Acute flaccid paralysis in pediatrics

1. Approach to a Child with Acute
Flaccid Paralysis
Dr: Eman Khammas Alsadi
Pediatrition

2. The objectives of this article are:
1. to provide a practical approach
2. to diagnosis in an individual patient; to provide an
3. approach to rational use of diagnostic tests and
discuss
4. the common causes of AFP in children.
The objectives

3. Acute flaccid paralysis (AFP)
is a clinical syndrome characterized by rapid onset weakness, that
frequent includes respiratory and bulbar weakness. The weakness
usually progresses to maximum within days to weeks.The term
“flaccid” indicates the absence of spasticity or hyperreflexia,or clonus
or extensor plantars
AFP is broad clinical entity with an array of diagnostic possibilities. An
accurate and early diagnosis of the cause has important bearing on the
management and prognosis.
If not managed appropriately, paralysis can progress to respiratory
failure and death. Another issue of public health importance is the
immediate reporting of all cases of AFP to the polio surveillance team

4. Any case meeting the AFP definition undergoes a
thorough investigation to determine if the paralysis is
caused by polio. Each case of AFP is to be reported and 2
stool samples (≥24 h apart, each 8–10 g) are collected
within 14 d of paralysis onset and sent to WHO accredited
laboratory.
Diagnostic Approach
1. Initial Assessment and Stabilization
Every child with AFP is a medical emergency requiring
systematic evaluation and management. Initial assessment of any
such acutely ill child should concentrate on rapid cardiopulmonary
assessment and resuscitation.
a. Detect and manage respiratory muscle weakness
Any child with acute weakness should be evaluated for respiratory
muscle weakness.

5. 1. Younger children with respiratory muscle weakness may present
with non-specific irritability, sweating, poor feeding and shallow
or paradoxical respiratory efforts.
2. Older children may complain of respiratory difficulty, may have
excessive sweating, agitation, air hunger, reduced single breath
count/chest expansion or shallow/paradoxical respiratory
efforts.
Careful serial examinations may be critical in such children to
pick up the weakness early. Early elective intubation and
respiratory support are critical to save these affected
children.
b. Detect and manage bulbar weakness:
Symptoms of voice change, poor cry, pooling of
secretions, gurgling sounds in throat, poor ability to
swallow and choking on feeds may be markers of
bulbar dysfunction . Care should be taken to avoid oral
feeding, providing regular suction and ensuring entral
nutrition via nasogastric feeding.

6. c. Evaluate for cardiovascular instability:
Conditions leading to AFP (Spine trauma, myelitis, Guillain Barre syndrome) can
also result in cardiac rhythm abnormalities and cardiovascular insufficiency.
These issues will require a priority management. Hence, attaching a
quadriparetic child to an ECG/cardiac monitor is an early step in the
management.
d. Rule out dyselectrolytemia or toxemia:
Hypokalemia and snake envenomation are important causes of flaccid paralysis.
These causes should be excluded in all children with AFP by history and
examination, early in management course. A rapid assessment of electrolytes
and ECG should be sought in all such children.
e. To rule out a spinal compression (traumatic, intraspinal collections).
At the outset, patients with possible spinal injury due to trauma or other lesions
requiring urgent neurosurgical intervention should be identified on history and
examination. Immediate spinal stabilization and administration of corticosteroids
in those with trauma would be a priority, while neurosurgical relief of spinal
compression may be warranted to prevent long term disability.

7. History
The first step is to determine if an unwell child actually has
muscle weakness. Many children with weakness present with
nonspecific symptoms of irritability, lethargy and clumsy walk or
refusal to walk. Children with abnormal gait, limp or refusing to
walk may present initially to orthopedic or trauma clinics.
Pseudoparalysis due to limb pain may result from:
trauma, arthritis/arthralgia, myostis, joint or periosteal bleeds or
joint or periarticular infections or inflammations.
It is useful to remember the possible causes of AFP in children
using a neuro-anatomical approach
Information is derived from the history and focused neurological
examination looking at pattern of tone, tendon reflexes, sensory
examination, signs and symptoms of bladder and/or bowel
involvement.

