CT findings and the prognostic value of the Koret CT score in cats with traumatic brain injury.

OBJECTIVES: The aims of this study were to evaluate associations between abnormal head CT findings and outcome, and to examine the prognostic value of the Koret CT score (KCTS) in cats sustaining acute traumatic brain injury (TBI). METHODS: The medical records of cats hospitalised with TBI that underwent head CT scans within 72 h of admission were retrospectively reviewed. CT scans were evaluated independently by a radiologist and a neurologist who were blinded to the outcome. A KCTS and modified Glasgow Coma Scale (MGCS) were assigned to each cat and the association between abnormal CT findings, KCTS, MGCS and outcome were analysed. RESULTS: Fourteen cats were included in the study: nine (64.2%) survivors and five (35.7%) non-survivors. Of the nine cats that were discharged, one was a short-term survivor (10 days) and eight (57.1%) were long-term survivors (⩾6 months). Abnormal CT findings included lateral ventricle asymmetry/midline shift (42.8%), intracranial haemorrhage (35.7%), caudotentorial lesions (14.2%) and cranial vault fractures (14.2%), all of which were depressed. Intracranial haemorrhage was found to be significantly and negatively associated with short-term (P = 0.005) and long-term (P = 0.023) survival. KCTS was significantly associated with short-term survival (P = 0.002) and long-term survival (P = 0.004). A KCTS cut-off value of 2 yielded a 100% sensitivity and 100% specificity for short-term survival and 100% sensitivity and 80% specificity for long-term survival. A MGCS cut-off value of ⩾13 was associated with a 100% sensitivity and 100% specificity for short-term survival, and with a 100% sensitivity and 80% specificity for long-term survival. CONCLUSIONS AND RELEVANCE: KCTS, performed up to 72 h from injury, can be used as an additional diagnostic tool for the prediction of survival in cats with TBI.

Blood-brain barrier dysfunction in canine epileptic seizures detected by dynamic contrast-enhanced magnetic resonance imaging.

OBJECTIVE: Dogs with spontaneous or acquired epilepsy exhibit resemblance in etiology and disease course to humans, potentially offering a translational model of the human disease. Blood-brain barrier dysfunction (BBBD) has been shown to partake in epileptogenesis in experimental models of epilepsy. To test the hypothesis that BBBD can be detected in dogs with naturally occurring seizures, we developed a linear dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI) analysis algorithm that was validated in clinical cases of seizing dogs and experimental epileptic rats. METHODS: Forty-six dogs with naturally occurring seizures of different etiologies and 12 induced epilepsy rats were imaged using DCE-MRI. Six healthy dogs and 12 naive rats served as control. DCE-MRI was analyzed by linear-dynamic method. BBBD scores were calculated in whole brain and in specific brain regions. Immunofluorescence analysis for transforming growth factor beta (TGF-ß) pathway proteins was performed on the piriform cortex of epileptic dogs. RESULTS: We found BBBD in 37% of dogs with seizures. A significantly higher cerebrospinal fluid to serum albumin ratio was found in dogs with BBBD relative to dogs with intact blood-brain barrier (BBB). A significant difference was found between epileptic and control rats when BBBD scores were calculated for the piriform cortex at 48 hours and 1 month after status epilepticus. Mean BBBD score of the piriform lobe in idiopathic epilepsy (IE) dogs was significantly higher compared to control. Immunohistochemistry results suggested active TGF-ß signaling and neuroinflammation in the piriform cortex of dogs with IE, showing increased levels of serum albumin colocalized with glial acidic fibrillary protein and pSMAD2 in an area where BBBD had been detected by linear DCE-MRI. SIGNIFICANCE: Detection of BBBD in dogs with naturally occurring epilepsy provides the ground for future studies for evaluation of novel treatment targeting the disrupted BBB. The involvement of the piriform lobe seen using our linear DCE-MRI protocol and algorithm emphasizes the possibility of using dogs as a translational model for the human disease.

Reversible paralysis and loss of deep pain sensation after topical intrathecal morphine administration following durotomy.

OBJECTIVE: To report 2 dogs that developed temporary pelvic limb paralysis with loss of deep pain sensation after topical intrathecal morphine administration during spinal surgery. STUDY DESIGN: Clinical report. ANIMALS: Dogs (n = 2). METHODS: A 5-year-old castrated male French Bulldog with a subarachnoid diverticulum at T9-T10 and a 9.5-year-old castrated male Belgian Shepherd dog with a herniated disc at T12-T13 and intradural component, had Gelfoam soaked with morphine placed over the dura mater defect. RESULTS: Pelvic limb paralysis and loss of deep pain sensation was noticed immediately after recovery from anesthesia. After intravenous naloxone administration, both dogs immediately regained ambulation and normal pain sensation; however the effect was temporary lasting only a few hours. Permanent resolution of clinical signs occurred 24 hours after surgery. CONCLUSIONS: Topical intrathecal morphine administration resulted in temporary pelvic limb paralysis and loss of deep pain sensation. This route of administration should be used cautiously until further determination of the efficacy and adverse effects associated with topical intrathecal morphine administration.

