"Polio
Above the Neck"
Written by
Tessa Jupp RN for the Post Polio Network of WA
In May 1999 Neurologist Dr Susan Perlman of the
University of California-Los Angeles (UCLA) gave a talk to a post polio support
group in California.
Complete article at www.skally.net/ppsc/neck.html
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Dr Perlman
notes that most people had polio that affected arms and legs but that not much
is written about people who had non-paralytic polio.
De Perlman
feels that these people had polio-enceph-alitis. From our own observations of polios in WA,
people who had polioencephalitis often had a really bad headache, so bad that
they still remember it as the worst headache they have ever had! Is this you?
Polioencephalitis
could well have caused changes in the brainstem (bulbar polio), presenting as
breathing and swallowing problems that may have been present even in people who
ostensibly had non-paralytic polio and also in others who may have no
complaints about their legs or arms. A
few of our WA polios fit this scenario but others may also have had both paralysis
and polioencephalitis too.
Autopsies
performed following the epidemic polio of the 1940s and 1950s report signs of
acute polio infection throughout the body, not just restricted to the spinal
cord. Changes were found in central
brain structures that control alertness, central fatigue, and autonomic
functions such as temperature regulation and also in the brainstem itself.
It is
estimated that more than 90% of a polio survivor’s motor neurons were
affected and damaged during the initial acute stage and some damage occurred
even if there was no paralysis. Autopsy
studies have shown that in the acute phase as few as 4% of motor neurons
escaped damage.
Many of
those with bulbar polio did not survive as if there is a 50% loss of the motor
neurons that control breathing or swallowing, a person is going to be in real
serious trouble. eg iron lungs.
Some people
only had mild breathing weakness, chest wall weakness or a little diaphragmatic
weakness. Recovery of injured or
orphaned nerve cells was not as common in the brain and brainstem as it was in
other parts of the body since the brainstem has less flexibility. This affected the pharyngeal and oesophageal
muscles too.
Compensatory
strategies, such as swallowing on the other side of their throat have long been
used by polio people. Vocal cord
paralysis is also evident in some of our WA polios and “new”
problems occur when the muscles on the “good” side of their throat
begin to weaken. Although facial, jaw
and throat muscles are controlled by the brain stem, they have rarely been
thought of in connection with polio.
Polios are more likely to have new problems if they
have - * more residual disability
* respiratory weakness
* were older than 10 at time of acute
polio
* recent falls
or injuries
* surgical procedures in
pharyngeal area
* weight gain,
because it puts more pressure on the diaphragm and pharyngeal area.
Our primary
muscle for breathing is the diaphragm and if this tires or weakens then our rib
muscles kick in and we chest breath.
Accessory respiratory muscles can help lift the chest from the shoulders
too
Poor
breathing in polios can also be from decreased respiratory drive from the brain
stem. This can be due to a carbon
dioxide (CO2) build-up as the sensor control in the brain stem
weakens more.
Scoliosis
can also cause restriction of breathing. Under-breathing develops as the
scoliotic spine cannot expand the chest as well as before.
Measuring
devices for patients with increasing respiratory problems include the forced
inspiratory and expiratory measurements that we undertook with Dr David Hillman
and Dr Peter Nolan at SCGH in 1990 as part of our initial WA Polio Clinic
Research.
Monitoring
CO2 levels in the blood is another good measuring device. We have a machine to do this that is
available for WA polios to borrow. It is not the amount of oxygen going in that
is important but the amount of CO2 going out. If you are not breathing well, your CO2
levels are going to go up. Polios at risk should have regular checks of CO2
levels and inspiratory/expiratory function - get a GP referral to Dr Hillman
SCGH.
Swedish
research on the impact of cardio-respiratory function in polios has found a
significant incidence of deconditioning.
Dr. Perlman says doctors are no longer saying post polios should do no
exercise. Conditioning or aerobic exercise, is important.
Survivors
can improve heart function, circulation, and breathing to some extent by doing
activities that increases the heart rate.
These researchers suggested increasing the heart rate to 70% of maximum
by using a swimming pool or other exercise equipment.
Polio
researchers in Toronto looked at 3 areas of muscles, (respiratory, diaphragm,
chest wall), bulbar symptoms, the control rate and scoliosis. They found that the control panel in the
brainstem was the least important of the group.
Most people were having problems because of the diaphragm, chest wall
fatigue or due to progressing scoliosis.
A few of
Dr. Perlman’s patients had experienced increased breathing problems at
higher altitudes for example when flying.
One of our WA polios was told he could no longer fly back to NZ when it
was found at SCGH that half of his diaphragm had been permanently paralysed
since childhood polio. He had not known
this was why he got so easily puffed on exertion. Now adjustments can be made so those polios
can travel at higher altitudes and not feel short of breath all the time. See a respiratory specialist.
Swallowing
The motor
neurons that control swallowing are located in the brainstem. In order to have an effective swallow, we use
various groups of muscles to insure that food is chewed, forms into a bolus,
and goes down properly. The swallowing
centre coordinates other activities related to swallowing: ie chewing, licking,
gagging, coughing, sneezing, vomiting, belching and breathing to some extent.
When we
swallow, we can’t breath at the same time, because there is a flap that
opens or closes the air pipe depending whether we are eating or breathing, so
the two groups of muscles and nerves are competing against each other.
There are
at least a dozen places in the body where a post-polio patient who had some
pharyngeal problems or brainstem related swallowing problems could begin to
have trouble now with swallowing – either in the steps or in the sequence
of swallowing.
For
example, people who have weakness in the jaw muscle as a complication of PPS
will find it hard to chew when fatigued.
People who have a weak soft palette can find that food is slipping into
their throat before it is fully chewed and food or drink - drink especially -
may be coming up out of their nose.
Swallowing
problems have been identified in polios in more recent world studies. In WA swallowing problems occur in about 16%
of our polios. However most polios do
not have constant choking. If you
concentrate on swallowing and eliminate distractions, like talking or watching
TV, choking on food can be lessened. Any
part of the gastro-intestinal tract - from the mouth all the way to the bottom
- could be slowed, weakened, or not working properly due to worsening late
effects. But don’t assume that
every symptom a polio survivor gets is due to PPS.
Dr Perlman
says, although common pathways are used for breathing and swallowing, not
everyone who has swallowing problems has breathing problems and not everyone
who has breathing problems has swallowing problems. Bulbar muscles can slowly dysfunction and
there can be silent swallowing problems.
In a 1991 polio swallowing study by Dr Marinos Dalakas in Philadelphia
USA, he concluded that “…in bulbar neurons there is a slowly
progressive deterioration similar to that in the muscles of the limbs.”
Blood Pressure and/or Variable Heart Rate
Dr Perlman
has been asked - “Can high or low blood pressure be a result of
polio and PPS” and “Can a variable pulse rate be made
worse, not because of heart disease, but because of post-polio symptoms
affecting the area?”
She says
that the average doctor may be hard pressed to believe it possible for polio to
be related to current blood pressure or pulse rate problems. However, vaso-motor centres that control
blood pressure and pulse rate are located in the medulla (in the lower
brainstem) and also in the autonomic area of the brain. Since polio damage has been seen in the brain
and in the brainstem, this relationship to blood pressure and pulse is an area
that needs further study.
As we
understand more of brain involvement in acute polio and the number of nerves in
the brain that were involved, areas that might have looked okay on the surface
could actually be functioning on very shaky ground. “The majority of motor neurons, in
whatever region the poliovirus got to, were probably affected in some way or
another,” said Dr Perlman.