8. Investigations
The choice of the initial investigations would depend on the
information gained from history and examination. A step wise
and judicious use of investigations would help reach the
diagnosis with the minimum use of resources
1. MRI Spine:
It is indicated when there is a suspicion of spinal cord
compression or transverse myelitis.
More specifically,
1. any child with history of neck or back trauma,
2. rapid onset
1. flaccid profound quadreparesis
2. , early or persistent bladder or bowel involvement,
3. sensory loss or sensory level on examination,
4. spinal tenderness,
5. neurocutaneous markers,
6. or appearance of UMN signs on examination(e.g., up going
plantars)
should get an MRI of the spine

9. CSF examination: This is helpful to narrow the
diagnostic possibilities.
a. A raised CSF cell count would be seen in patients with
1. transverse myelitis,
2. infective myelitis( polio or enteroviral myelitis,
varicellas or herpes myelitis, rabies, etc) .
b. A raised CSF protein with normal cell count
(albuminocytological dissociation)suggests
1. Guillain Barre syndrome,
2. post diphtheritic polyneuropathy
3. or rarely may be seen in transverse myelitis.
The CSF can be normal early in the course of these illnesses.

10. 3. Nerve Conduction studies and Electro
Myography(EMG): These studies confirm the involvement of
nerves and help in diagnosis of anterior horn cell diseases.These are
particularly helpful to confirm Guillain Barre syndrome.
The repetitive nerve stimulation test helps to diagnose
myasthenia gravis and botulism.
Rarely, these may aid the diagnosis of an inflammatory myopathy.
4. Creatine Kinase: Raised levels of muscle enzyme
creatine kinase reflects acute muscle fiber injury and may
point towards a muscle disease. In the setting of AFP this
may be seen in children with
1. viral myositis
2. inflammatory myopathy.

11. Table 1 A neuroanatomical differential diagnosis of acute flaccid paralysis
in children
Site Pathophysiology Disease
Spinal cord Compressive Traumatic spinal injury, epidural
abscess, hematoma, discitis
Inflammatory Transverse myelitis
Anterior horn cell Viral Poliomyelitis, vaccine associated
poliomyelitis, Enteroviral myelitis,
Japanese encephalitis
Vascular Anterior spinal artery infarction
Roots/nerves Immune mediated Guillain Barre syndrome,
Toxin Post diphtheritic, porphyria,
arsenic
Viral Rabies
Trauma Injection related sciatic neuritis
Neuromuscular
junction Immune mediated Myasthenia Gravis
Drugs, toxins Organophosphates, snake venom,
drugs (aminoglycosides),Botulism
Dyselectrolytemia Hypermagnesemia

12. Muscle Infection Viral myositis
Inflammation (polymyositis)
Channelopathy Hypokalemic periodic paralysis
Dyselectrolytemia Hypokalemia

13. Table 2 Selected clues in history and examination while evaluating a
child with acute flaccid paralysis
Points in history and/or examination Remarks
Fever at onset Polio or enteroviral myelitis, Transverse
myelitis, myositis, epidural abscess, and
Koch spine (prolonged history)
Trauma: head/neck Trivial trauma may lead to spinal
compression in patients with cervical
vertebral instability (Patients with
Downs syndrome, congenital
cervicovertebral anomalies or juvenile
idiopathic arthritis)
Exposure Toxins: lead, arsenic
Snake envenomation
Dog bite: Rabies
Preceding infectious
prodrome/vaccination Guillain Barre syndrome or transversemyelitis
Sore throat, neck swelling, diphtheretic
polyneuropathy (non/partly immunized)
Precipitating factors Diarrhea: Hypokalemia, enteroviral myelitis
Exertion or post parandial: Hypokalemic
periodic paralysis
Intramuscular injection: Polio, traumatic sciatic
neuritis

