Actinomycosis of the central nervous system

Abstract

Actinomyces species are rare but treatable causes of CNS infection. Differentiation of actinomycosis from nocardiosis is crucial to the selection of appropriate antimicrobial therapy. A review of 70 cases of CNS actinomycosis was conducted in an effort to characterize clinicopathologic features and identify patients with a high risk of death from infection. Types of lesions included brain abscess (67%), meningitis or meningoencephalitis (13%), actinomycoma (7%), subdural empyema (6%), and epidural abscess (6%). Most infections developed from distant sites (lung, 19 cases; abdomen, four; pelvis, three) or contiguous foci (ear, sinus, and cervicofacial region, 21 cases). For nonmeningitic infection, signs and symptoms were generally those of a space-occupying lesion and were indistinguishable from the manifestations of other pyogenic infections except for a longer interval before diagnosis. Risk factors included dental caries; dental infection; recent tooth extraction; head trauma; gastrointestinal tract surgery; chronic otitis, mastoiditis, or sinusitis; chronic osteomyelitis; tetralogy of Fallot; and actinomyces infection of an intrauterine device. Optimal management combined adequate surgical drainage with prolonged antibiotic therapy (mean duration, 5 months). Overall mortality from treated infection was 28%; 54% of survivors had neurologic sequelae. Features correlated with a poor prognosis were disease onset greater than 2 months before diagnosis and treatment, no antibiotic treatment, no surgery, and needle aspiration drainage of abscess lesions.