Sunday neurology

Re: Sunday neurology

David Mills — Tue, 02 Oct 2012 13:11:15 GMT

Thanks all for input. Unfortunately, the owner refused treatment and the cat was euthanased today. It had deteriorated in the last 24h and had showed some seizure activity in the last 12h.

Re: Sunday neurology

Alex Gough — Tue, 02 Oct 2012 10:22:47 GMT

Thanks Mark, that's helpful. I've never diagnosed an atonic seizure, but they do get mentioned in veterinary literature that discusses seizures, without usually pointing to any references! So I wasn't sure how common they were.

Cheers

Alex

Re: Sunday neurology

Mark Lowrie — Tue, 02 Oct 2012 10:07:22 GMT

[quote user="alex gough"]

Interesting videos, thanks for the posting David and the discussion Mark.

Could these be atonic seizures? Is this something you come across often Mark? I certainly don't rule out epilepsy in flaccid collapse because of atonic seizures, though I presume they are rare. Presumably the only ways to diagnose are EEG and response to treatment? Could be worth a trial treatment with anticonvulsants if treatment for narcolepsy fails?

Alex

http://www.youtube.com/watch?v=tsip--lR0bI

[/quote]

Hi Alex, I guess there is no way of ruling-out atonic seizures in dogs. The problem is that we cannot do nearly as complete a work-up in our patients vs humans. Sleep disorders are certainly more common (in humans and veterinary patients) and this is why I think a cataplexy syndrome in this cat is most likely. However, without polysomnography and the limited access to EEG in veterinary medicine it is possible we are missing the odd case of atonic seizures. However, if patients do not respond to the medications mentioned then I certainly would trial phenobarbitone.

As far as I am aware though there are very few human reports of atonic epilepsy and no veterinary literature on the subject. My basic understanding was that when atonic episodes are seen they frequently occur amid bouts of other paroxysmal episodes that are more representative of a seizure disorder e.g. myoclonus and tonic-clonic seizures. Given the literature is sparse I guess this is something that is poorly understood in human medicine. I think the rule of 'decreased tone = not a seizure' works pretty well in the vast majority of cases and haven't been caught out yet. However, tomorrow is another day...

Re: Sunday neurology

Alex Gough — Mon, 01 Oct 2012 17:34:25 GMT

Interesting videos, thanks for the posting David and the discussion Mark.

Alex

http://www.youtube.com/watch?v=tsip--lR0bI

Re: Sunday neurology

Mark Lowrie — Mon, 01 Oct 2012 13:01:05 GMT

[quote user="Jo Jones"]

What else would you suggest in a similar case where finances are not limiting?

[/quote]

In reference to these cases in general then (and not with any reference to David’s case!), sleep disorders can be primary (narcolepsy/cataplexy) or secondary (due to sleep deprivation). A stepwise approach would be to start with the clinical exam. Firstly ruling-out any sleep deprivation disorders e.g. due to chronic pain or chronic fatigue – i.e. is the patient painful? Then, perform the neurological exam (specifically proprioception, I like hopping but paw positioning is acceptable; and the menace response). If this is normal I would perform basic blood work (notably a fasting glucose!) and then move to ruling-out structural brain disease (e.g. MRI + CSF).

If this is all normal I would then move to doing the therapeutic drug trials.

Re: Sunday neurology

Jo Cobbett — Mon, 01 Oct 2012 11:53:45 GMT

[quote user="Mark Lowrie"]

Given this is a charity case then it would seem most appropriate to proceed straight to a pharmacological trial to see if this reduces the frequency of the episodes.

[/quote]

What else would you suggest in a similar case where finances are not limiting?

Re: Sunday neurology

Mark Lowrie — Mon, 01 Oct 2012 11:45:52 GMT

The two videos show numerous episodes of loss of postural tone and loss of consciousness for a brief period of time before the cat returns to normal. There aren’t many neurological conditions that will cause loss of tone, for example, a partial seizure is out as this should cause an increase in tone. The only neurological condition causing flaccidity would be a sleep disorder (i.e. narcolepsy/cataplexy syndrome).

Sleep disorders can be primary (narcolepsy/cataplexy) or secondary (due to sleep deprivation). Given you have a normal clinical and neurological examination (specifically proprioception and mentation), normal blood work and a normal cat in-between episodes then a primary narcolepsy/cataplexy would seem most likely.

