What are the clinical presentation and treatment of cavernous sinus thrombosis?

Clinical Presentation of Cavernous Sinus Thrombosis

Cavernous sinus thrombosis (CST) presents with a characteristic triad of fever, headache, and ocular manifestations including chemosis, periorbital edema, ptosis, ophthalmoplegia, and vision changes. 1

Key Clinical Features

Cardinal Symptoms and Signs

• Headache: Typically diffuse, progressive in severity over days to weeks 2
• Fever: Present in most cases, indicating infectious etiology 1
• Ocular manifestations:
  • Chemosis (conjunctival edema)
  • Periorbital edema
  • Ptosis
  • Ophthalmoplegia (restricted eye movements)
  • Visual acuity changes 1, 3

Cranial Nerve Involvement

• Cranial nerve VI (abducens): Most commonly affected, resulting in lateral rectus palsy and diplopia 1
• Other affected cranial nerves: III (oculomotor), IV (trochlear), and V (trigeminal) 1
• These nerves pass through or near the cavernous sinus, explaining their involvement

Neurological Manifestations

• Mental status changes or somnolence may occur, especially in elderly patients 2
• Bilateral neurological signs may be present due to the anatomical connection between the two cavernous sinuses 2
• Seizures can occur in up to 40% of patients with cerebral venous thrombosis 2

Diagnostic Pitfalls

Common Misdiagnoses

• CST may be confused with complicated fungal sinusitis, as seen in the case report 3
• Isolated mental status changes without obvious focal neurological signs can delay diagnosis 2
• Symptoms may mimic idiopathic intracranial hypertension when headache and papilledema are present 2

High-Risk Populations

• Patients with recent:
  • Sinusitis (especially sphenoid or ethmoid)
  • Facial infections
  • Maxillofacial trauma or surgery
  • Thrombophilia
  • Dehydration 1
• Diabetic patients are at increased risk 3

Pathophysiology and Progression

CST typically develops as a complication of infections in the "danger triangle" of the face, with the most common pathogens being:

• Staphylococcus aureus
• Streptococcal species
• Oral anaerobic bacteria
• Gram-negative bacilli 1

The infection spreads through the facial veins that lack valves, allowing retrograde flow directly into the cavernous sinus. This leads to:

1. Venous obstruction
2. Cranial nerve compression
3. Potential spread to other venous structures

Imaging Findings

CT Findings

• Hyperdensity of the thrombosed sinus on non-contrast CT
• "Empty delta" sign on contrast-enhanced CT (filling defect within the sinus) 2
• May show associated sinusitis, especially sphenoid or ethmoid 3

MRI Findings

• More sensitive than CT for early detection
• Shows thrombus within the cavernous sinus
• Can demonstrate associated parenchymal changes 2

Venography

• MR venography (MRV) has the highest sensitivity for diagnosis 1
• CT venography (CTV) is a reasonable alternative in the emergency setting 1

Management Approach

Early diagnosis and treatment are critical to reduce mortality and morbidity. Management includes:

1. Antimicrobial therapy: Broad-spectrum antibiotics targeting the common pathogens
2. Anticoagulation: To prevent thrombus propagation
3. Specialist consultation: Neurology, ophthalmology, and infectious disease
4. Surgical drainage: May be necessary for associated sinusitis 3

Prognosis

Without prompt treatment, CST carries significant mortality and morbidity:

• In the pre-antibiotic era, mortality was 80-100%
• With modern treatment, mortality has decreased but neurological sequelae remain common 4
• Visual outcomes depend on the timing of intervention 3

Early recognition and aggressive management are essential to improve outcomes in this rare but potentially devastating condition.