Meningitis and Cochlear Implants
I am considering obtaining a cochlear implant. I recently read the FDA statement (July, 2002) which said there were at least 25 cases of meningitis in cochlear implant recipients, and that there were approximately 60,000 people with cochlear implants. Given this situation, can you please tell me about meningitis, the vaccination available to prevent meningitis, and how all of this relates to cochlear implants?
Meningitis is an infection of the tissue layers surrounding the brain and cerebrospinal fluid. Bacterial meningitis has occurred rarely with cochlear implants since they have been in use; more frequently in young children. If not treated appropriately, meningitis can be severe and rarely even fatal.
To put meningitis in perspective, there have been roughly 5,000 young children implanted in the U.S. Of these, approximately 400 have had meningitis BEFORE their cochlear implant and 17 after their cochlear implant.
Most of the cases have occurred within months of receiving the implant.
However, some recent cases have caused concern. For this reason, Dr. Noel Cohen of NYU and I have undertaken a survey of approximately 400 centers that perform implantation in North America. We have had 130 responses representing 401 surgeons who performed approximately 18,000 of the 24,000 implants in NORTH AMERICA. All of our findings have been verified with the teams and manufacturers as well as incorporated with existing databases.
This is what we found:
Advanced Bionics 'Clarion'-8 cases of 7,271 implants
Cochlear Corporation 'Nucleus'-14 cases of 16,617implants
MedEl Corporation 'Combi 40+'-0 cases
There have been two deaths, both in Clarion cases.
Most of the Clarion cases have occurred in the past two years and have occurred with their 'positioner' type electrode.
We have also been in touch with a European group that met in Schiphol on July 5, 2002. They found a much higher rate of meningitis in Western Europe: 26 cases of meningitis (19 Clarion, 5 Nucleus, 2 Laura). There were 8 deaths, 7 Clarion and 1 Nucleus. These data have not been entirely verified yet and are not considered to be as solid as the U.S. data.
Although all data have not been confirmed, there has been enough suspicion for Advanced Bionics Corporation to voluntarily withdraw its positioner electrode from use at this time. The Clarion may become available without
the positioner in the near future.
What to do?
Because most cases of bacterial meningitis are caused by S. pneumoccocus, it is recommended that implanted children under 5 years of age receive pneumococcal vaccination. Studies by the CDC and American Academy of Pediatrics show the vaccines to be safe and effective. They recommend that all children (not just implanted children) under the age of 2 years receive the Prevnar vaccine. They also suggest that at-risk children between 2 and 5 years of age be vaccinated with Prevnar plus another vaccine called Pneumovax or Pnu-immune. At risk people over the age of 5 years are recommended to receive the Pneumovax or Pnu-immune.
That may sound a little confusing. We can simplify it by saying that implanted patients (or their parents) should consider the appropriate vaccination and that all children under age 2 be vaccinated.
It is up to each individual family to discuss these issues with their pediatrician or primary care physician to determine what is in the best interest of each patient. Cochlear implant teams can be helpful by providing information to families and many will have written materials or web-site addresses to provide further information. Each of the manufacturers listed above also provides information on their web-sites.
In summary, cochlear implants have helped thousands of hearing impaired people. Over the past 20 years, the device has been shown to be safe and effective. Our goal as otolaryngologists and audiologists is to protect our patients without depriving those in need of appropriate treatment.
Our work to further understand this issue includes obtaining all medical records and evaluating them with the cooperation of the FDA and CDC. We will make our findings available to all interested people.