Cervical Vertebral Compressive Myelopathy Research Articles

Shapes of cervical articular process joints and association with histological evidence of osteochondrosis in Warmblood foals: A post-mortem study.

Osteochondrosis dissecans (OCD) of articular process joints (APJs) is involved in cervical vertebral compressive myelopathy (CVM). Biomechanical forces, important in development of OCD, depend on joint conformation. Oval and flat APJ surfaces are considered normal. To identify and grade gross shape variation of cervical and cranial thoracic APJ surfaces and determine association with histological evidence of osteochondrosis. Case series. Eight hundred and four cervical and cranial thoracic APJ surfaces of 30 foals were evaluated for shape(s) and grades, and were correlated with osteochondrosis. Three top view shapes (oval, pointed, elongated) and seven lateral view shapes (flat, convex, concave, stepped, bevelled, folded edge, raised edge) were regularly encountered. The oval top view shape was most common. Flat and bevelled were the most common lateral view shapes. General shape grade of caudal articular surfaces was significantly higher than of cranial surfaces. The combinations of an oval top view shape and the lateral view shapes folded edge, concave, or flat with additional raised edge and/or folded edge (flat +), were more likely to have OC than oval with convex, bevelled or flat lateral view shapes (normal vs. oval and folded, odds ratio [OR] 2.49 [95% confidence intervals (CIs) 1.13-5.67]; normal vs. oval and flat +, OR 2.77 [95% CI 1.15-6.85]; oval and convex vs. oval and folded, OR 3.20 [95% CI 1.35-8.20]; oval and convex vs. oval and flat +, OR 3.56 [95% CI 1.43-9.54]; oval and bevelled vs. oval and concave, OR 2.02 [95% CI 1.14-3.60]; oval and bevelled vs. oval and folded, OR 3.50 [95% CI 1.91-6.60]; oval and bevelled vs. oval and flat +, OR 3.90 [95% CI 2.00-7.70]). Most foals (21/30) were less than 1 month old. Lack of observer reliability scores for shape and shape grade. APJs shape might contribute to CVM by increased likelihood to have OC.

Cerebrospinal fluid and serum proteomic profiles accurately distinguish neuroaxonal dystrophy from cervical vertebral compressive myelopathy in horses

Cervical vertebral compressive myelopathy (CVCM) and equine neuroaxonal dystrophy/degenerative myeloencephalopathy (eNAD/EDM) are leading causes of spinal ataxia in horses. The conditions can be difficult to differentiate, and there is currently no diagnostic modality that offers a definitive antemortem diagnosis. Evaluate novel proteomic techniques and machine learning algorithms to predict biomarkers that can aid in the antemortem diagnosis of noninfectious spinal ataxia in horses. Banked serum and cerebrospinal fluid (CSF) samples from necropsy-confirmed adult eNAD/EDM (n = 47) and CVCM (n = 25) horses and neurologically normal adult horses (n = 45). . A subset of serum and CSF samples from eNAD/EDM (n=5) and normal (n=5) horses was used to evaluate the proximity extension assay (PEA). All samples were assayed by PEA for 368 neurologically relevant proteins. Data were analyzed using machine learning algorithms to define potential diagnostic biomarkers. Of the 368 proteins, 84 were detected in CSF and 146 in serum. Eighteen of 84 proteins in CSF and 30/146 in serum were differentially abundant among the 3 groups, after correction for multiple testing. Modeling indicated that a 2-protein test using CSF had the highest accuracy for discriminating among all 3 groups. Cerebrospinal fluid R-spondin 1 (RSPO1) and neurofilament-light (NEFL), in parallel, predicted normal horses with an accuracy of 87.18%, CVCM with 84.62%, and eNAD/EDM with 73.5%. Cross-species platform. Uneven sample size. Proximity extension assay technology allows for rapid screening of equine biologic matrices for potential protein biomarkers. Machine learning analysis allows for unbiased selection of highly accurate biomarkers from high-dimensional data.

