Download ACUTE FLACCID PARALYSIS (AFP)

 Pediatrics lect. 7
Dr. Samah Abu-Rahma
11-11-2009
Please note that boxes with a dashed
line contain information from the
slides NOT mentioned by the doctor.
ACUTE FLACCID PARALYSIS (AFP)
GENERAL
AFP (acute flaccid paralysis) is a universal abbreviation because it is
very imp. as it can be caused by several disorders such as botulism, polio...
AFP is the acute onset of generalized flaccid weakness in the absence
of symptoms of encephalopathy, it implicates the motor unit so we mean
a lower motor neuron.
AFP is a top emergency because children who come with acute flaccid
paralysis can transition from inability to walk to being in a respiratory
failure within hours. it is very important to have a triage system and a
professional idea about where the problem is..if it's polio,nerve problem
or muscle problem, how involved the respiratory system is.. before you
leave the patient you have to have a management plan because many times
respiratory failure could be incipient (early) that goes unnoticed unless
you think about it and look for it .
>> We divide it into:
o Hyperacute generalized weakness : unusual , happens within hours.
o Subacute generalized weakness : usually happens ,over 2-3 days,
slowly progressive weakness.
o Chronic progressive weakness
- Lumbosacral region pathology could also cause flaccid weakness in the
legs, but there are usually other signs of spinal cord dysfunction.
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- Flaccid leg weakness without involvement of the arms could also arise
from cerebral disorders, but other signs of cerebral involvement are also
usually present, particularly cognitive involvement
THE INITIAL COMPLAINT
Almost always noticed in the lower extremities because
1. many disorders that we will mention soon are ascending starting
from the lower extremities.
2. symptoms of leg weakness are more easily to pick up and more
obvious than arm weakness...for example the parents may tell you
that their child's gait has changed, he can't walk or can't stand
up…. before they notice that he can't comb his hair or can't pick
things from his closet) . although it's generalized weakness but
problems are more easily noticeable in the lower extremities so you
have to ask about signs of weakness in other sites. When you hear a
low extremity complaint , that does not mean it's confined to that
region.
WITH PROXIMAL MUSCLE WEAKNESS
o You can see the waddling gait which is characteristic for
proximal muscle weakness ; when you stand on one foot ,
abductors will stabilize you, if you have weak abductors
( ‫; )ا‬the patient uses circumduction to
compensate for gluteal weakness
o Difficulty in going upstairs due to hip extensor weakness.
o Difficulty in going downstairs if the patient has
Quadriceps weakness and cannot extend his knee
o Difficulty rising up from a chair.
WITH DISTAL MUSCLE WEAKNESS
the patient will have foot drop so
o He will start stumbling ( ).
o He will fall down easily when he walks on uneven surfaces at first
and then on even surfaces (tripping by nothing at all!).
So they have spontaneous falls.
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o Repeated ankle spraining because of lateral instability.
o Children with foot drop will lift the knee high in the air so the foot
will clear the ground.
o Older children will complain of specific disabilities. For example the
child will till you he can't comb his hair or he can't open the door….
o limb weakness is often associated with weakness of muscles of the
head and neck, so you should ask about bulbar weakness (gait,
general power) then you ask about upper extremities.
o Inquire about diplopia, drooping eyelids (ptosis), difficulty chewing
and swallowing, facial expressions, and voice changes (nasal speech) ,
red urine in case of myositis , we will have myoglubinurea .. all these
you should ask about in the history of someone with muscle
weakness ( Hx of present illness).
PHYSICAL FINDINGS
Look for atrophy or hypertrophy.
Look for Fasciculations ; spontaneous contractions in single ms fiber
Palpate muscles for tenderness and texture.
Joint contractures ; children with myopathy will have fixed
contractures of the limbs then weakness in muscles ,myotonia.
o Strength and tendon reflexes
o Watch the child sit, stand, and walk. He usually has :
• Hunched shoulders
• Exaggerated lumbar lordosis ; he is trying to shift his center
of gravity so he won't fall down.