14. Sensory loss/level Compressive myelopathy, transverse myelitis
Early bowel/bladderinvolvement Compressive myelopathy, transverse myelitis
Constipation in <1 y Botulism (H/o honey exposure)
Prominent autonomic signs/symptoms Guillain Barre syndrome, Rabies, acute myelopathy
Ascending weakness Guillain B syndrome, Rabies, Va z.virus, ascending myelitis
Descending weakness Diphtheria, Botulism
Prominent and early ptosis Myasthenia Gravis, Botulism
Facial weakness Guillain Barre syndrome, Myasthenia Gravis, Botulism
Fluctuating symptoms, fatigability Myasthenia Gravis
Muscle tenderness Myositis, inflammatory myopathy, severe in Guillain Barre.s
Muscle stretch reflexes Absent: Guillain Barre syndrome, Polio,Diphtheria, spinal
shock, at level of spinal cord damage
Preserved : Myasthenia Gravis, periodic paralysis, Botulism
Exaggerated: Below level of spinal lesion,UMN lesion
Spinal tenderness,painful spine
movement Spinal trauma, epidural abscess or otherextradural compression
Neck stiffness Polio, enteroviral myelitis, Guillain Barre syndrome, transverse
myelitis

15. Acute paraparesis/plegia
Features of spinal cord compression* / Sensory level on examination
CE MRI spine as early as possible
Compressive
myelopathy
Noncompressive
myelopathy
AcuteTM:Treat with
high dose steroids
and consult
Neurosurgery
consult+ steroids
Ocular/bulbar
involvement?
Symmetric?
CPK,K+,
Urine
myoglobin
Myasthenia,
Botulism
GBS#
Polio, GBS,
Traumatic
neuritis.
Get
NCV
IVIG,Neuro
consult,NCV,
CSF
Viral myositis,
periodic paralysis,
Rhabdomyolysis
yes No
Deep tendon
reflexes

16. Differential Diagnosis of AFP (Table 3)
Guillain Barre Syndrome (GBS)
With the control of polio, GBS is the most common cause of AFP in children.
Worldwide its incidence is 0.6–4 cases per 100,000 per year [2]. It most commonly
occurs after an infection triggered immune mediated attack on the nerve axons or
myelin. Antecedant respiratory or gastrointestinal illnesses are commonly found in the
history [3]. The most common underlying subtype of the syndrome is the acute
inflammatory demyelinating polyradiculoneuropathy (AIDP) but the other common
subtype of acute motor axonal neuropathy (AMAN) may be equally common in Indian
children [4]. In the typical cases, the first symptoms are usually pain, paraesthesia, or
weakness in the limbs which spreads proximally. Weakness may progress rapidly, and
approximately 50 % of the children will reach nadir by 2 wk, 80 % by 3 wk, and the rest
by 4 wk. Risk factors for children requiring ventilation are
1. cranial nerve involvement,
2. increased CSF protein during first week of illness
3. and short period between antecedent illness and the onset of symptoms [5].
Investigations required for confirming the diagnosis are; nerve conduction studies
and lumbar puncture (to document CSF albumin-cytological dissociation). A raised
CSF protein concentration is present in about 80 % of patients, but CSF protein

17. content is more likely to be normal during the first days of the illness [3]. When a child
presents in the acute phase, the differentiation from polio or enetroviral myelitis can
be done based on CSF. Viral myeltis would show CSF pleocytosis,which would be
conspicuously absent in GBS.
CSF should be analyzed before treatment with intravenous immunoglobulin
(IVIG) as IVIG can cause aseptic meningitis.
Management of a child with GBS would involve a meticulous observation for
respiratory, bulbar muscle weakness. Early elective intubation and ventilatory support
are important in the acute phase.
During hospitalization,
monitoring for autonomic instability
and prevention of nosocomial complications are essential to optimize outcomes.
IVIG is the treatment of choice in the authors’ setting for GBS, given the availability,
ease of administration and the safety compared with plasmapheresis. It is given in the
dose of 2 g/kg spread over 2–5 days.

18. Anterior Horn Cell Viral Myelitis ,Poliomyelitis
Both the wild polio virus and the vaccine associated polio virus cause
anterior horn cell affliction to result in flaccid paralysis.
Children under 5 y are the most frequently affected. However, older
individuals and adults can also develop poliomyelitis. The initial
symptoms of polio are non-specific and include
1. fever, headache, vomiting, constipation, neck stiffness and pain in
limbs.
2. The paralysis follows or accompanies these symptoms. The
maximal weakness evolves quickly over 1–2 d.
3. A history of intramuscular injections precedes paralytic
poliomyelitis in about 50–60 % of patients, patients may present
initially with fever and paralysis (provocationparalysis).