Increased α-tocopherol metabolism in horses with equine neuroaxonal dystrophy.

BackgroundEquine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM) is an inherited neurodegenerative disorder associated with a vitamin E deficiency within the first year of life. Vitamin E consists of 8 isoforms metabolized by the CYP4F2 enzyme. No antemortem diagnostic test currently exists for eNAD/EDM.Hypothesis/ObjectivesBased on the association of α‐tocopherol deficiency with the development of eNAD/EDM, we hypothesized that the rate of α‐tocopherol, but not γ‐tocopherol or tocotrienol metabolism, would be increased in eNAD/EDM‐affected horses.AnimalsVitamin E metabolism: Proof of concept (POC) study; eNAD/EDM‐affected (n = 5) and control (n = 6) horses. Validation study: eNAD/EDM‐affected Quarter Horses (QHs; n = 6), cervical vertebral compressive myelopathy affected (n = 6) horses and control (n = 29) horses. CYP4F2 expression and copy number: eNAD/EDM‐affected (n = 12) and age‐ and sex‐matched control (n = 11‐12) horses.MethodsThe rates of α‐tocopherol/tocotrienol and γ‐tocopherol/tocotrienol metabolism were assessed in equine serum (POC and validation) and urine (POC only) using liquid chromatography tandem mass spectrometry (LC‐MS/MS). Quantitative reverse‐transcriptase PCR (qRT‐PCR) and droplet digital (dd)‐PCR were used to assay expression and genomic copy number of a CYP4F2 equine ortholog.ResultsMetabolic rate of α‐tocopherol was increased in eNAD/EDM horses (POC,P < .0001; validation, P = .03), with no difference in the metabolic rate of γ‐tocopherol. Horses with eNAD/EDM had increased expression of the CYP4F2 equine orthologue (P = .02) but no differences in copy number.Conclusions and Clinical ImportanceIncreased α‐tocopherol metabolism in eNAD/EDM‐affected QHs provides novel insight into alterations in vitamin E processing in eNAD/EDM and highlights the need for high‐dose supplementation to prevent the clinical phenotype in genetically susceptible horses.

Postmortem diagnoses of spinal ataxia in 316 horses in California.

To determine period prevalences of postmortem diagnoses for spinal cord or vertebral column lesions as underlying causes of ataxia (spinal ataxia) in horses. 2,861 client-owned horses (316 with ataxia [ataxic group] and 2,545 without ataxia [control group]). The medical records database of the University of California-Davis Veterinary Medical Teaching Hospital was searched to identify horses necropsied between January 1, 2005, and December 31, 2017. Results were compared between the ataxic and control groups and between various groups of horses in the ataxic group. Period prevalences were determined for the most common causes of ataxia. 2,861 horses underwent full necropsy, and the period prevalences for the most common definitive diagnoses for ataxia were 2.7% (77/2,861) for cervical vertebral compressive myelopathy (CVCM), 1.3% (38/2,861) for equine neuroaxonal dystrophy or equine degenerative myeloencephalopathy (eNAD-EDM), and 0.9% (25/2,861) for trauma; the period prevalence of ataxia of unknown origin was 2.0% (56/2,861). Horses in the ataxic group (vs the control group) were more likely to have been warmblood horses (OR, 2.70) and less likely to have been Arabian horses (OR, 0.53). In the ataxic group, horses < 5 (vs ≥ 5) years of age had greater odds of CVCM (OR, 2.82) or eNAD-EDM (OR, 6.17) versus trauma or ataxia of unknown origin. Horses in the ataxic group with CVCM were more likely Thoroughbreds (OR, 2.54), whereas horses with eNAD-EDM were more likely American Quarter Horses (OR, 2.95) and less likely Thoroughbreds (OR, 0.11). Results indicated that breed distributions differed for horses with CVCM versus eNAD-EDM; therefore, breed should be considered in the clinical evaluation of spinal ataxia in horses.

