Cervical Vertebral Stenotic Myelopathy Research Articles

Evaluation of real-time polymerase chain reaction for the diagnosis of protozoal myeloencephalitis in horses using cerebrospinal fluid.

Equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona remains an antemortem diagnostic challenge in some horses. Recent work suggested the use of real-time PCR (rtPCR) on cerebrospinal fluid (CSF) as a promising diagnostic tool. To evaluate the sensitivity and specificity of S. neurona rtPCR on CSF for EPM diagnosis using horses with EPM and S. neurona-seropositive horses with other neurologic conditions. Ninety-nine horses with neurologic disease that underwent complete neurologic examination, CSF collection, and, if euthanized, necropsy including the central nervous system (CNS). Retrospective case-control study using banked CSF samples. Samples from horses with neurologic abnormalities and necropsy-confirmed EPM diagnosis, presumptive EPM diagnosis using strict criteria (SnSAG2/4/3 ELISA serum:CSF titer ratios <50) and horses diagnosed with other neurologic diseases were used. Fifty-two horses had EPM; 23 were confirmed on necropsy, and 29 were presumptive clinical diagnoses. The other 47 horses all had necropsy-confirmed diagnoses. Four of the 47 horses had normal neurologic findings on necropsy and the remaining 43 horses had neurologic diseases including equine degenerative myeloencephalopathy (EDM), cervical vertebral stenotic myelopathy, trauma, and other miscellaneous conditions. One CSF sample was weakly positive for S. neurona by rtPCR, this sample was obtained from a horse with confirmed EDM. Samples from the other 98 horses were negative for S. neurona by rtPCR. Our study contradicts previous conclusions that S. neurona rtPCR is potentially useful for EPM diagnosis, because our results indicate that the assay has a low sensitivity (0%) for EPM.

Investigation of a contributing factor for cervical vertebral stenotic myelopathy using computed tomography for measuring the cervical vertebral volume.

Thoroughbred horses appear to be particularly predisposed to cervical vertebral stenotic myelopathy (CVSM), also known as wobbler syndrome. We hypothesized that variations in the cervical vertebral volumes can affect the dynamic instability of the cervical vertebrae. This observational study aimed to clarify whether cervical vertebral volume could be considered as a contributing factor in CVSM in Thoroughbred horses. Computed tomography (CT) was used to investigate a total of 21 male Thoroughbred horses (age range, 217–1,002 days; mean, 542.3 days). The study population comprised 17 CVSM horses (age range, 217–1,002 days; mean, 549.8 days) and 4 non-CVSM horses (age range, 244–682 days; mean, 510.5 days). The cervical vertebral volumes of three-dimensional CT were measured using the image-processing software. A significant difference in the variation of cervical vertebral volumes among C2 to C4 and C3 to C5 was identified in the CVSM group (P<0.05). While no significant differences were found in the variation in cervical vertebral volumes among C4 to C6. C3 demonstrated a significantly smaller cervical vertebral volume than C2 and C4 (P<0.05). In the non-CVSM group, no significant differences were found in the variation of cervical vertebral volume among C2 to C4, C3 to C5, and C4 to C6. Our findings suggest that variations in cranial cervical vertebral volume in CVSM male horses can be considered as an important contributing factor in CVSM development.

Sex differences in cervical spinal cord and spinal canal development in Thoroughbred horses.

Cervical vertebral stenotic myelopathy (CVSM), a common cause of cervical spinal cord compression, is a neurological disease characterized by general proprioceptive ataxia and weakness of hindlimbs that tends to develop in young adult Thoroughbred horses. Although male horses seem to be at increased risk for CVSM, the mechanism for the occurrence of sex differences in the prevalence of CVSM is still poorly understood. Hence, we hypothesized that sex differences in the development of cervical spinal cord and spinal canal would affect the development of CVSM. This study aimed to evaluate sex differences in the development of cervical spinal cord and spinal canal in Thoroughbred horses. A total of 29 Thoroughbred horses underwent computed tomographic myelography. Thereafter, the volumes of cervical spinal cord and spinal canal were calculated. Accordingly, male horses had significantly lager cervical spinal cord volume and cervical spinal cord-to-spinal canal volume ratio than those of female horses (P<0.05). Sex differences in the cervical spinal cord-to-spinal canal volume ratio gradually decreased until around 1,400 days of age. Younger male horses have narrower interspace between the cervical spinal cord and spinal canal than younger female horses, suggesting that an imbalanced cervical spinal cord and spinal canal growth is one of the causes of CVSM.

