Floppy Infant and Clinical manifestations of hypotonia

Floppy infant is a clinical syndrome characterized by severe hypotonia present at birth or early infancy.

Clinical manifestations of hypotonia:

  ● Frog-leg position of limbs (abducted and flexed) in supine position.

  ● Head lag when an infant is pulled to sitting position from supine.

  ● Curved trunk on ventral suspension.

  ● Generalized hypotonia and hyporeflexia. -

Differential diagnosis of floppy infant:

(A) Neuromuscular causes:

1- Werding-Hoffmann disease: it is the commonest cause of floppy infant. It is an autosomal recessive disease characterized by degeneration of anterior horn cells. Bulbar palsy, recurrent chest infections tongue fasciculation and normal mentality are characteristic for the disease. Hypotonia and hyporeflexia are present.

2- Congenital muscular dystrophy: an autosomal recessive disease characterized by muscle degeneration, thin atrophied muscles and joint contractures.

3- Benign congenital hypotonia: a non-progressive hypotonia of unknown etiology with normal mentality.

4- Congenital myopathies.

5- Glycogen storage diseases especially type II (Pompe disease): characterized by hypotonia, hepatomegaly and cardiomyopathy

(B) Central causes:

1- Atonic cerebral palsy: a non- progressive motor weakness and hypotonia resulting from perinatal insult affecting the developing brain. The deep reflexes are normal.

2- Chromosomal abnormalities: usually associated with hypotonia, e.g. Down syndrome.

N.B: Floppy infant may result from hypoxic ischemic encephlopathy from brain anoxia at birth.