I’m always looking for other reasons that cause migraines or headaches and came across this:
Chiari malformations (CMs) are structural defects in the cerebellum (the portion of the brain that controls balance).
For the most part, the cerebellum and parts of the brain stem sit in an indented area at the lower position of the skull but above the foramen magnum (funnel-like opening to the spinal canal). But if part of the cerebellum is below the foramen magnum, these are Chiari malformations.
~ Structural defects in the brain and spinal cord during pregnancy, possibly genetic or absence of proper vitamins or diet
~ Excessive draining of spinal fluid from area of the spine
Symptoms (just listing some)
~ Headache (most common symptom) usually begins in the back of the head, frequently radiating behind the eyes. Coughing, laughing, leaning forward, sneezing or tilting head may worsen a headache. This headache could be confused with a migraine.
~ Neck pain
~ Balance problems, dizziness
~ Numbness in arms or legs
~ Muscle weakness
Although Chiari malformation is normally present at birth (estimated at 1 in 1,000 births), the symptoms of the malformations are usually not felt until adulthood, possibly when the patient is in their 20s or 30s. Symptoms may develop before or after this age also.
More information from sources below:
I also found an online support group/forum for Chiari Malformation.