Ankara – Vets on the Balkans - an online journal for veterinarians from the Balkans

CHIARI-LIKE MALFORMATION AND SYRINGOMYELIA

January 22, 2016 Leave a Comment

Dr Ates Barut, DVM, PhD

Owner of Small Animal Veterinary Clinic PETCODE

Introduction

We can describe Chiari-like Malformation as an overcrowded and narrow caudal occipital fossa and cervicomedullar junction due to a congenital developmental malformation of caudal occipital bone. Disease is similar to Chiari Type I disease in humans and therefore named as «chiari like malformation» in dogs.

Chiari-like malformation is a hereditary condition and first described in king charles cavalier spaniels and altough several other small breeds can become effected king charles cavaliers are the most common breed effected by the disease.
The other reported breeds are; Griffon, Miniature poodle, Yorkshire terrier, Maltese, Chihuahua, Bichon frise, Staffordshire terrier, Pug, Shih Tzu, Dachsund, Pincher, French bulldog, Jack Russel Terrier, Pekingese and Boston terriers.
Affected patients has a kind of cerebellar compression and narrowing around foramen magnum and cervicomeduller junction.

Patho-physiology

Bony compression, progresive meningeal hypertrophy and dural fibrosis cause; several different neurological dysfunction like cerebellovestibuler disfunction, cervical myelopathy, seizure activity, syringomyelia, ventricle dilatation and hydrocephalus

Although in humans almost all chiari malformation patients has some degree of cerebellar herniation , in dogs cerebellar herniation is not that common and this is the main difference between these 2 species. Caudal occipital malformation syndrome is a genetic deformation of the mesoderm of caudal occipital bone causing cerebellar compression and herniation.
In normal dogs CSF move from cerebral subarachnoid space to cervical spinal subarachnoid space through foramen magnum in every sistom and diastol in a pulsative manner.

Compression and partial obstruction caused by Chiari malformation disturb CSF flow in both ways but because of high systolic pressure push CSF to central canal of cervical spinal cord and produce a cavity with this hammer effect. Valsa maneuras like barking and coughing, make sudden changes in intrathorasic and intraabdominal pressure which cause epidural venous distention and fast fluid acumulation to the cavity. Because of spinal epidural vein distention and compression in cervicomedullar junction syringomyelia cavity continue to enlarge gradually.

Herniated cerebellum increase the amount of obstruction , CSF flow and fluid accumulation. CSF will flow from intrcranial cavities to cervical region easier but can not come back again.

Symptoms and clinical presentation

Presentetion of the disease is different from patient to the other. The first signs can be seen from 5-6 months to 9-10 years.
The disease can cause several different neurological signs.

We can list the possible symptoms as; cervical hyperaesthesia, scratching( air scratchig or phantom scratching)

, facial rubbing, air licking, fly catching, tail chasing, vocalization, pain reaction during atlantoxipital palpation., cervical myelopathy, fore leg paresis characterized by lower motor neurons, multifocal CNS dysfunction, torticollis, scoliosis, seizure activity.
Pain due to or seconder to syringomyelia is a very important symptom and it happens because of the damage on the dorsal horn of spinal cord.

It usually happens Because of the hypersensitivity due to the damage on spinothalamic pathways and/or dorsal horn neurons
Abnormal sensitivity in head, shoulder, neck, axillar and sternal regions is prominent in several patients with syringomyelia but pain severity is not directly correlated with the amount of the fluid inside the spinal cord. Pain is most common in king charles cavaliers and usually more dominant in one side.
Scratching is another very common sign in king charles cavaliers and stress, excitement or a touch to the neck stimulate or increase sctraching. Some dogs has a scratch point and react to a simple touch to this point. The scratching style usually without touching the body is also unique and that is why named as air scratching or phantom scratching.

In some severe cases the patients can have cervical myelopathy, cerebellovestibüler dysfunction and multifocal central nervous system dysfunction. In these cases severe neck pain, strabismus, head tremor and nystagmus can be observed. Loss of muscle tone due to asimetric innervation of paraspinal muscles can cause opusthotonus.

