Myelographic Examination Research Articles

Deep learning-based reconstruction for 3-dimensional heavily T2-weighted fat-saturated magnetic resonance (MR) myelography in epidural fluid detection: image quality and diagnostic performance.

Heavily T2-weighted fat-saturated (HT2W-FS) magnetic resonance myelography (MRM) is useful for diagnosing the cause of intracranial hypotension. Recently, deep learning-based reconstruction (DLR) has been utilized to improve image signal-to-noise ratios and sharpness while reducing artifacts, all without lengthening acquisition times. This study aimed to compare the diagnostic performance and image quality of conventional reconstruction (CR) and DLR of 3-dimensional (3D) HT2W-FS MRM applied to detecting epidural fluid in patients with clinically suspected intracranial hypotension. This retrospective study included 21 magnetic resonance myelography examinations using both CR and DLR in 21 patients who experienced orthostatic headache between April 2021 and September 2022. Quantitative image quality evaluation was performed by comparing signal-to-noise ratios at the lower thoracic levels. The image quality and artifacts were graded by three readers. The presence of epidural fluid was reported with a confidence score by two readers, and the area under the receiver operating curve, interobserver agreement, and inter-image-set agreement were evaluated. The conspicuity of the dura mater where the epidural fluid was detected was also investigated. Quantitative and subjective image quality, and artifacts significantly improved with DLR (all P<0.001). Diagnostic performance of DLR was higher for both readers [reader 1: area under the curve (AUC) of CR =0.929; 95% confidence interval (CI): 0.902-0.950, AUC of DLR =0.965 (95% CI: 0.944-0.979), P=0.007; reader 2: AUC of CR =0.834 (95% CI: 0.798-0.866), AUC of DLR =0.877 (0.844-0.905), P=0.040]. Correlation with standard care of MRM in CR and DLR were both strong in reader 1 (rho =0.868-0.919, P<0.001), but was respectively strong and moderate in reader 2 (rho =0.734-0.805, P<0.001). Interobserver agreement was substantial (κ=0.708-0.762). The inter-image-set agreement was almost perfect for reader 1 (κ=0.907) and was substantial for reader 2 (κ=0.750). Dura mater conspicuity significantly improved with DLR (P<0.014, reader 1; P<0.001, readers 2 and 3). HT2W-FS magnetic resonance myelography with DLR demonstrates substantial improvements in image quality and may improve confidence in detecting epidural fluid.

Recurrent Spontaneous Bilateral Subdural Hemorrhage as a Consequence of High-Cervical Spontaneous CSF Leak—Lessons for Neurosurgeons

AbstractSpontaneous intracranial hypotension (SIH) is rare. It presents as intractable posture headache and is identified by radiological findings. It is confirmed by cerebrospinal fluid (CSF) manometry and myelography, and treatment is carried out with the help of epidural blood patch (EBP) therapy. SIH presenting with spontaneous bilateral recurrent subdural bleeds is uncommon. The cause being a high-spinal CSF leak is even more uncommon! Our patient had recurrent bilateral spontaneous chronic subdural hematomas. Myelographic examination of the spine showed a C1–C2 level leak of CSF. He was taken up for open microsurgery, and the leak was identified and closed with fibrin glue. The patient however deteriorated the next day. An EBP was applied in the lumbar region to cover the myelogram lumbar puncture site. We present a review of literature and an algorithm to detect the elusive CSF leak and effect definitive treatment, either open or EBP, to treat the source of the problem.

Safety of Consecutive Bilateral Decubitus Digital Subtraction Myelography in Patients with Spontaneous Intracranial Hypotension and Occult CSF Leak.

Digital subtraction myelography performed with the patient in the lateral decubitus position has the potential for increased sensitivity over prone-position myelography in the detection of spinal CSF-venous fistulas, a well-established cause of spontaneous intracranial hypotension. We report on the safety of performing routine, consecutive-day right and left lateral decubitus digital subtraction myelography in these patients. In this retrospective case series, all patients undergoing consecutive-day lateral decubitus digital subtraction myelography for suspected spinal CSF leak between September 2018 and September 2019 were identified. Chart review was performed to identify any immediate or delayed adverse effects associated with the procedures. Procedural parameters were also analyzed due to inherent variations associated with the positive-pressure myelography technique that was used. A total of 60 patients underwent 68 pairs of consecutive-day lateral decubitus digital subtraction myelographic examinations during the study period. No major adverse effects were recorded. Various minor adverse effects were observed, including pain requiring analgesics (27.2%), nausea/vomiting requiring antiemetics (8.1%), and transient neurologic effects such as syncope, vertigo, altered mental status, and autonomic dysfunction (5.1%). Minor transient neurologic effects were correlated with increasing volumes of intrathecal saline injectate used for thecal sac prepressurization. In patients with spontaneous intracranial hypotension and suspected spontaneous spinal CSF leak, consecutive-day lateral decubitus digital subtraction myelography demonstrates an acceptable risk profile without evidence of neurotoxic effects from cumulative intrathecal contrast doses. Higher intrathecal saline injectate volumes may correlate with an increased incidence of minor transient periprocedural neurologic effects.

