Progressive hemorrhagic myelomalacia (PHM) is a rare and fatal disorder which is characterized by acute and progressive ischemic necrosis of the parenchyma of the spinal cord, leading to its liquefaction. It may occur after intervertebral disc extrusion, spinal trauma or fibrocartilaginous embolism. The aim of this study was to evaluate cases of progressive hemorrhagic myelomalacia in dogs in the Veterinary Hospital of Universidade Estadual de Londrina between 2000 and 2011, through the analysis of medical records and following of cases. There were certain criteria to include a patient in this study, such a history of paraplegia with upper motor neuron signs, worse of signs progressing to flaccid tetraplegia, progressive clinical changes and/or changes in complementary exams. There were analyzed several aspects, such as epidemiological (breed, age and sex), clinical (progress of clinical and neurological signs), laboratory (cerebrospinal fluid analysis - CSF), radiographic (conventional radiography and contrasted) and elapsed time since the onset of clinical signs until death or euthanasia. The most affected breed was Teckel (43%), the average age was 5.04 years and the neurological syndrome observed initially was the thoracolumbar syndrome grade V. Another commons signs observed were hyperpathia and cranial progression of decreased cutaneous trunci reflex. In seven dogs the cause of the PHM was the thoracolumbar intervertebral disc disease, in a dog the cause was spinal cord trauma, in two dogs PHM was due to lymphoma and in four dogs the likely cause was intervertebral disc disease. CSF analysis, myelography changes and progress of clinical and neurological examinations were extremely important to diagnose PHM. Six animals progressed to tetraplegia and four dogs had already flaccid tetraplegia at the initial care. In four other patients, the identification of signs suggestive of PHM before this progression has led to indication for euthanasia. The prognosis is poor and causes animal suffering, so the clinician should be aware of the history of paraplegia with subsequent change of upper motor neuron syndrome to lower motor neuron, cranial decreased reflex panniculus and presence of abdominal breathing. Some alterations in complementary exams found in this study may also help in early diagnosis, as xanthochromic CSF with increased protein, erythrocytes and pleocytosis. Spinal cord edema and the presence of contrast within the nervous tissue together with clinical signs and CSF alterations are suggestive of PHM.
Spinal cord; nervous system; myelomalacia; dogs
