NOTE: This message was originally in conference "INTERNET - E-MAIL AREA"
      and was copied here by Tom Mckeever.
From: TOM  WALTER 
To: TOM McKEEVER 
Date: 11 Jul 95 18:40:02 EDT
Subject: PPS DOCS INFO FR EASTER SEALS 03/95
 
AN APPROACH TO THE PATIENT WITH SUSPECTED POST-POLIO SYNDROME
 
Originally written by Dr. Warren Anderson and the Medical Advisory Board of
the Post-Polio Program Easter Seal Society of Oregon
 
MEDICAL ADVISORY BOARD of the POLIO OUTREACH ADVISORY COUNCIL A Working
Advisory Council to the Easter Seal Society of Washington
 
Joshua Benditt, MD, Pulmonologist
Evan Cantini, MD, Physiatrist
Dianna Chamblin, MD, Physiatrist
Margarette Forgette, MD, Physiatrist
Bill Kelly, Physical Therapist
Dennis Lang, RN, MPH, Polio Survivor
Lawrence R. Robinson, MD, Physiatrist
Mark Sumi, MD, Neurologist
 
EASTER SEAL SOCIETY OF WASHINGTON
521 Second Avenue
Seattle, Washington 98119
 
March 1995
 
TABLE OF CONTENTS
 
I.  Introduction
A.  Definition of Post-Polio Syndrome
B.  Scope of the Problem
C.  Diagnostic Criteria 
 
II. Pathology: Physiologic and Clinical Consequences
A.  Extensive Neuronal Involvement in the Average Case
B.  Motor Unit Remodeling
C.  Decompensation Then Produces Post-Polio Syndrome
 
III. Patient Presentation
A.  Prime Symptoms
B.  Additional Presenting Symptoms
C.  Past History
 
IV. Evaluation Process
A.  Identify Areas of Dysfunction
B.  Formalize Treatment Goals
C.  Prognosis
 
V.  Resources in Patient Management
A.  Neurology Consultation
B.  Physiatry (Physical Medicine and Rehabilitation)
C.  Physical Therapy
D.  Occupational Therapy
E.  Speech Pathology
F.  Pulmonology
G.  Psychology 
H.  Support Groups
I.  Other
 
VI.  Bibliography
 
AN APPROACH TO THE PATIENT WITH SUSPECTED POST-POLIO SYNDROME
 
Polio survivors are at risk for the occurrence of certain physiologic changes
in the nervous system which result in a characteristic set of symptoms now
known as Post-Polio Syndrome. In addition to these unexpected physiological
changes there are anticipated complications such as arthritis, scoliosis, and
entrapment syndromes
that frequently accompany paralytic conditions. These anticipated 
complications
are not the problems that distinguish PPS from other diseases of the nervous
system.
Post-Polio Syndrome (PPS) is a major chronic illness and one which poses 
unique
problems
to its survivors and their physicians.
 
No diagnostic test exists for PPS, so clinical criteria must be used to
establish the diagnosis. Many physicians lack training in the diagnosis and
management of a syndrome only recently acknowledged as existing. Patients
are often uncomfortable with physicians they feel do not understand their
problems.
They also fear increased disability, often at the same time they are coping 
wit
h
limitations of
aging. Patients are often trapped in a "conquer the disease" mentality 
erived
from
the experience of recovering from the acute episode an average of 25 years
earlier. This is
incompatible with the lifestyle adjustments necessary for optimal results in
PPS rehabilitation.
 
I.  INTRODUCTION
A.  DEFINITION OF POST-POLIO SYNDROME
 
An otherwise unexplained constellation of symptoms which may include
weakness, fatigue, pain, heat or cold intolerance, and swallowing, breathing, 
o
r
sleep
disturbance developing in a patient who had paralytic polio. Post-Polio 
uscle
Atrophy (PPMA) has been used as the label for the above symptoms when they
include progressive
muscle atrophy.
 
