Cavernous Sinus Thrombosis – Need for Early Recognition: A Case Report

Introduction

A rare, yet fatal disorder, CST can aggravate some commonly seen facial infections, sinusitis, orbital cellulitis, otitis, or infections following injury or surgery of the nose and oral cavity. Prompt recognition of the disorder is essential in reducing complications. Patients usually present with fever, headache, periorbital edema, and ophthalmoplegia.

Loss of vision, stroke and diplopia are some significant complications even with the use of antibiotics and anticoagulants.

Case Report

A 37-year-old female patient presented with fever, bilateral periorbital edema, and headache. The day prior to the onset of her symptomsshe had a history of bursting a pustule in the inner margin of her right nostril. The patient also had a history of type 2 diabetes and hypertension for 6 years and was on medication for the same.

Along with the above clinical features, the patient also presented with the signs and symptoms of diabetic ketoacidosis on arriving at the hospital.

On examination, she was conscious and alert but febrile. She had marked facial and periorbital swelling with bilateral blepharoptosis, chemosis, and proptosis. Her systemic examination was normal, and there were no other neurological deficits.

A full range of eye movement was observed, but she complained of pain on moving her eyes. Thus, it was concluded that the optic nerve was not involved or showed any signs of compression.

At presentation, swabs were taken from the site of infection and the blood samples were sent for culture and sensitivity testing. Certain parameters were markedly raised which included white blood cell (WBC) count- 17 × 10⁹ /L, erythrocyte sedimentation rate (ESR) 75 mm/h, and C-reactive protein (CRP) 360 mg/L. The renal and hepatic functions of the patient were normal.

She was treated empirically with high-dose intravenous (IV) piperacillin (4g), tazobactam (0.5g), and IV metronidazole (500mg). Aspirin (75mg) was used as an anticoagulant. Corticosteroids were not used as a part of her treatment. Her blood sugar level was monitored strictly and was put on sliding scale insulin. Ophthalmological symptoms showed improvement post empirical therapy.

There was a spontaneous pus discharge seen in the left eye. One week after the initiation of therapy, her periorbital swelling was reduced. Figure 1 depicts the patient’s condition on day 0, day 3, and day 7.

Discussion

Anatomy

The cavernous sinus (CS) is an important component of the dural venous sinus. It is present in the cranial cavity and contains multiple neuro-vasculatures.^1,2 It extends from the temporal bone, posteriorly and to the superior orbital fissure (SOF), anteriorly, and is present bilateral to the sella turcica.^1,3 Furthermore, it measures about 2 cm long and 1 cm wide. Surrounding the infundibulum of the pituitary gland, the intercavernous sinuses are present that communicates between the left and right cavernous sinuses.³

Venous blood from the anterior and superior ophthalmic veins, superficial middle and inferior cerebral veins, sphenoid, and the spheno-parietal drain into the CS. The CS further drains into the internal jugular vein (IJV) and the sigmoid sinus through the inferior and superior petrosal sinuses, respectively.

There is a bidirectional spread of the infection due to the absence of valves in the CS. Therefore, there can be extensive thrombi throughout the network of sinuses.

Etiology

There are 2 types of CST- septic and aseptic. Infections, especially occurring in the danger triangle of the face i.e from the bridge of the nose to the corner of the mouth may lead to septic CST. These infections can include abscesses or cellulitis, pustules, furuncles, sinusitis (sphenoid and ethmoid sinuses), odontogenic infections, infections post-extraction of teeth, or certain nerveblock injections [posterior superior alveolar (PSA) nerve block piercing into the pterygoid plexus], rhinoplasties, and minor oral surgeries.^4,5 The aseptic CST cases are less commonly seen than septic cases, and are cuased bymaxillofacial trauma, nasal or oral surgery, or pregnancy.⁶

