Questions from Veterinary Neurology Lectures by Dr. Ryan Gibson (The Brain Dogtor)

Neuro-Optho Lecture

if I have a hyperesthesia feline, who is on antianxieties, gabapentin. Is this one who you would start on Phenobarbital?

-       It absolutely is! I would maybe also consider pregabalin (just because it has a higher affinity for the receptors), but this is a great description of when I would give pheno a chance! I would also make sure there are no derm or allergy issues either.

Are there certain clinical signs that scream “you MUST go to a specialist”?

-       Great question, for neuro-optho signs I do think if you have an animal that has cavernous sinus syndrome, or even just complete extra-ocular muscle signs, it is fair to consider referral as there is a high likelihood of needing imaging to evaluate this condition fully as there are a lot of limitations if owners want to know the definitive cause. I think you can also be fairly aggressive in general practice with optic neuritis if you have the support, but if you want to get a full picture it isn’t wrong to consider referral. I think for me it is the idea of do they want to go all in or not. For example, a cavernous sinus that wouldn’t do chemo or radiation, then steroids and antibiotics would cover for neoplasia and infection (though not as aspergillosis in a GSD – saw that once). So it comes down to 1.) do they need/want to know more and 2.) how will we use that information? Or 3.) is the animal not responding to initial therapy? Finally, anytime something is weird or atypical, consider either reaching out or referring.

How high yield are radiographs in diagnosing and developing a treatment plan for cats/dogs with neurologic signs, without a history of trauma /possible trauma?

-       So this is such a great question! I think it has play for head trauma for sure, but when it comes to cases without trauma it is certainly more difficult. I certainly have seen some rads that we can be like – yup, that skull is broken and needs advanced care. Of course it will have its limitations, but I do think we can look for big things and tell owners, there is a lot we can miss, but if we see something, then we know where we have to be super careful with! Without trauma it probably has a little bit more limitations. That said. . . I have also been proposing bringing back the use of rads to evaluate the bulla for inner ear disease! If nothing else, it can help us know if we have something (infection vs tumor) in the bulla and can tell us, hey, this is more than just idiopathic vestibular disease! It may mean we pull the imaging or referral trigger sooner. If we see a big ol nasty bulla, then hey, maybe this is cancer!

Feline Diseases:

When should I refer a cat for advanced imaging (MRI/CT)?

-       Consider referral if:

• There is a progressive neurological disease.

• The cat has seizures with normal bloodwork and systemic evaluation.

• You suspect central vestibular disease.

• The cat has a non-painful myelopathy or multifocal disease.

Can idiopathic epilepsy occur in cats?

-       Yes, but it is less common compared to dogs, but where we used to think cats had rare epilepsy, we now consider it much more common. Idiopathic epilepsy is usually diagnosed in cats aged 1-4 years, and they have normal neurologic exams between episodes. Any neuro signs that are atypical or strange, consider referral for imaging and advanced diagnosis.

How do cats present with myasthenia? Sorry I stepped out during the LMN lecture if you mentioned it there.

-       Oh they present much weirder! It is often more ambiguous, they may just want to sit down more frequently. Remember that MG can have different forms (focal, general, fulminant) and can present as a spectrum in all of those. Long story short, remember that MG in both species can have more normal proprioception and reflexes compared to the other LMN disorders.

LMN Diseases:

-       No new questions, but check out previous questions here!

I recently had a dog with difuse LMn signs and weakness but still alarmingly alert! Would not eat. Severe muscle wasting….i suspect a neuropathy but we could not do any more diagnostics. Febrile high wbc, unresponsive to pred, radiographs of chest/abdomen unremarkable. Any thoughts appreciated for my learning….dog was euthanized s.

• The febrile makes me think infectious myopathy or neuropathy. I’ve had a few toxo cases and one hepatazoonosis that presented with LMN signs.