• Toe walking ; also found with those who have Duchenne
Muscular Dystrophy (DMD) because achilles tendon is very
tight.
• Waddling.
• Foot drop.
• Gower’s sign =very important=
o
o
o
o
Gower's sign
>> When the child wants to stand , he has to
climb up his body. so he can't change from
position to another without holding onto
something .
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>> It is an indication of proximal muscle weakness. In textbooks it is
always mentioned with DMD but any proximal muscle weakness also will
give positive Gower's sign.
>> It is part of Motor system examination; you ask the patient to sit down
& then to stand up.
HYPERACUTE WEAKNESS
o Symptoms evolve very quickly and children reach the maximum
weakness within 24 hours .
o Diagnosis here depends mainly on history and physical examination ;
you can't find any lab or electrophysiological abnormality . for
example if you cut the ulnar nerve, there will be ulnar side weakness
but normal nerve conduction studies(normal distal stump) .So
accurate history is essential to assess peripheral causes because
electrodiagnosis (EMG, NCS) may not be helpful.
=Note= EMG (electromyogram) ----- NCS ( nerve conduction study)
o Etiologies : *periodic paralysis, intoxications (organophosphate
poisoning) , or psychogenic.
=Note= Guillain Barre syndrome may have a hyperacute course.
*Hyper/hypokalemic paralysis which are familial disorders can cause
hyperacute presentation
PERIODIC PARALYSIS
It is a temporary paralysis but NOT associated with respiratory failure,
either hyperkalemic or hypokalemic channelopathy.The doctor said:" you
don't have to memorize them,they are not uncommon &you may see them."
Familial hyperkalemic periodic paralysis
Autosomal dominant
Weakness severity is variable, usually lasts less than an hour, after
exercise or fasting
Daily acetazolamide may decrease frequency of attacks
Familial hypokalemic periodic paralysis
Autosomal dominant
Attack triggered by heavy meal, emotional stress, rest after exercise
Attacks last 6-12 hours, with no respiratory distress
Treatment of attacks is with repeat oral potassium
Hypokalemic periodic paralysis: a manifestation of hyperthyroidism.
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GUILLAIN-BARRE SYNDROME (GBS)
GENERAL
>> Guillain-Barre syndrome is the commonest cause of acute flaccid
paralysis (AFP) in healthy children.
>> It is an acute inflammatory demyelinating polyradiculoneuropathy
(AIDP) as the name implies ( !
‫ ) ا‬:
*Acute not chronic , usually has subacute presentation
*inflammatory; inflammation at the nerve root so we call it
*polyradiculoneoropathy ; the maximum inflammation is in the nerve roots
of the spinal cord leading most of the time to
*demyelination.
>> Acquired not genetic.
>> monophasic ; just one phase of increasing weakness then plateau then
improvement, so it is not a chronic recurrent illness.
>> roughly Symmetrical, progressive ascending weakness, associated with
areflexia (common , complete loss of reflexes), variable sensory
complaints ( numbness, pain, parasthesia).
>> the hallmark is elevated CSF protein without pleocytosis
=Note= GBS is one of rare causes of acellular hyperprotienemia in CSF.
? WHY
do we have high protein level ?
because of dumping of myelin products into the CSF as a result of
proximal demyelination.
and this is very important as we can distinguish it from infections where
we have high cell count & high protein level.
PATHOPHYSIOLOGY
(post infectious autoimmune disease)
>> It is an autoimmune mediated disease without known genetic factor.
>> It is known to follow gastrointestinal infection mostly 2 weeks after
gastroenteritis by Campylobacter jejuni (the most common) ,then there
will be autoimmune response attacking nerve roots leading to
demyelination.
BUT any kind of infection can precede it including ( respiratory,
CMV, EBV, HSV, enteroviruses, even in the time of seroconversion of
HIV)
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>> The main lesions are acute
inflammatory demyelinating with acute
axonal degeneration in some cases,
particularly those following
campylobacter infection … there are
specific autoantibodies against myelin
in the serum , associated with disease
following campylobacter infection or
following RSV infection (respiratory
syncytial virus).