An array of microorganisms can lead to CST, most commonly bacteria. Staphylococcus aureus accounts for most of the cases (two-thirds) of CST. In these cases, methicillin resistance has to be considered. Streptococcus species is seen in approximately 20% of the cases. Other microorganisms responsible for CST include gram-positive bacteria such as Actinomyces and Corynebacterium, and gram-negative bacteria such as Pseudomonas, Hemophilus, Proteus, and Fusobacterium. Most of these organisms such as Bacteroides, Fusobacterium, and Actinomyces are anaerobic. Fungal infection in CST is rare but can include Aspergillosis, Coccidiomycosis, and Mucormycosis. Immunocompromised individuals are more susceptible to these infections.^{7, 9}

CST associated risks and complications increase in conditions such as cancer. Patients undergoing chemotherapy, steroid use, and uncontrolled diabetes are immunocompromised. In the above case, uncontrolled diabetes was one of the main factors which facilitated the rapid progression of the infection causing the involvement of other facial spaces.

Investigations

The highly sensitive tests to diagnose CST are neuroimaging either with contrast-enhanced computed tomography (CT) or magnetic resonance imaging (MRI), CT venogram, and contrast-enhanced MR venogram. Non-contrast CT of the head is usually not recommended for the diagnosis of CST, although it might reveal superior and inferior ophthalmic vein dilation, engorgement of the CS especially in the lateral margins, ethmoiditis or sphenoiditis, and exophthalmos. Sphenoid or pituitary gland lesions can also be diagnosed.

Blood studies often reveal an elevated WBC count, D-dimer, ESR, and CRP. Frequent blood cultures can be performed and are positive for microorganisms.

Meningitis has to be ruled out by performing lumbar punctures.

Since most of the patients are on anticoagulation therapy, false results are obtained on the coagulation profile.^{[1] [6]}

Differential Diagnosis

It includes diseases that cause ophthalmoplegia such as

• Carotid cavernous fistula presenting with proptosis, retro-orbital fat showing a “dirty appearance”, dilated superior ophthalmic vein, and enlargement of the extraocular muscles on CT or MRI.

• Osteolytic lesions close to the pituitary gland or the sphenoid sinus.

• Cavernous hemangioma

• Metastatic cancers

• Meningioma or schwannoma

• Pituitary adenoma, chondrosarcoma, or nasopharyngeal carcinoma

• Sino-orbital aspergillosis

• Rhino-orbital cerebral mucormycosis

• SOFsyndrome

• Tolosa-Hunt syndrome which presents as a granulomatous pseudotumor of the retro-orbital region that extends into the CS

Treatment

The first line of treatment for CST includes antimicrobial therapy, specifically an anti-staphylococcal agent such as vancomycin. A 3^rd generation cephalosporin is also added along with metronidazole which provides anaerobic coverage. For antifungal coverage, therapy with amphotericin B is preferred. A long duration of antimicrobial therapy, usually 2 weeks or 3–4 weeks after the clinical improvement of the symptoms is suggested.

Anticoagulant is considered only if there are no strong contraindications. This can be done either with unfractionated heparin or low molecular weight heparin (LMWH) for several weeks to months. It prevents the progression of thrombosis and clot propagation. It may also increase the activity of antibiotics. Furthermore, it is contraindicated where there is a risk of intracranial spread, systemic spread due to the spread of emboli into the systemic circulation.⁸

Corticosteroids are added to the treatment regimen, but their efficacy is debated. The advantage of using corticosteroids is that it would reduce inflammation and edema of the involved vessels present around the cranial nerves and orbital structures. However, hypopituitarism warrants the use of steroids.¹⁰

Conclusion

Septic CST can cause serious morbidity and even mortality. They are mostly seen as a result of dangerous infections of the face. This can worsen further due to immunocompromised status such as uncontrolled diabetes which may lead to life-threatening complications. The favorable outcome depends on early diagnosis and treatment with high-dose IV antibiotics.

Conflicts of Interest

None