Some patients with chiari-like malformation can have seizures but pathogenesis is not so clear. This rare condition can be related with impaired cerebellar functions because cerebellum has an inhibitoric effect on seizure activity.

The most common neurological and physical examination finding is atlanto-occipital pain and increased sensitivity on pin point palpation on atlanto-occipital joint.

Magnetic resonans imaging is the only way for exact and definitive diagnosis of chiari-like malformation and syringomyelia. T2 and T1 weightened midsagital and transversal images of
the foramen magnum, caudal occipital fossa and cervical spinal cord will show syringomyelia.

We can describe magnetic resonans imaging findings as a narrow subarachnoid space in cervicomedullar junction, occipital bone compression on caudal cerebellum, rostral movement of caudal cerebellum, syringomyelia, cerebellar herniation from foramen magnum and kinked appearance of caudal medulla.

Lateral vetricle dilatation is a very common sign but hydrocephalus is a possible but rare condition.

Treatment

Most of the patients with syringomyelia can spend their whole lives with mild neurological symptoms without any need for medical or surgical treatment. Life quality is the main concern for treatment decision. Patients with obvious neurological signs and pain and non-responsive to pain managment therapies are candidates for surgery. Patients with mild symptoms and pain or non-responsive to pain medication are candidates for medical treatment.

Non-steroidal antinflamatoric medications are not effective against neurologic pain. In severe cases pain can be manage just by some anticonvulsants like gabapentin( 10mg/kg tid) or pregabalin (2-4 mg/kg bid). Last researches showed that omeprazol decrease cerebrospinal fluid production and can be used in some patients but some studies done in rats showed that long term use can cause hypergastrinemia and increase the risk of stomach cancer.

The other medicatios can be used to depress the clinical signs of syringomyelia are; acetozalamide, furosemide, corticosteroids, and phenobarbital. Another promising medication for neurologic pain is palmitoylethanolamide (pea) nad can be effective in several syringomyelia patients.

Surgical treatment is indicated in patients with worsening neurological signs and unresponsive pain. Aim of the surgery is to reorganize cerebrospinal fluid flow pathways and decrease the abnormal CSF in side the central nervous system by decompressing cerebellum. For this aim “Foramen magnum decompression” is indicated by a suboccipital craniectomy and partial dorsal laminectomy of first cervical vertebra that enlarge foramen magnum .

Foramen magnum decompression window limits and borders are so important. A small window will be effectless and a large window can cause atlanto-occipital instability or excessive bleeding in a very sensitive area which can cause life treating situations. Lateral borders of the window are atlantooccipital joints and lateral vertebral foramens of atlas , rostral borders are midpoint of the distance between protuberentia occipitalis and dorsal border of foramen magnum, caudal border is ¾ of atlas. Durotomy and marsupilization of dura to the muscular structures around the foramen magnum window is the common procedure but cerebrospinal fluid leakage can cause an inflamation and this inflamation can lead severe soft tissue thickening which can cause compression in the area. Altough durameter is firmly attached to the bony structures in atlantoaccipital region carefull dissection can be done without duratomy to prevent csf leakage.

Foramen magnum decompression will reorganize cerebrospinal fluid flow but the present fluid and the syringomyelia cavity will remain which means the present symptoms will continue most of the time. Foramen magnum decompression is most effective against pain which is the most common indication of surgical treatment.

To drain the present syrinx in syringomyelia cavity “syringosubarachnoid shunt application” is the most effective and popular method. Approach to spinal cord with a dorsal laminectomy where the syrinx cavity is most prominent has to be done first. After a “T” shaped duratomy placement of a shunt in 1-1.2mm thickness from syrinx cavity to subarachnoid space has to be performed to complete the procedure.