Characteristic computed tomographic myelography findings in 23 Thoroughbred horses.

The purpose of this observational study was to determine the characteristic computed tomographic (CT) myelography findings of cervical vertebral stenotic myelopathy (CVSM) lesions in Thoroughbred horses. A total of 23 Thoroughbred horses (age range, 155–717 days on CT examination; mean, 410.9 days) were analyzed. All 23 Thoroughbred horses underwent unenhanced radiography, radiographic myelography, and CT myelography. Unenhanced radiographs were observed the presence of cervical vertebral malalignment and osseous lesions. Radiographic myelograms were observed for signs of cervical spinal cord compression; additionally, CT myelograms were used to detect cervical vertebral osseous lesions. Ventral compressions were frequently observed in the cranial cervical vertebrae (C2–C4), whereas dorsal compressions were frequently observed in the caudal cervical vertebrae (C5–C7). Furthermore, osseous lesions of the caudal articular process developed more frequently than those of the cranial articular process. CT myelography in Thoroughbred horses is a useful method for detecting CVSM changes.

A Radiographic Technique for Assessment of Morphologic Variations of the Equine Caudal Cervical Spine.

Simple SummaryEquine Caudal Cervical Morphological Variation (ECCMV) has been acknowledged as a common finding in horses. The equine sixth cervical vertebrae (C6) with two caudal ventral laminae appears to be prone to the most congenital variation. The direct clinical relevance of this condition is currently unknown. A standardized method of assessment and diagnosis in live horses would allow for scientifically robust, quantitative studies into the relevance of this syndrome. Equine radiographic imaging is standard within veterinary practice and offers an accessible screening and diagnostic tool for veterinarians and provides a starting point for assessment. Here, we present a systematic method for locating cervical landmarks and radiographing with specific views as a reliable, repeatable imaging procedure for identifying ECCMV. If ECCMV is linked to poor performance, pain-based behaviors, lameness, and horse and rider safety and welfare, then a protocol for testing and diagnosis could be vital to improving horse rehabilitation, management, and wellness.Equine Caudal Cervical Morphologic Variation (ECCMV) is a congenital malformation of the caudal cervical spine distinct from the more commonly recognized Cervical Vertebral Stenotic Myelopathy (CVSM). The most common presentation of ECCMV is recognized on the sixth cervical vertebra (C6). In “normal” presentations, the transverse processes on the left and right sides have a caudal lamina projecting ventrally below the caudal vertebral body in a heel shape. With ECCMV, variations occur to the structure of the caudal ventral lamina on one or both sides of C6 and may include the seventh cervical (C7) and first thoracic (T1) vertebrae and ribs, in varying configurations. Whereas the prevalence of ECCMV is not known, it has been recognized for many years and has been reported to occur with relatively high frequency within multiple populations of domesticated horses. To date, there is no documented link between the occurrence of ECCMV and clinical signs. However, based on retrospective studies, multiple authors have recognized the potential impact on performance that this condition may have. Establishing a reliable radiographic protocol for the consistent diagnosis of ECCMV would allow quantitative, scientific evaluation of the problem and support clinicians working in this field. We present a radiographic technique, which has been illustrated by diagnosis of ECCMV in three horses and confirmation of the diagnoses in two cases via postmortem examination.

Comparison of the clinical and radiographic appearance of the cervical vertebrae with histological and anatomical findings in an eight-month old warmblood stallion suffering from cervical vertebral stenotic myelopathy (CVSM)

