CONTACT: JENNIFER CRONIN
2130 Medical Laboratories
Iowa City IA 52242
(319) 335-9917; fax (319) 335-8034
Release: Oct. 18, 1999
UI-led study indicates surgery is the best treatment
for severe Bells palsy paralysis
IOWA CITY, Iowa How to best treat patients
with Bells palsy who are at high risk of permanent loss of facial muscle
control has remained a controversial subject among physicians for decades.
However, results of a 15-year study led by University of Iowa Health Care
researchers may help to finally settle the debate.
"We hope these findings will help change the
attitudes of a lot of different people," said Bruce Gantz, M.D., UI professor
and head of otolaryngology.
Timing and strategy are critical when it comes to
the subgroup of patients with Bells palsy who are at the greatest risks
for permanent damage. The study results indicate that identifying this patient
population and their subsequent surgical treatment must occur within two weeks
of the onset of paralysis.
"If we are going to have any impact, the surgery
has to come within the first two weeks," Gantz stressed.
Bells palsy is partial or complete facial muscle
paralysis resulting from a certain dysfunctional cranial nerve that is believed
to be damaged by the herpes simplex virus type I. The condition affects about
40,000 Americans per year. Although medication will help most individuals
fully or almost fully recover from Bells palsy paralysis, about 10 to
15 percent of patients will not recover unless additional measures are taken.
The study had three related goals, all attempting
to answer the primary questions troubling many clinicians treating patients
with Bells palsy. The researchers wanted to determine how to best identify
which patients will be left with poor outcomes, establish whether surgical
decompression might improve these patients chances of recovery, and
finally, figure out what, if any impact time had on treatment.
The study results were based on patient outcomes of
individuals with Bells palsy treated at the UI Hospitals and Clinics,
the University of Michigan and the Baylor College of Medicine.
Through their investigation, the UI-led team determined
that electrical testing was the best method to differentiate a patient with
Bells palsy who has an excellent prognosis from an individual who might
have a poor return of facial movement. The testing relies on the use of two
strategies. The first, called electroneurography (ENOG), involves stimulating
facial nerves and recording their potential to trigger facial movement. Patients
with less than 90 percent degeneration in the first two weeks as measured
by ENOG recover normal or near-normal facial function. Patients whose tests
reveal higher than 90 percent degeneration subsequently receive electromyography
(EMG) testing, which involves inserting a needle electrode in the face and
measuring a patients ability to make forceful contractions. If the patient
fails to demonstrate voluntary motor function using EMG, the patient likely
has only a 42 percent chance of normal or near-normal recovery. However, if
individuals within this subgroup opt for surgical decompression of the facial
nerve within two weeks of the onset of paralysis, they increase their chances
of recovery to 91 percent.
To perform the decompression procedure, a surgeon
first makes a bone "window" by removing a piece of the skull on
the side of the head. The region where the facial nerve is tightly encased
with bone is exposed using microscopic dissection and a micro-drill. Relieving
the constricted portion of the nerve allows earlier recovery and improved
"Many physicians dont think surgical
management is worthwhile because of past controversial results and because
it is a very technically demanding procedure," Gantz said. "But
we demonstrated that electrical testing can identify a small subgroup that
will have residual facial dysfunction, and surgical decompression eliminated
poor outcomes in more than 90 percent of this group."
Risks involved in the procedure are minimal, Gantz
said. There is less than a 1 percent chance of hearing loss and a 4 to 5 percent
chance of temporary cerebral spinal fluid leakage, which can be controlled
with a drain.
"Deciding on surgery should be an individual
decision, and a physician should at least offer that option to patients if
they are potentially going to have a poor outcome," Gantz said. "I
would hope that neurologists and family medicine physicians, who are the ones
that see most of the facial paralysis, would recognize that there are some
test strategies that can differentiate those patients who may have a poor
outcome. And then, if they are in that category of poor outcome, the doctors
need to send the patients to someone within two weeks, not a month or six
Results from the UI-led Bells palsy investigation
appear in a recent issue of The Laryngoscope.
University of Iowa Health Care describes the partnership
between the UI College of Medicine and the UI Hospitals and Clinics and the
patient care, medical education and research programs and services they provide.