Medical Monday: Inferior Vermian Dysgenesis

It's that time again: Medical Monday! I blog each Monday about a different condition Connor has and then post a link to it on the side bar as I go. This way people can get a better idea of what Connor deals with on a daily basis and his family and friends can understand what I'm saying when I call and spout ridiculously long medical terms.

DISCLAIMER: I would like to emphasize for those people who stumble upon this blog that I'm not a doctor, and I have no medical experience other than the approximately 900 doctor's appointments I've been to in the past two years. I just know about these things in relation to how they apply to Connor and not anyone else's child, so if you want accurate info on this sort of thing, please please please ask your doctor or go to the medical library instead of looking it up on the Internet. The library is your friend.

So today we're diving back into the brain. We're going to be looking at a portion called the vermis.

First we have to talk about the cerebellum, though. The cerebellum, which is found at the very back of the brain, is the steering mechanism of the muscles. It helps regulate body movements, eye movements, balance, and the processing of sensory information. I've drawn you yet another happy brain picture here to show you where it is.

Now the cerebellum has two hemispheres just like the larger portion of the brain does ("cerebellum" in Latin actually means "little brain") and each of these hemispheres control a side of the body: the right side of the cerebellum controls the right side of the body, and the left side of the cerebellum controls the left side of the body. These two hemispheres are connected in the center by the vermis, which acts as a communicator of information and also has a role to play in directing balance and posture.

The vermis is divided up into a number of different pieces, each acting as a communicator for a different portion of the cerebellum. The part of the vermis we are interested in is called the inferior vermis. This part connects the two lower halves of the cerebellum. It is further divided into the nodule, the uvula, the pyramid, and the tuber vermis. Fun names, huh? Each of these pieces connects to a different part within the cerebellum. The vermis is kind of like the meat in a cerebellum sandwich, so in this picture I've pulled the two pieces of the cerebellum apart so you can see the vermis in the center. Otherwise it's hidden from view.

In Connor's brain, the inferior vermis is underdeveloped and very small. This is a condition called inferior vermian dysgenesis. Basically the parts are there, but they are malformed. So what does this mean for him?

Keep in mind that scientists still don't have a good grasp on how the brain functions, and also a lot of Connor's conditions could be caused by several different things. Here's the basics, though, of how Connor is probably affected by his inferior vermian dysgenesis.

First of all, the two hemispheres of his cerebellum probably have a hard time communicating. As a result, Connor has a tough time moving the right and left sides of his body together. This makes activities that involve this coordination, such as walking, very difficult.

Secondly, one of the parts of the inferior vermis, the nodule, along with it's corresponding part of the cerebellum, the flocculus, is at least partially in charge of balance and posture. There's also some evidence that these parts help control body awareness-- knowledge of where body parts are in space. This is what lets you close your eyes and touch your nose. Because Connor's nodule is small, his balance is very poor. Also he has a difficult time doing activities like feeding himself, because he's not sure where his head is in relation to his hand. We've noticed that when Connor is eating (we have him hold the spoon and we also hold the spoon and his elbow) that if we have him direct the spoon he jerks his arm around in space and seemingly has no idea where his mouth is. If we help him touch the spoon to any part of his face, he's able to guide it down or up to his mouth. However, he seems to be able to put his fingers in his mouth without too much trouble, so it's tough to tell if he really can't figure out where his mouth is, or if he just doesn't want to direct the spoon there.

On a rather scary note, a lot of people with schizophrenia have vermian dysgenesis. Hopefully this will not be the case with Connor. The kid has enough going on as it is, thank you very much.

So what's the treatment for this sort of condition? Once again, since the problem is neurological, there isn't really a treatment or cure. The parts aren't going to grow any larger in relation to the rest of the brain. We'll just continue to try and make new connections that help Connor bypass some of the issues, and we'll continue to make adaptations so that Connor is able to function as independently as possible.

There's not a whole lot of information on the internet about inferior vermian dysgenesis, but here's a few links:

Purkinje Cells in Posterior Cerebellar Vermis Encode Motion in an Inertial Reference Frame

National Institute of Neurological Disorders and Stroke: Joubert Syndrome (note: Connor does NOT have Joubert Syndrome, as he is diagnosed with his chromosomal issue. However, he does share the vermian dysgenesis that defines Joubert Syndrome.

Joubert Syndrome: a clinico-radiological study

Arquivos de Neuro-Psiquiatria- Cerebellar vermis hypoplasia- non progressive congential ataxia: clinical and radiological findings in a pair of siblings

~Jess