Myasthenia Gravis?

Is there anyone familiar with this? My little guy, Lester, is only 1 year old and suffering from frequent bouts of lameness. To be exact, he gets excited or exercises until his legs become useless. It started out as bunny hopping and has developed into all out tremors where his legs seize up as if he is having leg cramps and his back arches very abnormally as he tries to get around. Yesterday, he fell over and began shaking. I calmed him down and he was almost immediately better. I have taken him to 2 vets and together they ruled out syringomyelia, brain tumor and possibly he may have gotten a false negative on a blood test for myasthenia gravis. He needs yet another test for this which will might diagnose it or rule it out. I have spent all of my savings and currently swimming in vet bills trying to figure out what this is. He has had one MRI which was inconclusive and now needs another. I want to know if I am being swindled into needless testing and also what I can do to help my poor baby. Lester doesn't know there is anything wrong. He is quite alert during these episodes and doesn't seem to be in any pain. He had a bad day yesterday, today he is quite normal. He's my best bud, kind of a weirdo like me, silly, full of life and I would hate for anything serious to be wrong. He is an unusual animal; the most intelligent dog I have ever owned or met. It would be a crime to not have this thing at least diagnosed properly. If you could meet him...well, I'm sure all Cav owners think theirs is the best, but mine really is (for me)!! He rocks! If anyone has any suggestions on what my next move should be, please, please, please do not hesitate to reply.

Thanks!

Jen (and Lester the Molester) www.jencrowder.com/portfolio.html Click on pets and you'll see my little guy!

Oh I feel so sad for you and Lester. On the other Cavalier site I frequent there is a pup named Penny with similar symptoms. She has been diagnosed with Episodic Falling Syndrome. Her Mom's posting name is Luv2Camp53. Maybe it is not the same but seems to have similar enough symptoms to connect you two. There seems to be some sucessful treatment. Good Luck! Keep us posted and many good wishes sent your way. Here is the web address
http://www.ckcsboard.com/messageboard/

Jen, just read this post after responding on your intro thread, and see you have done an MRI and have given much more info over here. This DOES sound like episodic falling syndrome; I have seen several cav owners describe this on other lists and boards. It is not something that would be picked up on an MRI. Listen to this -- it is exactly what you are describing:

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Episodic Falling
Episodic falling or hypertonicity is a well-recognized paroxysmal disorder in Cavalier King Charles Spaniels in the UK [1,2], and has been seen in the United States and Australia [67]. After a variable period of exercise, affected animals develop a peculiar bounding, pelvic limb gait in which the limbs may be abducted and appear stiff. Other signs may include a bunny-hopping gait, arching of the spine, vocalization and collapse. There is no loss of consciousness. Some affected dogs assume a "deer-stalking" posture, with increasing limb stiffness, falling, and legs held in extensor rigidity [2]. Episodes appear to be triggered by stress, apprehension, and excitement. Signs are typically first observed between 3 and 7 months of age. Animals are neurologically normal between attacks, which appear to be a life-long event. Affected dogs do not respond to anticholinesterases, but slight, temporary improvement may occur following diazepam treatment. A greater clinical improvement is reported following following treatment with the benzodiazepine drug clonazepam which enhances GABA neurotransmission [67,70]. In one trial, clonazepam (at 0.5 mg/kg tid) resulted in almost complete remission of signs over a 2-year period [70]. Frequency of attacks is reportedly increased in some dogs using the antiepileptic drug carbamazepine (Tegretol) [1]. Results of hematology, blood chemistries, and electrodiagnostic testing are within normal limits. There is no evidence of lactic acidosis. No light microscopic lesions are seen in the central nervous system (CNS), peripheral nervous system (PNS), or viscera. Skeletal muscle appears normal microscopically, apart from presence of small vacuoles between myofibrils in some fibres stained with toluidine blue [2]. Histochemical staining using myosin ATPase, succinic dehydrogenase, and phosphorylase is normal. Ultrastructural alterations, however, have been reported in skeletal muscle, which include dilatation and proliferation of sarcotubular elements, mitochondrial swelling and degeneration of cristae, and tubular proliferations in the region of the triads [3]. Wright stated that she was uncertain if the morphological changes were causally related to the clinical signs [2]. The pathogenesis of this paroxysmal condition remains enigmatic, although both genetic and neuropharmacological factors may be involved. In one study, 7 of 8 dogs were males and 5 had a common male ancestor that suggested an inherited trait [2]. It has been suggested [67,70] that this disorder has some similarities to hyperexplexia (startle disease) in people, a hereditary (autosomal dominant) pathological exaggeration of the normal startle response to auditory, somesthetic or visual stimuli which sometimes results in falling [68,69].

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From: http://www.ivis.org/special_books/Br...isodic_Falling

More info: http://www.candog.com/cavaliers/Heal...POTPURRI96.htm

Where it says in part:

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The descriptions of the syndrome in these articles suggest this is a transient and intermittently occurring condition, which was first identified in the 1960s. The article "Episodic falling..." documents nine clinical cases, seven of which were female. In fact, in most of the cases the first signs of the syndrome were seen when the dogs were between three and four months of age. The article on "Muscle hypertonicity..." describes eight dogs which had this syndrome; seven of the dogs were male. Their ages ranged from five-and-a-half months old to four years old. Dogs described in both articles were given thorough neurological exams before and after exercising, and none of them showed any evidence of neurological problems. Blood tests all came back with normal values. As with the club member’s dog, Tensilon was given and no improvements for dogs described in both articles were seen with the administration of the medication. Muscle biopsies were taken from five of the dogs, with some abnormalities of the muscles seen. It appears the disorder is a type of metabolic muscle disorder. It is probable that the disease is an inherited condition.

