Can Patients with Cerebral Venous Sinus Thrombosis Develop Double Vision?
Yes, patients with cerebral venous sinus thrombosis (CVST) can develop double vision (diplopia), most commonly due to sixth nerve palsy caused by increased intracranial pressure. 1, 2
Mechanism of Diplopia in CVST
Diplopia occurs in CVST through increased intracranial pressure that affects the sixth cranial nerve (abducens nerve). Papilledema and diplopia from sixth nerve palsy are common manifestations of CVST, presenting as important diagnostic clues alongside headache. 1, 2
The sixth nerve is particularly vulnerable to increased intracranial pressure because of its long intracranial course. When venous drainage is impaired in CVST, intracranial pressure rises, causing:
- Stretching or compression of the sixth nerve, resulting in horizontal diplopia that worsens with lateral gaze toward the affected side 1
- Bilateral sixth nerve involvement can occur in severe cases with markedly elevated intracranial pressure 1, 3
Clinical Presentation Pattern
The diplopia in CVST typically presents as part of a constellation of findings related to increased intracranial pressure:
- Headache (present in ~90% of cases) is usually the dominant symptom, with diplopia occurring alongside papilledema 1, 2
- Some patients present with diplopia and papilledema even without other focal neurological signs, mimicking idiopathic intracranial hypertension 1
- The diplopia is horizontal and binocular, resolving when either eye is covered 1
Diagnostic Considerations
When evaluating a patient with acute diplopia, CVST should be considered if:
- Diplopia is accompanied by headache, papilledema, or signs of increased intracranial pressure 1, 2
- Ophthalmoscopic examination reveals bilateral papilledema 4, 5
- The patient has risk factors such as prothrombotic conditions, dehydration, or recent infection 2
MRI with MR venography is the most sensitive imaging modality for detecting CVST and should be obtained when this diagnosis is suspected. 1, 2 Non-contrast CT is often normal in CVST, though it may show the "empty delta sign" or hyperdensity of the affected sinus. 2
Severity and Prognosis
In rare severe cases, markedly elevated intracranial pressure from CVST can cause complete ophthalmoplegia (paralysis of all extraocular movements) along with other cranial neuropathies and even radiculopathy. 3 These extreme presentations emphasize the importance of early recognition and treatment.
Visual impairment from optic atrophy can occur in approximately 22% of patients at 1-year follow-up if papilledema is not promptly treated. 5 This underscores the urgency of diagnosing CVST when diplopia and papilledema are present together.
Key Clinical Pitfall
Do not dismiss diplopia with papilledema as simple idiopathic intracranial hypertension without obtaining MR venography to exclude CVST. 1, 6 The clinical presentations can be identical, but CVST requires anticoagulation therapy while idiopathic intracranial hypertension does not. Missing this diagnosis can lead to progression of thrombosis, permanent visual loss, and potentially fatal outcomes.