Myelography for dogs and cats is an image exam and consists of applying a radiographic contrast to the subarachnoid space of the spine - space between two, arachnoid and pia mater, of the three meninges that cover the nervous system. The exam is performed using general anesthesia and the puncture can occur in the cervical segment, most used, and / or lumbar. In summary, it is a radiographic technique that uses iodinated contrast in order to visualize the spinal path of the dog or cat.
THE myelography for dogs and cats much has already been used in veterinary medicine for complementary assessment indicated mainly when there is suspicion of comprehensive spinal cord injuries, which leads to neurological dysfunction, being the herniated disc, which can lead to paresis or paralysis of the thoracic and / or pelvic limbs affected animal, depending on its location.
This exam is considered a great tool to reveal the origin of intradural masses, whether intra or extramedullary. Nowadays, as we can count on the magnetic resonance exams, exam of choice for evaluation of the spine, and myelotomography / computed tomography, exams that provide more information, this exam is in disuse. Despite the risks of puncture and the use of contrast, they are necessary, as it is not possible to visualize the spinal cord on a common radiograph.
Myelography is not indicated in cases in which the animal has an infectious disease, especially when there is an indication of this type of condition by analyzing the spinal brain fluid, due to the risk of spreading the infection through the subarachnoid space.
As for the risks of this image examination, the most common is convulsion, representing 75% of the complication cases, due to the progression of the radiographic contrast to the neurocranium, however the animal may also present vomiting, apnea during puncture, hyperemia (fever) and hyperesthesia.
Read More: Patella dislocation in dogs and cats - Grades I, II, III and IV
How is the exam performed?
Especially used by neurology, myelography requires that the animal be pre-medicated and anesthetized, being placed in the lateral decubitus position - that is, lying on its side - so that the puncture is performed with an appropriate needle. The cerebrospinal fluid is drained first and then the contrast of choice is injected, which allows the visualization of the spinal canal.
Most of the time the puncture is cervical, being performed in the cisterna magna - one of the three openings in the subarachnoid space - and, when necessary, a new puncture is performed in the lumbar region, often between the fifth and sixth lumbar vertebrae (lumbosacral space) . Then, the radiographic study of the place is done.
THE liquor collection it is of great importance to aid the diagnosis of the dog or cat. In many cases, veterinary myelography is not conclusive, but the analysis of CSF in combination can guide or even close the diagnosis.
Generally, the procedure is accompanied by an anesthetist and by the radiologist veterinarian, and although it is not risk-free, it has a very low incidence of complications when performed by judicious professionals.
Before this imaging test is indicated, the veterinarian submits the animal to a thorough neurological examination and other tests are used as the first choice. Myelography is used when plain radiography is not compatible with neurological examination or does not show lesions, in addition to cases where it is necessary to know the exact location of the lesion in order to plan a surgical procedure to be performed by a doctor. veterinary neurologist.