dr. arun agrawal md, mnams, fiap, fiams, miuat (paris), ficmch

Neurology Chapter of IAP

Dr. Arun AgrawalMD, MNAMS, FIAP, FIAMS, MIUAT (Paris), FICMCH

• Consultant Pediatrician & Neonatologist, Ghaziabad• National Chairperson – Neurology Chapter of IAP • Honorary Professor of Pediatrics ICMCH • National Convener – Community Pediatrics, Chapter of IAP • National Vice President IAP 2004

Approach to

Floppy Infant


Floppy Infant

Floppy infant refers to those children

presenting with generalized hypotonia, most

often arising out of an insult incurred during

fetal or neonatal period.


Posture

The floppy infant assumes a frog legged position. On ventral suspension, the baby can not maintain limb posture against gravity and assumes the position of a rag doll.


Movements

The muscles appear flabby. There is diminished resistance to passive movement of the limbs and the range of movement of the peripheral joints is increased.


Scarf Sign

Put the child in a supine position and hold one of the infant’s hands. Try to put it around the neck as far as possible around the opposite shoulder. Observe how far the elbow goes across the body. In a floppy infant, the elbow easily crosses the midline.

Pull to sit:When pulled up from the supine to the sitting position, the head of the baby lags.


Causes of Floppy Infant Syndrome1. Central nervous system

Perinatal asphyxia, neonatal, encephalopathy, kernicterus, cerebral palsy (atonic type), intracranial hemorrhage, chromosomal anomalies including down syndrome and inborn errors of metabolism e.g., aminocidurias, mucopolysaccharidosis and cerebral lipidosis.

2. Spinal cord lesionsAnterior horn cell disease – werdnig Hoffman spinal muscular atrophy, poliomyelitis.

3. Peripheral nervousAcute polyneuropathy, familial dysautonomia, congenital sensory neuropathy.

4. Myoneural junctionNeonatal myasthenia gravis, infantile botulism, following antibiotic therapy.


Causes of Floppy Infant Syndrome (Contd.)

5. Muscles Muscular dystrophies, congenital myotonic dystrophies, congenital myopathies (including central core disease and nemalin myopathy), polymyositis, glycogen storage disease (pompe’s), and arthrogryposis multiplex congenital.

6. Miscellaneous Protein energy malnutrition, rickets, prader willi syndrome, malabsorption syndromes, Ehler-Danlos syndrome, cutis laxa, cretinism.


Differentiating Features of a Floppy Infant according to Site of Involvement

Site of involvement Extent of weakness

Proximal vs. distal weakness Face Arms Legs

Central - + + > or =

Anterior horn cell + ++++ ++++ > or =

Peripheral nerve - +++ +++ <

Neuromuscular junction

+++ +++ +++ =

Muscle Variable ++ + >


Differentiating Features of a Floppy Infant according to Site of Involvement (Contd.)

Site of involvement Deep tendon

reflexes EMG Muscle biopsy

Central Normal or increased

Normal Normal

Anterior horn cell Absent Fasciculation / fibrillation

Denervation pattern

Peripheral nerve Decreased Fibrillation Denervation pattern

Neuromuscular junction

Normal Decremental / incremental

Normal

Muscle Decreased Short duration small amplitude potential

Characteristic


• Signs: Perform complete physical examination • Infant with decreased muscle tone • Exam distinguishes site of disorder

– Upper motor neuron lesion – Lower motor neuron lesion

• Radiology • Head CT • Head MRI • Diagnostic Studies • Electromyogram (EMG) • Nerve Conduction Studies • Labs: Initial • Serum electrolytes • Serum Calcium • Serum Glucose

Look for

Sepsis


• Creatine Phosphokinase (CPK) • Toxic scan• Blood Culture • Lumbar Puncture with Cerebrospinal Fluid Examination • Thyroid Function Tests • Labs: Test as indicated • Toxicology screen • Serum Ammonia and Venous pH

– Serum amino acids – Urine amino acids and organic acid

• Karyotype • TORCH Virus Screening

LooksLike

Sepsis without Sepsis


Common causes of floppy infant

Cerebral PalsyMany hypotonic children due to causes in central nervous system are mentally retarded. In atonic or hypotonic cerebral palsy, reflexes are brisk in spite of generalized flaccidity. Floppy infant due to cerebral causes is associated with lethargy, poor feeding, and lack of alertness, poor Moro’s reflex, and seizures during the neonatal period.


