVT. Among these are oral contraceptives, including the third-generation formulations; corticosteroids; epsilon-aminocaproic acid; thalidomide; tamoxifen; erythropoieten; phytoestrogens and L-asparaginase. Heparin therapy has been reported to produce thrombotic thrombocytopenia with associated venous sinus thrombosis.

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