Fecal incontinence associated with epidural spinal hematoma and intervertebral disk extrusion in a dog

CASE DESCRIPTION: A 7-year-old castrated male Great Dane was evaluated because of a 2-month history of fecal incontinence. CLINICAL FINDINGS: On the basis of the presence of paraparesis and apparently normal spinal reflexes, the neurologic signs were localized in the region of the third thoracic to the third lumbar spinal cord segments. On the basis of the findings of magnetic resonance imaging, a presumptive diagnosis of a compressive intervertebral disk extrusion with secondary hemorrhage and epidural hematoma formation was made. TREATMENT AND OUTCOME: A right-sided hemil-aminectomy was performed (centered at the T13-L1 intervertebral space) to further characterize the lesion and decompress the spinal cord. The histopathologic diagnosis was extruded intervertebral disk material with chronic hemorrhage and inflammation. Three weeks after surgery, there was complete resolution of the dog's fecal incontinence and moderate improvements in its hind limb function. CLINICAL RELEVANCE: Thoracolumbar spinal cord injuries can result in upper motor neuron fecal incontinence in ambulatory dogs. Epidural spinal hematomas may develop secondary to intervertebral disk herniations and cause spinal cord compression resulting in neurologic deficits.     

Eosinophilic meningomyelitis associated with T‐cell lymphoma in a cat

A 12‐year‐old cat was presented for evaluation of progressive tetraparesis. Magnetic resonance imaging of the cervical spine demonstrated T2‐hyperintensity, and contrast enhancement within the C4–C7 spinal cord, with marked meningeal contrast enhancement and segmental nerve root thickening. Lumbar cerebrospinal fluid contained 407 total nucleated cells/μL, with 99% eosinophils. The cat transiently improved with prednisolone, clindamycin, and ivermectin therapy, but subsequently worsened and was euthanized. Necropsy revealed an asymmetric infiltration predominantly of the white matter, meninges, and nerve roots of the C4–C6 spinal cord segments by an unencapsulated, poorly demarcated neoplasm composed of atypical lymphocytes admixed with eosinophils, causing perivascular hemorrhage and lytic necrosis. The neoplastic cells were immunoreactive for CD3, ultimately confirming T‐cell lymphoma.     

Postanesthetic hemorrhagic myelopathy in a horse

Acute hemorrhagic myelopathy developed in the sixth cervical to the eighth thoracic spinal cord segments of a 1-year-old Quarter Horse colt that was castrated under general anesthesia while in dorsal recumbency. Clinical signs were consistent with severe transverse myelopathy caudal to the brachial enlargement and cranial to the lumbosacral enlargement of the spinal cord. Histologic examination of the spinal cord revealed hemorrhage in the gray matter, with multiple blood-filled clefts in otherwise normal neuropil. Hemodynamic changes in the spinal cord associated with anesthesia and dorsal recumbency may have led to hypoxic vessel damage, with massive hemorrhage after surgery, when the horse was returned to lateral recumbency. Postanesthetic hemorrhagic myelopathy is a possible complication of positioning in dorsal recumbency, during anesthesia, in rapidly growing, young horses.     

Hypotensive infarction of the spinal cord in a rhesus macaque (Macaca mulatta)

A 6.5-year-old male rhesus macaque (Macaca mulatta) was presented with acute paraplegia following a surgical procedure. During surgery, he experienced an acute hypotensive episode that required 3 hours of supportive therapy before hemodynamic stability was restored. Paraplegia remained unchanged until euthanasia 72 hours later. At necropsy, spinal cord segments T10-S3 had acute, massive panmedullary necrosis, which involved most of the central and middle spinal cord, sparing the peripheral white matter. Additional lesions included arterial border zone necrosis of the brain, centrilobular hepatic necrosis, and proximal renal tubular necrosis. The histologic findings of central spinal cord necrosis with a preserved rim of white matter is consistent with severely decreased flow in the anterior spinal artery. Such lesions can result from episodes of generalized hypoperfusion. Possible factors contributing to the hypotensive episode in this case included the addition of xylazine to ketamine and atropine in the preanesthetic medication, positioning during anesthesia, and decreased blood pressure during surgery.     

Proliferative potential of a spinal nephroblastoma in a young dog

The proliferative potential of a spinal nephroblastoma was studied in a young dog. A 4-month-old, female golden retriever showed developing deterioration in her gait and subsequent paralysis of her hind legs. At necropsy, a well-demarcated grayish brown tumor mass was found in the lumbar spinal cord segments between L2 and L3. Histologically, a blastemal cell tumor with a tubule- or glomeruli-like structure was found to be infiltrating intradurally. Proliferating cells at the S-phase, assessed using the bromodeoxyuridine (BrdU) labeling method, were seen occasionally in the tubular cells and glomeruli-like structures and were frequently seen in the blastemal cells. Immunohistochemically, the tubular epithelial cells were positive for cytokeratin, and the blastemal cells were positive for vimentin. The present tumor showed a high potential for growth and invasion, which suggests that it the potential to expand into the adjacent spinal cord.     