B.  SCOPE OF THE PROBLEM
 
1987 National Health Interview Survey estimated 1.63 million American polio
survivors (=0.625% of population), 50% with some Post Polio Syndrome 
ymptoms.
 
C.  DIAGNOSTIC CRITERIA
 
1.  PPS is a diagnosis of exclusion and should be based on a thorough history
and physical exam.
 
2.  Evidence of prior paralytic polio: via EMG, an appropriate history, or
characteristic residual atrophy.
 
3.  Period of apparent stability before any new symptoms. New symptoms may
often be seen after an illness or injury.
 
4.  Exclusion of other conditions (especially motor neuron diseases and
overuse syndromes).
 
II.  PATHOLOGY:  PHYSIOLOGIC AND CLINICAL CONSEQUENCES
A.  EXTENSIVE NEURONAL INVOLVEMENT IN THE ACUTE POLIO INFECTION
 
1.  The extent of central nervous system infection by polio virus is not well
appreciated. Infection is far more widespread than anterior horn cells alone.
Often anterior horn cell infection is largely subclinical due to residual
capacity of 
uninfected and surviving neurons. Infection outside the anterior horns is 
likel
y
to be
largely subclinical also, but may help to explain the disabling symptoms of
fatigue and pain which are subjective and controversial (because the
physiologic basis is uncertain).
 
2.  Ninety-five percent (95%) of motor neurons are infected in an average
acute infection, with a 50% neuronal fatality rate.
 
3.  There is frequent segmental involvement, accounting for the lack of
symmetry of weakness.
 
4.  In addition to the anterior horns in the spinal cord, infection involves
intermediolateral horns and dorsal root ganglia.
 
5.  Infection also involves motor cortex, hypothalamus, and globus pallidus,
brainstem nuclei, reticular formation, cerebellar roof nuclei, and vermis.
 
B.  MOTOR UNIT REMODELING IN THE POST RECOVERY PHASE
 
1.  A normal quadriceps has, on average, 200 muscle fibers/anterior horn 
ells
and a normal anterior horn cell can adopt as many as 1,000 orphaned muscle
fibers.
 
2.  Over 50% of motor units may be lost without symptoms. (Normal walking
uses only 15-20% of maximum muscle strength.)
 
3.  Clinical improvement occurs acutely through recovery of mildly affected
neurons, collateral sprouting, and strengthening (hypertrophy) of intact
musculature.
 
4.  Increased demand on surviving motor units results in increased firing
frequency which in turn produces a change in fiber type to predominantly
aerobic "slow twitch" fibers with increased vascularity.
 
C.  DECOMPENSATION THEN PRODUCES POST-POLIO SYNDROME
 
While a single underlying etiology for PPS has not been proven, several
theories exist:
 
1.  There is an increased metabolic burden on surviving anterior horn cells
(even in asymptomatic muscles) as they direct more muscle fibers to contract,
more often, to achieve the same force of contraction. This leads to anterior
horn cell fatigue and can lead to premature metabolic injury, perhaps even 
cell
loss. Fatigued
neurons may be unable to continue to trophically support as many muscle 
fibers.
The collateral sprouts to some muscle fibers will degenerate. The strength of
these muscle fibers will be lost to the motor unit, and a spiral of decline 
may
set in. This
mode of decompensation augured by fatigue, may be anterior horn cell based. 
Thi
s
appears not to be a static process and there may be dynamic denervation and
reinervation.
 
2.  Another mode of decompensation is muscle fiber based: Rapidly firing
muscle fibers produce more lactic acid which may not be adequately 
issipated.
This is especially true with any degree of isometric contraction. Muscle 
iber
fatigue may lead to muscle fiber injury, lost function, and a spiral of 
decline
.
 
3.  Any increase in mechanical load (such as would result from increased
weight or increased physical activity) or decrease in force generating 
capacity
(such as would result from inactivity following illness or injury) may 
rigger
metabolic failure in motor units or in muscle fibers functioning close to 
their
capacity.
 