Serum and cerebrospinal fluid phosphorylated neurofilament heavy protein concentrations in equine neurodegenerative diseases.

Currently, there is little information regarding the concentrations of phosphorylated neurofilament heavy protein (pNfH) in the serum and cerebrospinal fluid (CSF) of horses with neurodegenerative diseases. Specifically, pNfH concentrations have not yet been evaluated in horses with equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy (eNAD/EDM). To determine pNfH concentrations using a commercial enzyme-linked immunosorbent assay (ELISA) in serum and CSF from control horses and horses with eNAD/EDM, cervical vertebral compressive myelopathy (CVCM) and Shivers. Case-control study using biobanked samples from diseased horses and prospective or biobanked samples from control horses. The pNfH ELISA was performed on samples from horses diagnosed with eNAD/EDM (n=64), CVCM (n=26) and Shivers (n=9) and 51 neurologically normal control horses. Median and 95% confidence interval (CI) serum pNfH concentrations in control, CVCM, and eNAD/EDM horses were 0.08ng/mL (0.07-0.15), 0.07ng/mL (0.07-0.15) and 0.07ng/mL (0.07-1.13), respectively. Serum pNfH concentrations were below the limit of detection (<0.07ng/mL) for all Shivers horses. CSF pNfH concentrations in control, CVCM-, eNAD/EDM- and Shivers-affected horses were 1.26ng/mL (1.06-1.5), 3.07ng/mL (1.15-29.9), 1.78ng/mL (1.5-2.28) and 1.39ng/mL (0.74-3.89), respectively. CSF pNfH concentrations were significantly higher in CVCM (P=.001) and eNAD/EDM (P =.01) affected horses compared to control horses. Serum pNfH concentrations >1ng/mL were significantly associated with eNAD/EDM (P=.01) with only 12% sensitivity but 99% specificity. CSF pNfH concentrations >3ng/mL were significantly associated with CVCM (P=.0002), with 50% sensitivity and 86% specificity. A limited number of control horses tested were <1 year of age. Serum pNfH concentrations are specifically increased (>1ng/mL) in some horses with eNAD/EDM. Increased CSF pNfH concentrations (>3ng/mL) can be observed with eNAD/EDM or CVCM.

Outcomes after cervical vertebral interbody fusion using an interbody fusion device and polyaxial pedicle screw and rod construct in 10 horses (2015-2019).

Further development of surgical techniques for equine cervical stabilisation is necessary to make the procedure less technically demanding, reduce complications and improve outcomes. To describe clinical outcomes and owner reports in horses undergoing placement of an interbody fusion device and polyaxial pedicle screw and rod construct for cervical vertebral fusion in horses with cervical vertebral compressive myelopathy. Retrospective case series. Data were retrieved from medical records of 10 horses undergoing cervical vertebral fusion (2015-2019). Records were evaluated for signalment, duration of clinical signs, number and location of compression sites, grade of ataxia, duration of hospitalisation and complications. Long-term follow-up was obtained through clinical re-evaluation, postoperative radiographs and owner contact. Breeds were mixed. Median age was 24 (range 12-168) months. There were 2/10 mares, 4/10 geldings and 4/10 stallions. Preoperative grade of ataxia ranged from 1-3/5. Fusion was performed at one (n=3) or two (n=7) sites. Two horses were euthanised within the first year. In 6 of 8 horses with ≥1-year follow-up, ataxia improved by 1-3 grades, with an average improvement of 1.25 grades. In four horses, ataxia improved to grade 0-1. In two horses the gait was unaffected, but neck comfort improved. Complications included seroma formation (n=9), pain (n=5), fever (n=4), upper respiratory tract obstruction (n=2), azotemia (n=2), screw breakage (n=2), progression of neurological signs (n=1), Horner's Syndrome (n=1), dysphagia (n=1), hives (n=1), implant infection (n=1) and nondisplaced fracture (n=1). Small case series, heterogeneous patient population. This technique resulted in ≥1 grade gait improvement in 6/10 cases operated and 6/8 cases for which ≥1-year follow-up was available, similar to other methods. Fatal complications related to implant placement did not occur. This technique may represent a safer alternative to current techniques of ventral interbody fusion with similar outcomes.

