Suppurative Intracranial Thrombophlebitis

A. Clinical manifestations

The clinical manifestations of suppurative intracranial thrombophlebitis depend on the sinus involved, the involvement of anatomical structures within the sinus, and coexisting central nervous system infection. The onset of symptoms may be abrupt or gradual depending on the extent and location of infection.

1. Cavernous sinus: fever (>90%), periorbital oedema (73%), change in mental status (55%), headache (52%), meningism (40%), diplopia, eye tearing, photophobia, ptosis, proptosis, chemosis, weakness of extra-ocular eye muscles, papilledema (65%), cranial nerve palsies (CN II, III, IV, VI, and maxillary branches of V), cortical vein thrombophlebitis.

2. Lateral sinus: headache (>80%), fever (79%), abnormal ear findings (98%), photophobia, vomiting, vertigo, CN VI palsy, facial pain / altered sensation, papilledema, mastoid tenderness, nuchal rigidity, Griesinger’s sign (posterior auricular swelling and pain), otitic hydrocephalus.

3. Superior sagittal sinus: altered mental status, motor deficits, nuchal rigidity, papilledema, seizures (>50%).

4. Inferior petrosal sinus: ipsilateral facial pain and lateral rectus muscle involvement.

B. Aetiology

The aetiological agents depend on the associated primary condition and the sinus involved.

1. Sinusitis: staphylococci, streptococci, gram-negative bacilli, and anaerobes.
2. Facial infection: S. aureus.
3. Cavernous sinus: S. aureus (60-70%).
4. Lateral sinus: S. aureus, streptococci, E. coli, Fusobacterium necrophorum, Bacteroides fragilis, mixed infection.
5. Others: rhinocerebral mucormycosis, invasive aspergillosis.

C. Diagnosis

1. Laboratory studies may be non-specific. CSF: mild pleocytosis and elevated protein. Occasionally, findings compatible with frank meningitis may be present in patients with septic thrombosis of the superior sagittal sinus. Blood culture: may be positive.

2. Radiological studies including CT and MRI are superior to conventional sinus radiographs. MRI and MR angiogram / venogram are the diagnostic procedures of choice. CXR may reveal evidence of septic pulmonary emboli (propagation of the thrombus into the inferior petrosal sinus and jugular vein).

D. Management

Suppurative intracranial thrombophlebitis is associated with a high mortality rate (80-100% without antibiotics; 0-79% with antibiotics). The choice of antimicrobials depends on the primary condition and the likely causative agents. The usual duration of antimicrobial therapy is at least 3-4 weeks. Surgery may also play a role in certain situations. The use of anticoagulation is controversial.