19. Clinical characteristics of poliomyelitis :include;
1. Fever at onset
2. Rapid progression of paralysis within 24–48 h
3. A symmetric
4. proximal more than distal limb paralysis
5. Preservation of sensory function often with severe myalgia
6. Residual paralysis at 60 d
7. Most of the children with paralytic polio die from complications of
bulbarparalysis and respiratory failure.
8. Management is mainly focused on meticulous supportive care.
Non polio enteroviruses can cause a polio like paralytic disease. Among
all known nonpolio enteroviruses,enterovirus-71 has been most strongly
implicated in outbreaks of central nervous system disease and AFP. The
clinical syndrome frequently is associated with aseptic meningitis
,hand, foot and mouth disease and hemorrhagic conjunctivitis.
Weakness associated with enterovirus disease can be severe and
permanent.

21. .
Other Viruses Causing AFP
1. Herpes group of viruses:can lead to AFP by triggering
GBS or transverse myelitis, causing
polyradiculoneuropathies in immunocompromized
hosts .
2. Japanese encephalitis viruscan also preferentially affect
the anterior horn cell and cause paralysis associated
with encephalitis.

23. Rabies :
The common presentation of human rabies is with
1. fever,
2. behavioral and autonomic instability
3. and hydro/aerophobia.
4. However, a minority of the patients can present primarily
with paralytic disease.
This type of presentation follows a prodrome of paraesthesias
in the bitten area, ascending paralysis or paralysis progressing
from the bitten limb.
Sphincter disturbances and autonomic instability is common.
Disease progression is slower in paralytic rabies.
The disease can be easily missed if a history of animal bite is
not actively sought. Frequently the bite may not be recent and
the parents may not give the history, unless specifically asked
for.

24. Transverse Myelitis
1. It is an acute demyelinating disorder of the spinal cord. It
may occur alone or in combination with demyelination in
other portions of the nervous system.
2. It is believed commonly that previous infection or
immunization triggers transverse myelitis, but no evidence
supports such a notion
3. The common presentation includes an acute phase of
spinal shock with flaccid paraparesis or quadreparesis,
urinary retention or incontinence, absent reflexes and
mute plantars, sensory loss/level is frequently present.

25. 4. After a few weeks, the signs of UMN dysfunction
appear, in the form of spasticity, and hypereflexia.
5. This disorder should be suspected in any child with
rapid onset flaccid profound quadreparesis, early or
persistent bladder or bowel involvement, sensory loss
or sensory level on examination, with suggestion of
UMN signs on examination (e.g., up going plantars). In
such a situation an urgent spinal MRI is needed to
establish the diagnosis. Other
6. causes of acute myelopathy like trauma,
paraspinal/epidural spinal abscess, hematoma or
anterior spinal artery syndrome need exclusion in this
setting. The management of transverse myelitis

28. consists of
1. immunosuppression
2. and supportive care.
3. Attention is needed to maintain airway, breathing and
circulation,
4. bladder catheterization
5. and exclusion of compressive myelopathy by imaging.
6. High dose pulse corticosteroids are the recommended
form therapy .
Methylprednisolone is given in a dose of 10–30 mg/kg/d
(max:1 g/d) for 5 d followed by oral prednisolone 1–2
mg/kg/d for 2 wk and then tapered over subsequent 2–4
wk.

29. Traumatic Neuritis (Following Injection)
Traumatic neuritis is suspected in cases in which there is
one limb involvement and definite history of injection in
that limb (usually less than 24 h) before the onset of
paralysis. It is associated with pain and hypothermia of
affected limbs. It is sometimes difficult to distinguish it
from polio. However, sensory deficits and lack of CSF
pleocytosis favor the diagnosis of traumatic neuritis. It is
probable that some cases of polio are misdiagnosed as
traumatic neuritis. Residual sensory deficits strongly favor
the diagnosis of injection neuritis.
Management is entirely supportive.

30. Hypokalemic Paralysis
This is an important differential in any child
particularly in a younger child with AFP. An early
recognition can prevent potentially fatal cardiac
complications. In the developing countries, it most
commonly results from diarrheal diseases.
However,
rarer familial chanellopathies, underlying disorders,
such as renal tubular acidosis, primary/secondary
hyperaldosteronism
also need to be considered. Correction of
potassium levels rapidly reverses the paralysis in
these children.