Seizures in the immediate post operative period can indicate a poor prognosis for humans undergoing brain surgery. The same is suspected for dogs, but isn't known. A recent article (see below) recently discussed this question and I thought you might be interested in reading some key points from the article.
Key points:
88 dogs underwent 125 procedures. Most had either a brain biopsy or a brain surgery, but some had both.
All included surgeries were rostro tentorial because caudal tentorial surgery and tumors have a very low incidence of seizures.
Most dogs (72%) had seizures before brain surgery was performed, therefore diagnosed with structural epilepsy.
All types of seizures were noted (35% generalized only, 29% focal and generalized and 17% focal only)
Forty-one of 88 dogs (46%) had a normal interictal neurologic examination. This is MUCH higher than some other studies have shown and is worth noting in general practice. The neurologic examination can help guide you towards advanced diagnostic testing, or not. According to this study, almost 1/2 of the dogs had a normal exam and had a brain tumor!
About 42% of dogs had an abnormal neurologic examination consistent with a focal lesion and 11% had examination findings consistent with multifocal disease.
What I learned from this article
This article was full of data, so if you're a practicing brain surgeon, it is worth a full read. That said, there were a few points that may benefit the non-neurosurgeons amongst us. I've summarized them below and included a link to the open access article at the bottom if you'd like to read more yourself.
Early post-operative seizures in humans, are diagnosed in the first month after brain surgery. One of the hypotheses was that dogs receiving anticonvulsant drugs (ACD) would have a lower incidence of post-operative seizures. Interestingly, this article did not detect a difference in post operative seizures between dogs with or without ACD pre-operatively!
Tumor location nor brain herniation were associated with the development of post operative seizures.
Curative intent surgery carried a higher risk of post operative seizures when compared to biopsy procedures.
Dogs with glioma had a higher incidence of seizures compared to other tumor types, except meningioma.
Dogs with early post operative seizures were less likely to survive to discharge.
Early post operative seizures occurred in the first 24 hours for all dogs, and were associated with longer hospitalization.
Take Away Message
What does this mean? It means that seizures are a small, but mighty way for the brain to express it's displeasure with human touch. Even the most careful surgeon risks causing seizures that could be life threatening for their patients. I still give ACD pre-operatively but am compelled, by this data, to consider stopping that practice. Why administer an ACD if it isn't associated with a lesser chance of seizures? For most of you, brain surgery is not a part of your daily practice, so I would suggest that the most important take away from this article might be that almost half of dogs had a normal neurologic exam and yet were diagnosed with a brain tumor. Also, if a client asks you about post operative seizures, you can refer to this article! Thank you, Science.
Thanks for reading all the way through! I hope you have a great week and look forward to working with you, and your patients, soon.
Article links: https://onlinelibrary.wiley.com/doi/full/10.1111/jvim.16391