Infantile Hypotonia (Floppy Infant Syndrome)

What is Infantile Hypotonia?

Hypotonia, or severely reduced muscle tone (the amount of tension or resistance to movement in a muscle), is seen primarily in children. It is not the same as muscle weakness but it can co-exist with muscle weakness. Hypotonia may be caused by trauma, environmental factors, or by genetic, muscle, or central nervous system disorders. Sometimes it may not be possible to find the cause of the hypotonia. While most children tend to flex their elbows and knees when resting, hypotonic children hang their arms and legs by their sides. They also may have substantial weakness and little or no head control, giving them a "floppy" appearance. Typical symptoms also include problems with mobility and posture, breathing and speech difficulties, lethargy, ligament and joint laxity, and poor reflexes. Hypotonia does not affect intellect. However, depending on the underlying condition, some children may take longer to develop social, language, and reasoning skills. When hypotonia starts in adults, it may be due to cerebellar degeneration.

Is there any treatment?

When hypotonia is caused by an underlying condition, that condition is treated first, followed by symptomatic and supportive therapy for the hypotonia. Physical therapy can improve fine motor control and overall body strength. Occupational and speech-language therapy can help breathing, speech, and swallowing difficulties. Therapy for infants and young children may also include sensory stimulation programs.

What is the prognosis?

Hypotonia can be life long. In some cases, however, muscle tone improves over time. Hypotonia due to cerebellar dysfunction or motor neuron diseases can be progressive and life-threatening.