Intraspinal epidermoid cyst in a dog

A 2-year-old female Rottweiler was examined because of progressive gait deficits consistent with transverse myelopathy between the T2 and L3 spinal cord segments. Myelography confirmed an intramedullary spinal cord lesion between T13 and L1, so the dog was euthanatized. At necropsy, an intramedullary epidermoid cyst was confirmed in the T13 and L1 spinal cord segments. The epidermoid cyst probably resulted from a congenital cause.     

Poliomyelomalacia, pancreatic necrosis, and cerebellar malacia in turkey poults

Two-to-5-week-old turkey poults from three large Minnesota flocks exhibited ataxia, flaccid paralysis, and up to 5% mortality as unexpected death. The major post-mortem finding was cerebellar hemorrhage and softening detected in 22 of 89 clinically affected poults. Histologic findings were severe focal or multifocal poliomyelomalacia in the lumbosacral intumescentia of the spinal cord, cerebellar malacia, and single-cell or multifocal coagulative necrosis of pancreatic acinar cells. Thirty of 32 clinically affected poults examined had microscopic spinal cord lesions, 12 of 48 had cerebellar lesions, and 26 of 47 had pancreatic lesions. Gross and microscopic cerebellar lesions resembled those of vitamin E deficiency in chicks. Hepatic selenium levels were approximately twice normal expected levels for poults.     

Vascular malformations and hemangiomas of the canine spinal cord.

An arteriovenous malformation and two hemangiomas in the canine spinal cord were found in three dogs. The malformation was ventral, extramedullary and largely subdural. Chronic hypoxia, consequent upon the shunt, had led to extensive local edema, necrosis and hemorrhage at T13-L1. Prominent intramedullary perivascular fibrosis, mineralization and obliteration were the presumed consequences of the hemodynamic insult. The hemangiomas, one of which was multiple, were deep lesions that produced compressive changes in the adjacent cord tissue. The masses were regarded as benign neoplasms with central sclerosis. These conditions appear not to have been reported previously in the dog.     

Compressive myelopathy associated with ectasia of the vertebral and spinal arteries in a dog

A 4-year-old dog was presented for acute, progressive tetraparesis and cervical hyperesthesia. Symmetrical tubular structures coursing along the lateroventral aspects of the spinal cord at the fourth and fifth cervical vertebrae were identified in magnetic resonance images. At necropsy, vertebral arteries and their spinal branches were severely ectatic bilaterally, and the cervical spinal cord was compressed. Histologically, the ectatic branches of the vertebral and ventral spinal arteries were surrounded by fibrosis with scant mononuclear cell infiltrates and hemorrhage. Spinal branches of the vertebral arteries had focally severe reduction in the tunica media. A thrombus was in an arterial branch. Smaller vessels in adjacent tissue had fibrinoid degeneration. Axonal degeneration was detected in the affected spinal cord and nerve roots. The segmental degenerative radiculomyelopathy in this dog was attributed to anomalous ectasia of the vertebral and ventral spinal arteries.     

狗肾上腺交感节前神经元在脊髓内的定位及节段性分布──HBP法

用ＨＲＰ技术对８只狗肾上腺交感节前神经元位置及节段性分布进行了研究。将ＣＢ－ＨＲＰ注入一侧肾上腺，标记的交感节前神经元胞体分布于注射侧脊髓Ｔ３－Ｌ３节段，高峰在Ｔ６－Ｔ９，占标记细胞总数５８．７４％。标记细胞主要位于注射侧脊髓中间外侧核主部（ＩＬｐ，９０．８２％），其次是中介核（ＩＣ，６．２８％）、中间外侧核索部（ＩＬｆ，２．０３％）、中介核室管膜旁部（ＩＣｐｅ，０．８７％）；以卵圆形、梭形、多边形的中小型细胞为主，平均直径为２３μｍ。标记细胞树突野广阔，横向伸廷于同侧侧索、中间带区，还有少数至中央管室管膜层或沿灰质背联合伸至对侧中间带区。     