Taenia multiceps brain cyst removal in two wild Nubian ibex (Capra nubianas).

Two wild adult Nubian ibex (Capra nubiana) were captured and admitted to the Hebrew University Veterinary Teaching Hospital with various neurologic signs, including alerted mentation, head tilt, and pathologic nystagmus. The lesion in the central nervous system was localized to the forebrain in one ibex and to the cerebellum of the other. Both ibex's were diagnosed with brain cyst using computed tomography (CT). Craniectomy was performed to remove the cysts, and both animals returned to their natural environment after a rehabilitation period. Parasitologic examination revealed cysts of Taenia multiceps coenurus. This is the first report to describe the neurologic signs, CT findings, surgical procedure, and follow-up postsurgery information in wild Capra nubiana.

Needle biopsy for hepatic vitamin A levels in lions (Panthera leo).

Hypovitaminosis A (HA)-related skull malformations resulting in neurologic abnormalities and death have been, and still are, reported in captive lions (Panthera leo) worldwide. Liver vitamin A (VA) concentration is the most reliable indicator of animals' VA status, and its assessment is essential in prevention and treatment of HA in lions. A percutaneous needle liver biopsy using high-performance liquid chromatography ultraviolet retinoid analysis for VA concentration measurement was validated. It was first assessed in vitro using chicken liver. Later, the safety and feasibility of ultrasound-guided percutaneous needle liver biopsy was assessed in living lions. Hepatic VA concentrations in lion liver were measured using the above laboratory method. Mean chicken hepatic VA concentration in needle biopsy (NB) and wedge biopsy (WB) of the same liver lobes were 108.66 and 60.89 microg/g wet tissue, respectively, and were significantly (P = 0.03) correlated (r = 0.74). The calculated linear regression for predicting VA concentration in WB using NB VA for chicken liver was 25.194 + 0.3234x NB (microg/g). Four ultrasound-guided percutaneous needle liver biopsies were obtained from each of the four lions under general anesthesia. Mean hepatic VA concentration was 8.25 microg/g wet tissue (range 1.43-25.29 microg/g). Mean serum VA concentration, measured in these four lions was 1,011.1 nmol/L with a standard deviation of 337.91 nmol/L (range 590.26-1,077.2 nmol/L). The lions recovered uneventfully, and no complications were observed during a 4-yr follow-up period. In conclusion, the percutaneous needle liver biopsy technique is a reliable, practical, safe tool for obtaining liver tissue samples antemortem for assessment of the VA status in lions and can be used in future studies.

Spontaneous intradural disc herniation with focal distension of the subarachnoid space in a dog.

Myelo-computed tomography of a paraparetic 14-year-old dog revealed subarachnoid distension with an intradural filling defect above the T13-L1 disc space. T12-L1 hemilaminectomy followed by durotomy allowed removal of a large piece of degenerated disc material that compressed the spinal parenchyma. Full return to function was achieved 10 days post-surgery. The distension was likely secondary to the intradural herniation, and is a rare and distinct finding.

Hernie discale intra-durale spontanée avec distension focale de l'espace sous-arachnoïdien chez un chien. Une myélo-tomographie par ordinateur d'un chien paraparétique âgé de 14 ans a révélé une distension sous-arachnoïdienne avec un défaut de remplissage intradural au-dessus de l'espace du disque T13­L1. Une hémilaminectomie de T12­L1 suivie d'une durotomie ont permis l'enlèvement d'un grand morceau de matériel dégénéré du disque qui comprimait le parenchyme rachidien. Un retour complet à la fonction a été obtenu 10 jours après la chirurgie. La distension était probablement secondaire à l'hernie intradurale et représente une constatation rare et distincte.(Traduit par Isabelle Vallières).

Magnetic resonance imaging findings of spinal intramedullary spirocercosis.

Spirocerca lupi is a nematode infecting dogs in tropical and subtropical areas. Aberrant S. lupi migration to different body organs, including the spinal cord, has been documented. To date, the diagnosis of aberrant spinal cord migration was made at post-mortem examination or as an incidental finding, during spinal surgery. We describe two dogs with acute asymmetric paraparesis that were subsequently diagnosed with spinal cord spirocercosis. In magnetic resonance (MR) images of the spine, T2 hyperintense lesions were seen in the spinal cord of both dogs. The lesions appeared isointense on T1-weighted images and focal enhancement was detected after gadolinium administration. The MR imaging findings were compatible with focal inflammation, presumably along the parasite migration tract. Gross and microscopic pathologic findings confirmed the diagnosis of aberrant spinal intramedullary migration of S. lupi in one dog, and in the other dog, the clinical and imaging findings were supportive of this diagnosis.

Sub-occipital craniectomy in a lion (Panthera leo) with occipital bone malformation and hypovitaminosis A.

