Arachnoid cysts typically develop during development while inuterine. The arachnoid membrane will sometimes, and doctors don't really understand why, but it splits and the split portion will begin to fill with cerebral spinal fluid. The arachnoid membrane is a protective mebrane around the brain.
Sometimes the cerebral fluid, getting into the arachnoid membrane, will cause the membrane to grow and get larger, creating a cyst. Not all cysts grow. Many times it depends on whether or not membrane walls build within the cyst. These walls collect cerebral fluid beind them. The fluid can get trapped inside the walls, unable to find its way out, so the cyst will grow.
Depending on where the cyst develops, it can then begin to put pressure on the different areas of the brain. Mine, is a posterior fossa arachnoid cyst. It sits on the back of the brain and has grown, over the years, to bigger than a grapefruit. It consumes a very large portion of my brain. My brain has essentially grown around it over the years, and it expects the cyst to be there now. The cyst has caused my brain to shift up and forward. It has also pushed the back of the brain, where the cerebellum and brainstem are, downward. My optic chiasm is narrowed. This is where the optic nerves pass. My fourth ventricle is narrowed, as well as my pituitary gland is compromised.
I began to have symptoms in 2003 when I was 35. I noticed slight differences in myself, like I would forget things easily; lose my train of thought easily. I also had physical symptoms. One of the first signs something wasn't right was when I would wake up in the middle of the night and my head would be numb, just like if a limb lost feeling. I couldn't move my head off my pillow. Then that developed into my head aching, right at the back of the head where the cyst was. It would hurt after leaning it against a recliner, or the seat in the car. After that, things just spiraled fairly quickly downward. I began to get dizzy alot, forgetful, confused and unable to put things together...like where was the dairy section in the grocery store I'd shopped in so many times. And does red mean stop or go on a stop light.
It was a frightening and unnerving feeling, especially because I didn't know what was causing these odd symptoms. I saw many doctors, had MRI's, and no one wanted to associate these odd symptoms with my cyst. Even I began to believe them, that there was something else going on other than the cyst. Or maybe, I was just crazy. But when I started getting paralyzed at night when I slept, waking up not able to move an arm, a leg, or a finger, I knew it had to be my cyst. I even stopped breathing in the night, now having sleep apnea. This, I found out later, was due to the cyst putting pressure on my brainstem, which controls your breathing.
Something was gravely wrong and I had to get to the bottom of it. With no one else to believe me, or even halfway listen to me, I had to became my own advocate. I had to take charge of my body and of me. I was going to get to the bottom of this, and I was going to find a doctor who believed me and didn't think I was cuck-koo. I was going to make someone listen to me, because the way I was feeling, I just knew that my time was running out. If I didn't get someone to help me with this cyst, I was surely going to die!