Gliomatosis cerebri in two dogs

A 3.5 yr old Saint Bernard was evaluated for nonambulatory tetraparesis and cranial nerve dysfunction, and a 7 yr old rottweiler was evaluated for progressive paraparesis. Clinical signs of left-sided vestibular and general proprioceptive ataxia and cranial nerve VII dysfunction in the Saint Bernard suggested a lesion affecting the brain stem. Signs in the rottweiler consisted of general proprioceptive/upper motor neuron paraparesis, suggesting a lesion involving the third thoracic (T3) to third lumbar (L3) spinal cord segments. MRI was normal in the Saint Bernard, but an intra-axial lesion involving the T13-L2 spinal cord segments was observed in the rottweiler. In both dogs, the central nervous system (CNS) contained neoplastic cells with features consistent with gliomatosis cerebri (GC). In the Saint Bernard, neoplastic cells were present in the medulla oblongata and cranial cervical spinal cord. In the rottweiler, neoplastic cells were only present in the spinal cord. Immunohistochemistry disclosed two distinct patterns of CD18, nestin, and vimentin staining. GC is a rarely reported tumor of the CNS. Although GC typically involves the cerebrum, clinical signs in these two dogs reflected caudal brainstem and spinal cord involvement.     

Anatomical Studies on the Spinal Cord Segments of the Impala

The anatomy of the spinal cord segments was studied and recorded for the impala. The root attachment lengths were greatest at C₃, T₁₀ and L₃ cord segment levels in the respective regions. As to the root emergence length the greatest lengths were observed at C7, T_]0> L5 and S₁ cord segment levels respectively. The interroot interval was longest at C₂, T₈ and L₁ segments respectively. The longest cord segments were C2, T13, L₂ and S₂ segments. The widest cord segments of their respective regions were C₇, T₁, L5 and S₁ cord segments. As to segment volume C3, T₁₃, L₂ and S₁ were the most voluminous cord segments in the respective cord regions. Statistical analysis revealed a high correlation among all of the study parameters suggesting a high degree of multicolinearity. Gross anatomical relationships concerning the location of the spinal cord segments with respect to the vertebrae were studied. The cord segments C], T_s–T₄ and Li–L₃ were within their vertebral limits. In the impala the spinal cord terminated at the midlevel of S₄ vertebra.     

THE COMPUTED TOMOGRAPHIC APPEARANCE OF ACUTE THORACOLUMBAR INTERVERTEBRAL DISC HERNIATIONS IN DOGS

The appearance of herniated intervertebral disc material in the thoracolumbar vertebral canal was evaluated in 23 dogs using computed tomography (CT). The images were then compared with the myelographic and surgical findings. The normal spinal cord, outlined by epidural fat over intervertebral disc spaces, was of intermediate attenuation on transverse CT images. Herniated disc material was identified in all animals as a heterogeneous hyperattenuating extradural mass. The attenuation of the disc material increased with the degree of mineralization. In seven dogs, the herniated material was only slightly more attenuating than the spinal cord. In these dogs, small fragments of mineralized disc material and significant hemorrhage were found in the epidural space at surgery. In dogs with a long standing history of disc herniations, disc material identified in the vertebral canal had a more hyperattenuating and homogeneous appearance than recently herniated disc material. We conclude that mineralized, herniated disc material and hemorrhage can be identified quickly and safely in dogs using CT.     

A retrospective study of spinal cord lesions in goats submitted to 3 veterinary diagnostic laboratories

A retrospective study of spinal cord lesions in goats was conducted to identify the range of lesions and diseases recognized and to make recommendations regarding the best tissues to examine and tests to conduct in order to maximize the likelihood of arriving at a definitive etiologic diagnosis in goats with clinical signs referable to the spinal cord. Twenty-seven goats with a spinal cord lesion were identified. The most common lesion recognized, in 13 of 27 goats, was degenerative myelopathy. Eight goats with degenerative myelopathy were diagnosed with copper deficiency. Non-suppurative inflammation due to caprine arthritis encephalitis virus, necrosis due to parasite larvae migration, and neoplasia were each diagnosed 3 times. Based on these findings, it is recommended that, in addition to careful handling and histologic examination of the spinal cord, samples of other tissues, including the brain, liver, and serum, be collected for ancillary testing if warranted.     

Intramedullary cavernous malformation of the spinal cord in two dogs

Intramedullary cavernous malformations (CVMs) of the spinal cord were diagnosed in 2 adult dogs that presented for paraparesis. An intramedullary spinal cord lesion was identified on a myelogram in the first dog, and expansion of the vertebral canal was evident on radiographs in the second. Extensive intraparenchymal hemorrhage was found on gross postmortem examination in both dogs, and a distinct lobulated intramedullary mass was evident in the second dog. Microscopically, both lesions were composed of dilated, thin-walled vascular channels with little-to-no intervening neural parenchyma. Both dogs had evidence of channel thrombosis along with perilesional hemorrhage and hemosiderin accumulation. The second dog had additional degenerative changes, including thickened fibrous channel walls with hyalinization, foci of mineralization, and occasional tongues of entrapped gliotic neuropil. CVMs appear to be an uncommon cause of both acute and chronic spinal cord disease in the dog.     

