Home > Encyclopedia of Neurological Disorders > Hypotonia

Definition

Hypotonia means "low tone," and refers to a physiological state in which a muscle has decreased tone, or tension. A muscle's tone is a measure of its ability to resist passive elongation or stretching.

Description

Hypotonia is more a description than a diagnosis. It is most often seen in newborns (congenital) and infants, but it may persist through adolescence into adulthood. Another name for infantile hypotonia is "floppy baby syndrome." This refers to the tendency of a hypotonic infant's arms, legs, and head to "flop," or dangle loosely, when they are picked up or moved. In the past, the term "benign congenital hypotonia" was used for many cases in which no obvious cause for the hypotonia could be detected. Better diagnostic techniques and increased knowledge of neuromuscular disorders, however, have resulted in much less frequent use of this term.

Demographics

Hypotonia is the most...