FORMS OF GBS
1. Acute inflammatory
demyelinating polyneuropathy
(AIDP): the prototype and the
most common form in developed
countries. It has the best px ☺
2. Pure sensory
3. Mixed axonal and demyelinating
4. Pure axonal – the worst prognosis
5-Miller Fisher syndrome: is similar to GBS but it comes as a triad of
1- external ophthalmoplegia ( inability to move pupils),
2-ataxia (unstable wide based gait)
3-areflexia with muscle weakness.
~It is part of differential diagnosis of ataxia not weakness.~
-Acute inflammatory demyelinating polyneuropathy (AIDP): the
prototype and the most common form in developed countries
-Acute motor axonal neuropathy (AMAN) :more common in developing
countries. More severe with common respiratory involvement. Strong
association with Campylobacter infection
-Acute motor sensory axonal neuropath (AMSAN)
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CLINICAL FEATURES OF GBS
>> Two to four weeks after a benign febrile illness.
>> Common presentations are tingling, sensory sensations,
paresthesias in the fingers and toes, pain (is a common
presentation in children (79%), particularly low back pain
(common), muscle pain.
>> Symmetrical ascending (starting from longer nerves then ascending to
shorter nerves) muscle weakness in the lower extremities, that a scends
over hours to days to involve the arms, and in severe cases it will involve
respiratory muscles leading to respiratory failure so the patient has to be
on ventilator.
>>Cranial nerves are affected in 30% of the cases, most commonly the
facial nerve with bilateral facial palsy.
>>More than 90% of patients reach the nadir (the maximum deficit) of
their function within 2-4 weeks then a period of plateau, after that the
patient starts to improve because it is a self limiting disease. BUT we
start treatment by immune modulation to hasten/accelerate improvement.
PHYSICAL EXAMINATION
>> You will find symmetrical weakness with diminished or absent deep
tendon reflexes.
>> Vibration & position sensation are commonly affected in 40% of cases.
>> 50% of patients will have evidence of autonomic dysfunction; as the
autonomic nerves are small peripheral nerves so they could be involved:
- Cardiac arrhythmias
- Paralytic ileus
- Orthostatic hypotension, hypertension
- Urinary retention
=Note=These are very important symptoms because the most common
cause of death (acutely) in the first 24 hours of GBS is the autonomic
dysfunction ;apnea ,severe hypo/hypertension NOT the weakness.
DIAGNOSIS
>> it is a clinical diagnosis, based on typical findings and exclusion of other
illnesses ( polio & transverse myelitis ).
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Cerebrospinal fluid
-test CSF after the first week of
symptoms because in the first
week, CSF may be normal.
-CSF typically reveals
normal pressure, normal cell
count, and elevated protein
~the more severe the disease
the more protein in the CSF~
? WHEN
Electrophysiologic studies
(NCS)
-Most specific and sensitive tests
for diagnosis.
-Normal (NCS) after 10days-2wks
of illness make the diagnosis of GBS
unlikely.
-Evidence of evolving multifocal
demyelination.
should we suspect this is NOT GBS?
The problem is not missing diagnosis of GBS but it's diagnosing it in
someone who doesn't have it. Everyone automatically assumes that anyone
with acute flaccid paralysis has GBS and misses other important
differential diagnoses (mis-label them as GBS).
~~ GBS is highly unlikely if...
1. marked asymmetry of weakness this is seen with polio NOT GBS
2. persistent bladder or bowel dysfunction (weakness, urinary
retention or inability to urinate) early sign of spinal cord patho.
3. leukocytosis in CSF (infection) seen in polio
4. sharp sensory level seen in spinal cord dysfunction (sensory level
is related to the spinal cord NOT the brain because the brain is
divided into right and left; for example, loss of sensation below T5,
normal sensation above T5). So any patient with weakness must
have testing for sensory level to rule out spinal cord pathology.