Sequestered Disc Herniation in a Dog

Background: Dogs are frequently affected by intervertebral disc degeneration, a structural failure associated with changes accelerated by aging. Disc degeneration may occur in the presence or absence of clinical signs, which are variable and common to other spinal cord diseases and therefore early diagnosis is crucial to a successful outcome. Treatment may be conservative or surgical according to severity of the clinical signs and should be combined with a rehabilitation protocol. Prognosis depends on the location of the spinal cord compression, volume and velocity of the disc material herniation and time between initial clinical signs, definitive diagnosis and therapeutic approach. Case: A nonchondrodystrophic 14-year-old dog with acute clinical manifestation of paraparesis and proprioceptive deficit in hind limbs was submitted to myelography examination. There was contrast column deviation in the T13-L1 region, determining spinal compression, and spondyloses were also noted in several thoracolumbar vertebrae. Hemilaminectomy was performed with complete removal of the compressor fragment. Histological analysis confirmed the presence of fibrocartilaginous material that corresponds to the part of the annulus fibrosus. The kidnap of the fragment was characterized by loss of continuity with the remaining disk. In these cases, magnetic resonance imaging does provides the definitive diagnosis, since neoplasm, arachnoid cysts and abscesses may be remaining differential diagnosis. Therefore, surgical approach followed by histopathological analysis of the obtained material are necessary to confirm the diagnosis.Discussion: The present report differs from most cases of disc herniation because it is a thoracolumbar lesion with an acute manifestation of significant neurological deficit in an elderly dog of non-chondrodystophic breed. Also, material of the free fibrous annulus itself in the medullary canal is not a common histopathological presentation of disc extrusion usually composed by nucleus pulposus. After neurolocalization of the lesion by clinical neurological examination, the radiographic evaluation shall precedes the myelography, since this is contraindicated when there is suspicion of discoespondylitis, fracture, dislocation or vertebral subluxation, which had not yet been discarded. Even if the MRI is performed, in the cases of a sequestered fragment, it still remais differential diagnoses include arachnoid cysts, discoespondylitis, hematomas, abscesses and neoplasms, including metastases, so only surgical approach to obtain material for histopathological analysis may provide definitive diagnosis. According to the histopathological examination, the herniated material had a fibrocartilaginous characteristic: several concentric fibrous blades, composed of collagen and fibrocartilage, thus characterizing the herniated material as a fragment of the fibrous ring. When removed from the vertebral canal, the contents did not show resistance, being withdrawn completely and without continuity with its origin intervertebral disc. The patient's disc herniation could not be classified as a disc protrusion because this affection is described as a projection of the fibrous annulus towards the vertebral canal due to the partial rupture of fibers and mineralization of the nucleus pulposus, without discontinuity of some content. Disc protrusion shows mild and progressive signs, except if there is complete rupture of the fibrous ring as can be seen in the sequestered disc herniation. Although infrequent, elderly animals of non-chondrodisiotic races may show acute signs of neurological deficits. Sequestrated disc herniation may mimic other lesions, requiring a surgical approach to obtain material for histopathological analysis to confirm the diagnosis.

