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CHAPTER 71: Bacterial Infections of the Central Nervous System 663

irrespective of neurologic abnormality at presentation ; however, the oropharynx, and it may involve additional vessels by propagation
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numbers of patients in each of the outcome groups were small. In or discontinuous spread. Septic thrombophlebitis may also occur in
another study of 52 patients, 24 of 29 treated with medical therapy alone association with epidural abscess, subdural empyema, or bacterial
had a good or excellent outcome. There have been no prospective, meningitis. Occasionally, there is metastatic spread from distant sites
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randomized trials comparing the efficacy of antimicrobial agents plus of infection. Conditions that increase blood viscosity or coagulability,
surgery with antimicrobial therapy alone. Antimicrobial therapy alone such as dehydration, polycythemia, pregnancy, oral contraceptive use,
can be considered in patients who have localized pain and radicular sickle cell disease, malignancy, and trauma, increase the likelihood of
symptoms without long-tract findings, although these patients require thrombosis.
frequent neurologic examinations and serial MRI studies to demon- The antecedent conditions that predispose to the development of
strate resolution of the abscess. Rapid surgical decompression should intracranial venous sinus thrombosis depend on the close proximity
be performed in patients with increasing neurologic deficit, persistent of various structures to the dural venous sinuses 64,74 (Fig. 71-2). The
severe pain, or increasing temperature or peripheral white blood cell usual predisposing conditions for cavernous sinus thrombosis are
count. Surgery is unlikely to be helpful in patients who have experi- paranasal sinusitis (especially frontal, ethmoidal, or sphenoidal) and
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enced complete paralysis for longer than 24 to 36 hours, although some infection of the face or mouth. Likely infecting bacterial pathogens
experts would perform surgery if complete paralysis has lasted less than depend on the initial source—staphylococci, streptococci, gram-
72 hours; surgical therapy may also be required to treat the epidural negative bacilli, and anaerobes—if the antecedent condition is sinus-
infection and control sepsis. 64,68 itis, and predominantly S aureus in the case of facial infections. Otitis
media and mastoiditis are infections associated with lateral sinus
Adjunctive Therapy: Patients may also require various adjunctive mea- thrombosis and infection of the superior and inferior petrosal sinuses.
sures to control increased intracranial pressure. Preoperative use of Infections of the face, scalp, subdural space, and epidural space and
mannitol, hyperventilation, and/or dexamethasone may be effective meningitis are associated with suppurative thrombophlebitis of the
in controlling intracranial pressure before surgical decompression. superior sagittal sinus. The likely infecting microorganisms depend
However, corticosteroids should be tapered rapidly after surgical therapy on the associated primary condition.
because of the increased risk of secondary infection. We believe a short In cavernous sinus thrombosis, S aureus is the most important infect-
course of corticosteroids is appropriate in cases in which surgical inter- ing microorganism, having been isolated in 60% to 70% of cases. This
vention is delayed or contraindicated. Anticonvulsants should be used relates to the importance of this organism in infections of the face and
in patients with seizures. scalp and in acute sphenoid sinusitis. Less common isolates include
streptococci (isolated in about 17% of cases), pneumococci and gram-
SUPPURATIVE INTRACRANIAL THROMBOPHLEBITIS negative bacilli (5% each), and Bacteroides species (2%).
■ EPIDEMIOLOGY AND ETIOLOGY ■ CLINICAL PRESENTATION

Septic intracranial thrombophlebitis involves venous thrombosis and The clinical manifestations of suppurative cortical thrombophlebitis
suppuration. It may begin within veins and venous sinuses or may depend on the location of involvement. With involvement of the cortical
follow infection of the paranasal sinuses, middle ear, mastoid, face, or venous system, the appearance of neurologic deficits depends on the

Cortical
veins
Sup. sagittal sinus Inf. sagittal sinus

Falx cerebri

Great vein
of galen

Straight sinus

Cavernous sinus
Sphenoid sinus
Sup. petrosal sinus
Inf. petrosal sinus
Transverse sinus Tentorium cerebelli

FIGURE 71-2. Lateral cross section of the skull, demonstrating the major dural venous sinuses. Note that the cavernous sinus is close to the sphenoid air sinus and that the anterior
segment of the superior sagittal sinus is near the frontal air sinus. (Reproduced with permission from Southwick FS, Richardson EP Jr, Swartz MN. Septic thrombosis of the dural venous
sinuses. Medicine. March 1986;65(2):82-106.)

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