Mesenchymal stem cell transplantation into the spinal cord of healthy adult horses undergoing cervical ventral interbody fusion.

To determine the feasibility of umbilical cord-derived mesenchymal stem cell (UC-MSC) transplantation into the cervical spinal cord of horses by using fluoroscopy with or without endoscopic guidance and to evaluate the neurological signs and tissue reaction after injection. Experimental study. Eight healthy adult horses with no clinical signs of neurological disease. After cervical ventral interbody fusion (CVIF), ten million fluorescently labeled allogeneic UC-MSC were injected into the spinal cord under endoscopic and fluoroscopic guidance (n=5) or fluoroscopic guidance only (n=3). Postoperative neurological examinations were performed, and horses were humanely killed 48 hours (n=4) or 14 days (n=4) postoperatively. Spinal tissues were examined after gross dissection and with bright field and fluorescent microscopy. Needle endoscopy of the cervical canal by ventral approach was associated with intraoperative spinal cord puncture (2/5) and postoperative ataxia (3/5). No intraoperative complications occurred, and one (1/3) horse developed ataxia with cell transplantation under fluoroscopy alone. Umbilical cord-derived MSC were associated with small vessels and detected up to 14 days in the spinal cord. Demyelination was observed in six of eight cases. Fluoroscopically guided intramedullary UC-MSC transplantation during CVIF avoids spinal cord trauma and decreases risk of ataxia from endoscopy. Umbilical cord-derived MSC persist in the spinal cord for up to 14 days. Cell injection promotes angiogenesis and induces demyelination of the spinal tissue. Umbilical cord-derived MSC transplantation into the spinal cord during CVIF without endoscopy is recommended for future evaluation of cell therapy in horses affected by cervical vertebral compressive myelopathy.

Equine degenerative myeloencephalopathy: prevalence, impact, and management.

Equine neuroaxonal dystrophy/equine degenerative myeloencephalopathy is an inherited neurodegenerative disorder affecting many horse breeds. Clinical signs include a symmetric ataxia and an abnormal stance at rest, similar to cervical vertebral compressive myelopathy, equine protozoal myeloencephalitis, and equine herpesvirus 1 myeloencephalopathy. This review will provide an update on the disease prevalence, management, impact, and ongoing research.

Safety and tracking of intrathecal allogeneic mesenchymal stem cell transplantation in healthy and diseased horses

BackgroundIt is currently unknown if the intrathecal administration of a high dose of allogeneic mesenchymal stem cells (MSCs) is safe, how MSCs migrate throughout the vertebral canal after intrathecal administration, and whether MSCs are able to home to a site of injury. The aims of the study were: 1) to evaluate the safety of intrathecal injection of 100 million allogeneic adipose-derived MSCs (ASCs); 2) to assess the distribution of ASCs after atlanto-occipital (AO) and lumbosacral (LS) injection in healthy horses; and 3) to determine if ASCs homed to the site of injury in neurologically diseased horses.MethodsSix healthy horses received 100 × 106 allogeneic ASCs via AO (n = 3) or LS injection (n = 3). For two of these horses, ASCs were radiolabeled with technetium and injected AO (n = 1) or LS (n = 1). Neurological examinations were performed daily, and blood and cerebrospinal fluid (CSF) were evaluated prior to and at 30 days after injection. Scintigraphic images were obtained immediately postinjection and at 30 mins, 1 h, 5 h, and 24 h after injection. Three horses with cervical vertebral compressive myelopathy (CVCM) received 100 × 106 allogeneic ASCs labeled with green fluorescent protein (GFP) via AO injection and were euthanized 1–2 weeks after injection for a full nervous system necropsy. CSF parameters were compared using a paired student’s t test.ResultsThere were no significant alterations in blood, CSF, or neurological examinations at any point after either AO or LS ASC injections into healthy horses. The radioactive signal could be identified all the way to the lumbar area after AO ASC injection. After LS injection, the signal extended caudally but only a minimal radioactive signal extended further cranially. GFP-labeled ASCs were not present at the site of disease at either 1 or 2 weeks following intrathecal administration.ConclusionsThe intrathecal injection of allogeneic ASCs was safe and easy to perform in horses. The AO administration of ASCs resulted in better distribution within the entire subarachnoid space in healthy horses. ASCs could not be found after 7 or 15 days of injection at the site of injury in horses with CVCM.