Assessing Spinal Cerebrospinal Fluid Leaks in Spontaneous Intracranial Hypotension With a Scoring System Based on Brain Magnetic Resonance Imaging Findings

Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice. To develop a probability score based on the most relevant brain MRI findings to assess the likelihood of an underlying spinal cerebrospinal fluid (CSF) leak in patients with SIH. This case-control study in consecutive patients investigated for SIH was conducted at a single hospital department from February 2013 to October 2017. Patients with missing brain MRI data were excluded. Three blinded readers retrospectively reviewed the brain MRI scans of patients with SIH and a spinal CSF leak, patients with orthostatic headache without a CSF leak, and healthy control participants, evaluating 9 quantitative and 7 qualitative signs. A predictive diagnostic score based on multivariable backward logistic regression analysis was then derived. Its performance was validated internally in a prospective cohort of patients who had clinical suspicion for SIH. Likelihood of a spinal CSF leak based on the proposed diagnostic score. A total of 152 participants (101 female [66.4%]; mean [SD] age, 46.1 [14.3] years) were studied. These included 56 with SIH and a spinal CSF leak, 16 with orthostatic headache without a CSF leak, 60 control participants, and 20 patients in the validation cohort. Six imaging findings were included in the final scoring system. Three were weighted as major (2 points each): pachymeningeal enhancement, engorgement of venous sinus, and effacement of the suprasellar cistern of 4.0 mm or less. Three were considered minor (1 point each): subdural fluid collection, effacement of the prepontine cistern of 5.0 mm or less, and mamillopontine distance of 6.5 mm or less. Patients were classified into groups at low, intermediate, or high probability of having a spinal CSF leak, with total scores of 2 points or fewer, 3 to 4 points, and 5 points or more, respectively, on a scale of 9 points. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. This 3-tier predictive scoring system is based on the 6 most relevant brain MRI findings and allows assessment of the likelihood (low, intermediate, or high) of a positive spinal imaging result in patients with SIH. It may be useful in identifying patients with SIH who are leak positive and in whom further invasive myelographic examinations are warranted before considering targeted therapy.

Predicting Spinal CSF Leaks in Intracranial Hypotension: A Scoring System Based on Brain MRI Findings

Background: Various signs may be observed on brain magnetic resonance imaging (MRI) in patients with spontaneous intracranial hypotension (SIH). However, the lack of a classification system integrating these findings limits decision making in clinical practice. The objective was to assess the likelihood of an underlying spinal CSF leak based on a probability score taking into account the most relevant brain MRI findings. Methods: Three blinded readers retrospectively reviewed the brain MRI of 56 SIH patients with a proven spinal CSF leak and 60 healthy controls, evaluating seven quantitative and nine qualitative signs. We then derived a predictive diagnostic score based on multivariable backward logistic regression analysis. Its performance was further validated internally in a prospective cohort of 20 patients presenting with clinical signs of SIH. Findings: Six imaging findings were included in the final scoring system. Three were weighted as major (2 points): pachymeningeal enhancement, engorgement of venous sinus, effacement of the suprasellar cistern 5, respectively. The discriminatory ability of the proposed score could be demonstrated in the validation cohort. Interpretation: The three-tier predictive scoring system we propose is based on the six most relevant brain MRI findings and allows to assess the likelihood (low, intermediate or high probability) of finding a spinal CSF leak in SIH patients. It may be useful in triaging patients who may or may not benefit from further invasive myelographic examinations before considering targeted therapy. Funding Statement: The authors declare: This study was not funded, as all examinations were part of our routine clinical protocol. Declaration of Interests: PJM receives Swiss National Science Foundation (SNSF) grants for research on brain aneurysms. JG is a global PI of STAR, CEC member of the PROMISE study (Penumbra) PI for the SWIFT DIRECT study (Medtronic), Consultancy; and receives Swiss National Science Foundation (SNSF) grants for magnetic resonance imaging in stroke. JB is global PI of SWITCH and TOSCAN studies. He received SNSF grant for ultrasound perfusion imaging. All other authors declare no competing interests. Ethics Approval Statement: Institutional review board approval was obtained for this single-center study (Kantonale Ethikkommission Bern, Switzerland, number: 2017–00861).

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.

A rare cause of gluteal swelling: lateral sacral meningomyelocele

A full-term, 2-month-old boy was presented with spinal deformity and right gluteal swelling. On physical examination, there was a soft and fluctuant swelling in the right upper gluteal region. There was no obvious neurologic deficit. Spinal magnetic resonance imaging (MRI) and magnetic resonance myelography examinations were performed. Spinal MRI with coronal plane revealed a left-sided scoliosis with several hemivertebra and butterfly vertebra anomalies in the upper and mid-thoracic vertebrae, and a cystic lesion in the right gluteal region (Fig. 1). Axial MRI images showed a smoothcontoured, thin-walled cystic lesion containing neural elements. At the level of S1–S2, the spinal canal was expanded, including a tethered spinal cord. The right neural foramen was enlarged at this level. The cystic lesion in the right upper gluteal region was integrated with cerebrospinal fluid through this enlarged neural foramen, revealing a lateral meningomyelocele (Fig. 2, Left and Right). Magnetic resonance myelography examination showed a clear continuity of the meningomyelocele with the thecal sac (Fig. 3).