5. pupillary abnormalities seen in botulism, which causes weakness
and autonomic dysfunction. So the pupil is dilated and sluggish.
(GBS only ophthalmoplegia, the pupil is NOT involved and remains
equally round and reactive).
MANAGEMENT
>>Critical
>>Steroids are NOT effective and are
contraindicated.
care monitoring is essential.
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The #1 cause of death is autonomic dysfunction, while the 2nd most
common cause of death is respiratory failure. Because medical care has
become so advanced, no one should die of respiratory failure - it would be
a travesty (ridiculous )! It is very important to remember that good
supportive care can prevent death following autonomic dysfunction or
respiratory failure.
When do we worry about respiratory failure due to GBS?
The risk factors include:
1) Cranial nerve involvement
2) Short time from preceding respiratory illness – acute case of
respiratory infection or gastroenteritis 3 days before GBS
(signifies severe autoimmune reaction).
3) Rapid progression over < 7 days
4) Elevated CSF protein in the first week (severe inflammation)
5) Severe weakness – high risk for resp. failure (unable to lift elbows
above bed, unable to lift head above the bed, or unable to stand)
OUTCOME
Prognosis is good ☺, especially in children because they
have a shorter clinical course than adults. 85-90% of
children have excellent recovery by the end of the year.
By "recovery" we mean they return to >90% of baseline
health status. The degree of recovery depends on the severity of
inflammation (only few children recover fully). For example, children with
mild demyelination recover fully while those with axonal pathology recover
only partially. 50% of children are ambulatory by 6 months and 70% walk
within a year of onset of the disease. Remember that GBS has a chronic
course, so it is NOT an easy disease. Children may walk by the end of the
year, but improvement afterwards is very slow.
Severity of the illness acutely does NOT predict the extent of future
improvement (it does NOT correlate with long term outcome). For
example, the recovery for 2 patients – one presenting with a mild form of
the disease (can sit but not stand) and the other presenting with
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respiratory failure – may be the same during a certain year (both may be
able to walk with assistance)!
TRANSVERSE MYELITIS
GENERAL
The major differential diagnosis of GBS is a spinal cord
problem, the most common being transverse myelitis
(inflammation of the spinal cord).
Like GBS, it is also a post-infection (viral) or postvaccination autoimmune disease.
PATHOPHYSIOLOGY
Transverse myelitis is an acute demyelinating disorder of the spinal cord
that usually evolves over days, but may have a hyperacute presentation.
It may be associated with demyelination in other parts of the CNS.
CLINICAL FEATURES
Symptoms progress rapidly (peak within 2 days). Recovery usually begins
after a week of onset of the illness
1) Mean age of onset is 9 years
2) Patients present with ascending weakness.
3) In the initial phase of the disease, reflexes may be depressed or
lost (like GBS) because of spinal shock or involvement of the nerve
roots. With time, these reflexes become brisk.
4) Thoracic level of myelitis (usually)
5) Sensory level
6) Asymmetrical leg weakness
7) *Early bladder & bowel involvement (v. imp).
8) *Back pain is also very common at the onset
9) Tendon reflexes may be decreased or increased
To rule out other differential diagnoses, it is important to remember that
weakness (localized to limbs) is highly suggestive of spinal cord
pathology and is NOT associated with bulbar involvement (ex. patients
with limb weakness and bilateral facial weakness are unlikely to have a
spinal cord problem because the face and cranial nerves are involved). So
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in cases of weakness without bulbar involvement you must consider and
rule out spinal cord involvement.
DIAGNOSIS
#1 MRI of the spine (diagnostic tool of choice)
In patients with transverse myelitis, the MRI usually
shows swelling (inflammation) of the spinal cord.
However, at times it is normal.
