A comparison between neurological clinical signs, cerebrospinal fluid analysis, cross-sectional CNS imaging, and infectious disease testing in 168 dogs with infectious or immune-mediated meningoencephalomyelitis from Brazil.

This retrospective study evaluated canine patients with presumptively diagnosed meningoencephalomyelitis (ME) based on neurological clinical signs, cerebrospinal fluid (CSF) analysis, cross-sectional imaging, and infectious disease testing with a limited neurological-focused polymerase chain reaction (PCR) panel performed on blood and CSF. The first goal was to determine the proportion of dogs where the condition was caused by an infectious agent versus a probable immune-mediated etiology (i.e., meningoencephalomyelitis of unknown origin; MUO) in our geographic region. The secondary goals of this study were to examine and define associations between abnormal CSF test results and cross-sectional neuroimaging findings, in addition to defining the age and most common neurological clinical signs in each group of ME. A total of 168 dogs matched the inclusion criteria with magnetic resonance imaging (MRI) performed in 130 dogs and computed tomography (CT) performed in 38 dogs. Presumptive MUO was observed in 152/168 (90.5%) of dogs and infectious ME was identified in 16/168 (9.5%) of dogs (p < 0.0001). Canine distemper virus (CDV) was the most common cause of infectious ME in 10/16 dogs (62.5%). Of the total cases with a positive infectious disease result, 3/16 (18.7%) had normal CSF results and 13/16 (81.3%) had abnormal CSF results (p = 0.0078). MRI and CT abnormalities in the brain were detected in 74 and 39% of dogs with inflammatory CSF, respectively. MRI and CT abnormalities in the spinal cord were detected in 90 and 57% of dogs with inflammatory CSF results, respectively. Age was not significantly different between infectious ME and presumptive MUO groups (p = 0.15). Seizures were the most common clinical sign reported for both MUO (36.8% of cases) and infectious ME (31.2% of cases). In conclusion, presumptive MUO is significantly more common than infectious ME in this population of dogs. Furthermore, although normal CSF results were uncommon in dogs with infectious ME, this finding occurred in several patients (3/16), suggesting that infectious disease testing should be considered even in the face of normal CSF results. Finally, MRI was more sensitive than CT in the detection of abnormalities when dogs with ME had inflammatory CSF results but was not 100% sensitive, suggesting CSF analysis should be performed to rule out inflammation even when no abnormalities are detected on MRI or CT.

Association between spinal cord compression ratio in magnetic resonance imaging, initial neurological status, and recovery after ventral slot in 57 dogs with cervical disc extrusion.

This retrospective, unblinded, single rater study evaluated images obtained from magnetic resonance imaging (MRI) of dogs with cervical intervertebral disc extrusion before being submitted to ventral slot decompression (VSD). Dogs were re-evaluated systematically at 10 and 30 days after VSD. The objectives of this study were to investigate the associations between the following parameters: (1) The maximal spinal cord compression ratio (SCCR) as seen on transverse MRI and pre-surgical neurological status (NS) grade; we hypothesized that dogs with greater SCCR will have worse pre-surgical NS grade at presentation; (2) Pre-surgical NS grade and postoperative recovery; we hypothesized that worse pre-surgical NS grade will be associated with longer postoperative recovery time; (3) SCCR and postoperative recovery; we hypothesized that dogs with higher SCCR will have longer recovery time; (4) Location of extrusion (cranial vs. caudal) and initial NS grade and outcomes; we hypothesized that caudal cervical extrusion will have worse NS grade and longer time to recovery; (5) Longitudinal extension of ventral CSF signal loss on HASTE pulse sequence and NS grade and time to recovery; we hypothesized that dogs with longer HASTE CSF attenuation will have higher NS grade and longer time to recovery. There was no significant association between SCCR and NS grade, suggesting that this relationship in the cervical region is similar to what is observed in the thoracolumbar region, rejecting our first hypothesis. There was a significant difference between ambulatory tetraparesis dogs versus non-ambulatory tetraparesis dogs regarding complete recovery at 10 days: dogs with NS grade 1, 2, or 3 overall recovered faster than dogs with NS grade 4. However, there was no significant difference between these groups regarding complete recovery at 30 days, thereby accepting our second hypothesis at 10 days and rejecting it at 30 days. There was no correlation between SCCR and recovery time, rejecting our third hypothesis. Caudal cervical extrusion did not show higher NS grade or longer recovery time than cranial extrusion, rejecting our fourth hypothesis. CSF attenuation length ratio on HASTE images was not significantly correlated with NS grade but weakly correlate with post-surgical recovery time, partially accepting our fifth hypothesis.

Comparison of the Efficacy of Surgical Decompression Alone and Combined With Canine Adipose Tissue-Derived Stem Cell Transplantation in Dogs With Acute Thoracolumbar Disk Disease and Spinal Cord Injury.

Paraparesis and paraplegia are common conditions in dogs, most often caused by a disc herniation in the thoracolumbar spinal segments (T3-L3), which is a neurological emergency. Surgical decompression should be performed as soon as possible when spinal compression is revealed by myelography, computed tomography, or magnetic resonance imaging. Mesenchymal stem-cell therapy is a promising adjunct treatment for spinal cord injury. This study sought to compare the effects of surgical decompression alone and combined with an allogeneic transplantation of canine adipose tissue-derived mesenchymal stem cells (cAd-MSCs) in the treatment of dogs with acute paraplegia. Twenty-two adult dogs of different breeds with acute paraplegia resulting from a Hansen type I disc herniation in the thoracolumbar region (T3-L3) were evaluated using computed tomography. All dogs had grade IV or V lesions and underwent surgery within 7 days after symptom onset. They were randomly assigned into two groups, 11 dogs in each. The dogs in Group I underwent hemilaminectomy, and those in Group II underwent hemilaminectomy and cAd-MSC epidural transplantation. In both groups, all dogs with grade IV lesions recovered locomotion. The median locomotion recovery period was 7 days for Group II and 21 days for Group I, and this difference was statistically significant (p < 0.05). Moreover, the median length of hospitalization after the surgery was statistically different between the two groups (Group I, 4 days; Group II, 3 days; p < 0.05). There were no statistically significant between-group differences regarding the number of animals with grade IV or V lesions that recovered locomotion and nociception. In conclusion, compared with surgical decompression alone, the use of epidural cAd-MSC transplantation with surgical decompression may contribute to faster locomotor recovery in dogs with acute paraplegia and reduce the length of post-surgery hospitalization.