Discussion

As a result chiari-like malformation and syringomyelia is one of the most important breed predispositions of veterinary medicine and although the disease is reported in several other breeds it creates a very important clinical problem among king charles cavalier population. Most of the patients with syringomyelia can live whole their lives with very mild symptoms within a normal life expectancies but some patients will have cervical myelopathy, cerebellovestibüler dysfunction and multifocal central nervous system dysfunction. Pain and life quality is the main concern and criteria for treatment. Patients with obvious neurological signs and pain and non-responsive to pain managment therapies are candidates for surgery. Foramen magnum decompression and syringo-subarachnoid shunt application are the two surgical procedures described to reorganize normal cerebrospinal fluid flow and drain syrinx from its cavity.

PETCODE Veterinary Hospital on the Balkans….. is it real?

January 15, 2016 Leave a Comment

PETCODE ANIMAL HOSPITAL; where our dreams came true

Just before starting to make our new animal hospital I asked my collegues to write me about their dreams. I was not wondering what we can do, I was wondering about a small animal practioner’s dreams . It is not easy to understand the meaning of these dreams for a vet working in Germany, Holland or England but I am sure you can understand how important this is for us. In countries like Turkey or in Balkans, there is always some thing is absent while we are practicing. I asked the same question to some of my patient owners. I was sure that as the people who love their pets they would also have dreams about a perfect hospital. I knew that it was impossible to make a perfect hospital but I believed that all these dreams will guide us to create a close one.

After I collected all these notes from my friends I read them may be a hundred times. I saw that some of my friends was dreaming about wider and bigger spaces to practice, some of them was dreaming about high technologies like MRI and CT, some about a better laboratory and etc. The list was so long but we did our best to make them true one by one. Of course we could not manage to make them all but we are still on work and continue .That is why I am not calling PetCode as “the perfect animal hospital” I am calling us as “The hospital where the dreams come true.”

Now I will try to tell you about Petcode, the sum of our dreams.

Our Petcode Animal Hospital is serving in a 1400 square meter building and it is physically the biggest animal hospital in Turkey. We are using 2 different entrance and 3 separate parts in Petcode. In polyclinics section you can find our account office, secretary and information desk, pharmacy, a wide waiting room with different waiting areas for dog and cat owners, two examination rooms for dogs and two examination rooms for cats, physical therapy and rehabilitation service with a hydrotherapy pool, hemodialysis unit, pet coiffeur and meeting room. In hospital section we have emergency entrance, emercency waiting and examination room, computered radiography, colored doppler ultrasonography, electrocardiography and office rooms, hospitalization section, central examination room for hospitalized patients, reanimation rooms, oral health and dentistry unit, surgery preperation room, half sterile room and full sterile operation room. You can enter our hospital’s third section with our elevator and here you can find computered tomography, restaurant and, changing rooms for our staff, laudry and storage.

In PetCode Animal Hospital we believe that “ Cats are not small dogs ” and with this policy we divided our wide waiting room to 2 parts, one is for dog owners and the other is for cat owners. There are 4 routine examination rooms in our hospital and 2 of them is for cats and 2 for dogs. Dogs are never alouded to enter cat examination rooms just to reduce the stress of cats. We have special hiding places in our cat examination rooms so when they jump and escape from the examination table we never try to catch them because we already know where they will enter.

“Physical Therapy and Rehabilitation”(FTR) is one of the most popular branches in veterinary medicine all over the world. The high percentage of geriatric animals among the pet population,and the important tendency of dogs and cats to obesity is increasing the risk of osteoarthritis. Osteoarthritis creates the main need for physical therapy and rehabilitation in most cases. The increasing number of advanced surgeries we are performing is also increasing the demand of patient owners for a better and faster recovery period. So physical therapy and rehabilitation is becoming more and more popular every year and of course we made a big investment for FTR in PetCode. Our hospital has a hydrotherapy pool supported with a lifting crane for paraplegic animals. We have a gait analysis system which shows given weight to each extremity quantitatively . Our treadmil, electrotherapy, therapeutic ultrasound, laser therapy and laser acupunture systems are the other feautures of Petcode FTR service.

