Hypotonia is diminished muscle tone. The infant or child with hypotonic cerebral palsy appears floppy — like a rag doll. In early infancy, hypotonia can be easily seen by the inability of the infant to gain any head control when pulled by the arms to a sitting position (this symptom is often referred to as head lag).
Children with severe hypotonia may have the most difficulty of all children with cerebral palsy in attaining motor skill milestones and normal cognitive development.
Hypotonic cerebral palsy is often the result of severe brain damage or malformations. It is believed that hypotonic cerebral palsy is the result of an injury or malformation at an earlier brain developmental stage than that which causes spastic or choreoathetoid cerebral palsy.
Hypotonia in infancy is a common finding in many neurological conditions, ranging from very mild abnormalities to severe or even fatal neurodegenerative or muscle disorders.
It is important to note that many children with spastic cerebral palsy go through a short stage of being somewhat hypotonic in early life, before presenting the full syndrome.
What is mixed cerebral palsy?
Many (possibly most) children with cerebral palsy have multiple symptoms with combinations of the various forms of cerebral palsy. For example, children with spastic cerebral palsy often continue to have a head lag, which is representative of hypotonia.
Children with choreoathetoid or hypotonic cerebral palsy often have increased deep tendon reflexes, which are suggestive of some spasticity. Children with bilateral spastic cerebral palsy may also have dystonic movements in the limbs affected.
The different types of cerebral palsy described above are rarely seen as pure clinical forms, more often the child with cerebral palsy has a mixture of signs or symptoms.
Nevertheless, in clinical practice the type of cerebral palsy is defined on the basis of the predominant manifestations.
Distinct Symptoms of Hypotonic Cerebral Palsy
People with hypotonic cerebral palsy have noticeably “floppy” muscles and no control of their head. The arms and legs hang down like a “rag doll.” Joints may be lax. Reflexes may be poor, and walking is usually difficult.
The condition causes posture problems and may cause breathing and swallowing difficulties. Speech may also be difficult, although intelligence is usually unaffected.
Causes of Hypotonic Cerebral Palsy
Like other categories of CP, hypotonic cerebral palsy is caused by brain damage or by abnormal brain development. The location and extent of the brain damage or malformation determines the kind of impairment produced.
Hypotonia is generally associated with damage to the cerebellum—the part of the brain which controls coordination and balance. The unborn baby’s brain is particularly vulnerable to damage caused by toxins or infections during the first five months of development.
When the mother has an infection it can be damaging to her unborn child. Infections of any sort cause the levels of cytokines (a type of immune cell) to rise; this produces inflammation.
Inflammation is a normal part of the infection fighting process; however, inflammation can cause brain damage to the fetus.
Many people are unaware of the devastating effect the mother’s infection may have on the unborn baby; they are also unaware that unborn babies may have strokes.
Most people think of stokes as being a risk for the elderly, but not for newborn babies. Unfortunately, unborn babies can have strokes which cause brain damage.
Most strokes suffered by unborn babies are the type which cause bleeding. Poorly formed or weak blood vessels in the fetal brain are frequently responsible for this type of stroke.
Unborn babies may also have ischemic strokes—strokes caused by clots which block circulation and prevent oxygen from traveling to a part of the brain.
Brain cells die if this blockage continues for any length of time. Blood clots in the placenta sometimes cause the fetus to have a stroke.
Decades ago, doctors thought that most cases of cerebral palsy were caused by oxygen deprivation during delivery, but it now known that lack of oxygen when the baby is still in the womb is a greater risk, than lack of oxygen during delivery.
Damage to the umbilical cord or rupture of the uterus can also cause lack of oxygen.
In addition, the risk of stroke in the fetus increases if the mother has an infection or high blood pressure. Inflammatory pelvic disease is especially likely to cause a fetal stroke.
Monitoring the mother’s blood pressure is a vital part of prenatal care, since too high or too low of blood pressure can cause serious problems for both the mother and child.
Possible Complications of Hypotonic Cerebral Palsy
The swallowing difficulties caused by hypotonic CP can lead to malnutrition. All forms of CP can lead to falls.
Patients with hypotonic cerebral palsy are not as prone to contractures (a stiffened muscle deforms the bone by pulling on it) as people with the spastic form of CP; however, hypotonic cerebral palsy can contribute to joint problems.
Sometimes the brain damage which causes CP can also cause other problems, such as vision problems and hearing problems.
Age at Diagnosis
Hypotonic cerebral palsy is usually easily recognized early in the baby’s life. Babies with this condition have little muscle tone; their limbs are “floppy” and limp. They cannot hold their heads up.
If hypotonic cerebral palsy is suspected, imaging tests and ECGS will be used to confirm the diagnosis.
Treatment of Hypotonic Cerebral Palsy
Hypotonic cerebral palsy is treated primarily with physical therapy to strengthen the muscles, help the posture, and prevent future problems.
Therapy can also help speech problems, swallowing problems, and breathing problems. A new, somewhat controversial therapy approach called conductive therapy or conductive education is helping some CP patients.
Conductive therapy is done in a group setting. Songs and games are used to keep the children interested. Unlike regular physical therapy, which may only be done every other day, conductive therapy is conducted five days per week.
The sessions integrate learning life skills and academic skills, along with the physical exercises; conductive therapy is a total education program. It may benefit some hypotonic cerebral palsy patients.
Sometimes medications may be used for complications that may accompany hypotonic cerebral palsy. Surgery may be used to help joint problems or to correct bone deformities.