Lumbar Myelography in a Crab-Eating Raccoon (Procyon cancrivorus)

Background: The Crab-eating raccoon (Procyon cancrivorus) is a nocturnal mammal and lives in savannah, but loss of their natural habitat makes increase cases of traffic accidents on the roads. A growing number of wildlife are treated in veterinary hospitals, but we have some limitation about the correct interpretation of the diagnostic test, specially because, even the tests were not described. Myelography is a radiographic technique indicated for compressive lesions of the spinal cord that are not seen on plain radiographs. The present report aims to describe, for the first time, a lumbar myelogram performed in a paraplegic crab-eating raccoon after it suffer a traffic trauma.Case: A free living adult, 8-kg, female raccoon was presenting acute paraplegia and swelling in the region of the left humerus was referred at veterinary hospital. The patient was alert and aggressive, good body score and no signs of active bleeding. The animal temper did not allow approaching it; therefore, physical and neurological examinations were not feasible. The raccoon was tranquilized (1.6 mL of nilperidol® intramuscular), anesthetized (propofol, dose-effect intra­venous) and tracheal intubation to provide oxygen and the patient was monitored continuously, followed by referred for radiology service. The simple radiograph showed a complete transverse fracture in the humerus and compression fracture of the twelfth thoracic vertebra (T12), being then indicated the myelographic examination to assess the extent of spinal cord compression. The lumbar region was surgical antisepsis prepared. After being properly positioned in lateral decubitus with moderate cranial flexion of the trunk, the patient underwent lumbar puncture by inserting a spinal needle between the 5th and 6th intervertebral lumbar spaces. The spinal needle was introduced slightly caudolaterally to the spinous process of the 6th lumbar vertebra and cranioventrally directed at an angle of 45º. Then, the needle was pierced through the ligamentum flavum and the dura mater while, concomitantly, we observed the tail moving and the cerebrospinal fluid (CSF) output while the contrast was injected. The contrast iohexol (300 mg/mL) was used at a dose of 0.25 mL/kg. Immediately after the slow injection of contrast (approximately 3 min), radiographs were taken in the latero-lateral and ventrodorsal projections to identify the location of the spinal cord disorder. The extension degree of the lesion was evidenced by the reduction of the contrast column width at the location of instability. The patient was referred for surgical decompression and stabilization.Discussion: In cases where paraplegia results from trauma, spinal radiography and myelography are important means to confirm the diagnosis, specially the extent of the compression and prognosis. There are certain risks inherent in the myelography procedure as arrhythmias and bradycardia during collection, transient apnea during contrast injection and seizures during recovery. Furthermore, deteriorating neurological signs, emesis, urinary retention and hyperthermia are other possible complications. Most of these complications are seen predominantly during cervical myelography compared to lumbar puncture because in the first exam, the contrast hardly reaches the brain and there is no risk of iatrogenic injury to the medulla oblongata. To minimize the neurotoxic effects, the ideal contrast should be radiopaque, water soluble, mis­cible with the cerebrospinal fluid (CSF), nontoxic and removed from the CSF by physiological processes. Iohexol contrast was used effectively, without neurotoxicity upon clinical evaluation while the volume used was sufficient to determine the injury site. The reported case demonstrated the possibility of performing lumbar myelography on Procyon cancrivorus effectively without significant complications or difficulties.Keywords: wildlife, neurology, myelographic examination, Procyon cancrivoru.

