2 Chiari Specialist 2 Dx's. Very confused!

Im so confused. I went and saw Dr. Seiff in Vegas and had a new MRI. It showed hypo plastic posterior fossa and 7mm chiari. Dr. said it was not 7mm and the radiologist is wrong. It is between 3-5mm but he was more concerned with the measured indicating a hypo-plastic posterior fossa. he told me my symptoms are very likely coming from this. I have had 3 mri's 2 say 3mm and 2 say a bit elevated flow at the foramen magnum. 2 say 3mm, and the other 7mm. Had 5 doc's look at it. 2 said 3-5mm. One doc said 3.5, one said 3mm and DR ORO said NO CHIARI AT ALL!

Very frustrated and confused. Dr. Seiff said alot of doc's are not aware of the new research regarding the hypo-plastic Fossa. He also worked closely with Dr. Rosner years ago. his PA was the first to tell me I had Chiari. He said he looked at the films and saw it instantly. But Dr. Oro is supposed be great. So sorry but WTF ??!!

Thoughts please,


I understand your frustration. Have you had a CINE MRI? If not I would request one to see if your CSF flow is blocked or impeded. From what I am reading, hypo plastic posterior fossa kind of goes along with Chiari and is also treated w/ decompression surgery....feel free to correct me if I have misunderstood.

As for Dr. Oro I have read that he will not see anyone with a herniation under 5mm so that maybe why he told you it's not chiari. Though studies are showing lesser herniations are still problematic a lot of doctors still use the old 5mm guideline.

Have you told Dr. Oro of the different results you have received? I would contact his assistant and leave him a message explaining everything you posted. I have heard of Dr. Rosner but not Dr Seiff. Dr. Oro would then know and be able to address your concerns. That's what I would do. My NS & I correspond by email. I don't know if your dr's do that or not???

Kgirl I have surgery with Dr. Seiff on wed. as soon as I'm feeling well enough I will let you know how it goes! I feel very confident with him! I have heard he is one of the only Drs that does surgery on those with smaller herniation.

I would echo what many have already said. Don't get caught up in the numbers(the degree of cerebellar tonsillar herniation). The accuracy of an MRI is only about 1mm, so measuring 4mm could really be 5 or 3. To makes things more frustrating, the cuts of an MRI are 2-3mm cuts(the distance between images) so exactly where the slices occur may make a difference. surgery should always be based on symptoms(with rare exceptions, e.g. huge syrinx, tethered cord, etc).

In terms of posteror fossa size, you are getting mixed up in a semantics game. Is the brain too big? Is the skull too small? Every chiari patient is somewhere in that spectrum. Now, how do you treat a small posterior fossa? An operation to expand the posterior fossa(sub-occipital decompression). How do you treat a Chiari malformation? An operation to expand the posterior fossa(sub-occipital decompression). You are hearing similar opiniions with different words.

Using specific critieria, unless you have >5mm of cerebellar tonsillar ectopia, you do not have a Chiari I malformation. This is another semantic issue that should not affect patient care. It is important to know that the surgical failure rate is higher in the patient population with <5mm of cerebellar tonsilar ectopia, but many patients still improve with decompression(Chiari 0). Again, that should be part of the informed consent process. Creating a relationship with the treating MD allows them to better understand the way in which Chiari/cerebellar tonsillar ectopia is affecting their life and helps the treating MD better educate the patien, who ultimately needs to make the decision to proceed with surgery or not.

1 Like