Vertebral Basilar Insufficiency

Madison was just diagnosed by MRI with Vertebral Basilar Insufficiency. She has a 4 mm spot right at her C1 verterbrae that showed consistent blood loss. Her neurologist also called it a cervical spinal cord ischemic lesion. He suggested that it was from a narrowing or stenosis of an artery that then decreased blood flow to her brain, which is why she collapses on her walks. If all of her blood clotting tests come back normal, he said the treatment may be as simple as a baby aspirin a day.

Has anyone any information about this or know where I can go to look?

At least she doesn't have SM like her half-sister Riley. She does have a mild malformation which her neurologist says he sees on 90% of cavaliers that he scans.

Any help you can give me on her disorder is greatly appreciated. Thanks.

I'm sorry. I hope pat or others will know more but I hope its easy to treat like neurologist said with asprin.

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I presume that you have googled and read about this. I can only find references to this in humans. There is nothing in dvm360.com and there is nothing in any of my (extensive collection of) veterinary textbooks. However, I do not have a veterinary neurology specialty textbook. I did do a google book search in a veterinary neurology text but found nothing. Human references:

http://www.nebraskamed.com/neuro/surgery/vertebral-basilar-insufficiency

http://www.ucdmc.ucdavis.edu/vascular/diseases/vertebrobasilar.html

In humans, it is generally caused by atherosclerosis, but dogs don’t have atherosclerosis – so in canines it would likely be caused by stenosis (narrowing of the artery which can decrease blood supply probably exacerbated by certain things like exercise or posture - in humans they talk about "beauty chair" episodes caused when your head is tilted back into the shampoo basin) or possibly by clots or embolism. That is the purpose of aspirin therapy – to keep the blood thin and prevent clots and help the blood flow through the narrowed part of the artery. What she is experiencing is called a “drop attack.” I never like to use human references because they often don’t extrapolate to canines, especially in this instance but I can’t find canine references.

It would be good if neurologist could differentiate between stenosis and lesion or both. If there is truly a lesion, what is the prognosis? Is this progressive?
I don't understand his reference to "blood loss" - I presume he means "loss of blood flow" rather than loss of blood as in free flowing blood escaping the artery. Aspirin therapy would make a bleeding disorder worse but would help restricted blood flow because it is a blood thinner.

I did read a good bit about peripheral vascular disease in canines but this didn’t fit. Fibrocartilaginous embolism (FCE) is well described in vet texts; this is similar but is an ischemic accident caused by embolism of disk material rather than by a clot or narrowed artery. Similar presentation, painless, no definitive treatment.

I could find a lot on spinal cord stroke but that is different.

http://www.medlink.com/medlinkcontent.asp

"Transient spinal ischemia. Transient ischemia of the cervical cord may cause "drop attacks." The clinical picture in the lumbar region ("spinal cord claudication") may be of weakness of the lower extremities precipitated by effort and relieved by rest. The pedal pulses should remain palpable. Episodes are typically painless."

Discussion of spinal cord infarcts

http://cal.vet.upenn.edu/projects/saortho/chapter_64/64mast.htm

http://emedicine.medscape.com/article/1164217-overview

I would ask the neurologist for reference material that you can read. If you do aspirin therapy, be really careful to give it with a meal and to watch for black, tarry stools that could be a sign of gastric ulceration.

Pat

I edited a bit this morning to clarify. I wrote this at midnight after reading for a couple of hours. This apparently isn't very common or I would have found more references - or perhaps it isn't diagnosed much because most dog owners wouldn't do an MRI for such transient episodes. Are you going to talk to the neurologist again? I really hope he can give you some reference material to read.

Thanks Pat. You are such a wealth of information. You are right that he did say it was stenosis and a loss of blood flow rather than blood loss. (The blood loss was my unfortunate wording.) Which is why he was doing extensive clotting tests on her. He sent off a D- Dimer clotting test, which I guess is a more sensitive clotting test than the blood tests that are done in the office. He wants to wait for the results of that before he decides on her treatment plan - which wil probably be blood thinners (baby aspirin).

Dr. Podell is calling again when he gets the results of the clotting tests. I'll ask for some reading material then. I'll also ask about prognosis and progression and clarify what he meant about the lesion. When you first get a diagnosis, sometimes you forget to ask all the right questions and you think about them later or it takes someone else to remind you to ask them.