Werdnig Hoffman diseaseIt is characterized by marked hypotonia, sluggish fetal movement, and fasciculation of tongue. The child is alert. Feeding behaviour and cry are poor. Deep tendon reflexes are absent. Muscle biopsy shows neurogenic type of atrophy or that the muscle spindles are atrophied in groups. Disease is inherited as an autosomal may be available. Death occurs by 2-4 years of age.


Myasthenia gravisMmyasthenia gravis may occur in about 12 percent of the babies born to mothers with the disease. It is characterized by marked hypotonia, pooling of oral secretions, poor feeding, feeble cry and generalized muscle weakness appearing within 2-3 days after the birth. Baby is alert. Facial weakness manifests by mark-like facies, open mouth and staring look. External opthalmoplegia and ptosis are rare. Deep tendon reflexes are normal. The prognosis is substantiated by improvement in the muscle functions following intramuscular injection of edrophonium chloride 1 mg or neostigmine methyl sulfate 0.1 mg. the condition lasts for 3 to 4 weeks. The child is treated with neostigmine methyl sulphate 0.1 to 0.5 mg IM 10 minutes before each feel for 1 or 2 days followed by neostigmine bromide, 1 to 4 mg orally half an hour before each feed.


Congenital myopathies

These are rare inherited disorders resulting in a benign congenital hypotonia, with generally good outlook for normal life span. Nemaline myopathy is the most common variant. Other disorders of this group include the central core disease, myotubular myopathy and congenital fiber type disproportion.


OthersIn polyneuritis there is symmetrical weakness of the limbs with sensory changes. The diagnosis of Pompe’s disease is suspected when the child has macroglossia, cardiomegaly and generalized hypotonia. Babies with prader-willi syndrome are mentally retarded and obese; deep tendon reflexes are diminished. Diabetes mellitus occurs later in life. Testes may be undescended. Ehlers-danlos syndrome is characterized by hyperelasticity of the skin, hyperflexibility of joints and extreme, fragility of skin. Wound healing is delayed and there are frelly movable subcutaneous nodules. In cutis laxa, the child has loose skin hanging in baggy folds.


Profile of Floppy Patients (n = 70) Prof. V. Kalra et.al. 2001

Disorder No. %Spinal muscular atrophy – Type I 13 18.6Spinal muscular atrophy – Type II 17 24.3

Spinal muscular atrophy – Type III 7 10.0Diaphragmatic SMA 1 1.4Congenital myopathy 7 10.0Congenital muscular dystrophy 5 7.1

Mitochondrial myopathy 4 5.7Hereditary sensory motor neuropathy 3 4.3Hereditary sensory autonomic neuropathy type IV 2 2.9

Unclassified 11 15.7


Key Messages of this Study

• Spinal muscular atrophy emerged as the commonest cause of floppy children followed by congenital muscle disease.

• 11% of the cases still remained unclassified despite sophisticated investigative techniques.

• EMG was a good screening modality for floppy children.

• A low gene deletion rate (50%) was observed in our phenotype


Key Messages in Approach to a Floppy Child

• First ABC of resuscitation • Try to find out cause but again simple clinical

examination is the first thing• Any sedative drug given during labour • Investigations • Only those investigations which are necessary • Sepsis • Sepsis without sepsis• Another sophisticated investigations• Improve the quality of life probably quantity can not be

improve in most of the cases

dr. arun agrawal md, mnams, fiap, fiams, miuat (paris), ficmch

Documents

neurology chapter of

floppy infant syndrome

supine position

congenital myopathies

sitting position

muscles muscular dystrophies

prader willi syndrome

ehlerdanlos syndrome