Acute flaccid paralysis

Acute flaccid paralysis

Dr Nebal Waill
CWTH / Pediatric neurology department

Definition

Acute Flaccid Paralysis (AFP) occurs when there is rapid evolution of motor weakness (< than 4 days), with a loss of tone in the paralysed limb. This excludes weakness due to trauma and spastic paralysis.

AFP is a medical emergency as unnecessary delays can result in death and disability

The list of underlying causes of AFP is broad, and there is substantial variation by age, ethnicity, and geographic area.

In the absence of wild virus-induced poliomyelitis, the acute demyelinating form of Guillain-Barre syndrome (AIDP) accounts for at least 50 percent of AFP cases globally followed in frequency by paralytic non-polio enterovirus infection, the motor axonal form of Guillain-Barre syndrome (AMAN), traumatic neuritis, and acute transverse myelitis.

Background

• • 1916- Guillian, Barre and Strohl described 2 French soldiers with motor weakness, areflexia, and “albuniocytological dissociation” in the cerebrospinal fluid. They recognized the peripheral nature of the illness.
•
•

Guillian

Barre
Andre Strohl

Epidemiology

• Annual incidence of GBS = 1-3/ 100000 persons annually.
• Rare in infants.
• Male & female have similar risk
• Any age but most frequent at 4-9 years

GBS subtypes

• Sporadic AIDP
• AMSAN
• AMAN
• MFS


Pathology
Both motor and sensory fibers are affected

AIDP

Segmental demyelination occurs at all levels of peripheral nervous system

CNS alterations are secondary to axonal degeneration and affect

Segmental demylination

Axonal degeneration ( less extensive )

Anterior + posterior roots
Sympathatic chain and ganglia
peripheral nerves
Anterior horn cells in spinal grey matter

Neurons of motor cranial nerves neucli in brainstem

Pathogenesis

Pathogenesis

node of Ranvier

myelin sheath
myelin sheath

Antecedent Events

Documented in 2/3 of cases

Agents :

Campylobacter jujeni
CMV
EBV
HSV
H.Influenzae
Mycoplasma
Vaccines :
Rabies
Swin-flu
Tetanus
Mumps
Measles
Rubella
Hepatitis A
Hepatitis B
H. Influenzae type b
Trauma
Sugrical procedures
C.Jujeni accounts for 1/3 of GBS because of mimicry between gangliosides and lipopolysaccharides of the bacteria


Clinical features
• AIDP
Infection (GIT: Campylobacter, Respiratory: Mycoplasma) within 2 weeks of onset

Weakness(lower extremities then ascend up to the trunk then upper limbs and bulbar weakness.
May start in the arms and move downward
May begin in the arms and legs at the same time
May occur in the nerves of the head only
In mild cases, weakness or paralysis may not occur

This weakness is symmytrical ( minor sides differences may occure), proximal and distal

9% is asymmetrical

progress slowly over days or weeks Or abrupt and rapid

Clinical features
• Child becomes irritable .
• Parasthesia may occur, 89% pain accompany weakness
• 50% bulbar involvement .
• Facial nerve involved. also VI,III,XII,IX,X
• Some show viral meningitis or meningoencephalitis.
• Papillodema ( unexplained pathogenesis )
• Respiratory muscules : reduced vital capacity CO2 retention even in absence of respiratory symptoms


Clinical features
• Features required for diagnosis
• Progressive motor weakness of more than one limb.
• Areflexia or hyporeflexia (loss of ankle jerks and diminished knee and biceps reflexes will suffice if other features are consistent with the diagnosis.

Clinical features

• Featrues supportive of diagnosis
• Progression :weakness may develop rapidly but cease to progress after 4wk . Roughly 50%will plateau within 2 wks , 80% by 3wks,and 90%by 4wks.
• Relative symmetry .
• Mild sensory symptoms and signs.
• Cranial nerve involvements like facial weakness develops in about 50% of patients.
• Autonomic dysfunction.
• Absence of fever at the onset of neurological symptoms.
• Recovery without specific therapy, begins 2-4wks after progression ceases, occasionally delayed for months.

Clinical features

• Features casting doubt on the diagnosis
• Marked persistent asymmetry in motor function.
• persistent bowel or bladder dysfunction at onset of symptoms .
• Discrete sensory level .
• Progressive phase longer than 4wks .
• CSF pleocytosis ( > 50wcc/mm3).
• Complete ophthalmoplegia (internal or external).