Who knows if I jumped the gun on having an MRI on her after only two episodes. Her half sister Riley has severe SM and something about these "drop attacks" looked neurological to me. Since SM could have been lurking in her gene pool, I decided to go ahead with the MRI. That's what I really feared he was going to find. At any rate, it's nice to find another "oldie " without SM even though she does have mild CM. I now have two "oldies" with no SM. Oliver had an MRI at age 9 for disc problems and was confirmed no SM. I sent his disc off to Clare.

Thanks again Pat for doing all that research and for sharing your knowledge.

Love my Cavaliers said:

Who knows if I jumped the gun on having an MRI on her after only two episodes. Her half sister Riley has severe SM and something about these "drop attacks" looked neurological to me. Since SM could have been lurking in her gene pool, I decided to go ahead with the MRI. That's what I really feared he was going to find. At any rate, it's nice to find another "oldie " without SM even though she does have mild CM. I now have two "oldies" with no SM. Oliver had an MRI at age 9 for disc problems and was confirmed no SM. I sent his disc off to Clare.

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No, I think it is WONDERFUL that you were able and willing to have an MRI done! More great info for the RF/older Cavalier project and you are able to pinpoint exactly what is going on rather than guessing. I think that Cavalier owners are more familiar with and accustomed to MRIs for their dogs while other breed owners might be shocked by the cost and the thought of such high tech testing. I'm certain that many canine neurological problems can't be exactly diagnosed because of owners' inability to have an MRI done. I am very interested in hearing anything that you learn - can you also ask how often Dr. P sees this in his practice? It sounds to me as if you have an excellent neurologist and the two of you are heading in the right direction. In reading last night I was awed at the complexity of the neurological (and vascular) "system" and just how many problems there are that most of us never hear about. Those drop attacks are really similar to the TIAs that we read about in humans. Again though, humans have the additional burden of atherosclerosis which fortunately isn't a factor in canines. I think I've mentioned before that I had a shih tzu who threw a clot to her lungs (pulmonary thromboembolism) that resulted in serious acute pulmonary hypertension - so dogs definitely can have embolism and ischemic events.

I'm thinking of both you and Madison - she is so fortunate to have such a loving and capable mom!

Pat

Love my Cavaliers said:

At any rate, it's nice to find another "oldie " without SM even though she does have mild CM. I now have two "oldies" with no SM. Oliver had an MRI at age 9 for disc problems and was confirmed no SM. I sent his disc off to Clare.

Click to expand...

I'm so pleased it was not the result you were dreading. It will be great if it is something that can be controlled with a cheap, simple medication.

Will you also be sending Madison's results to Clare?

Margaret, yes, I'll get a copy of the MRI on a disc and send it to Clare. I'm just so happy that I have two oldies without SM. It's been a while though since I sent Oliver's MRI off - would I contact Nicki for the address?

Pat, I'm fortunate that I could afford the MRI also since I don't have pet insurance. Ever since Rupert's Fund started though, I have been curious about whether she had SM just because of Riley, even though she was totally asymptomatic. Now she just gave me a good excuse to get an MRI on her!

The thing that worries me about this, that I will talk to Dr. Podell about, is if these events are similar to TIAs in humans, then is the damage to her brain cumulative? They only occur during walks. They both occurred only about 15 minutes into the walk. I'd hate to take them away from her, especially when the other three are going out. More questions to ask Dr. P. He mentioned something about her blood pressure being raised during walks and that caused the decrease in blood flow through the narrowed artery to her brain. Don't know why it happens only sporadically though. Whatever else I find out, I'll let you know. I'm hoping her clotting factors will come back normal so she doesn't have an event like your poor little shih tzu!

Thanks again!

Ah - you reminded me that I intended to say that I'd do a blood pressure check - probably a series of checks - to make sure she doesn't have hypertension!

My guess (underscore guess) is that thus far there has not been cumulative damage to her brain. The events are so transient - almost like cardiac syncope. If this decreased blood flow is caused only by stenosis, I would guess that it won't get worse but would only get better with the blood thinner treatment. I am curious about the "lesion" though - is that something that might get larger or worse and if so would that cause more episodes? I would do a BP check to make sure she shouldn't be on a med for hypertension. And I'd have a serious talk about any exercise restrictions. You may try her in a stroller so she can still be on walks.

Pat

Clare's address is on her website - that is where I sent Tucker's CD.

Sorry to hear the diagnosis and will be interested to know more as you get more info.

I think Clare and Penny would really value those scans and perhaps will ask about getting DNA via swabs -- very very valuable I think to DNA work to have two related clear oldies with MRIs!

My grandmother BTW had those 'beauty bowl' TIAs.