Minutes from neurologists' roundtable, London CKCS SM Conference, Nov 2006

The neurologists who attended the November 2006 SM conference in London have issued these minutes to outline the agreements they came to and the directions in which they believe further research should go. They also agreed upon and issued these revised breeding recommendations in February 2007.

You can download these minutes here.
You can download the pain scale here.
You can download the revised breeding and scoring guidelines here.

International Conference on Syringomyelia
Saturday 11th November 2006 – Royal Veterinary College, London. UK.

Report from the CM/SM Working Group Round table
Organiser – Rodolfo Cappello
Chairman Round Table– Clare Rusbridge

This meeting was hosted by the Cavalier Club UK and sponsored by Boehringer Ingelheim Ltd and enabled veterinarians with an interest in syringomyelia to share views and ideas on this poorly understood disease. In addition to inviting veterinarians from Europe, Canada and the USA, the Cavalier Club UK also included breed club representatives from across the UK with the aim of disseminating information about this disease to the wider breeder and dog owning population.

The round table meeting took place after very interesting and stimulating oral presentations covering a wide range of subjects including pathogenesis of syringomyelia associated pain, surgical management, MRI studies, new technological advances, experiences from France and update on progress of the CKCS genome scan.

Members present
Rodolfo Cappello (Royal Veterinary College), Clare Rusbridge (Stone Lion
Veterinary Centre), Harvey Carruthers (Stone Lion Veterinary Centre), Laurent
Cauzinille (Centre Hôspitalier Vétérinaire Fregis), Nick Jeffery (Cambridge
Veterinary School), Catherine Louglin (Long Island Veterinary Specialists), Dominic
Marino (Long Island Veterinary Specialists), James Anderson (Glasgow Veterinary
School) Martin Deutschland (Chestergates Referral), Imelda McGonnell (Royal
Veterinary College) and Steven Dean (Dogs World Magazine)

The meeting was conducted in the presence of representatives from the UK CKCS
club; the UK Kennel Club (Jeff Sampson) and UK, Eire, French and North American
CKCS dog owners.

The Round table meeting had, and achieved, the following objectives

1) Agreement for a name for the canine disorder
The participants recognised that there are uncertainties about the correct terminology
to use. The pros and cons of the terms syringomyelia, syringohydromyelia, hindbrain
herniation/ descent, Chiari malformation, occipital hypoplasia and caudal occipital
malformation syndrome were discussed and the main points for and against each term
are summarised.

Syringomyelia -- generally this term is accepted however it was rejected as a name for
the condition that predominantly occurs in Cavalier King Charles spaniels and other
small breeds because there are many potential causes of syringomyelia.
Hindbrain herniation / descent – this term was rejected because hindbrain is an
embryological term and does not describe the adult anatomy. Equally, the cerebellum
is only a component of the hindbrain.

Chiari malformation – There was general resistance to use this term because it uses
the name of the first scientist that described the disease. However in humans this term
no longer reflects the original description of the disease but any condition
characterised by reduced posterior fossa volume and caudal descent of the brain stem
and cerebellum. It was pointed out that although there is general resistance to the use
of “proper nouns” to describe diseases in veterinary medicine it is not without
precedent especially where the name is a simple term used to describe a complicated
process e.g. “Wallerian degeneration”.

Occipital hypoplasia and Caudal occipital Malformation Syndrome (COMS) -
These terms were rejected because there is no proof yet that the condition is related to
either a malformed or hypoplastic occipital bone(s). Current evidence suggests that
there may be other significant factors in the pathogenesis. In addition these terms can
be confusing as for example the term COMS may imply the malformation only or the
malformation and syringomyelia.

The majority vote was for the term Chiari-like malformation and syringomyelia
(CM/SM) to be adopted (at the current time). This term was perceived to have the
following advantages.

1. Chiari malformation is accepted for the description of the disease in the human
species and is the most commonly used term in scientific publications.
2. Chiari-like malformation refers to the complex syndrome seen in the human
species however the “like” implies some differences in the canine.
3. The term can be easily abbreviated to CM/SM– having a simple acronym is
especially important to dog breeders and owners.
4. The term Chiari-like malformation (CM) can be used to distinguish dogs that
do not have syringomyelia

Chiari-like malformation (CM) is currently defined as decreased caudal fossa
volume with caudal descent of the cerebellum, and often the brainstem, into or though
the foramen magnum.

Syringomyelia (SM) is currently defined as a condition that results in the
development of fluid-containing cavities within the parenchyma of the spinal cord as
a consequence of abnormal cerebrospinal fluid movement.

2) At the request of the UK CKCS club formulate and agree on breeding guidelines
for CM/SM.

Clare Rusbridge presented the very early but promising results of the breeding
program in the Netherlands. It was suggested that before genetic studies are
completed that “commonsense” strategies aiming to limit possible widespread
dissemination of the disease be implemented. The main aim was to limit early onset
and potentially painful SM and to avoid using such dogs in a breeding program. The
current breeding guidelines were discussed and were simplified and modified
(See Breeding Advice) The presence or absence of the Chiari-like malformation (CM) was
dropped from breeding guidelines because of 1) of the ubiquity of this malformation
within the CKCS population 2) Lack of uniformity between veterinarians at
recognising and consistently grading the severity of CM 3) the lack of evidence that
apparent severity of CM was related to severity of syringomyelia. It was agreed that
MRI screening of subsequent generations should be continued so that these early
breeding guidelines could be adapted as more information on the hereditability
becomes available.

3) Formulate and agree on a pain scoring system that could be used in prospective

Future prospective studies require uniformity in grading the severity of the clinical
signs. An existing pilot system was adapted (download it here).

4) Implement protocols for dealing with pathological material.
One of the recurring themes during the oral session was that the pathogenesis of
CM/SM is not understood and to improve understanding of the disease there is a need
for post mortem studies at different stages of the disease and ages of dog. All cavalier
King Charles spaniels that die for related or unrelated causes would be valuable and
the following centres are willing to participate in this program. Breeders and owners
willing to donate their pet for this purpose should contact:

• Professor Nick Jeffrey, Department of Veterinary Medicine, University of
Cambridge, Madingley Road, Cambridge, CB3 OES tel 01223 337621
• Dr Jim Anderson, Glasgow University Gvsa07@udcf.gla.ac.uk
• Dr Rodolfo Cappello The Royal Veterinary College, University of London
• Dr Curtis Dewey, Cornell University, Phone: (607) 253-4445

Fetal and neonatal specimens
Another area of great interest is developmental studies looking at anomalies in
different stages from the early growth in the uterus to the maturity of the dog.
These studies would be also useful to confirm or characterize the genetic defect
for CM/SM. This area of research is difficult because of a requirement for
foetuses and young puppies therefore a request was also made for any aborted
foetus or puppies that die for related or unrelated disease. Any dog owner or
veterinarian with such material should contact Dr Imelda McGonnell (Dept.
Veterinary Basic Sciences, Royal Veterinary College, Royal College St, London,
NW1 0TU). Tel 020 7468 1223 Imcgonnell@RVC.AC.UK

NOTE - As the nervous system degenerates rapidly and must be handled
appropriately contact with these centres should be made as soon as or ideally before
the pet has been euthanatized.