BackgroundCervical vertebral stenotic myelopathy (CVSM) remains one of the most important abnormalities of the cervical spine resulting in neurological deficits in horses. The aim of the following study was to compare the results of the clinical and neurological examination, the results of myelography and the post mortem anatomical and histological appearance of the spinal cord and cervical vertebrae in a horse with CVSM.Case presentationThe following study describes a clinical case of an eight-month-old stallion with ataxia. Plain cervical radiographs indicated narrowing of the spinal canal. Conservative therapy using NSAIDs did not result in any improvement in the gait of the horse. Due to economic constraints, surgical intervention was excluded. The owner chose to humanely euthanise the horse. Immediately after euthanasia, post mortem myelography was performed, and measurements of the myelographic dye column were taken. They revealed a 67% DMC reduction and a 64% DD reduction at the C3/C4 level. Afterwards, an anatomical dissection was performed. The cervical vertebrae and vertebral canal were macroscopically inspected and measured and indicated a 44% narrowing of the canal at the C3/C4 level. The spinal cord was removed and underwent histological evaluation after staining. Microscopic lesions were visible at the level of the compression and included axonal degeneration with partial or complete loss of myelin in the white matter of the lateral and dorsal funiculi as well as the formation of dysfunctional so-called “spongy structures”. An increase in the number of microglial cells and collagen was also observed. The formation of glial scars was excluded. Immunohistochemical studies revealed a negative transmembrane glycoprotein CD68(−) – monocyte response and a negative tumor necrosis alpha TNFα (−) reaction.ConclusionsCVSM may be difficult to diagnose, even for experienced veterinary surgeons. Currently, an ex vivo histopathologic examination of the spinal cord is thought to be the gold standard in the diagnosis of CVSM. Our histological examination revealed no CVSM-specific glial scar formation and a CD68(−) negative and TNF-α negative reaction, which have not been previously reported. Histological lesions in CVSM may vary depending show inter-individual variability and on the treatment, which further hinders ex-vivo diagnostics.

Utility of C-reactive protein and serum amyloid A in the diagnosis of equine protozoal myeloencephalitis.

BackgroundAccurate antemortem EPM diagnosis requires evidence of intrathecal antibody production. Some advocate the use of acute phase proteins in addition to serology, which alone results in substantial false positives.Hypothesis/ObjectivesThe purpose of this study was to determine if serum C‐reactive protein (CRP) or serum amyloid A (SAA) concentrations were elevated in cases of equine protozoal myeloencephalitis (EPM) compared to other neurological diseases.Animals25 clinical cases of equine neurological disease: EPM (10), cervical vertebral stenotic myelopathy (CVSM) (10), neuroborreliosis (2), equine motor neuron disease (1), degenerative myelopathy (1), and leukoencephalomalacia (1).MethodsSerum and CSF CRP and SAA were measured. Selection criteria included neurologic disease, antemortem diagnosis of EPM or CVSM, or postmortem diagnosis of EPM, CVSM, or other neurologic disease, and availability of serological results and archived samples for testing.ResultsSerum SAA and serum CRP levels were generally undetectable or low in horses with EPM (median CRP ≤0.1 mg/L, ≤0.1‐14.4 mg/L; median SAA ≤0.1 mg/L, ≤0.1‐6.11 mg/L) and CVSM (median CRP ≤0.1, ≤0.1‐2.41 mg/L; median SAA ≤0.1mg/L, ≤0.1‐13.88 mg/L). CSF CRP and SAA for horses with EPM (median CRP 3.35 mg/l, 0.19‐13.43 mg/l; median SAA ≤0.1 mg/L, ≤0.1‐2.4 mg/L) and CVSM (median CRP 4.015 mg/L, 0.16‐9.62 mg/L; median SAA 0.62 mg/L, ≤0.1‐2.91 mg/L) were also undetectable or low. Kruskal–Wallis test showed no statistically significant differences between serum CRP (P = .14), serum SAA (P = .79), spinal fluid CRP (P = .65), or spinal fluid SAA between horses with EPM and CVSM (P = .52).ConclusionNeither SAA nor CRP in serum or CSF aid diagnosis of EPM.

Protozoal coinfection in horses with equine protozoal myeloencephalitis in the eastern United States.

BackgroundInfection by 2 or more protozoa is linked with increased severity of disease in marine mammals with protozoan encephalitis.Hypothesis/ObjectivesTo assess whether horses with equine protozoal myeloencephalitis (EPM) caused by Sarcocystis neurona also have evidence of infection with Neospora hughesi or Toxoplasma gondii. We hypothesized that horses with EPM would be more likely than horses with cervical vertebral stenotic myelopathy (CVSM) to be positive for antibodies to multiple protozoan parasites.AnimalsOne hundred one horses with neurologic disease: 49 with EPM and 52 with CVSM.MethodsCase review. Archived serum and cerebrospinal fluid (CSF) from 101 horses were examined. Inclusion criteria included neurologic disease, antemortem or postmortem diagnosis of EPM or CVSM, and availability of serological results or archived samples for testing. Additional testing for antibodies was performed on serum for T. gondii, as well as serum and CSF for N. hughesi.ResultsHorses with EPM were more likely than horses with CVSM to have positive immunologic results for S. neurona on serum (95.9% versus 76.9%, P = .0058), CSF (98.0% versus 44.2%, P < .00001), and serum : CSF titer ratio (91.8% versus 0%, P < .00001). Positive results for Neospora and Toxoplasma were uncommon, with total seroprevalence rates of 12.9% and 14.9%, respectively. The proportions of EPM cases testing positive for Neospora and Toxoplasma (16% and 12%) were not different from the proportions of CVSM cases testing positive (10% and 17%, P = .31 and .47, respectively).ConclusionResults do not indicate an important role for protozoal coinfection in EPM in the eastern United States.

