Floppy Infant
Brain
Spinal cord
Hypotonia
Clinical features:
• In early infancy, there is decreased muscular activities
both spontaneous and in response to postural reflex
testing and to passive motion.
• In young infants , hypotonia manifested as ‘Frog
posture”.
• In older infants, there is delay in motor milestones.
• Ventral suspension: In this position floppy infant
droops over the hand like an inverted U shape.
• Head lag when pulled up from supine to sitting
position.
Clinical features
• Weak cry
• Abdominal breathing.
• No or depressed tendon reflexes.
• Fasciculation's of the tongue.
• Normal mentality in infantile progressive
muscular atrophy
• Mental retardation in congenital muscular
dystrophy.
Lower Motor Neuron
Etiology:
A- Paralytic causes: Lesion of the lower motor
neuron.
1- Infantile progressive muscular atrophy (IPSMA):
Decreased movement in-utero – Gradual weakness –
Delay in gross motor milestones- Weak cry – Absent
deep tendon reflexes – Fasciculation's of tongueNormal personal and social behaviors.
2- Infantile botulism: Poor feeding, constipation, failure
to thrive, facial weakness, ptosis- ocular palsy, inability
to suck or swallow, apnea (Source: soil dust, honey).
Etiology
3-Myasthenia gravis (Neonatal transient and
congenital persistent): Poor sucklingchocking- respiratory distress- weak crymother may have myasthenia.
4- Myotonic dystrophy: AD, Polyhydramnios,
failure of suckling, facial diplegia,
arthrogryposis, thin ribs, developmental delay.
Myathenia gravis
Etiology:
continue
5- Congenital muscular dystrophy : Early onset facial
weakness, joint contractures, mental retardation,
seizures.
6- Rare types of myopathy (Nemaline and Central
core): Proximal weakness( shoulders, hips),but the
finger movement is preserved, intelligence, fine
motor, language and social milestones are normal.
7- Spinal cord lesion: Upper thoracic spinal cord injury
after breech extraction.
8- Glycogenosis: Type II glycogen storage = pompe
disease, type V= McArdle disease).
B- Non-Paralytic causes:
1- CNS disorders: Atonic diplegia, choeoathetosis , ataxic and
atonic cerebral palsy.
2- Syndromes with hypotonia:
1-Tisomy 21.
2- Prader willi syndrome (deletion of 15q11 gene)
3- Marfan syndrome.
4- Turner syndrome.
3- Degenerative disorders:
-Tay-Sack’s disease.
- Metachromatic leukodystrophy.
Non- paralytic causes Continue
4- Systemic diseases:
-Malnutrition.
-Celiac disease, and Cystic.Fibrosis.
- Chronic illness .
- Metabolic diseases: Hypercalcemia.
- Endocrinopathy: Hypothyroidism.
5- Benign congenital hypotonia:
mild to moderate hypotonia with weakness.
Celiac Disease
Hypothyroidism
Differential diagnosis of flaccid paralysis (LMNL):
• 1-Guillain Barre syndrome (postinfectious
polyneuritis): It is the most common cause of acute
paralysis in children/Although infants can be affected,
most cases are seen in children above the age of 3
years. History of preceding viral infection, one or two
weeks before the onset of ascending symmetrical
paralysis, is usually obtained.
• 2-Poliomyelitis: It is going to be eradicated in many
countries of the world. The spinal lesion lead to
Asymmetrical flaccid paralysis.
Differential diagnosis of flaccid paralysis
(LMNL):
• 3-Post diphtheritic paralysis: This form of toxic
polyneuritis is uncommon nowadays because of the
routine vaccination.
History of preceding sore throat and swollen
neck (pharyngeal diphtheria) or stridor (laryngeal
diphtheria), 1 - 2 week before the onset of paralysis
can be obtained.
• 4-Transverse myelitis: It is the second most common
cause of acute symmetric paralysis.
-It is a segmental dysfunction of the spinal cord
without an evidence of spinal cord compression. The cause is probably either a direct viral infection or
an autoimmune disease.
Transverse Myelitis
Differential diagnosis of flaccid paralysis
(LMNL): continue
• 5- Botulism:
It is a toxic neuromuscular blockade caused by clostridium
botulinum (anaerobic gram positive bacteria).
Three forms are present :
(1) Infant botulism occurs in infants. Germination of spores in
gastrointestinal tract follows exposure to soil, house dust.
honey or corn syrup ;
(2) Food-induced botulism occurs with ingestion of improperly
home-preserved foods containing the toxins.
(3) Wound botulism occurs due to wound contamination with
the clostridium botulinum organisms.
Differential diagnosis of flaccid paralysis (LMNL):
continue
• 6- Acute spinal cord compression: Trauma to the back, spinal
epidural abscess and vascular anomalies of the cord may
produce acute paralysis.
- Occasionally, spinal cord tumors may also present with acute
paralysis.
- Myelography is essential to demonstrate the obstruction. CT
scan of the spine or MRI are more sensitive.
• 7- Hypotonia with movement disorders:
- In acute cerebellar ataxia, hypotonia is usually present, but the
truncal ataxia with unsteady gait is the most characteristic
feature.
- In rheumatic chorea, hypotonia is present and may be marked
simulating acute paralysis but abnormal involuntary choreic
movements is the dominating finding.
GB Syndrome
Spinal cord
syndrome
poliomyelitis
Eitiology
Delayed
hypersesitivity.
antibody mediated
Trasverse
myelitis,spinal
cord abscess,TB
Poliovirus type
I,II,III
History
GI or URTI, 5 to
14days preceding
symptoms
Rapid progression Unimmunized,
of symptoms
URTI or GI
infection
Symptoms
Symmetric weakness
in LL gradually
ascending with
parasthesias. normal
bowel & bladder
function
Back pain.
Sensory loss
below the level of
lesion, sphincter
problems
Fever,.
meningism,
muscle
tenderness,
asymmetric
weakness
Signs
Symmetric flaccid
weakness, sensations
intact, gradually
ascending
Symmetric
areflexia,sensory
loss below the
level of lesion.,
pain, bowel and
bladder
dysfunction
Assymmetric
flaccid weakness,
sensations intact,
muscle wasting
CSF findings
Normal cell count
with raised protiens
2nd week of illness
Pleocytosis with
raised protiens
Pleocytosis with
raised protiens
EMG/NCS
Signs of denervation, Normal initially
NCS shows delayed
conduction
NCS normal,
EMG denervation
later
Course and
prognosis
Recovery in majority Depends on
within 12 months
eitiology
Permanent
disability in 1%
cases
Diagnosis:
Differentiate hypotonia with hyporeflexia from hypotonia with
hyperreflexia.
-Brisk reflexes point to cerebral dysfunction.
-Creatine kinase level and EMG are normal in neurological lesions.
-Prolonged nerve conduction in polyneuropathy.
-Muscle biopsy to diagnose the type of myopathy.
Management:
-Treat the cause.
-Physiotherapy.
-Genetic counseling.