Hi, Arnold chiari malformation is the condition in which the part of the brain stem enters into the spinal canal which causes symptoms based on the part of the brain involved. Most common cause for this herniation is that there is no enough room for the posterior brain tissue. There are 3 types in it. In type 1, the condition is mild in which the lower part of the brain tissue enters the spinal canal. Headache is the symptom most commonly the individuals present to the doctor. Magnetic resonance imaging (MRI) helps to identify the defect. Other symptoms are numbness and tingling of hands and foot, dizziness, choking, gagging, breathing difficulty, etc. In type 2, the brain tissue herniation is often always associated with spinal cord defect called as spina bifida. The symptoms are somewhat severe than type 1. Speech difficulty is also seen in Chiari type 2 defect. In type 3, lower part of the brainstem or the cerebellum get into the defect in the posterior part of the skull. This condition is rare and found since birth. This condition is congenital. Treatment depends in the type. If headache is the presenting symptom, analgesic such as paracetamol is enough. If there is increased pressure in the brain due to obstruction of the cerebrospinal fluid, surgery is needed to correct the flow. Surgical correction to increase room space for brain is also advised in case of severe pressure on brain tissue. Take care. Hope I have answered your question. Let me know if I can assist you further. Regards, Dr. Pradeepraj, General & Family Physician