"Its not a tumor" is the only line I remember from the movie Kindergarten Cop. I think it stuck with me for two reasons: 1) I used to get a lot of headaches, and 2) if my choices were teaching a kindergarten class or having a brain tumor, I'd probably opt for the tumor. But that's all beside the point.
Duncan's been having a lot of cognitive issues over the last several months, including - but not limited to - not recognizing basic commands or even his own name. Combine that with the changes in the seizures that started in September and the really bad weekend we had recently and I decided it was time for Duncan to see a neurologist. His appointment was Monday, October 29. The neuro actually remembered Duncan from a couple of years ago when he was having trouble with his back end. He reviewed the video, seizure log and medication log I provided, asked a lot of questions, and agreed that it sounded like Duncan was dealing with something other than just standard seizures. He was less concerned about the changes in the seizures than in the cognitive issues.
While we were there, they took samples and did a full blood panel including Phenobarbital (Pb) levels. They also did a bile acid test to check Duncan's liver function. The blood work came back pretty much normal. A couple of values were a little outside the typical range, but nothing to worry over too much. Duncan's Pb was low (15 is the low end of the theraputic range, his value was 14.9) which is clearly why we don't have good seizure control. Thankfully, his liver function was normal - its always a concern for dogs on Pb, Novox, etc.
They couldn't get Duncan in for imaging Monday, so he had to go back to the vet school Thursday. Poor fellow, that was two days in the same week that he didn't get to have breakfast.
Thursday afternoon the neuro told me that Duncan does *not* have a brain tumor. That was confirmed late Friday by the senior radiologist who reviewed the images. They also checked his spinal fluid and confirmed no infection or inflammation. So, unless there's some odd thing that's too small to see but big enough to cause major problems, Duncan has idiopathic epilepsy. Since there's no tumor, the neuro thinks the screaming at the wall episode a couple of weeks ago was probably a partial seizure. Which brought us back to the cognitive issues.
The vets all got together and decided that, barring the weird option I mentioned above, Duncan is just one of the very few dogs with an extreme sensitivity to Pb. Of course, since Reyna and I both have trouble taking medication that works for 99.9% of the population, why shouldn't Duncan? The good thing is that a sensitivity to medication is pretty easily resolved - stop taking that medication. Granted, we still have to worry about the seizures. But that's okay, because we have a plan. We've started Duncan on Zonisamide. He's taking a higher-than-normal dose of that for now because the Pb actually makes the Zoni metabolize faster. After he's been on the Zoni for a week, which will give it time to build up in his system, we'll start slowly weaning him off of the Pb. We can't go too fast because it could spark more seizures. Ideally, once Duncan is off the Pb, we'll be able to lower the dose of Zoni while still controlling the seizures. The neuro and I spent a chunk of time talking about what we consider "good" seizure control. If we can average one seizure a month, we'll both be happy. Since Zoni has fewer side effects than Pb, Duncan should start getting his brains back together. Duncan's been on the Zoni since Thursday, and so far he hasn't shown much more in the way of new side effects. A bit more sedated (is that even possible??) but none of the extreme drunkenness he showed when we tried the Keppra. This isn't going to be a quick process, but we'll get there.