Given this is a charity case then it would seem most appropriate to proceed straight to a pharmacological trial to see if this reduces the frequency of the episodes.

Current management of this type of syndrome in cats consists of a symptomatic therapeutic trial using various drugs. I tend to start with a serotonin reuptake inhibitors e.g. imipramine (0.5 – 1 mg/kg SID-BID). I would try this for 3 weeks and see if it makes a difference. I would recommend the owner keeps a diary of these events while undergoing this treatment trial to determine if the frequency/severity/intensity is altered. Obviously a complete erradication of the episodes is unlikely so the aim is the get them to a more managable level.

Other drugs can be used such as clonazepam, desipramine or venlafaxine. However, the dose range for some of these medications is not really determined and so I usually extrapolate the dose from dogs. I would always only give one drug at a time and obviously spend time explaining that these are not licensed for use in cats and side-effects are a bit of an unknown quantity therefore careful monitoring is important.

Thanks for sharing this video with us David.

Re: Sunday neurology

Luciano Nebiante PGCertSAS — Sun, 30 Sep 2012 19:56:58 GMT

Any cranial nerves deficit?

At this stage, I think it's inflammatory vs neoplasia. And for the age, I think (and hope for the cat) inflammatory cause is more likely.

Re: Sunday neurology

David Mills — Sun, 30 Sep 2012 18:41:32 GMT

Dinner plates - colleague gave it some vetergesic overnight at a decent dose, not normally like this. O is abou 60+ which in London doesn't r/o recreational drugs but it's been chronic really. Spayed.

No hx if trauma. Increasing frequency of these episodes over last 4-6 weeks, worsening in last 24-48h.

Re: Sunday neurology

Luciano Nebiante PGCertSAS — Sun, 30 Sep 2012 17:53:17 GMT

[quote user="David Mills"]

, been going on for 'a while'

[/quote]

Was the onset acute or progressive? Is it progressing now or stable?

In the 1st video appears that cat keeps fore limbs crossed. Is this common presentation in this case?

Any history of trauma? Falling from height?

So far seems a forebrain lesion, but I'm not a neuro expert.

Re: Sunday neurology

Anthony Dennison — Sun, 30 Sep 2012 13:40:36 GMT

Is the cat female and entire? Only ask as I saw a cat about the same age last week where the owners rang up in a panic, cat was falling over, shaking tail all around and wafting tail around like that, and had been behaving oddly for past few days. Nothing on CE, DUDE normal, temp normal, and on taking temp cat completely wriggled and fell on side with any sort of stimulation. probing deeper cat had also been calling and rubbing head against everything, so suspected it was on heat and told them as much. Haven't heard anything since.

Probably not in this case as it's pupils are like dinner plates and I am only an inexperienced noob - possible toxic cause, including human recreational drugs?

Re: Sunday neurology

Utlendigur — Sun, 30 Sep 2012 12:47:10 GMT

Probably way off the mark but I can vaguely remember seeing something very similar in a middle aged siamese cat many years ago. That had a cranial mediastinal mass (suspected thymoma given the age of cat but I'm not sure whether the neuro signs were particularly associated with the type of neoplasia or the fact it was a cranial medistinal site)

Re: Sunday neurology

Mark Hedberg — Sun, 30 Sep 2012 12:42:13 GMT

Yeah, i think IgM is more useful with toxo.

Re: Sunday neurology

David Mills — Sun, 30 Sep 2012 11:50:24 GMT

Proprioception is normal between episodes, some question mark over vision but seems OK today. Process is normal,. walking then knuckles, flops, about 10s later gets up. No full seizures since hosp yesterday.

No toxo serology done - beyond our charity realms. I was under the impression that there's poor correlation between IgG and clinical disease in any case (we normally just treat young neuro cats anyway).

Re: Sunday neurology

jd2008 — Sun, 30 Sep 2012 11:41:54 GMT

Focal seizure activity would be my guess.

Re: Sunday neurology

Louise6732 — Sun, 30 Sep 2012 11:15:30 GMT

Odd!

What's the neuro exam like? Does the cat have proprioception on its forelimbs? In the 2nd video it seems to be knuckling on its LF, proprioceptive deficit or is this the collapse?

Have you checked for toxoplasma?

Louise