Hypotonic cerebral palsy is another common form of cerebral palsy. The term ‘hypotonia’ refers to low muscle tone, meaning people with hypotonic cerebral palsy have noticeably weaker muscle tone than normal.

Hypotonia is generally caused by damage to the cerebellum, the area of the brain that controls coordination and balance. Normally, this damage occurs while the baby is still in the womb. Infections in the mother during pregnancy can also cause hypotonic cerebral palsy, as infections cause the levels of cytokines to rise drastically. The spike in cytokines produces inflammation, a normal part of the infection fighting process. However, a developing baby cannot handle the inflammation, and it can cause brain damage to the brain. Lack of oxygen to the brain as the result of damage to the umbilical cord or ruptures in the uterus during development can also cause lesions to form around the cerebellum, which can lead to hypotonic cerebral palsy. In rare cases, hyptonic cerebral palsy can also be the result of oxygen deprivation during delivery.

Lesions in the cerebellum disrupt the brain’s ability to communicate correctly with the nerve sensors in the spine that control muscle tone. The decrease in muscle tone causes the muscles to be relaxed when they need to flex, as well as the joints to become lax. People with hypotonic cerebral palsy have a difficult time performing everyday tasks such as chewing, swallowing, speaking and walking.

Symptoms of hypotonic cerebral palsy are usually evident in infancy. The arms and legs of healthy babies usually offer some amount of resistance when moved. In children suffering from hypotonic cerebral palsy, the limbs move too easily and the muscles are floppy; causing the child to look almost like a rag doll. Babies with healthy muscle tone have flexed elbows and knees; babies with hyptonic cerebral palsy rest with their elbows and knees extended. Head control is generally very poor in babies with hyptonic cerebral palsy; their heads often fall to the side, backward or forward. In some cases, this can make it incredibly difficult for the baby to breathe and respiratory problems can develop.
Many people with hypotonic cerebral palsy have a difficult time maintaining proper posture because of their weakened muscles. It is extremely difficult for them to sit up straight, and efforts to sit or stand without assistance require a high level of physical exertion that can lead to fatigue. Physical therapy exercises can help people with hyptonic cerebral palsy improve their muscle tone.

As with other forms of cerebral palsy, hypotonic cerebral palsy is non-progressive and the damage to the brain does not worsen with time. However, many people with hypotonic cerebral palsy find their symptoms worsen with time as they continue to lose muscle tone. Hyptonic cerebral palsy is also not contagious, as it is not caused by a virus or bacteria.

The severity of hyptonic cerebral palsy depends on the location and extent of the lesions in the brain. Hypotonic cerebral palsy may be classified as:

• Mild (minimal symptoms and high ability to function)
• Moderate (more pronounced symptoms)
• Severe (extreme symptoms that interfere greatly with a person’s ability to function)

References:
BrainAndSpinalCord.Org
U.S. National Library of Medicine