Hypotonia (Muscle Weakness)

Programs that treat this condition


General Orthopedic Program






What is hypotonia?

Hypotonia means decreased muscle tone. It can be a condition on its own, called benign congenital hypotonia or it can be indicative of another problem where there is progressive loss of muscle tone, such as muscular dystrophy or cerebral palsy. It is usually detected during infancy.
An infant with hypotonia exhibits a floppy quality or "rag doll" feeling when he or she is held. Infants with this problem lag behind in acquiring certain fine and gross motor developmental milestones that enable a baby to hold his or her head up when placed on the stomach, balance themselves or get into a sitting position and remain seated without falling over.

Since the muscles that support the bone joints are so soft, there is a tendency for hip, jaw and neck dislocations to occur. Some children with hypotonia may have trouble feeding, if they are unable to such or chew for long periods. A child with hypotonia may also have problems with speech or exhibit shallow breathing.


What causes hypotonia?

Hypotonia can be caused by a variety of conditions including those that involve the central nervous system, muscle disorders and genetic disorders. Some common causes can include but are not limited to Down syndrome, Muscular dystrophy, Cerebral palsy, Prader-Willi Syndrome, Myotonic dystrophy, Marfan syndrome and Tay-Sachs disease.
Some hypotonias are not progressive and are of an unknown origin. Central nervous system function and intelligence in children with this kind of hypotonia, benign congenital hypotonia, is normal. Children with benign congenital hypotonia may not experience developmental delay, although some children acquire gross motor skills (sitting, walking, running, jumping) more slowly than most.


What are the symptoms of hypotonia?

The following are common symptoms associated with hypotonia. Each child may experiences symptoms differently. Symptoms vary depending on the underlying cause of the problem:
decreased muscle tone, muscles feel soft and doughy
ability to extend limb beyond its normal limit
failure to acquire motor related developmental milestones (such as holding head up without support from parent, rolling over, sitting up without support, walking)
problems with feeding (inability to suck or chew for prolonged periods)
shallow breathing
mouth hangs open with tongue protruding (under-active gag reflex)
The signs and symptoms of hypotonia resemble that of other conditions. Always consult a physician for a diagnosis.

How is hypotonia diagnosed?

Your child's doctor will obtain a medical history for your family and your child and will perform a physical examination that will likely include a detailed muscle function and neurological examination. The latter, also called a neuro exam, may be performed with instruments, such as lights and reflex hammers, and usually does not cause any pain to the child. The nervous system consists of the brain, the spinal cord, and the nerves from these areas.
There are many aspects of this examination, including an assessment of motor and sensory skills, balance and coordination, mental status (the child's level of awareness and interaction with the environment), reflexes, and functioning of the nerves.

The following diagnostic tests may also be used. (Tests will vary depending on the suspected cause of hypotonia):

blood tests
computerized tomography scan (Also called a CT or CAT scan) - a diagnostic imaging procedure that uses a combination of x-rays and computer technology to produce cross-sectional images (often called
magnetic resonance imaging (MRI) - a diagnostic procedure that uses a combination of large magnets, radiofrequencies, and a computer to produce detailed images of organs and structures within the body.
EMG (electromyogram) - a test used to evaluate nerve and muscle function.
EEG (electroencephalogram) - a test that measures the electrical activity in the brain, called brain waves. An EEG measures brain waves through small button electrodes that are placed on your child's scalp.
spinal tap - also called lumbar puncture, a spinal tap is done to measure the amount of pressure in the spinal canal and/or to remove a small amount of cerebral spinal fluid (CSF) for testing. Cerebral spinal fluid is the fluid that bathes your child's brain and spinal cord.
karyotype - This test, a chromosomal analysis from a blood test, is used to determine whether the problem is the result of a genetic disorder. muscle biopsy - a sample of muscle tissue is removed and examined under a microscope.


Treatment for hypotonia:

Specific treatment for hypotonia will be determined by your child's physician based on:
your child's age, overall health, and medical history
the extent of the condition
the underlying cause of the condition
your child's tolerance for specific medications, procedures, or therapies
expectations for the course of the condition
your opinion or preference
No specific therapy is required to treat benign congenital hypotonia, but children with this problem may periodically need treatment for common occurrences associated with hypotonia, such as recurrent joint dislocations. See Dislocations.
Treatment programs to help increase muscle strength and sensory stimulation programs are developed once the cause of your child's hypotonia is established. Such programs usually involves physical therapy through an early intervention or school-based program among other forms of therapy.