How quickly must you do an MRI for a patient who
presents with lower limb weakness (to detect sensory
level)? Should you do it immediately, tomorrow or
postpone it for a couple of days??? The MRI should
be performed IMMEDIATELY on admission because
it is needed to rule out a mass lesion of the spinal cord (exclusion of acute
cord compression is essential). If a lesion is detected, then surgical
intervention must follow (ex. epidural mass, tumor, abscess, hematoma,
etc). Any delay in its management may lead to development of
irreversible paraplegia or irreversible damage to the spinal cord.
MANAGEMENT
To treat a patient with transverse myelitis, immediately give him/her high
doses of IV steroids (followed by tapering doses of prednisone).
OUTCOME
Unfortunately, transverse myelitis has a poor prognosis. Only 50% make
a full recovery, 40% recover incompletely, and 10% do not recover (these
patients continue to suffer from severe neurological dysfunction).
Prognosis depends on the severity of the inflammation detected in the
MRI (ex. a patient with mild edema has better prognosis than a patient
with necrosis and hemorrhage). Generally, it is NOT a good disease.
ENTEROVIRUS INFECTION Polio Myelitis
GENERAL
Enteroviruses include polio virus, cosxackie virus, and the
echovirus group (feco-oral transmission). The most important
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virus to consider in AFP (most likely to cause severe paralytic disease) is
the polio virus. You must rule out polio myelitis in any patient presenting
with GBS (due to our strict vaccination program, polio has been
eradicated from HKJ, but it continues to be a worldwide disease).
Coxsackie and echoviruses are more likely to cause aseptic meningitis.
PATHOPHYSIOLOGY
Enteroviruses are RNA viruses that inhabit the GI tract of humans
They are neurotropic and produce paralytic disease by irreversibly
destroying the motor neurons of the brainstem and spinal cord. They
specifically target the anterior horn cells (the most important part of the
motor neuron).
CLINICAL FEATURES
Poliomyelitis usually occurs as epidemic in
the spring and summer.
1) Initially, the patient suffers from
brief illness characterized by fever,
malaise and GI symptoms. Because
the cause of this AFP is infectious,
the patient displays symptoms
typical of someone with an
infection (toxic appearance, fever,
meningismus meningeal signs , and
pleocytosis in CSF as if the
patient has paralytic meningitis or
CNS infection). To rule out polio
myelitis it is very important to do *lumbar puncture (LP) if patient
presents with AFP, toxic appearance, fever & meningeal signs.
2) After recovery from the above, he/she develops paralytic illness.
(muscle atrophy, weakness, severe asymmetrical paralysis and
diminished reflexes)
After the febrile illness, there is a brief period of apparent well being,
after which the fever recurs, with headache, vomiting and meningeal
irritation. Pain in the limbs and spine is followed rapidly by limb weakness
Pattern of limb weakness is variable, but is generally asymmetric
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DIAGNOSIS
The most important steps in the diagnosis of polio myelitis are:
1) Clinical suspicion (v. imp)
2) *LP CSF leukocytosis is seen in the acute phase (because it is an
infection). Elevated CSF protein may also be seen.
3) CBC shows leukocytosis (because it is an infection)
4) Virus recovery from stool & stool analysis is essential.
5) Serological testing. Obtain stool, blood and throat samples for viral
serology, demonstrating a 4-fold rise in IgG is helpful but not
always easy. Positive IgM antibodies is diagnostic
MANAGEMENT
Treatment of polio myelitis is mainly supportive for pain and other
symptoms until the patient's condition improves
1) Mechanical ventilation may be needed in bulbar involvement
2) Pain management for paresthesias
3) Physical therapy
OUTCOME
There are different types of polio.
• Bulbar polio, only the cranial nerves are involved. This can be life
threatening because it may lead to respiratory dysfunction
(prolonged periods of apnea), swallowing dysfunction, and other
problems. So, they may require mechanical ventilation.
