7th July 2006, 12:54 PM
Ozzy's Report from Clare
Clare has kindly sent report to me (sorry it is a bit long).....
I think from the sounds he is sort of going to be okay.... just have to keep an eye on him.
Ozzy was presented with a 1 month history of ear scratching. Mrs Price noticed that Ozzy scratches his ears more than her other CKCS. The scratching is much more apparent in the early morning. There was no history of neck/shoulder scratching or sensitivity to touch(typical for syringomyelia).
Ozzy’s neurological examination was normal
Given the breed I was suspicious that Ozzy had a Chiari malformation (occipital bone hypoplasia) with or without syringomyelia. The clinical sign of rubbing ears (facial) pain is more common with Chiari malformation alone. There is still much about this disorder that we do not understand. Chiari malformation is extremely common in the breed – studies find about 90% affected. However only a proportion have pain directly related to this.
Ozzy had a MRI scan which confirmed the Chiari malformation. In Ozzy’s case I can be more certain thet this could be related to the facial discomfort as there is considerable ventricular discomfort indicating obstruction of CSF flow at the foramen magnum.
There was a little central canal dilation in the C2-C3 region. This is the earliest stage of syringomyelia and in Ozzy’s case I do not think is clinically significant. I think that his pain is explained by the chiari malformation, the interruption to CSF flow and possibly medullary compression resulting in a neuropathic pain syndrome.
MRI of the ears including tympanic bullae was normal.
A routine haematology and biochemistry were obtained to look for any other problems that might preclude certain drug therapy. There are mild nonspecific chances
Total protein * 53 g/L Low (54.0 -77.0 )
Albumin 28 g/L (25.0 -37.0 )
Sodium 146.0 mmol/L (139 -154 )
Potassium 4.8 mmol/L (3.5 -6.0 )
Total calcium 2.69 mmol/L (2.0 -3.0 )
Phosphate * 2.56 mmol/L High (0.8 -1.6 )
Urea 6.5 mmol/L (2.0 -9.0 )
Creatinine 64 umol/L (40.0 -106.0)
Alk Phos * 163 U/L High (0.0 -50.0 )
ALT * 33 U/L High (0.0 -25.0 )
Total bilirubin 5 umol/L (0.0 -20.0 )
Bile acids 3 umol/L (0.1 - 10.0 )
Glucose 3.7 mmol/L (2.0 -5.5 )
Cholesterol 3.8 mmol/L (3.8 -7.0 )
Triglycerides 0.6 mmol/L (0.45 -1.9 )
RBC 5.70 x10^12/L (5.0 -8.5 )
Hb 12.4 g/dl (12.0 -18.0 )
HCT 38.1 % (37.0 -55.0 )
MCV 67.0 fl (60.0 -80.0 )
MCH 21.8 pg (19.0 -26.0 )
MCHC 32.6 g/dl (31.5 -37.0 )
Platelets See haematologist's comment
WBC 7.67 x10^9/L (6.0 -15.0 )
Neutrophils 6.21 x10^9/L (3.0 -11.5 )
Lymphocytes 1.38 x10^9/L (1.0 -4.8 )
Monocytes 0.00 x10^9/L (0.0 -1.3 )
Eosinophils 0.08 x10^9/L (0.0 -1.25 )
Haematologist Comment Scanty polychromatic cells , Crenated cells + , Giant platelets - Actual platelet count appears normal
The phosphate and Alp elevations are likely age related.
Oliver Coldrick BSc BVMS MRCVS TDDS-Cambridge Resident in Clinical Pathology
As you are probably aware Chiari syndrome may be managed medically and/or surgically. In most cases without syringomyelia I use medical management.
My first choice is Frusemide on the basis that this can reduce CSF production/pressure. I have suggested a 2-4week trial of 10mg Frusemide twice daily. If this improves Ozzy’s signs then frusemide may be continued although if used on a long term basis I suggest adding an oral potassium supplement to counteract the increased potassium loss in the urine (e.g. Tumil K extrapolating from the feline dose)
Other possible management
If this is unsuccessful then instance I try NSAIDS such as Rimadyl and Metacam.
For more severe or persistent pain I use Gabapentin (Neurontin dose rate 10-20mg/kg BID/TID). This is an anticonvulsant, which has a neuromodulatory effect on hyperexcitable damaged nervous system.
These are not licenced for dogs as they are “human” drugs. The only side effect I have seen has been sedation at higher dose rates. The smallest capsule size is 100mg.
In cases with inadequate relief of pain from Gabapentin or with significant neurological deficits I use corticosteroids however in these cases surgical management should also be considered. There is also an argument in these cases for repeating the MRI scan on a yearly basis and considering surgery if syringomyelia develops.
The aim of surgery is to restore CSF dynamics. The most common procedure for Chiari like malformation is foramen magnum decompression where the supraoccipital bone and the cranial dorsal laminae of the atlas are removed (with a durotomy and expansion of the dural sac). In my experience surgery is usually successful at significantly reducing the pain and improving the neurological deficits; signs may recur in a proportion of dogs after several months/years.
I would appreciate a progress report on the effectiveness of the frusemide in 2-4 weeks. Please do not hesitate to contact me if you wish to discuss this case in further detail.