Editorial Published in Otology and Neurotology 2002
Meningitis and Cochlear Implantation
Gerard O’Donoghue (Nottingham, UK), Thomas Balkany (Miami, U.S.A),
Noel Cohen (New York, U.S.A.), Thomas Lenarz (Hannover, Germany), Larry
Lustig (Baltimore, U.S.A.), John Niparko (Baltimore, U.S.A.),
Cochlear implantation has transformed the lives of thousands of profoundly
deaf children and adults throughout the world. Concern about the safety
of the treatment was raised when the Food and Drug Administration (FDA)
in the United States (1), the UK’s Medical Devices Agency (MDA)
(2) and the Federal Institute for Drugs and Medical Devices (BfArM)
in Germany recently issued notices that cochlear implant recipients
could be at greater risk of developing meningitis. The commonest organism
grown from culture of the cerebrospinal fluid in these patients was
the Pneumococcus. The news was reported in the international media
raising widespread public concern. This placed an immediate onus on
implant teams worldwide to respond to these concerns by better defining
the level of risk and taking action to protect present and future patients.
A survey of all cochlear implant centres was begun in the U.S. in June
2002. The study is still underway but cases of meningitis after cochlear
implantation have been identified, the majority occurring in children,
some within days and some many months after surgery. In addition, a
meeting of European implant surgeons was convened in early July 2002
and cases were presented from a number of countries. As of this writing,
a total of 52 cases worldwide have been presented to the FDA. The cases
occurred principally, but not exclusively in children. Nor was there
necessarily an antecedent history of acute otitis media. One implanted
child who had previously been vaccinated against the pneumococcus,
developed meningitis. The onset of the meningitis varied from days
to years following implant surgery. Three deaths have been reported
from each continent. Surgeons on both sides of the Atlantic expressed
concerns about the possibility that the addition of the positioner
to the electrode of one family of devices may have put patients at
a greater risk of meningitis accounting for many but not all of the
recent cases.
It should be borne in mind that the incidence of spontaneous
meningitis in profoundly deaf patients may be greater than in a control
population
as some of these individuals will have cochlear anomalies that predispose
them to meningitis. A rough accounting of meningitis in the U.S. shows
that of some 5,000 children under the age of 5 who received implants,
300 – 400 had meningitis before their cochlear implant and 17 had
meningitis after their implantation. Unfortunately, the reported cases
of meningitis have often lacked sufficient clinical information to accurately
discern causative factors. This uncertainty underscores the need for
diligent data collection in all suspected cases of meningitis.
What should now be done to protect past and future patients?
- In spite of uncertainty about the nature and extent of the
risk of meningitis, it appears that of the recent cases, there may
have been an association
with the positioner type electrode. This device has been withdrawn
from the market by the manufacturer in several European countries,
the U.S.
and Canada. The electrode system has been reintroduced in several
European markets without the positioner portion of the system.
- The FDA, MDA and BfArM suggest that cochlear implant candidates as well
as those already implanted may benefit from vaccination (1, 2).
All patients should consider vaccination and those at high risk should definitely
be vaccinated (children under 5, those with inner ear structural
abnormalities
such as enlarged vestibular aqueduct or Mondini dysplasia and those
with altered immunity). As vaccination needs may need to be individualised,
patients should seek the advice of their primary care physicians.
These governmental agencies have not differentiated between individual implant
systems with respect to immunization protocols. It should be emphasised
that vaccination recommendations conform to existing recommendations
from the U.K. and U.S. health departments.
- Implant physicians worldwide may wish to seek the advice
of their public health physicians as to what strategy is most appropriate
in their particular communities.
- The risk of meningitis must be communicated sensitively to
implanted patients (or their parents or carers) and physicians should
put the risk
in context for them.
- Implanted patients who develop symptoms or signs of acute
otitis media or meningitis or other febrile illness should be treated
as a matter
of urgency by their physicians. Delays in treatment of meningitis carry
immense implications for morbidity and mortality.
- All serious infections in implanted patients should be reported
to the appropriate public health authorities in each country as well
as to the
relevant implant manufacturer.
Standard medical texts clearly indicate that meningitis can be a capricious
disease entity and that enigmatic cases are not infrequent. There are
critical lessons to be learned from the information that has come to
light. Firstly, implant teams should strive to assure quality through
an audit of their practices so as to best address the many uncertainties
that surround this issue. In the UK, an audit of implant practice is
being undertaken by a third party (the Medical Research Council’s
Institute of Hearing Research), which will give the findings the integrity
and independence that is needed to allay public concerns. In the U.S.,
the FDA, the Center for Disease Control and the device manufacturers
are seeking to better understand and to more closely track the health
of implant patients. A European survey including all cochlear implant
centres is intended. The evidence that emerges from these endeavours
will hopefully remove much of the uncertainty that surrounds this issue
and lead to the implementation of evidence-based policies. Our first
duty is to protect our patients, both current and future. While further
investigation is needed to demonstrate more fully the cause and extent
of this problem, the steps outlined above are recommended now in an
abundance of caution. Primum non nocere.
- Cochlear implant recipients may be at greater risk for meningitis.
http://www.fda.gov/cdrh/safety/cochlear.html
- Risk of pneumococcus meningitis in non-vaccinated cochlear implant
patients. August 7, 2002 http://www.medical-devices.gov.uk
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