Cervical Vertebral Compressive Myelopathy Associated with Articular Processes Osteoarthritis in Horses: Report of Three Cases

Cervical Vertebral Compressive Myelopathy Associated with Articular Processes Osteoarthritis in Horses: Report of Three Cases Cervical vertebral compressive myelopathy is a neuropathy resulting in ataxia in horses. Three horses with different signs of incoordination were presented for further evaluation. A fiveyear-old gelding with a long history of abnormal head and neck carriage, a six-year-old gelding with a history of previous neurological episodes and a two-day history of acute episodes of walking difficulties, and a sixteen-year-old mare with a onemonth history of left fore-limb ataxia were diagnosed with osteoarthritis of the facet joints of the caudal cervical vertebrae. Lateral radiographs of caudal cervical vertebrae confirmed osteoarthritis of the articular processes. Radiographic changes, such as enlargement of the articular process joint, periarticular new bone growth and reduction or narrowing of the intervertebral foramen, were observed in all three cases. Cervical vertebral compressive myelopathy should be considered in ataxic horses with normal laboratory findings.

Cervical Vertebral Compressive Myelopathy associated with articular processes osteoarthritis in three horses

Cervical Vertebral Compressive Myelopathy associated with articular processes osteoarthritis in three horses

Evidence of the Primary Afferent Tracts Undergoing Neurodegeneration in Horses With Equine Degenerative Myeloencephalopathy Based on Calretinin Immunohistochemical Localization.

Equine degenerative myeloencephalopathy (EDM) is characterized by a symmetric general proprioceptive ataxia in young horses, and is likely underdiagnosed for 2 reasons: first, clinical signs overlap those of cervical vertebral compressive myelopathy; second, histologic lesions--including axonal spheroids in specific tracts of the somatosensory and motor systems--may be subtle. The purpose of this study was (1) to utilize immunohistochemical (IHC) markers to trace axons in the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts in healthy horses and (2) to determine the IHC staining characteristics of the neurons and degenerated axons along the somatosensory tracts in EDM-affected horses. Examination of brain, spinal cord, and nerves was performed on 2 age-matched control horses, 3 EDM-affected horses, and 2 age-matched disease-control horses via IHC for calbindin, vesicular glutamate transporter 2, parvalbumin, calretinin, glutamic acid decarboxylase, and glial fibrillary acidic protein. Primary afferent axons of the spinocuneocerebellar, dorsal column-medial lemniscal, and dorsospinocerebellar tracts were successfully traced with calretinin. Calretinin-positive cell bodies were identified in a subset of neurons in the dorsal root ganglia, suggesting that calretinin IHC could be used to trace axonal projections from these cell bodies. Calretinin-immunoreactive spheroids were present in EDM-affected horses within the nuclei cuneatus medialis, cuneatus lateralis, and thoracicus. Neurons within those nuclei were calretinin negative. Cell bodies of degenerated axons in EDM-affected horses are likely located in the dorsal root ganglia. These findings support the role of sensory axonal degeneration in the pathogenesis of EDM and provide a method to highlight tracts with axonal spheroids to aid in the diagnosis of this neurodegenerative disease.

