Meningitis following Cochlear Implantation: Pathomechanisms, Clinical Symptoms, Conservative and Surgical Treatments

Abstract

Pneumococcal otogenic meningitis is a rare postsurgical complication that can develop following stapedectomy or after cochlear implantation. The bacterial infection can be fatal in some instances. A recent increase in the incidence of otogenic meningitis among cochlear implant wearers is of concern. The majority of meningitis cases are associated with a 2-component electrode manufactured by one cochlear implant company. The device with the added ‘positioner’ component has been withdrawn from the market (FDA Public Health Web Notification: Cochlear Implant Recipients may be at Greater Risk for Meningitis, Updated: August 29, 2002, www.fda.gov/cdrh/safety/cochlear.html). Not all cases have been subsequent to otitis media and symptoms have developed from less than 24 h up to a few years after implantation. The purpose of this paper is to review and discuss the pathogenesis, pathology/bacteriology and to elaborate on some clinical features of otogenic meningitis in implanted children and adults. Essential aspects of surgery, electrode design, and cochleostomy seal are discussed. Conclusions are drawn from the available data and recommendations are made for good practice in cochlear implantation and follow-up.

Cochlear Implants in Children: Surgical Site Infections and Prevention and Treatment of Acute Otitis Media and Meningitis

“…In the absence of a surgical procedure to reduce such risks, these children remain at increased risk of meningitis after cochlear implantation. In addition, as postulated by Arnold et al 21 and studied experimentally by Wei et al, 25 cases of bacterial meningitis in implant recipients may originate via pneumococcal bacteremia with hematogenous seeding of the cochlea, such as at a site of tissue necrosis related to the electrode or positioner (locus minoris resistentiae) with contiguous spread to the CSF and meninges.…”

“…16,19 A consensus report prepared by 8 cochlear implant surgeons recommended, on the basis of theoretical considerations and a series of otitis media-related meningitis episodes in adults, 20 avoidance of implantation if middle-ear fluid is present. 21 The surgeons stated that if middle-ear fluid is encountered at the time of implantation, they recommended high-volume irrigation of the middle ear, administration of topical antimicrobial agents into the middleear space, and systemic therapy with ceftriaxone. 21 …”

“…21 The surgeons stated that if middle-ear fluid is encountered at the time of implantation, they recommended high-volume irrigation of the middle ear, administration of topical antimicrobial agents into the middleear space, and systemic therapy with ceftriaxone. 21 …”

“…Pathways of bacterial access to the cerebrospinal fluid (CSF) from the inner ear include entry into the labyrinth, infiltration of the cochlear turns along the electrode entering the Schuknecht bony channels, and following perineural and/or perivascular pathways into the internal auditory canal to the meninges. 21 In patients with a malformed cochlea in which there is a connection to the subarachnoid space, meningitis also can occur via the cochlear aqueduct. In the absence of a surgical procedure to reduce such risks, these children remain at increased risk of meningitis after cochlear implantation.…”

Group A Streptococcal Meningitis in a Pediatric Patient following Cochlear Implantation: Report of the First Case and Review of the Literature

“…Some cases may be attributed to the procedure itself, justifying the use of perioperative antimicrobial prophylaxis targeting gram-positive skin flora and middle ear organisms by administration of a narrow-or expanded-spectrum cephalosporin (1). Based on the most commonly recovered organisms in the CSF (S. pneumoniae and H. influenzae), it is often assumed that the infection has taken the route of the middle ear through the cochlea to the meninges (1).…”