Management of equine ataxia caused by cervical vertebral stenotic myelopathy: A European perspective 2010–2015

SummaryThe diagnosis and therapy of cervical vertebral stenotic myelopathy (CVSM) are challenging and have been most frequently described in racehorses. We aimed to analyse CVSM cases presented for diagnostic work‐up and treatment in a nonracing horse population. We hypothesised that our diagnostic work‐up protocol including clinical/orthopaedic/neurological/radiographic and myelographic examinations may provide practical reference points for in vivo diagnosis/prognosis and adequate CVSM management. Medical records from 2010 to 2015 were reviewed retrospectively. Cases were included if our standardised work‐up protocol was followed, there was no evidence of any infectious diseases causing the neurological signs, and native cervical radiographs and myelograms confirmed CVSM. Age/breed/sex/type of performance/degree of neurological deficits and number/sites/quality/therapy of stenosis were recorded. Sixty‐two horses met the inclusion criteria. The majority of the horses were aged 5–10 years (44%) or &gt;10 years (35%); nine horses (15%) were 1–4 years and four &lt;1 year (6%) old. Forty‐six horses were Warmbloods (73%), 10 ponies (16%) and six of other breeds (11%). Males were more affected (69%) than females (31%). Sixty‐one percent were pleasure‐horses, 26% were sport‐horses and no information was available for 13%. Most cases presented with mild–moderate neurological signs (grade 2/5 = 18%, grade 2–3/5 = 31%). On myelograms, 23 horses (37%) had single‐level, 22 (35%) had double‐level, and eight (13%) triple‐level stenosis, while nine cases (15%) did not have stenosis. Fifty horses (55%) showed dynamic and 41 (45%) static stenosis. Dynamic stenosis was more common (46%) than static (29%) stenosis and/or combined stenosis (25%). Stenoses were more frequently observed in the mid‐to‐caudal vertebrae. Static stenoses tended to be located more caudally. Based on our protocol, 15% of horses were subjected to euthanasia without therapy, 62% treated conservatively and 23% underwent cervical ventral interbody fusion. In conclusion, our diagnostic work‐up protocol provided practical reference points for in vivo diagnosis/prognosis and adequate management of CVSM in a nonracing horse population.

Modified steel basket technique for the treatment of equine cervical vertebral stenotic myelopathy - a case report

A mielopatia estenotica cervical (MEC), tambem conhecida com ataxia cervical ou sindrome de Wobbler, e causada por um estreitamento do canal vertebral devido a malformacao das vertebrais cervicais, resultando em uma compressao da medula espinhal e alteracoes neurologicas como ataxia, fraqueza e postura anormal. As opcoes de tratamento podem ser conservador ou cirurgico, sendo que ambos apresentam eficacia variavel. A tecnica cirurgica mais apropriada para a maioria dos casos e a artrodese, promovendo rapida e eficiente descompressao da medula espinhal. O objetivo deste trabalho e relatar o caso de um equino com MEC que foi tratado cirurgicamente aplicando-se uma tecnica modificada com um novo tipo de cesto metalico. O diagnostico foi realizado por meio do historico, sinais clinicos e evidencias radiograficas de compressao medular entre as vertebras C3 e C4, apos descartar possiveis agentes infecciosos. O procedimento cirurgico para descompressao e estabilizacao do ponto de estenose foi realizado utilizando-se a tecnica modificada de Cloward e um novo modelo de cesto de aco fixado com dois parafusos. Evidencias de fusao foram obtidas por exames radiograficos periodicos durante seis meses de pos-operatorio. O novo modelo de cesto de aco utilizado nessa cirurgia provou ser eficiente para descompressao e estabilizacao das vertebras, permitindo o desenvolvimento da artrodese e remissao dos sinais clinicos. A fixacao do cesto com parafusos reduziu o risco de migracao do implante.

