Chiari malformation is a congenital condition for which parts of your brain protrude out the skull and into the spinal column. This health condition is classified according to how severely and which parts bulge. There are 4 different types of Chiari malformation.
Type I Chiari malformation is caused by the lower part of your cerebellum projecting through the opening in the skull and into the spinal cord canal. It doesn’t involve your brainstem and is usually accompanied by syringomyelia. It’s often not noticed through symptoms until later in life.
Type II, aka classic Chiari malformation, is more severe than type I because it includes a more significant herniation of cerebellum, part of the fourth ventricle, parts of the brain stem and this brain tissue protrudes farther into your spinal column. Type II is typically accompanied by hydrocephalus and a myelomeningocele, a form of spina bifida.
Type III and IV are very rare and serious forms of Chiari malformation. And some neurologists do not consider them a type of Chiari malformation.
Although the exact cause of Chiari malformation is unknown, there are several accepted theories of what may cause fetal brain development problems:
- infection
- toxin exposure
- genetic or familial factors
- poor nutrition during pregnancy
- certain vitamin deficiencies while pregnant
- maternal use of prescription/illegal drugs or alcohol
It can also be caused by spinal fluid that drains excessively from the lumbar or thoracic areas of your spine because of injury, harmful substance exposure or infection.
Many with a Type I Chiari malformation don’t experience symptoms, thus you may not even be aware you have this health condition. When symptoms are present, frequent complaints include:
- vomiting
- insomnia
- dizziness
- neck pain
- depression
- balance problems
- muscle weakness
- scoliosis, kyphosis
- difficulty swallowing
- impaired muscle coordination
- ear ringing, buzzing, hearing loss
- frequent respiratory tract infections
- numbness, other abnormal arm or leg feelings
- headache that worsens with coughing, straining
- blurred vision, double vision, involuntary eye movements, other vision problems
Symptoms of Type II Chiari malformation include these plus other symptoms, like vocal cord paralysis and apnea.
If your Chiari malformation causes insignificant symptoms, treatment may not be necessary. For those with serious functional issues, surgery is the only course of treatment for reducing symptoms.
Surgery treatment for Chiari malformation largely involves relieving pressure in the area. And this will likely mean making more room via some restructuring.