Neurologic dysfunction accompanied by malformation of both the skull and the cervical vertebrae has been previously described in lions kept in captivity worldwide, and this dysfunction and malformation were most often related to vitamin A deficiency. Diagnosis of the bone malformation and its effects on the neural tissue was until recently limited to postmortem examination, with characteristic thickening of the bones of the cranial vault, cerebellar herniation, compression of the foramen magnum, and enlargement of the lateral ventricles. For some mildly affected lion cubs with neurologic signs, improvement was reported with excessive vitamin A supplementation. However, definitive diagnosis was only available for those that eventually died or were euthanized. This case documents the antemortem diagnosis of the disease using computed tomographic imaging and liver biopsy. While conservative treatment failed, suboccipital craniectomy removed the thickened occipital bone and was demonstrated to be a successful surgical intervention that can be used to treat more severely affected lions.

A method for intervertebral space distraction before stabilization combined with complete ventral slot for treatment of disc-associated wobbler syndrome in dogs.

OBJECTIVE: To evaluate the use of a modified K-wire spacer for maintaining intervertebral distraction after ventral decompression and during stabilization as a treatment for disc-associated wobbler syndrome in large breed dogs. STUDY DESIGN: A retrospective study. ANIMALS: Dogs (n=7) with disc-associated wobbler syndrome. METHODS: Medical records (2003-2006) of dogs treated by a modified surgical method were evaluated. Data retrieved were signalment, onset and duration of clinical signs, neurologic abnormalities, diagnostic methods, surgical procedure, immediate, and long-term (>or=1 year) postoperative clinical and radiographic outcome. RESULTS: Mean duration of clinical signs was 4.8 months. Neurologic signs included ataxia (2), ambulatory tetraparesis (2), and non-ambulatory tetraparesis (3). Three dogs had disc protrusion in 2 sites, 2 dogs had the procedure in 1 location and stabilization of both affected sites. All dogs improved dramatically and remained for 1-3 years. One dog had recurrence of cervical discomfort 13 months later. CONCLUSIONS: Despite the limited number of dogs, overall initial successful outcome with only 1 dog having mild recurrence 13 months later supports further use and evaluation of this technique. CLINICAL RELEVANCE: Distraction using a K-wire spacer after ventral decompression followed by stabilization should be considered in dogs with disc-associated wobbler syndrome to prevent collapse of the intervertebral space.

Efficacy of 780-nm laser phototherapy on peripheral nerve regeneration after neurotube reconstruction procedure (double-blind randomized study).

OBJECTIVE: This pilot double-blind randomized study evaluated the efficacy of 780-nm laser phototherapy on the acceleration of axonal growth and regeneration after peripheral nerve reconstruction by polyglycolic acid (PGA) neurotube. BACKGROUND DATA: The use of a guiding tube for the reconstruction of segmental loss of injured peripheral nerve has some advantages over the regular nerve grafting procedure. Experimental studies have shown that laser phototherapy is effective in influencing nerve regeneration. METHODS: The right sciatic nerve was transected, and a 0.5-cm nerve segment was removed in 20 rats. A neurotube was placed between the proximal and the distal parts of the nerve for reconnection of nerve defect. Ten of 20 rats received post-operative, transcutaneous, 200-mW, 780-nm laser irradiation for 14 consecutive days to the corresponding segments of the spinal cord (15 min) and to the reconstructed nerve (15 min). RESULTS: At 3 months after surgery, positive somato-sensory evoked responses were found in 70% of the irradiated rats (p = 0.015), compared to 30% of the non-irradiated rats. The Sciatic Functional Index in the irradiated group was higher than in the non-irradiated group (p < 0.05). Morphologically, the nerves were completely reconnected in both groups, but the laser-treated group showed an increased total number of myelinated axons. CONCLUSION: The results of this study suggest that postoperative 780-nm laser phototherapy enhances the regenerative process of the peripheral nerve after reconnection of the nerve defect using a PGA neurotube.

Partial esophagectomy with single layer closure for treatment of esophageal sarcomas in 6 dogs.

OBJECTIVE: To report partial esophagectomy (PE) as a treatment for esophageal sarcoma in dogs. STUDY DESIGN: Retrospective study (2000-2002). ANIMALS: Six dogs with caudal thoracic esophageal tumors. METHODS: Medical records of 6 dogs that had surgical removal of esophageal tumors were reviewed. Signalment, medical history, physical examination results, complete blood count, surgical procedure, tumor classification, postoperative treatment, and complications were retrieved. RESULTS: Esophageal masses were approached by thoracotomy and esophagotomy on the side opposite the mass, removed with 1 cm margins by full thickness excision, and the defects closed with a single layer of interrupted sutures. All dogs recovered rapidly without major complications. Tumors were fibrosarcoma (3 dogs), undifferentiated sarcoma (1), and osteosarcoma (2). Five dogs were administered doxorubicin chemotherapy after surgery. Good quality of life was observed postoperatively in 5 dogs until deterioration necessitated euthanasia; survival ranged from 2-16 months. The remaining dog was alive, 20 months after surgery. CONCLUSIONS: Partial esophagectomy and closure using 1 suture layer, was an effective, simple, and safe technique for removal of sarcomas of the distal thoracic esophagus. CLINICAL RELEVANCE: Removal of esophageal masses by partial esophagectomy can be used reliably as a method of esophageal surgery.