Extraoccular muscles are spared
• Paralytic polio, rarely seen (due to introduction of polio vaccine)
MYASTHENIA GRAVIS (MG) ‫اه ا‬
GENERAL
MG is one of the differential diagnoses of AFP (some patients present for
the first time with AFP due to myasthenia). As its name implies,
myasthenia gravis is a "grave" (very serious) disease because 50 years ago
anybody affected by it died secondary to myasthenic crisis and
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respiratory failure (before the introduction of steroids and mechanical
ventilation)!
PATHOPHYSIOLOGY
MG is an autoimmune, T-cell mediated disease directed at proteins in the
post-synaptic membrane. It causes *fluctuating muscle weakness and
*fatigability of muscles (v. imp hallmark of disease – ex. child is normal in
the morning but becomes increasingly tired by the end of the day until
he/she can no longer walk OR he/she develops ptosis after looking
upwards for 30 seconds and can no longer open his/her eyes).
Because it is linked with certain HLA haplotypes, MG has also been
associated with other autoimmune diseases (ex. Grave's disease) and
genetic factors may play a role (family history).
CLINICAL FEATURES
There are 2 clinical forms of MG:
• Ocular myasthenia
• Generalized myasthenia
The most common presentation of someone with
MG is *ptosis (v. imp ocular finding). Ptosis
acquired secondary to MG may be unilateral or
bilateral. Pupils are spared. 50% of patients
with ocular myasthenia have generalized
symptoms within 2 years.
1) > 50% of patients present with occular weakness and ptosis
2) 15% present with bulbar weakness: dysphagia, dysarthria
3) < 5% with limb weakness alone
4) Deep tendon reflexes are ALWAYS normal, or even hyperactive
at times (this is evident even in cases of severe myasthenic crisis)
DIAGNOSIS
Diagnosis is suspected clinically based on:
1) history (ex. history of fluctuating muscle weakness) physical
examination (ex. intact reflexes) Bedside tests include Tensilon
test, used for patients with ptosis and ophthalmoplegia, where a
clear response is easy to recognize= Edrophonium chloride
(anticholinesterase) is injected IV and a response is monitored
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2) nerve conduction studies - NCS (ex. repetitive nerve stimulation –
reveals characteristic abnormal pattern in 60% of patients with
MG, may be difficult to perform in children)
3) serological tests and antibody assays (ex. anti-acetylcholine
receptor antibodies, positive in 85% of cases)
MANAGEMENT
1) Myasthenic crisis is the involvement of respiratory muscles with
severe, increasing, generalized muscle weakness. It is a serious life
threatening condition that requires ICU admission and respiratory
support, in addition to MG specific treatment (high dose steroids,
IVIG IV immunoglobulins, plasmapheresis, and oral anticholinesterases).
2) Children with generalized myasthenia, with positive antibodies
should undergo thymectomy as soon as possible for thymoma or
thymus hyperplasia (about 1 in 10 MG patients have a thymoma.
There is a true "cause and effect" association between MG and
thymomas because thymus is responsible for production of T-cells).
BOTULISM ‫ا اا‬
GENERAL
Botulism is another cause of AFP. Unlike polio myelitis, we still see cases
of botulism. There are different types of botulism:
1) Food borne botulism: ingestion of pre-formed
botulinum toxin (very rapid progression of
disease and appearance of symptoms). Most
common sources include: *expired canned
foods and homemade honey (minimal reports
of botulism resulting from honey but it is still
contraindicated in infants < 1 year of age).