Clinical Phases

Guillian-barre can be divided into five distinct clinical phases :

Phase 1- first 24 hr from presentation
Phase 2- disease progression
Phase 3- plateau phase
Phase 4- initial recovery
Phase 5- rehabilitation

Dx
• Clinical
• CSF
• Electrophysiologic
• MRI

Investigation

• MRI of the brain and spinal cord
• Should be considered in all patients ,usually done if :
• The presentation is acute or rapidly progressive
• There are predominantly sensory symptoms (including back pain)
• There is predominant sphincter disturbance of presentation
• There is a clear sensory or marked motor level


Investigation
• Lumber puncture
• Elevated CSF protein without pleocytosis is a supportive diagnostic finding ,however the CSF may be normal within seven days of onset of symptoms
• Protein level :elevated (>45mg/dl ) after the first week of symptoms , peak 4-5 wks
• WCC <10/mm3 , occasionally up to 50 mm3
• Glucose level normal

Investigation

Neurophysiology
Normal nerve conduction studies in the first week does not exclude the diagnosis of GBS

In AIDP nerve conduction impairment = conduction block , decrease compound action potential amplitude

Investigation

Since the median duration of excretion of Campylobacter in stools of infected persons is only 16 days and because of the 1- to 3-week lag time between infection and the onset of GBS, many GBS patients with preceding Campylobacter infection might have falsely negative stool cultures.

multiple stool samples (or rectal swabs) should be obtained from GBS patients immediately upon admission to the hospital, preferably 3 over a 3-day period.

Investigation

Other investigations
Full blood count, blood culture ( if pyrexial )
Urea and electrolytes ( hypokalemia )
Creatine kinase (myositis)
Chest x-ray , ECG
Abdominal x-ray ( palpable bladder , constipation )


Treatment
• Admission
• IVIG
• Plasma exchange
• Supportive treatment
• Rehabilitation

treatment

• Symptomatic treatment is an essential part of the management of GBS.
• Children should admitted to the pediatric intensive care unit if they have one or more of the following :
• Flaccid tetraparesis
• Severe rapidly progressive course
• Reduced vital capacity at or below 20 ml/kg
• Bulbar palsy with symptoms
• Autonomic cardiovascular instability that is persistent hypertension or labile blood pressure or arrhythmias.

Plasma exchange

Plasmapheresis has remained the gold standard treatment for GBS over the last 20 years.
Should be used within 4 weeks of onset of neuropatic symptoms in non-ambulatory patients
Should be used within 2 weeks of onset of neuropathic symptoms in ambulatory patients


treatment
• Plasmapheresis is generally safe in children who weigh 10 kg or more . A series of exchange with a cumulative total of approximately 250 ml/kg volume exchange or roughly a triple volume exchange .
• Disadvantages of Plasmapheresis include its rare complications, such as sepsis, risk of acquiring viral infections such as hepatitis and HIV.

treatment

• IVIG treatment has advantages over plasmapheresis because
• it is easier to administer,
• has significantly fewer complications,
• and is more comfortable for the patient.
• Side effects of IVIG
• expands the plasma volume so it must be administered with caution in patients with congestive heart failure and renal insufficiency
• fever, myalgia, headache, nausea, and vomiting, but these "influenza-like" symptoms are self-limiting.
• aseptic meningitis, neutropenia, and hypertension
• Anaphylaxis
• Thromboembolic events
• risk of serious hepatitis C infection transmission has been reduced

IVIG should be used within 2 weeks

Corticosteroid not recommended


Sequential treatment with PE then IVIG not recommended

PE & IVIG recommended for the severe disease

treatment
• Pain management
• Pain of discomfort is present in 50-80%of children with GBS at the time of presentation .

treatment

Managing pain by:
Opioids
Non steroidal anti-inflammatory drugs ( ibuprofen)
Anti-epileptic drugs ( carbamazepine, gabapentine)
Tricyclic antiderpessants (amitryptine)

Prevention of pain:

Air matresses
Turning patients and carful positioning of limbs
Continuation of enteral feeding ,effective antacids as omeprazole
Preventing constipation
Prevent and treat urinary retention.


treatment
• Supportive treatment directed to:
• Hypertension , hypotension
• Cardiac arrhythmia
• Pulmonary embolism (Prophylaxis for deep venous thrombosis should be provided because patients frequently are immobilized for many weeks).
• Bladder and bowel
• Psychological support
• Nutrition , fluid , electrolytes
• Pain
• Skin
• Cornea
• Joints
• Infection
• communication

prognosis

• 40% bed bound
• 15% require ventilation
• 90-95% complete recovery within 6-12months
• Remainder ambulatory with minor residual deficit
• 4% mortality rate
• Antecedents C.jujeni infection correlates with poor Px
• Causes of death :
• Autonomic (bradycardia , tachycardia , hypertension)
• Respiratory failure
• Pulmonary embolism
• Complication of ventilation
• Cardiovascular collapse


prognosis
• Chronic relapsing or chronic unremitting (7%)
• Features suggestive relapsing are:
• Severely weak
• Flaccid tetraplagia
• Bulbar and respiratory muscle involvement
• One or more relapses over 2mo.- years = CIDP
• Congenital GBS
• Weakness , areflexia , hypotonia .
• CSF and electrophysical studies suggestive of GBS .
• No treatment , gradual improvement.

