IUBio Biosequences .. Software .. Molbio soft .. Network News .. FTP

Need HELP: on "Acoustic Neuroma" Tumor..................

Steve Hoffman steve at accessone.com
Tue Jan 16 15:58:42 EST 1996

Here's some info on acoustic neuroma - just picked it up fom the Web:


steve at accessone.com
Seattle, WA


Acoustic neuromas are being more frequently diagnosed as those with 
hearing loss  and sometimes other symptoms are obtaining MRIs 
(Magnetic Resonance Imaging scans) which can show small tumors at 
an early stage.  

The several names used for this benign tumor include acoustic 
neuroma, acoustic neuronoma and vestibular schwannoma.  It involves 
the 8th cranial nerve which has two branches - acoustic and vestibular

and under the microscope resembles schwann cells.  For that reason, 
vestibular schwannoma is a synonym.

The phrase "benign" generally implies a course unmarked by 
progression or death.  Unfortunately, in the brain, this is not
the situation.   Because the brain is so delicate and encased in bone,

there is little extra space for unusual growths of any type.

The incidence of acoustic neuromas is modest - approximately 1 per 
100,000 people per year.   It's equivalent to approximately 2,500 
people being diagnosed each year in the United States.   That is of
relief to those diagnosed.   Because MRI can detect lesions which were

previously not visible by other means, it is likely that the true
is higher.
Symptoms include decreased hearing, ringing in the ears and a change 
in balance.  While acoustic neuromas can affect either ear and 
sometimes both ears, most often it is unilateral.

The vast majority have asymmetric loss in hearing.  Most commonly it 
is a high frequency hearing loss but some will have normal hearing -
symmetric hearing with modest diminishment or distortion.  An early 
sign is avoiding one ear while using a telephone.  

As the tumor grows, it can encroach on the adjacent brainstem.  This 
may create headaches, difficulty walking and damage to cranial nerves.

Cranial nerves are neurologic structures that originate from the brain

performing certain motor or sensory functions.

Late symptoms are pain, numbness or weakness in the face.  With 
increasing size, progressive symptoms include nausea, vomiting and 
even coma, respiratory depression and death. 

People with bilateral acoustic neuromas commonly have an inherited 
disease called neurofibromatosis.  By radiographic appearance there is

no difference between the sporadically occurring unilateral acoustic 
neuromas and the bilaterally occurring disease.  The bilateral type is

usually more aggressive in its invasion, however.

Much acoustic neuroma data was presented at a National Institute of 
Health Consensus Development Conference.  In a subsequent report, it 
was noted that "tumors tend to enlarge unpredictably.  Some do not 
change size for many years, while other may grow at the rate of up to 
20 millimeters in diameter per year." 

The Consensus report stated "all cases of vestibular schwannomas are 
thought to result from the functional loss of a tumor suppressor gene 
which has been localized to the long arm of chromosome 22.  In at 
least 95% of patients, however, the disease is unilateral and the 
majority of these cases are sporadic, resulting from somatic mutation 
that are not associated with an increased risk for other tumors in
the individual or close relatives."

The Consensus report addressed the who and when of treatment.  It 
was felt that since most at diagnosis have a symptomatic tumor, 
treatment should be carried out quickly.   Especially included in this

group were the young with progressive neurologic deficits or evidence 
of tumor growth. 

With MRI detecting small lesions, the natural history is unknown.   An

option is follow-up scans to determine the growth rate.  The consensus

panel alludes to "the risk of neurologic deterioration in
managed patients."

Traditionally, radiation has been used in those who refuse to undergo 
invasive surgery.   The National Institute of Health's panel writes
"the greatest experience to date has been with stereotactic 
radiosurgery."  They wrote that "early reports indicate the
of tumor growth as observed in the majority of patients."

Peri-operative surgical complications can include air embolism, 
intracranial hemorrhage and stroke.  "Cerebral spinal fluid leak and 
meningitis can occur in a delayed fashion and also can require 
immediate therapy."

"Loss of hearing in the operated ear is the most common adverse 
consequence and can be a serious handicap.  These patients have 
difficulty in even modestly noisy environments and do not have 
directional hearing", the NIH panel reported.

