The brain and the spinal cord both are surrounded by a special fluid called cerebrospinal fluid (CSF). It serves many functions for the brain and spinal cord. It provides insulation, nutrition, lubrication and waste removal. The spinal cord and brain are always happily "swimming" in a sea of CSF.
Inside the brain are ventricles. This is where the CSF is made. The CSF is made in the ventricles and then passes down the spinal canal and it is eventually absorbed by the blood. There is a continuous cycle of CSF production and CSF absorption.
What is syringomyelia?
Syringomyelia is also called Chiari like malformation, caudal occipital malformation syndrome or occipital dysplasia.
There are many causes of this syndrome including malformation, tumour and trauma. By far the main cause is congenital malformation.They all result in the same defect. The normal flow of CSF is changed. This abnormal CSF flow leads to cavities of fluids forming in the spinal cord. This progresses to swelling and then pain.
The main sign of Syringomyelia is pain in the neck but it has a few other characteristic signs.
Which dogs are affected?
Any breed can be affected but the vast majority of cases are seen in Cavalier King Charles Spaniels.
What is the process that is happening in Syringomyelia?
The driver of the pumping of the CSF from the brain through the spinal cord is the heartbeat and the pulse. Every heartbeat starts a pressure wave that moves the CSF gradually along the spinal cord. In a healthy dog this results in even CSF pressure throughout the brain and spinal cord.
When there is a malformation ,often at the top of the neck , a bottleneck is formed and there is a local increase in pressure. The pressure becomes so great that CSF is pumped into the spinal cord (the spinal cord should not take on CSF - remember it is normally swimming in the CSF). This results in cysts forming in the spinal cord. A vicious circle is then started. As the cysts form this causes more blockage and further build up of CSF pressure. This process is what unfortunately makes this usually a progressive disease.
What are the signs of Syringomyelia
As mentioned neck pain may be a telltale sign of syringomyelia.
A very common sign is scratching at one side of the face or neck. People who have syringomyelia get neck pain, headaches, back pain, face pain. So we have to assume this is likely for our canine friends also.
How is Syringomyelia diagnosed.
The only way this disease can be diagnosed is with MRI.
Important to Identify Primary Secretory Otitis Medi (PSOM)
PSOM is a disease which can is inherited in Cavalier King Charles which can exhibit signs similar to syringomyelia including neck scratching and head shaking. It is a condition where thick mucus accumulates in the middle ear. Surgery can alleviate the problem - although it cannot cure it.
For this reason an MRI should be considered to differenciate POSM and Syringomyelia.
How can Syringomyelia be treated?
Surgery can be helpful in some dogs but success rates would have to be considered moderate at best.
Some conventional medications can be helpful for these dogs. These include cortisone and gabapentin.
Conservative options have shown promise. These include using a supplement called Palmitoylethanolamide which has shown benefit in dogs in a small pilot trial.
Alleviation of signs can also be acheived using manual therapies. There are no studies to date but personal experience and personal communications with other Animal Biomechanical Practitioners suggests benefits can be achieved using this modality.