Most doctors will not diagnose Chiari without at least a 7mm herniation. However, it's not the amount of herniation, but the blockage of the CSF (cerebrospinal fluid) that causes the symptoms. If the CSF is being blocked, you're going to have increased intercranial pressure resulting in the classic Chiari symptoms.
As far as getting 4mm on one reading and 5mm on the next, there's usually a +/- 2mm margin of error given due to slight differences in measurement.
I would recommend that you look at the website for the Chiari Institute in New York. They have research there about "Chiari 0". It's relatively new research, but they are finding people that are symptomatic without the same extent of cerebellar herniation that they usually diagnose Chiari Malformation with. In the case of Chiari 0, the cerebellar tonsils are typically low-lying, but still cause blockage of the CSF. Print the research information and take it along with you. I've had more than a few doctors and radiologists I have presented this to that told me they had never heard of this and learned alot. If the doctor isn't willing to read it and learn, it's not worth you being their patient either.
Best of luck to you!
Jackie
nurse with Chiari 1
Hi...low lying tonsils can result from an outside force, such as a fall, it can be acquired...whereas chiari is the malformation of the skull...not the size of the herniation even tho many drs will classify a herniation of 5mm of larger chiari...u will have chiari symptoms, but, it does not mean the herniation is a result of the cerebellum being too small.
Have u had a fall or been in a MVA in the last few yrs?
Once u get to a true chiari specialist u will get more details and info.....Please keep us posted.
"selma"
My husband told me I was borrowing trouble by getting the radiologist report prior to going to the neurologist but I feel like had I not got my hands on these I would have fallen through the cracks AGAIN. I've been fighting this battle for over 4 1/2years. I had given up hope and then this Dr. brought it to my attention when he saw the 4mm notes on the MRI of my neck, which was done to see if pinched nerve was causing the numbness in my arms. I mean from what I see 5mm can cause problems for some and then others have no symptoms with 10mm....I would love to hear from anyone with 5mm that was given the diagnosis of Chiari 1
I'd love to know the answer to that to because I'm in a similar scenario.