Latero‐Oblique Radiography as a Diagnostic Tool for Equine Cervical Osteoarthritis

Reasons for performing studyEquine cervical osteoarthritis is a common disease known to contribute to both neck pain and cervical vertebral compressive myelopathy. There are no published studies demonstrating the usefulness of latero‐oblique radiography as a diagnostic tool for cervical osteoarthritis.ObjectivesTo determine the sensitivity, specificity and positive and negative predictive values of latero‐oblique radiography as a diagnostic tool for cervical articular process joint osteoarthritis.Study designProspective cadaver study.MethodsLatero‐oblique radiographs and CT images were collected, and post mortem examinations performed, on 27 cadaver necks from Thoroughbred‐type horses of various ages and sexes. Two equine clinicians independently reviewed each set of images for the presence of osteoarthritis. The authors, under the guidance of a veterinary pathologist, reviewed all articular process joints for bony changes indicative of osteoarthritis.ResultsThe prevalence of osteoarthritis identified on CT images was 57.9% (Assessor A) and 23% (Assessor B). The prevalence of lesions identified on post mortem examination was 25.6%. Latero‐oblique radiography showed a low sensitivity for identifying osteoarthritis when compared to both CT imaging (6.3–16.1%) and post mortem examination (2.2–4.4%). However, it showed a high specificity when compared to both CT imaging (92.1–97.8%) and post mortem examination (87.2–95.0%). The positive predictive value for identifying osteoarthritis was moderate (40.9–80.0%) when compared to CT imaging and poor (4.2–18.2%) when compared to post mortem examination. The negative predictive value was moderate when compared to both CT imaging (42.9–76.3%) and post mortem examination (78.0–79.8%).ConclusionsLatero‐oblique radiography has low sensitivity, but high specificity for the detection of cervical osteoarthritis when compared to both CT imaging and post mortem examination. Further investigation comparing the sensitivity, specificity and positive and negative predictive values of latero‐oblique radiography vs. laterolateral radiography would determine whether taking latero‐oblique radiographs, which can be more difficult to obtain and interpret, is necessary for the diagnosis of cervical osteoarthritis in practice.Ethical animal research: Ethical committee oversight not currently required by this congress: The study was performed on material obtained from an abattoir. Sources of funding: None. Competing interests: None.

Antibody Coefficients for the Diagnosis of Equine Protozoal Myeloencephalitis

Diagnosis of equine protozoal myeloencephalitis (EPM) remains a challenge for equine practitioners. Current utilized methods have inadequate sensitivity and specificity, because of a high number of false positive results. Evaluation of antibody indices to Sarcocystis neurona should provide high sensitivity and specificity for diagnosis of EPM. Archived samples from 29 clinical patients. Archived serum and cerebrospinal fluid (CSF) samples from clinical patients with either EPM (14) or cervical vertebral compressive myelopathy (CVM) (15) were examined and tested for anti-S. neurona antibodies by the SnSAG2 ELISA. The results were used to calculate the antibody index (AI) and C-value. Sensitivity and specificity were calculated, and the AI, C-value, immunoglobulin G (IgG) concentrations, and anti-S. neurona titers compared. In addition, negative CSF was spiked in varying concentrations with blood from a horse with a high anti-S. neurona titer, and the tests repeated. Results demonstrated that the IgG concentration, anti-S. neurona titer, AI, and C-value were significantly higher (P < .05) in horses with EPM than in those with CVM. Sensitivity and specificity of the AI was 71 and 100%, respectively, and that of the C-value was 86 and 100%, respectively. In addition, the AI and C-value from the samples spiked with S. neurona positive blood remained below 1 (eg, negative) in CSF with a red blood cell (RBC) count up to 10(5) RBC/μL. CONCLUSIONS/CLINICAL IMPORTANCE: Results of the study demonstrate the value of calculating the AI and C-value in the diagnosis of EPM in horses. In addition, the test is robust in the presence of blood contamination.