The value of serial plasma and cerebrospinal fluid nuclear and mitochondrial deoxyribonucleic acid levels in aneurysmal subarachnoid hemorrhage

Increased plasma nuclear and mitochondrial DNA levels have been reported in critically ill patients, and extracellular DNA may originate from damaged tissues having undergone necrosis. This study tested the hypothesis that nuclear and mitochondrial DNA levels in CSF and plasma are substantially increased in patients with acute spontaneous aneurysmal subarachnoid hemorrhage (SAH) and decrease thereafter, such that nuclear and mitochondrial DNA levels may be predictive of treatment outcomes. Serial nuclear and mitochondrial DNA levels in CSF and plasma from 21 adult patients with spontaneous aneurysmal SAH and 39 healthy volunteers who received myelography examinations during the study period were evaluated. Data showed that circulating plasma nuclear DNA concentrations and both nuclear and mitochondrial DNA levels in CSF significantly increased in patients with aneurysmal SAH on admission compared with the volunteers. In patients with poor outcome, the CSF nuclear and mitochondrial DNA levels were significantly higher on Days 1 and 4, and plasma nuclear DNA levels were significantly higher from Day 8 to Day 14. Higher CSF nuclear (> 85.1 ng/ml) and mitochondrial DNA levels (> 31.4 ng/ml) on presentation were associated with worse outcome in patients with aneurysmal SAH. Higher CSF DNA levels on presentation, rather than plasma DNA levels, are associated with worse outcomes in patients with acute spontaneous aneurysmal SAH. More prospective multicenter investigations are needed to confirm the predictive value of CSF and plasma DNA levels on outcome.

Obstetric Brachial Plexus Lesions: CT Myelography

To evaluate the value of computed tomographic (CT) myelography in the detection of root damage and differentiation of root avulsions from neurotmesis in a large cohort of patients with an obstetric brachial plexus lesion (OBPL). Institutional review board approval was obtained. Informed consent was waived by the medical ethics committee. One hundred eighteen patients with OBPL born in the cephalic position and six patients born in the breech position were selected for surgery by two neurosurgeons in a multidisciplinary team. Functional loss of the C5 through T1 innervated muscles was noted. All patients underwent preoperative CT myelography at an average age of 19 weeks. CT myelographic examination results were reviewed by two radiologists, who were blinded to the clinical findings, for the presence of root avulsions and pseudocysts. Interobserver agreement was assessed by calculating κ values. CT myelographic results showed root avulsions in at least one level in 66 (56%) of 118 patients born in the cephalic position and in six (100%) of six patients born in the breech position. Levels C7 and C8 showed the most root avulsions, even if not expected from clinical examination results. A large number of root avulsions showed pseudocysts (73 [68%] of 107 levels in patients born in the cephalic position and 11 [73%] of 15 levels in patients born in the breech position). CT myelographic results showed root avulsions in more than half of patients with OBPL. Root avulsions were even detected at levels that were not expected at clinical examination. Because root avulsions require specific reconstructive techniques, CT myelography is recommended for every preoperative patient with OBPL.

Clinical and Histopathologic Characterization of a Central and Peripheral Axonopathy in Rouge-des-prés (Maine Anjou) Calves

Recently, a progressive pelvic limb ataxia and paraparesis leading invariably to recumbency has been reported in Rouge-des-prés calves. To characterize the clinical and pathological findings of this newly reported disease and to investigate its potential causes. Nine calves from 7 different farms were prospectively studied from initial diagnosis through postmortem examination. Physical and neurological examinations, blood tests, cerebrospinal fluid (CSF) analysis, and myelographic examinations were performed. Neuropathology was carried out on both central and peripheral nervous systems. Copper deficiency and organophosphate intoxication also were investigated. Pedigrees were analyzed. Age of onset varied from 2 to 6 weeks. Initial signs included pelvic limb ataxia and paraparesis. The neurological signs systematically progressed, over a 1-3-month period, to severe pelvic limb and truncal ataxia along with moderate paraparesis, leading to permanent recumbency. Animals remained alert. Cranial nerve function was normal. Muscle atrophy was not observed and spinal reflexes were normal. Blood tests, CSF analysis, and myelographic examination did not identify any abnormality. Neuropathology indicated neuronal fiber degeneration particularly in the dorsolateral and ventromedial funiculi of the spinal cord and in the peripheral nerves. Degenerative lesions also were observed in lateral vestibular and thoracic nuclei. No environmental factors such as copper deficiency or organophosphate intoxication could be incriminated as the cause of this axonopathy. Pedigree analysis suggested an inherited defect. The first description of a central and peripheral axonopathy is reported in Rouge-des-prés calves. An inherited defect is highly suspected.