The description of what happens when Episodic Collapse occurs is as follows. After a period of exercise, which may be of variable length, animals that are afflicted develop a laboured, bounding gait in the hindlimbs which appear stiff and are partially turned out. The movement resembles the hopping of a rabbit. The dog’s back may become arched, with the head close to the ground and the rear high in the air, and the dog often cries out. With the lack of coordinated movement, the dogs collapse on their sides or pitch over on to their noses. There is no loss of consciousness or change in colour, although muscle tone in the legs was noted to be increased in the "Muscle hypertonicity..." article, and the legs were held in ‘extensor rigidity’. After a short time, which can vary, the animal gets back on its feet; some were noted to be quite distressed, while others acted as though nothing had happened. Stress, apprehension, and excitement can cause an episode. There is no known effective treatment, although if the owner picks the dog up, this seems to help with the recovery phase.

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You should inform your dog's breeder that it has this if this is confirmed -- actually any odd condition should be reported to the breeder so that they do not do further matings with that dog.

It is now believed that it MAY be related to SM but isn't a progression or anything like that.

Some further info on treatment and contacts:

Quote:

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Treatment

Until recently, no medications appeared to remedy the condition, and there was no known effective treatment. However, in a study concluded in 2003, a group of affected Cavaliers was treated with Clonazepam, a drug used to treat humans for hereditary hyperekplexia ("startle disease"). With treatment, the episodes decreased in frequency from between 25 and 30 per week to as few as one every two to three months. After two years of treatment with Clonazepam, dogs in the study were described as clinically normal.

However, in a study currently being conducted by Dr Jacques Penderis, senior research neurologist at the Animal Health Trust in the UK, he has found that although some Cavaliers initially respond well to treatment with Clonazepam or Diazepam, the dogs tend to develop tolerance to the drugs after a while and the beneficial effect wears off. Dr. Penderis states that the current treatment options for CKCSs with episodic falling syndrome are extremely limited.

Current Research

The Animal Health Trust is conducting research to try to establish the pattern of inheritance of episodic falling in the Cavalier. It is collecting pedigrees from affected dogs for pedigree analysis, particularly where the disease status of related dogs (e.g. parents and litter mates) are known.

In an attempt to develop a more effective treatment for dogs that are severely affected, Dr. Penderis is conducting a trial of some other drugs that have been shown to be beneficial in human patients and to which the Cavaliers' tolerance does not develop. He advises that the initial results for one drug have so far been promising. The current trials are restricted to those dogs that have very frequent collapse episodes and are arranged through the owners' veterinarians.

Dr. Penderis also is collecting blood samples for DNA extraction to conduct genetic linkage analysis in order to determine the offending gene. In order to perform genetic linkage analysis, Dr. Penderis requires blood samples from known affected dogs and from as many normal related dogs as possible (particularly litter mates, parents, grandparents and offspring). The study's goal is to develop a genetic test to allow identification of the affected dogs and asymptomatic carriers, so that the disease may be totally eradicated from all tested breeding lines.

In order to reduce the incidence of the disease and eventually develop a genetic test, Dr. Penderis is interested in information from as many affected dogs as possible from the Cavalier King Charles Spaniel breed. He states that what is essential to the research is that no dogs that do not have episodic falling syndrome are inadvertently included in the study (e.g. have similar appearing stiffness or collapse episodes that are not due to episodic falling) as this could severely hamper the genetic analysis. The disease will therefore need to be confirmed by video footage of an episode or examination of the dog at the Animal Health Trust. Please contact Dr Jacques Penderis at the Animal Health Trust if you wish to participate in the research project. He may be reached at Animal Health Trust, Lanwades Park, Kentford, Newmarket, CB8 7UU, UK. Telephone: (+44) (0)1638 552700; Fax: (+44) (0)1638 555600; email: Jacques.Penderis@aht.org.uk

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From: http://www.cavalierhealth.org/episodic_falling.htm

WOW.....Sure sound like the same symptoms to me....
Jen, Please keep us updated as to what your vet says...Im interested to see if it is the same thing that little Penny has.

Jan, so sorry to hear about little Lester - this must be heartbreaking for you to watch.

It does sound very like Episodic Falling - there is some more information here too:

http://www.cavaliers.co.uk/articles/...%20falling.htm

http://members.lycos.co.uk/tambrocav.../newpage5.html



If they are not too severly affected, they can lead a very good quality of life, so hopefully that will be the case for Lester.

Sending lots of positive, healing thougths for you both, and please keep us posted as to how he is doing.[/url]

Thanks Nicki, I thought you would also have some links. icon_thumbsup

Sounds very much like Penny who has been definately diagnosed with Episodic Falling Syndrome. She has had all the tests you have mentioned, and then some. We started her on Clonazepam last Wednesday. So far, we have not yet gotten the dosage correct, and she is still having attacks, although they are not so frequent (maybe I am just doing some wishful thinking). She is currently getting 1 mg four times aday. Today is her first day on that dosage. According to my vet, we can go up to 9mg per day, so we have a ways to go before we hit the maximum dosage. I know what you are going through, and my prayers and good thoughts are with you. You are in Minnesota. I got my Penny from a breeder in Minnesota. Maybe you could PM me and we could talk. Donna

So happy to see that Karlin and others on these Cavalier sites brought Jen and Donna together on this. I know that if Audrey ( and I hate to say it but when) has problems there are such great folks to come to. Our best of luck for the help you and your sweet babies need right now comes forth.
Many prayers and fond wishes,
Dee and Audrey

That's great that Donna and Jen can be in contact, I know how much it helped me having contact with other Cavalier guardians whose doglets sadly have the same conditions as my two.

Sending healing thoughts and prayers to Penny and Lester.