Source: DGNews  |  Posted 9 years ago

WASHINGTON, DC -- July 29, 2002 -- The FDA has become aware of a possible association between cochlear implants and the occurrence of bacterial meningitis. At least 25 cases of meningitis have been diagnosed worldwide in children and adults ranging in age from 21 months to 63 years who have undergone cochlear implantation for severe to profound deafness. A total of 9 known deaths resulted from these cases. At this time, 2 out of 3 companies have reported cases of bacterial meningitis in patients who have been implanted. FDA is following up with all the manufacturers of cochlear implants. Surveys of cochlear implant centers currently underway suggest there are additional, unreported, cases of meningitis in the cochlear implant population.

Cerebrospinal fluid culture results are available in 11 cases. Seven have grown Pneumococcus and four have grown Diplococci (most likely Pneumococcus). The vaccination history against Pneumococcus was available in 5 cases and none had been vaccinated. The onset of meningitis symptoms ranged from less than 24 hours to greater than 5 years from time of implant.

What are Cochlear Implants?

Cochlear implants are devices containing electrodes which are positioned in the cochlea (inner ear) to activate auditory nerve fibers allowing for transmission of sound signals to the brain. Approximately 60,000 implantations have been performed worldwide to date.

Meningitis

Meningitis is an infection of the lining of the surface of the brain. Early symptoms of meningitis include fever, irritability, lethargy and loss of appetite in infants and young children. Older children and adults may also manifest headache, stiff neck, nausea and vomiting, and confusion or alteration in consciousness. Physicians are encouraged to consider a diagnosis of meningitis in cochlear implant patients when such symptoms exist and to begin appropriate diagnosis and treatment as soon as possible.

The younger patient population (< 2 yr) and the elderly are most vulnerable to meningitis.

Predisposition to Meningitis

A small percentage of deaf patients may have congenital abnormalities of the inner ear which predispose them to meningitis even prior to implantation. Other predisposing factors may include otitis media, immunodeficiency status, prior history of meningitis, or surgical technique. The cochlear implant, because it is a foreign body, may act as a nidus for infection when patients have bacterial illnesses.

Cochlear Implants and Otitis Media

In some of the reported cases of meningitis in cochlear implant recipients, patients may have had overt or sub-clinical otitis media prior to surgery or before the meningitis developed. Physicians are encouraged to consider prophylactic antibiotic treatment prior to implantation, as appropriate, and to diagnose and treat otitis media promptly in patients with cochlear implants.

Cochlear Implants and Vaccination

Cochlear implant candidates, as well as those already implanted, may benefit from vaccinations against organisms that commonly cause bacterial meningitis, particularly Streptococcus pneumoniae and Haemophilus influenzae. The immunization status should be ascertained for all candidates for cochlear implants prior to surgery as well as for those with an existing implant.