Guide To The Causes And Complications Of Chiari Malformation

Spina Bifida

Spina bifida is a neural tube defect that affects some point or portion of an individual's spinal cord when the neural tube fails to close as it should. The bones in the individual's back that are meant to protect their spinal cord do not develop when the neural tube does not close completely. When the protective bones do not develop around the spinal cord, the individual can experience damage to the nerve branches and spinal cord fibers. This abnormal and incomplete development of the spinal cord and its protective coverings can cause the brain stem and cerebellum to protrude into the foramen magnum abnormally. The types of Chiari malformations that are most often the result of spina bifida include type II Chiari malformation and type IV Chiari malformation. Both spina bifida and Chiari malformation occur as defects when the individual is developing as a fetus and are discovered upon birth.

Hydrocephalus

Chiari malformation may occur due to a condition referred to as hydrocephalus, which is when too much fluid accumulates in an individual's brain ventricles, the cavities in the brain where cerebrospinal fluid is produced by the ependymal cells. The spinal cord central canal is continuous with the ventricles in the brain, allowing for the circulation of cerebrospinal fluid. While a certain amount of cerebrospinal fluid in the ventricles is normal, an excessive amount causes the ventricles to become enlarged and compress neighboring brain tissues. When the ventricles become enlarged from too much fluid, it is referred to as hydrocephalus. The enlarged brain ventricles of a hydrocephalus patient can cause tissues in the brain to become displaced because the bones of the skull are not flexible and cannot adapt to swelling tissues. When brain tissues are pushed into the spinal canal from enlarged ventricles, it causes the individual to develop Chiari malformation.