Mielopatía estenótica vertebral cervical (MEVC) en un caballo criollo colombiano.

Se expone el caso de un caballo criollo Colombiano, de trocha fina, color moro, macho entero y 17 años de edad, el cual fue diagnosticado con Mielopatía Estenótica Vertebral Cervical (MEVC), procedente del municipio de Chimá (Córdoba, Colombia). Al examen neurológico se le detectó ataxia simétrica que empeoró al tapar los ojos, signos de incoordinación con tropiezos a la prueba de latero pulsión, debilidad y pérdida de la propiocepción principalmente en los miembros posteriores detectada con la prueba de propiocepción consciente, la prueba de Hoping o hemisalto fue positiva, razón por la cual se le realizó radiología cervical en proyección latero-lateral, detectando doble estenosis de canal medular a nivel de las vértebras cervicales C2-C3 y C3-C4. Estos hallazgos obedecen principalmente a Mielopatía Estenótica Vertebral Cervical (MEVC). Esta alteración es también conocida en equinos como Síndrome de Wooblers, la cual es una enfermedad del desarrollo caracterizada por estenosis del canal vertebral cervical resultando en compresión intermitente o continua de la médula espinal.

Síndrome de Wooblers en un caballo

RESUMENSe describe un caso de síndrome de Wooblers en un caballo, macho entero, de 14 años de edad, procedente del municipio de Cereté (Córdoba, Colombia). Esta patología es también conocida en equinos como mielopatía estenótica vertebral cervical (MEVC), la cual es una enfermedad del desarrollo caracterizada por estenosis del canal vertebral cervical resultando en compresión intermitente o continua de la médula espinal. A este paciente se le detectaron signos de incoordinación con tropiezos, ataxia simétrica, paresia o debilidad, espasticidad y pérdida de la propiocepción, principalmente en los miembros posteriores, por lo que se le realizó radiología cervical detectando estenosis de canal medular a nivel de la vértebra cervical C4. Estos hallazgos obedecen principalmente al síndrome de Wooblers.

Cervical vertebral canal endoscopy in a horse with cervical vertebral stenotic myelopathy

A 3-year-old Thoroughbred gelding presented with a history of neurological signs, including incoordination in his hindlimbs, of about 7 months' duration. On initial examination, the horse exhibited ataxia and paresis in all limbs with more severe deficits in the hindlimbs. Cervical radiographs displayed severe osteoarthritis of the articular processes between C5 and C6. On subsequent cervical myelography the dorsal contrast column was reduced by 90% at the level of the intervertebral space between C5 and C6. Cervical vertebral canal endoscopy, including epidural (epiduroscopy) and subarachnoid endoscopy (myeloscopy), was performed under general anaesthesia. A substantial narrowing of the subarachnoid space at the level between C6 and C7 was seen during myeloscopy, while no compression was apparent between C5 and C6. Epiduroscopy showed no abnormalities. After completion of the procedure, the horse was subjected to euthanasia and the cervical spinal cord submitted for histopathological examination. Severe myelin and axon degeneration of the white matter was diagnosed at the level of the intervertebral space between C6 and C7, with Wallerian degeneration cranially and caudally, indicating chronic spinal cord compression at this site. Myeloscopy was successfully used to identify the site of spinal cord compression in a horse with cervical vertebral stenotic myelopathy, while myelography results were misleading.

Cervical vertebral canal endoscopy in the horse: Intra- and post operative observations