Poliomyelitis

polioviruses
RNA viruses, Picornaviridae family, enterovirus
3 genetically distinct serotypes
Spread from intestinal tract to CNS
90 – 95 % inapperant infections
Transmission: human is the only reservoir
Fecal – oral route
Isolated from stool for 2 weeks before paralysis to several weeks after onset of symptoms


Pathogenesis
Wild type and vaccine strains
Gain host entry through GIT
Pass to the regional lymph nodes
Goes to the blood causing viremia
Wild type access the CNS through peripheral nerves
Incubation period 8-12 days

Clinical manifestions

Wild type follow one of the following courses :
• 90 -95 % inapparent infection (no disease & no sequelae
• 5% inabortive disease (influenza – like syndrome 1-2 wk after infection, fever, malaise, anorexia , headache +/- vomiting) then recovery complete

3- Non-paralytic poliomyelitis

1%
Signs of abortive type, fleeting paralysis of bladder and constipation.
This is first phase (minor) then symptoms-free period then major phase
O/E: nuchal rigidity, changes in the deep and superficial reflexes (impending paralysis). No sensory defects

4- Paralytic poliomyelitis

0.1%
Spinal type : major phase , sensory (paresthesia, hypersthesia), motor( fasiculation and spasms) progress to
Asymmetric paralysis of one leg, then 1 arm
DTR initially active then diminished and absent
Variable course: some progress, some recover


5- Bulbar type
+/- spinal cord involvement
Nasal voice or cry
Difficulty in swallowing
Accumulated pharyngeal secretion
Absence of effective coughing
Nasal regurgitation
Deviation of palate, uvula, tongue
Involvement of vital centers in the medulla
Paralysis of vocal cords … hoarseness, aphonia
Sometimes culminate into ascending paralysis (Landry type)

6- polioencephalitis

Rare
Seizures , coma , spastic paralsysis , increased reflexes
Respiratory insufficiency

7- Paralytic polio with respiratory insufficiency

Anxious expression
Inability to speak without frequent pauses
Increased RR
Movement of ala nasi, accessory muscles
Inability to cough or sniff
Paradoxical abdominal movement
Relative immobility of intercostal space


Diagnosis
Should be considered in any unimmunized or incompletely immunized child with paralytic disease
Or any child with paralytic disease occurring 7-14 days after receiving the oral vaccine

Diagnosis

Stool : Isolate the virus in 2 stool specimen collected with 24 – 48 hr apart
Can isolate polio virus in 80 – 90 % in the first week and less than 20% within 3-4 wk

CSF : normal in minor disease

Cells 20 -200 / mm3 initially then reduced
Protein : increase to reach 50 -100 mg/dl by 2nd week
CSF serology : seroconversion or 4 folds rise in antibody titers

Treatment

No specific treatment

Supportive: Limit progression, prevent skeletal deformities, prepare child and family for prolonged treatment

Abortive poliomyelitis

Analgesics, sedatives
Attractive diet
Bed rest until temperature normalize
Avoidance of exertion for ensuing 2 wks
Careful neurologic and musculoskeletal examination


Non paralytic poliomyelitis
Same as abortive
Relief muscle tightness
Analgesics
Hot packs for 15-30 min every 2-4 hr
Hot tub baths
Firm bed
Footboard or splint to keep feet at right angle to legs
Later gentle physical therapy

Paralytic poliomyelitis

Hospitalization
Physical rest
Suitable body alignment to prevent deformity
Change position every 3-6 hr
Active and passive movement indicated as pain disappear
Moist hot packs
Opiates and sedatives
Treat constipation
Parasympathetic stimulant for bladder paralysis
Adequate dietary and fluid intake
Orthopedist, physiatrist should see them


Bulbar
Maintain airway
Avoid risk of inhalation
Gravity drainage of accumulated saliva
Nursed in lateral or semi-prone position
Aspirators with rigid tips for oral pharyngeal secretion or flexible catheter for nasopharyngeal
Fluid and electrolytes equilibrium
Blood pressure taken at least twice
Impaired ventilation signs should be noticed to decide tracheostomy

Prognosis

Inapparent, abortive and aseptic meningitis = good outcome

Paralytic = depends on the extent and severity of CNS involvement, recovery phase last 6 months

Severe bulbar = MR 60%

30 – 40 % of persons survived paralytic polio… may experience muscle pain and exacerbation of exisiting weakness after 30 -40 yr

prevention

Vaccination
Hygienic mearures


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