4.  The resulting relative weakness may lead to joint and muscle misuse and
overuse. This may lead in turn to both arthritis and overuse syndromes.
 
5.  In addition to anterior horn cell and muscle fiber modes of fatigue,
central fatigue may also be a factor. Polio virus infection of the motor 
trip
and
the reticular activating system is well described. A working definition for
central fatigue is: "Increased mental effort necessary to perform a fixed 
amoun
t
of muscle
contraction". This is very much how Post Polio Syndrome patients describe
their feelings of fatigue, many report hitting a "post polio wall".
 
III.  PATIENT PRESENTATION
A.  PRIME SYMPTOMS
 
A common presentation is a polio survivor who previously had lower extremity
involvement in a well defined polio episode. The patient may have restricted
ambulation from hiking or jogging, lived a sedentary life, and did not feel
disabled. After a period of relative stability he or she may begin to notice
unusual fatigue and
discomfort and may further restrict activity. Denial of decreased functional
capacity may lead to a crisis as the patient can no longer meet occupational, 
social, and family commitments. Persistence and attempts to continue at a
previous activity
level may lead to a downward spiral of decreasing functional capacity with
resulting depression and despair. On examination, relative obesity may be
present 
and weakness is easily demonstrated, often in the "good" leg; limbs 
onsidered
unaffected are
often subclinically affected with polio and may present with "new" polio. A
statistical summary of the clinical characteristics of several series of PPS
patients is as follows:
 
1.  Fatigue, Pain, and Weakness are almost always present. Fatigue (89%);
Pain in Muscle or Joint (86%); New weakness (83%) in previously symptomatic
(69%)
or asymptomatic (50%) muscles.
 
2.  New Atrophy (28%); this equates to Post Polio Muscular Atrophy (PPMA).
 
3.  Activities of daily living difficulties (78%) = functional loss. Walking
 (64%); Climbing Stairs (61%); Dressing (17%).
 
B.  ADDITIONAL PRESENTING PROBLEMS
 
1.  Pulmonary dysfunction:
 
Patients with Post-Polio Syndrome may suffer from weakness of the breathing
muscles, namely the diaphragm and ribcage. Occasionally, this can be severe
enough to cause symptoms of dyspnea on exertion and even at rest, poor
clearance of respiratory secretions increasing the risk of pneumonia, and
elevations in the resting
arterial CO2 level. Measurement of pulmonary function tests in these patients
usually shows a significant restrictive pattern (small lung volumes) on the
basis on
neuromuscular weakness.
 
If respiratory muscle weakness is severe enough mechanical ventilation may be
required. Small mechanical ventilators have been developed which deliver
breaths through a comfortable plastic nose mask. This is often performed
while the patient is asleep at night and results in improved daytime 
unction.
 
2.  Sleep Disorders:
 
Patients with Post-Polio Syndrome have a high incidence of sleep disturbances
with poor sleep quality and frequent awakenings which may be due to several
factors. However, the most important etiology to rule out is central,
obstructive and  
mixed sleep apneas. Nocturnal hypoxemia and hypercarbia can lead to worsening 
o
f
daytime
function of the breathing muscles. Nocturnal non-invasive ventilation can
be used in these patients to improve sleep quality and reduce symptoms of
daytime sleepiness, and perhaps improve daytime respiratory muscle function.
 
3.  Dysphagia:
 
Many PPS patients reported some new difficulty with eating or swallowing more
commonly in those with bulbar polio. Video fluoroscopy has been used for
evaluation and has frequently revealed pharyngeal constrictor weakness.
Laryngeal penetration and loss of the cough reflex may occur without 
ymptoms,
suggesting an underestimation
of the presence and severity of dysphagia in this population. Many patients
have already employed compensation such as altering diet, cutting solids into
small pieces, chewing it thoroughly, taking small sips of liquids, eating
slowly, and using
postural maneuvers. Most patients with dysphagia had also experienced some
progressive speech difficulty such as increased hoarseness, weakness, or
slurring.
 