Petcode Hemodialysis Service is the only hemodialysis chance for dogs in Turkey so patients with kidney failure and differenttoxications are coming to us everywhere from Turkey. Of course keeping a chronic renal failure patient alive just with hemodialysis is so expensive and not efficient and logical most of the time but we are mostly helping acute renal failure patients successfuly. Our hemodialysis machine is just suitable for patients over 15kg and we are performing peritoneal dialysis for our smaller dogs and cats.

According to American Animal Hospital Association veterinary dentistry creates the biggest income for every small animal practice in USA and in Petcode we made a serious investment for veterinary dentistry. We are not only performing tartar cleaning and teeth extractions we are also using intraoral cameras, taking x-rays, performing fillings, coverings and implants.

In PetCode we are closing our polyclinic section everyday at 20.00 but emergency entrance is open for the rest of the night with an on duty veterinarian and a veterinary technician. When we had a surgical emergency we always call all our surgical team and perform the surgery.

During day time all our staff pass the hospital section door with a card reader. Our patient owners are not alouded to enter to the hospital section by themselves and even for visiting for their patiens we always guide them. They can pass to hospital section just with special plastic overshoeses, galoshes.

Because of our huge street animal population Turkey is a heaven for all kinds of infection diseases and in PetCode we are fighting with hospital infections seriously. We are using hepafilters in all risky points, all our cages are made from chrome-nickel steel for better disinfection, and they all have full glass doors to prevent the spread of infections via splashig, coughing, sneezing. We keep patients with infectious diseases in an isolated room. We are always trying to obey high standart disinfection and sterilization rules everywhere in the hospital.

Oxygen is life and in PetCode we produce our own oxygen with a very special system and we safely use this oxygen in our anesthesia machine, intensive care units and everywhere in our hospitalization section.

Our hospitalization service has 4 sections. We keep our patients with all kinds of infectious diseases in our infectious disease room. Our staff enter this room with special outwear. There is a special antibacterial plastic curtain in the entrance of this room which keep the infections inside and we are using special hepafilters for the ventilation so that possible infections are not entering to the general ventilation system of the hospital. When we have patients that we are not sure about their health and vaccination status we keep them in cages in our quarantinedepartment until we feel sure that they do not carry any kind of infectious disease to our other visitors. In our regular hospitalization section we have 2 parts and of course one is for dogs and the other one is for cats. All these parts are openning to a central examination room and we carry our patients here for their regular applications.

In PetCode we are able to perform almost all kind of surgeries. We are doing a lot of brain and spinal surgeries,total hip replacements, tuberositas tibia advancements, tuberositas tibia transpozitions, eksteranl fixators, vertebral stabilisations, ventriculoperitoneal and syringosubarachnoid shunts, different types of reconstructive and oncological surgeries, and eye surgeries including phacoemulsifications. All these advanced surgical procedures give us a big responsibility as well.

. If you are planning to perform that sort of sophisticated and advanced surgical procedures , of course just good surgical skills are not enough for these plans. You need experience, a good team, perfect medical equipment and a very sterile surgical room.

That is why Petcode brought “Full sterile operation room term” to Turkey. We enter to our operation room through a half sterile room always with head caps and masks. Floor surface of our operation room is made from esd conductive, antistatic and antibacterial material. Our walls are covered with chrome- nickel steel because bacterial contamination of this material is diffucult and disinfection is always easy. Ventilation of this room is special because air is entering to the room through hepafilters and a system always aspirates the dirty air inside the room again through hepafilters so there is always positive pressure inside the room and air entrance is limited even we are openning our doors during enterance. Our surgical room is also full of state of art medical equipments that allow us to perform all kind of surgeries.

Petcode is the one and only private animal hospital that has its own computered tomography machine in Turkey. With the help of our three dimentional reconstruction programmes we use, we are able to obtain very high qualified images almost compatible with high field magnetic resonans images so we can diagnose several neurological and oncological problems easily.

As you can see, PetCode Animal Hospital is the biggest investment done for small animal practice in Turkey but we are still dreaming about a perfect animal hospital with our lives coded to animal love,and veterinary medicine.