2) Infant botulism: ingestion of clostridial
spores that inhabit the GI tract and release
toxin in vivo
3) Wound botulism: infection of a wound with in vivo toxin production
(spores enter through wound then form toxins in the body)
4) Adult enteric infectious botulism: ingestion of clostridial spores
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PATHOPHYSIOLOGY
C. botulinum is a heterogeneous group of gram-positive, rod-shaped, spore
forming, obligate anaerobic bacteria. Spores of C. botulinum are heatresistant (can only be destroyed by heating to 120ºC for five minutes)
Factors favoring toxin production:
• Restricted O2 exposure (anaerobic or semianaerobic environment)
• Low acidity (pH >4.6) water
• temperature of 25 to 37ºC for ideal growth
Botulism - Pathogenesis
The toxin disperses widely via the vascular system and binds to a specific
receptor (synaptotagmin II) on the presynaptic sides of peripheral
cholinergic synapses at ganglia and neuromuscular junctions. After gaining
entrance to the cell's cytoplasm, the toxin produces an irreversible
disruption in stimulation-induced acetylcholine release by that presynaptic
nerve terminal. Return of synaptic function requires sprouting of a new
presynaptic terminal…about 6 months
CLINICAL FEATURES
Like MG, botulism is a neuromuscular junction disease associated with
*pure motor weakness and is pre-synaptic (NOT post-synaptic). Presynaptic function returns to normal after 6 months. Severity of symptoms
is variable (some people have mild weakness, others require ventilation)
1) Acute onset bilateral cranial neuropathies associated with
symmetric descending weakness are very common
2) Symmetric neurologic deficits.
3) NO fever (unlike polio)
4) Patient remains responsive (NO encephalopathy)
5) Features of autonomic dysfunction include: constipation, normal or
slow heart rate, normal blood pressure
6) NO sensory deficits with the exception of blurred vision because
it is a disease of the neuromuscular junction NOT of the nerve
itself (intact vibration and position sense, unlike GBS).
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Symptoms of food-borne botulism usually appear quickly (within 12 to 36
hours) after ingestion of the preformed toxin. Prodromal symptoms
include: nausea, vomiting, abdominal pain, diarrhea, and dry mouth. Resp.
difficulties requiring intubation & mechanical ventilation are common.
Cases of wound botulism have been described involving abrasions,
lacerations, open fractures, surgical incisions, and even closed hematomas.
This type does NOT have the prodromal GI symptoms common to foodborne botulism and has a longer incubation period of approximately 10
days. Fever may be present.
DIAGNOSIS
1) Food borne toxin: toxin in blood, stool, vomitus & suspected foods
2) Repetitive nerve stimulation (NCS) reveals a pattern characteristic
of pre-synaptic neuromuscular junction disease.
3) Serum analysis for toxin by bioassay in mice, demonstration of
toxin in the blood is diagnostic
4) Adult enteric and infantile botulism: isolation of spores from stool
5) Triage: classification of patients
according to type and severity of injury,
usually in times of war or crisis, to
determine whom to treat first and whom
to send home (ex. mild, moderate,
severe or life-threatening injury).
*CSF in botulism is completely normal
MANAGEMENT
Management of botulism is supportive and includes:
1) clinical evaluation of ventilation, perfusion & upper airway integrity
2) prevention of DVT, prevention of aspiration in patients who can't
swallow, turning over non-ambulatory (bedridden) patients to
minimize bed sores, etc
3) monitoring pulse oximetry, spirometry, arterial blood gas
measurement (ABG)
4) severe cases: intubation, mechanical ventilation and nutritional
support(ex. nasogastric tube for patients who can't swallow)
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Treatment:
1) Antitoxin therapy (equine serum botulism antitoxin or humanderived botulinum Ig) reduces fatality rates compared to untreated
patients, but it must be given ≤24 hours of the onset of the
illness. Antitoxin treatment initiated after 24 hours of symptom
onset is useless and (according to the slides, it does NOT shorten
the duration of symptoms, but may decrease fatality rates).
2) Antibiotics: Penicillin G (3 million units IV every four hours in
adults) provides effective coverage of other clostridial species
***Aminoglycosides are contraindicated because they affect the
neuromuscular junction and may increase weakness.
OUTCOME
Respiratory failure is the #1 cause of death in patients with botulism
RAPIDLY PROGRESSIVE WEAKNESS
GENERAL
Rapidly progressive weakness is an emergency. This is how you evaluate
any patient who presents with AFP:
1) Assure integrity of ABCs (v. imp) –airways, breathing & circulation
2) Support and stabilize patient
3) Focused hx to determine exact cause (is it GBS? MG? Botulism?)