4.  Cold intolerance (29%):
 
Limbs may be cold and cold exposure produces weakness. This is thought to be
due to intermediolateral column involvement resulting in vasoparesis, venous
pooling, and excessive heat loss.
 
5.  Degenerative arthritis:
 
A joint that is biomechanically disadvantaged may develop degenerative
arthritis.
 
6.  Social and psychological problems:
 
Long term disability and denial may result in social and psychological 
problems
.
 
C.  PAST HISTORY
 
1.  Average age of polio onset is 7 years. Median time to maximum recovery
is 8 years. Median period of stable neurologic and functional status is 25
years.
Median post-polio symptom duration before patient presents for evaluation is 

years.
 
2.  Variables associated with shorter interval to PPS: greater severity and
greater age.
 
3.  Initial symptoms are most frequent in the lower limb most affected in the
acute illness. (Upper extremity weakness is easier to compensate for without
overuse resulting.)
 
4.  The onset is usually insidious but is frequently precipitated by injury,
illness, bed rest, or weight gain.
 
IV.  EVALUATION PROCESS
A.  IDENTIFY AREAS OF DYSFUNCTION
 
1.  The history is especially useful in identifying fatigue, dysphagia, sleep
disorders, and alteration in activities of daily living.
 
2.  The Neurologic exam will identify atrophy or weakness and verify that
reflexes are not increased. Pay special attention to the "good" limb as
significant weakness may be present of which the patient has never been 
ware.
With leg muscles, functional tests must be used because manual testing may 
ot
detect 
quadriceps weakened to 30% of normal even though this is sufficient strength 
fo
r
routine daily
activities. Seek a mechanical advantage in manual muscle testing: Test the
triceps or quadriceps with the elbow or knee flexed more than 90 degrees.  
Test the psoas in the supine position.
 
3.  The general physical exam and biomechanical exam note obesity, joint
deformity, overuse syndromes, and scoliosis.
 
4.  Electromyography may be requested when needed to document previous 
anterior
horn cell disease (especially when the previous history of polio is in 
oubt).
EMG can also be used to rule out other neuromuscular pathologies or to 
identify
subclinically involved muscles.
 
5.  CK elevation may be seen in patients but may not correlate with 
progressive
weakness.
 
B.  FORMALIZE TREATMENT GOALS
 
After the diagnosis of PPS is established, a patient conference is a 
convenient
way to formalize treatment goals and begin patient education. These areas
should be addressed:
 
1.  Lifestyle Modifications:
 
This item is the "sine qua non" of all attempts at successful management of 
PPS
.
At the time of formal diagnosis, patients are often desperate, yet imbued 
ith
a belief in their own ability to overcome their disability through the "no
pain, no gain" approach. This approach may have served them very well after
their acute attack
of polio many years ago but is now actually self-destructive. Persistence in
this approach of "overcoming" illness has led to a spiral of deteriorating
function and frequently a parallel decline in self worth. Patients must
understand 
the concept of "living with" PPS in order to lead the fullest life possible.  
A
n
understanding of the need for lifestyle modification is rarely achieved at 
he
first visit
and is often best reintroduced by a knowledgeable Occupational or Physical
Therapist and
reinforced and monitored at subsequent physician office visits.
 
2.  Increase Muscle Capacity:
 
a.  Muscular capacity can be increased by achieving increased strength or
endurance. Strength can be increased through isometric exercise. However,
muscles must be carefully selected for isometric exercises. Some muscles will
already be functioning at their maximum. Exercise may actually have a
deleterious effect by forcing
these muscles beyond their metabolic capacity and producing injury.
 
b.  Endurance may be increased, susceptibility to fatigue decreased, and long
term deterioration minimized through appropriate exercise supervised by a
physical therapist experienced with post polio patients. Almost all patient
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