Possible intraspinal metastasis of a canine spinal cord nephroblastoma

A 2-year-old Basset Hound was admitted to the University of Florida Veterinary Medical Teaching Hospital with progressive spastic paraparesis. At necropsy, intradural extramedullary tumors produced areas of spinal cord swelling and softening in spinal cord segments T11-T12 and L4-L6. Histologic examination of the masses revealed sheets of polygonal blastemal cells, epithelial cells forming tubules and rosettes, and embryonal glomeruloid-like structures in the thoracic mass. Cells in the lumbar mass were less differentiated, forming rare tubules and no glomeruloid-like structures. The occurrence of two tumors in the spinal cord along with the less differentiated appearance of the lumbar tumor raises the possibility that the lumbar mass arose as a result of intraspinal metastasis. To our knowledge, this is the first report of multifocal or metastatic canine spinal nephroblastoma. In addition, the vimentin and cytokeratin immunohistochemical staining characteristics of these spinal cord nephroblastomas are described.     

Continuous lumbar hemilaminectomy for intervertebral disc disease in an Amur tiger (Panthera tigris altaica)

A 13-yr-old Amur tiger (Panthera tigris altaica) was presented for an acute onset of paraplegia. Spinal imaging that included plain radiographs, myelography, and computed tomography performed under general anesthesia revealed lateralized spinal cord compression at the intervertebral disc space L4-5 caused by intervertebral disc extrusion. This extrusion was accompanied by an extensive epidural hemorrhage from L3 to L6. Therefore, a continuous hemilaminectomy from L3 to L6 was performed, resulting in complete decompression of the spinal cord. The tiger was ambulatory again 10 days after the surgery. This case suggests that the potential benefit of complete spinal cord decompression may outweigh the risk of causing clinically significant spinal instability after extensive decompression.     

Fibrocartilaginous emboli in a tayra (Eira barbara): a case report.

An 8-yr-old male tayra (Eira barbara) was presented with acute onset of pelvic limb paralysis. Radiography was unremarkable. Neurologic examination showed signs consistent with an intramedullary lesion between the second thoracic and fifth lumbar spinal cord segments. The animal's condition did not improve after 4 days of aggressive glucocorticoid therapy, and euthanasia was performed. Histologic examination of the spinal cord showed amorphous emboli suggestive of cartilaginous fragments within spinal veins. A diagnosis of fibrocartilaginous emboli was made, the first known case in a mustelid.     

The histopathogenesis of paralytic rabies in six-week-old C57BL/6J mice following inoculation of the CVS-11 strain into the right triceps surae muscle

A fatal encephalomyelitis was developed after intracerebral and hind limb inoculation of in 6-week-old C57BL/6J mice by the inoculation of fixed rabies virus (CVS-11 strain), intracerebrally and into hind. After the intracerebral inoculation, virus antigens were detected in the cerebral cortex and hippocampus at 2 days postinoculation (PI), and later spread centrifugally to thalamus, brain stem, cerebellum, spinal cord and spinal ganglia. At 4 days PI, severe apoptosis and DNA fragmentation were observed in the hippocampus and cerebral cortex. All mice infected intracerebrally were dead without limb paralysis at from 10 to 11 days PI. In contrast, mice infected with virus intramuscularly were persistently observed virus antigens in the myocytes at the site of inoculation from 2 days PI. At 4 days PI, the antigens were demonstrated in the spinal dorsal root ganglia, spinal cord and muscle spindles without their detection in the cerebrum and hippocampus. There were no apoptosis in the spinal cord and dorsal root ganglia, however hind limb paralysis was found in all infected mice. Hind limb paralysis was progressed to quadriparalysis, and mice were dead from 11 to 13 days PI. From 4 days PI, necrosis of neuron was observed in the the spinal and dorsal ganglia with infiltration of lymphocyte. This study suggested that the necrosis of spinal neurons was more important to cause the paralysis of hind limb rather than the severe cerebral infection and apoptosis in C57BL/6J mice infected with CVS-11 strain. The virus primarily replicated in the muscles was ascended the spinal cord via afferent fibers and retrogradely invaded the cerebrum, and with subsequent spread to muscle spindles.     

Fibrocartilaginous embolic myelopathy in a horse

Fibrocartilaginous embolic myelopathy was diagnosed in a 11-year-old, male, Tennessee Walking Horse by histopathological examination of the spinal cord after the horse was killed because of severe neurological dysfunction. Both ventral funiculi of C6 and C7 cervical spinal cord had extensive necrosis with blood vessels containing fibrocartilaginous emboli. A similar fibrocartilaginous embolus was observed in a single large spinal artery adjoining the vertebral leptomeninges.