Also reported by the panel was the fact that "abnormal vestibular 
function occurs in almost all patients."   Additionally noted was "one

distressing complication of surgery is disfiguring facial nerve
or paralysis with consequent physical, emotional, psychosocial and 
possibly professional dysfunction."  The panel reported treatment 
approaches to "reanimation" of the face includes surgery and physical 
occupational therapy.  "As yet, none of these can restore normal 
function appearance."  Also discussed were other cranial nerves being 
damaged by surgery including the fifth, seventh, ninth, tenth and 
twelfth.   The panel describes recurrence after surgery where the
was apparently either totally or partially removed; thus all cases
need to 
be followed by imaging.  Those that have recurred may be managed by 
re-operation, fractionated stereotactic or standard radiation.  

 Stereotactic radiosurgery avoids all cutting, bleeding and
The panel reported that "stereotactic radiosurgery, a newer modality 
has benefit of a low early complication rate, but unknown long term 
complications."  New approaches developed since the National 
Institute of Health Consensus meeting are lower radiation dose for 
stereotactic radiosurgery as well as  fractionated radiosurgery.

Traditionally, fractionated radiation divides the total dose into
segments in an attempt to protect vital surrounding tissues.  Normal 
tissues may repair radiation changes while tumors accumulate the 
radiation damage.  

Our recently submitted data that has been accepted by the European 
Neuro-Oncology meeting in Holland shows a very high control rate.  
All patients having received radiation have had cessation of growth or

shrinkage of the tumor.   Furthermore, a significant share of patients

with symptoms have had an improvement.   There have been no 

patients who have suffered facial nerve damage unlike single fraction 

Fractionated stereotactic radiation is an alternative to invasive
After radiosurgery, people return to their normal activities
immediately with no recuperatory period.  The vast majority 
undergoing stereotactic radiosurgery for acoustic neuromas have 
cessation of growth or more commonly, dramatic shrinkage in the size 
of the tumor.   

The goals of stereotactic radiosurgery in the treatment of acoustic 
neuromas as well as metastases, meningiomas, arteriovenous 
malformations and brain tumors are obviously to stop tumor growth, 
avoid invasive surgery and eliminate the need for any surgical 
intervention as best as possible.

Stereotactic radiosurgery is a viable option for those who seek 
successful treatment without invasive surgery.

apopat at oracle.com (Ajay Popat) wrote:

>(My first try bounced back, so I am trying again.)
>Just two days back, my wife has has been diagonised with "Acoustic Neuroma" Tumor
>of 4cm x 3cm size, just behind her righ ear, under the skull (and not in the brain).
>Our Doctor has advised us to get it removed surgically ASAP.  We are planning to do
>it, but meanwhile we wanted to educate ourselves for what to expect.
>I appreciate, if you send me your feedback or lead pointers on this subject at:
>apopat at us.oracle.com
>Some questions we have are:
>1) How serious is the surgery??
>   Tumor has already damaged Nerve#5 and 8 (Right side hearing loss, and facial sensation),
>   and it is close to damaging Nerve#7 for Facial Deformation.
>2) Considering the seriousness, how soon we should do the surgery??
>   There is a long queue.  Do we need to press hard, to get it done today?
>3) What are the chances of any complications??
>   What kind of Complications are possible??
>4) We have a TWO month old baby.  Will she be able to take it the absence of her Mom??
>5) How did the Tumor start??
>   Does it have any dependency on Genes??  on Heredity??
>6) Any other alternatives we have, other that surgical removal??
>7) What are the percentage rate of success and failures??
>8) Can it re-occur after few years??
>9) Will my 2 month old daughter be in danger of similar problem in future??
>10)We will be getting our first appointment of Neuro-Surgeon this week.
>   Other than these questions, what kind of other questions we need to ask, and
>   be aware of??
>If you know anything on this subject, please reply to me ASAP at apopat at us.oracle.com
>Thanking you in advance.............

More information about the Neur-sci mailing list

Send comments to us at biosci-help [At] net.bio.net