A Necropsy Survey of Neurologic Diseases in 4,319 Horses Examined in Normandy (France) from 1986 to 2006

The frequencies of neurologic diseases and various corresponding causes were analyzed in 4,319 Norman horses examined by autopsy between 1986 and 2006. Five hundred forty-three cases of nervous system disorders were detected, or a total prevalence of 12.6%. One hundred eighty-seven of the 543 horses (34.4%) exhibited lesions of a traumatic origin affecting the skull or the vertebral column at different levels. Their frequency was less in foals younger than 1 month of age and higher in horses aged 6 months to 2 years. Eighty-three cases of cervical vertebral compressive myelopathy (CVCM) (15.3%) were identified. Males and geldings were more often affected than females. CVCM was diagnosed mostly in animals aged 6 months to 2 years. Horses affected with lesions in the mid-cervical region (region C3–C5) were significantly younger than those exhibiting more caudal lesions (region C5–C7). Neonatal maladjustment syndrome was diagnosed in 62 foals younger than 3.5 days (4.8% of the causes of death between birth and 1 month) by using clinical or lesional criteria. The prevalence was higher in Thoroughbreds as well as in the miscellaneous breed category and less in French Standardbreds. Bacterial meningoencephalomyelitis and meningitis represented 9.6% of nervous system disorders (52 cases) and most often affected foals aged 1 to 6 months. The main bacteria identified were beta-hemolytic Streptococci , Escherichia coli, Listeria monocytogenes, Staphylococcus aureus, and Actinobacillus sp. The other causes diagnosed were, in decreasing order of frequency: grass sickness or equine dysautonomia (6.3% of neurologic diseases), hepatic encephalopathy syndrome (5.2%), septic vertebral arthritis or osteitis mainly caused by Rhodococcus equi (2.6%), congenital defects of the nervous system (2.4%), equine herpesvirus 1 myeloencephalopathy (2.2%), botulism (2.2%), malformations of the vertebral column other than CVCM (2%), and neighboring polyneuritis associated with guttural pouch mycosis (1.5%).

Associations of sex, breed, and age with cervical vertebral compressive myelopathy in horses: 811 cases (1974–2007)

To determine sex, breed, and age distributions in a population of horses with cervical vertebral compressive myelopathy (CVCM), compared with contemporaneous control horses. Retrospective case-control study. 811 horses with CVCM and 805 control horses. The Veterinary Medical Database was searched to identify horses with CVCM and contemporaneous control horses registered between July 1974 and August 2007. Admission date, admitting institution, sex, breed, age at the time of registration in the database, weight, and discharge status (alive, died, or euthanized) were recorded for each case and control horse. On the basis of results of multivariable logistic regression analysis, geldings and sexually intact males had a significantly higher likelihood of having CVCM than females (odds ratio [OR], 2.0 [95% confidence interval, 1.5 to 2.6]; and OR, 2.4 [95% confidence interval, 1.8 to 3.2], respectively). Thoroughbreds, Tennessee Walking Horses, and Warm-bloods were overrepresented in the CVCM group, compared with Quarter Horses. Horses that ranged from < 6 months to < 7 years of age had significantly higher odds of having CVCM, compared with horses > or = 10 years of age. Sex, breed, and age predilections were detected in horses with CVCM. Improved understanding of these factors will aid clinical recognition of the disease in groups that may have a high prevalence of CVCM or were previously not recognized to be commonly affected. The results may also stimulate future investigations to further delineate etiopathogenesis, such as breed-related genetic causality.