Despite modern medical diagnostic imaging, it is not possible to identify reliably the exact location of spinal cord compression in horses with cervical vertebral stenotic myelopathy (CVSM). Vertebral canal endoscopy has been successfully used in man and a technique for cervical vertebral canal endoscopy (CVCE) has been described in equine cadavers. To determine the feasibility and safety of CVCE in healthy mature horses. Six healthy mature horses were anaesthetised. A flexible videoendoscope was subsequently introduced via the atlanto-occipital space into the epidural space (epiduroscopy, Horses 1-3) or the subarachnoid space (myeloscopy, Horses 4-6) and advanced to the 8th cervical nerve. Neurological examinations were performed after surgery and lumbosacral cerebrospinal fluid (CSF) analysed in horses that had undergone myeloscopy. All procedures were completed successfully and all horses recovered from anaesthesia. Anatomical structures in the epidural space (including the dura mater, nerve roots, fat and blood vessels) and subarachnoid space (including the spinal cord, blood vessels, arachnoid trabeculations, nerve roots and the external branch of the accessory nerve) were identified. During epiduroscopy, a significant increase in mean arterial pressure was recognised, when repeated injections of electrolyte solution into the epidural space were performed. In one horse of the myeloscopy group, subarachnoid haemorrhage and air occurred, resulting in transient post operative ataxia and muscle fasciculations. No complications during or after myeloscopy were observed in the other horses. CSF analysis indicated mild inflammation on Day 7 with values approaching normal 21 days after surgery. Endoscopic examination of the epidural and subarachnoid space from the atlanto-occipital space to the 8th cervical nerve is possible and can be safely performed in healthy horses. Cervical vertebral canal endoscopy might allow accurate identification of the compression site in horses with CVSM and aid diagnosis of other lesions within the cervical vertebral canal.

Endoscopic anatomy of the cervical vertebral canal in the horse: A cadaver study

Localisation of spinal cord compression in horses with cervical vertebral stenotic myelopathy is inexact. Vertebral canal endoscopy has been used in man to localise spinal cord lesions and has the potential to become a useful diagnostic technique in horses. To establish a surgical approach via the atlanto-occipital space to the cervical vertebral canal in equine cadavers and describe the endoscopic anatomy of the cervical epidural and subarachnoid spaces. The cadavers of 25 mature horses were used to assess 3 surgical methods to approach the cervical vertebral canal, including 2 minimally invasive and one open technique. Once the approach had been made, a flexible videoendoscope was inserted into the epidural space (epiduroscopy) or the subarachnoid space (myeloscopy) and advanced caudally until the intervertebral space between C7 and T1 was reached. The epidural and subarachnoid spaces could not be accessed reliably using the minimally invasive techniques. Furthermore, damage to the nervous tissues was a frequent complication with these procedures. The open approach allowed successful insertion of the videoendoscope into the epidural and subarachnoid spaces in all horses and no inadvertent damage was observed. Anatomical structures that could be seen in the epidural space included the dura mater, nerve roots, fat and the ventral internal vertebral venous plexus. In the subarachnoid space, the spinal cord, nerve roots, blood vessels, denticulate ligaments and external branch of the accessory nerve were seen. Using the open approach, epiduroscopy and myeloscopy over the entire length of the cervical vertebral canal are possible in the mature horse. Cervical vertebral canal endoscopy may become a valuable tool to localise the site of spinal cord injury in horses with cervical vertebral stenotic myelopathy and could aid in the diagnosis of other diseases of the cervical spinal cord.

Onchocercosis of an Intervertebral Joint Capsule Causing Cervical Vertebral Stenotic Myelopathy in a Horse

A novel case where onchocercosis was identified as a cause of cervical myelopathy in the horse is described. A 15-year-old Connemara mare was euthanized due to progressive locomotion disturbance. Postmortem examination revealed soft-tissue swelling in the intervertebral joint capsule of C6-7 with narrowing of the vertebral canal. On light microscopy, axonopathy was pronounced in the corresponding segment of the spinal cord. Fibrous tissue and eosinophilic granulomas were found in the joint capsule, together with parasites identified histologically as Onchocerca sp.

Radiographic and myelographic assessment of the equine cervical vertebral column and spinal cord

Radiography and myelography are extremely valuable diagnostic tools for evaluation of the equine cervical vertebral column and spinal cord, being useful for identification of malformations, fractures and osteomyelitis in this region. A frequent application of cervical radiography and myelography is in the evaluation of suspected cases of cervical vertebral malformation (CVM). For a thorough review of CVM (‘wobbler syndrome’ or cervical vertebral stenotic myelopathy), the reader is directed to the recent paper by Nout and Reed (2003). These radiographic diagnostic modalities are used after thorough physical and neurological examinations have localised the suspect lesion(s) to the cervical spinal cord. This article accompanies the paper in this issue by Walmsley (2005) that details the experiences in an English equine hospital of the surgical treatment of CVM. As the author notes, that article highlights the importance of confirming the presence of cervical spinal cord compression and, most critically for the surgeon, determining the exact site(s) of compression in order to decide upon a targeted surgical approach.