4) Attempt to localize weakness
5) Labs and studies appropriate for patient
6) Triage the patient (ex. decide whether to send the patient to ICU
vs. mild GBS so admit as regular patient?)
DIAGNOSIS
What are the clinical features of someone with acute weakness and
associated respiratory compromise?
1) Confusion, agitation, headache, lethargy (due to hypercapnea)
2) Dyspnea, worsens during sleep and relieved by sitting
3) Use of accessory muscles
4) Orthopnea
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MANAGEMENT
Do labs to check for early respiratory failure:
1) *Forced Vital Capacity (v. imp to determine respiratory status
of patient) Check FVC as soon as the patient is admitted. If it
is normal (70 cc/kg) at admission, repeat test after 2 hours then
every 4-5 hours if it remains normal. If the FVC is initially
abnormal, then you must recheck it after 1 hour. Admit the patient
to the ICU if the patient's condition continues to deteriorate and
consider intubation when it decreases to 25 cc/kg.
2) CXR
3) ABG
4) Further triage according to severity of illness
AFP-pearls- SUMMARY
• Acute and subacute weakness, or rapidly progressive weakness is a
medical emergency
• Management priorities are to support vital functions
• Detailed history and examination are essential for reaching a diagnosis
and tailoring investigations
Done by: We'am Al-Zayadneh
& Ruba Al-Abwah
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DISEASE
GBS
GENERAL
- acute inflammatory
demyelinating
polyradiculoneuropathy
Transverse
myelitis
-
Polio
myelitis
- Enterovirus
(coxsackie/echovirus)
- Feco-oral
-
MG
Botulism
-
Spinal cord inflamm
post-infection (viral)
post-vaccination
autoimmune dis.
Myasthenic crisis:
resp. ms + general
muscle weakness
NM jn disease
pre-synaptic
food borne/
infant/wound
PATHOPHYSIOLOGY
- post infectious
- autoimmune disease
CLINICAL FEATURES
-
-
acute demyelinating
disease
-
RNA viruses
Neurotropic
dmg ant. horn cells
of motor neurons
-
Autoimmune, Tcell
Dmg post-synapse
HLA haplotypes
family history
-
C. botulinum
heterogeneous
Gram +ve rod
heat-resist spore
obligate anaerobes
-
-
self limiting disease
Symmetrical ascending
low back pain muscle pain
bilateral facial palsy.
ascending, asymmet.
weakness of limbs
bladder & bowel dmg
Back pain
↓ or ↑ tendon reflex
febrile illness
meningismus
pleocytosis in CSF
paralytic dis.
-
ocular vs. generalized
MG
fatigability of ms
ptosis
-
motor weakness
acute bilat.neuropath
symmetric desc.
Autonomic dysfn
DIAGNOSIS
- elevated CSF protein
w/o pleocytosis
- Electrophysiologic
studies (NCS)
- clinical , by exclusion
-
MRI of spine
-
Clinical suspicion
CSF= ↑WBC & ↑ ptn
stool analysis (virus)
+ve IgM,↑IgG
-
hx & pe
NCS nerve stim.
anti-acetylcholine
receptor abs
*
toxin (blood/stool/
vomitus)
NCS nerve stim.
Toxin in serum
Spores from stool
Normal CSF
www.shifa2006.com
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MANAGEMENT
- Steroids are NOT
effective and C/I
- Critical care
-
IV steroids
+prednisone
-
Supportive
-
steroids, IVIG,
plasmapheresis
oral anticholinesterase
thymectomy
-
- Anti-toxin Ry
- Penicillin G
*C/I aminoglycoside
OUTCOME
- good px, esp.
children
-Demyelinating
good px
- Axonal
worst px
- death due to
auton.dysfx +
RS.failure
-
Poor px
- Bulbar polio =
life threatening
- Paralytic
polio= rare
- death due to
respiratory
failure
-
Resp. failure