Confirmed and Presumptive Cervical Vertebral Compressive Myelopathy in Older Horses: A Retrospective Study (1992–2004)

Background: Cervical vertebral compressive myelopathy (CVCM) is a common cause of myelopathy in horses aged 6 months to 4 years. Little information is available regarding the types of lesions, treatment, and outcomes in horses with CVCM that are ≥4 years old.Animals: Twenty‐two affected horses (10 with a confirmed diagnosis of CVCM and 12 presumptive cases) and 210 contemporaneous control horses.Methods: Horses ≤4 years old that were diagnosed with CVCM between January 1992 and January 2004 were identified from medical records at Texas A&amp;M University and the University of Florida. Data analyzed included history, signalment, neurologic examination findings, lesion location, treatment, and outcome. Signalment was also recorded in a population of contemporaneous controls.Results: Horses identified had a median age of 8.4 years, and there was a greater percentage of male horses among the cases than among the controls. The most common breeds represented were warmblood (n = 6) and quarter horse (n = 5) types; warmbloods were significantly (P&lt; .05) overrepresented relative to control horses. The caudal cervical vertebral column was the most common site of CVCM lesions, and the C5‐C6 (4/9) and C6‐C7 (3/9) articulations were most often identified as abnormal via myelography. The most common lesions seen with radiography and myelography were articular process osteophytes. Of the 22 affected horses, 8 were euthanized and a diagnosis of CVCM was confirmed by necropsy for all; 5 of 8 of these horses had spinal cord compression caused, entirely or in part, by articular process osteophytes. Medical management was the therapy chosen in all horses, and administration of corticosteroids and nonsteroidal anti‐inflammatory drugs resulted in improvement in the greatest number of horses.Conclusions and Clinical Importance: CVCM should be a differential diagnosis in older horses with cervical myelopathy. Articular process osteophytes are the most frequently identified cause of spinal cord compression in this group. Male horses and horses of warmblood or Tennessee Walking Horse breeds may be predisposed to this condition.

Confirmed and Presumptive Cervical Vertebral Compressive Myelopathy in Older Horses: A Retrospective Study (1992–2004)

Cervical vertebral compressive myelopathy (CVCM) is a common cause of myelopathy in horses aged 6 months to 4 years. Little information is available regarding the types of lesions, treatment, and outcomes in horses with CVCM that are > or =4 years old. Twenty-two affected horses (10 with a confirmed diagnosis of CVCM and 12 presumptive cases) and 210 contemporaneous control horses. Horses > or =4 years old that were diagnosed with CVCM between January 1992 and January 2004 were identified from medical records at Texas A&M University and the University of Florida. Data analyzed included history, signalment, neurologic examination findings, lesion location, treatment, and outcome. Signalment was also recorded in a population of contemporaneous controls. Horses identified had a median age of 8.4 years, and there was a greater percentage of male horses among the cases than among the controls. The most common breeds represented were warmblood (n=6) and quarter horse (n=5) types; warmbloods were significantly (P < .05) overrepresented relative to control horses. The caudal cervical vertebral column was the most common site of CVCM lesions, and the C5-C6 (4/9) and C6-C7 (3/9) articulations were most often identified as abnormal via myelography. The most common lesions seen with radiography and myelography were articular process osteophytes. Of the 22 affected horses, 8 were euthanized and a diagnosis of CVCM was confirmed by necropsy for all; 5 of 8 of these horses had spinal cord compression caused, entirely or in part, by articular process osteophytes. Medical management was the therapy chosen in all horses, and administration of corticosteroids and nonsteroidal anti-inflammatory drugs resulted in improvement in the greatest number of horses. CVCM should be a differential diagnosis in older horses with cervical myelopathy. Articular process osteophytes are the most frequently identified cause of spinal cord compression in this group. Male horses and horses of warmblood or Tennessee Walking Horse breeds may be predisposed to this condition.

Cervical Vertebral Compressive Myelopathy: Diagnosis

In this article, we attempt to summarize all aspects of making a diagnosis of cervical vertebral compressive myelopathy, from signalment, clinical examination, ancillary diagnostic tests, to pathological examination. In addition, it is important to stress that each of these has inherent limitations regarding their accuracy, and we will therefore discuss diagnostic accuracy as well.