Acute Myelomonocytic Leukemia (AML-M4) in a Dog with the Extradural Lesion

A two-year-old dog having presented with neurological signs showed marked leukocytosis and appearance of blast cells in the peripheral blood. Hematological and bone marrow examination showed an increase in blasts having both myeloid and monocytic cells characteristics. The dog was diagnosed with acute myelomonocytic leukemia (AML-M4) on the basis of bone marrow findings. Although the dog was treated with a multi-combination chemotherapy, the neurological abnormalities progressed and the dog was euthanized. Myelographic examination and necropsy revealed the extradural lesion formed by AML-M4 around the cervical spinal cord and this lesion was considered as a cause of the neurological signs.

Meningomyelitis due to nematode infection in four cats

Spinal cord parasitic migrations in cats are uncommon. This report describes four cases of chronic hindlimb paraparesis in cats associated with nematode infection. Complete neurologic, hematologic, serum chemistry and radiographic examination was performed on all animals. Computed tomographic (CT)-myelographic examination at the lumbar area in one cat showed a slight swelling of the spinal cord. Necropsy examination of the spinal cord revealed generalized edema and marked submeningeal hemorrhage at the thoracic region in three cats. On histopathologic examination, numerous sections of adult nematodes and eggs were present in histological sections of the affected spinal cord segments in all cats. The morphologic features of the nematode, location and appearance of the lesions suggest that the parasite responsible for the paralysis in these cats is Gurltia paralysans.

Cytologic and histologic features of spinal cord ependymoma in a young dog: a case report

A case of intramedullary ependymoma in a young dog is reported. A two year old dog was presented with paralysis of the forelimbs. At myelographic examination, an intramedullary pattern, blocking the progression of contrast medium, was observed. At necropsy, a 3 × 2 cm white-greyish mass was found extending from the 3&lt;sup&gt;rd&lt;/sup&gt; to 5&lt;sup&gt;th&lt;/sup&gt; lumbar levels. At cytological and histological examination, the mass was highly cellular and was comprised of ovoid cells with indistinct borders, elongated eosinophilic cytoplasm and round to oval vesicular nuclei. Cytoplasmic processes formed a fibrillar network wherein true rosettes and many pseudorosettes around a fibrovascular stroma were observed. Immunohistochemistry for vimentin and GFAP gave strong positive results in the neoplastic cells, especially around pseudorosettes and confirmed the diagnosis of intramedullary spinal ependymoma.

Cervical Spondylotic Myelopathy

Cervical spondylotic myelopathy, the most frequent type of spinal cord's function impairment in patients over 55 years of age, is caused by mechanical and dynamical changes in the degenerating lower cervical segment of the spine leading to the reduction of the perimedullar space, disturbing thus the blood supply or spinal cord per se. The clinical picture of neurologic changes and their development is very variable. The suspicion of CSM is supported by the finding of the stenosis of the spinal canal to 11 mm, or the decrease in Pavlov's index below 0.8. The diagnosis is based dominantly on CT myelographic examination and MRI. Operative solution has a favourable prognosis providing that the irreversible changes in the spinal cord are absent. (Tab. 1, Fig. 7, Ref. 12.)

Pleuropneumonia as a sequela of myelography and general anaesthesia in a Thoroughbred colt

A 3-year-old Thoroughbred colt was presented to the University Veterinary Centre Camden for evaluation of ataxia. The horse was anaesthetised to facilitate cervical radiography and myelographic examination of the spinal cord. Recovery from anaesthesia was uneventful. Five days after general anaesthesia the horse re-presented with pleuropneumonia. It was euthanased 24 hours after presentation on humane grounds. Necropsy revealed severe tracheal erosion over the middle third of the ventral surface of the trachea, pleuropneumonia and narrowing of the cervical cord between C4 and C6. It is postulated that extension and flexion of the neck during myelography resulted in movement of the endotracheal tube cuff, causing the tracheal lesion and predisposing the colt to pleuropneumonia. Severe tracheal lesions and pleuropneumonia have not been reported as sequela of equine myelography, and should be considered as possible complications following repeated cervical manipulation during myelography in the horse.

Myelography Complications and Current Practice Patterns

Relatively few data are available in the literature on postmyelography complications. Also, no consensus exists on the need to screen myelography patients for use of potentially epileptogenic drugs, metformin, and aspirin or other nonsteroidal antiinflammatory drugs (NSAIDs) or to routinely check prothrombin time (PT) and partial thromboplastin time (PTT). We designed a Web-based survey to obtain information on myelography complications and current practice patterns. An e-mailing was sent to 2,296 members of the American Society of Neuroradiology (ASNR), requesting their participation in a survey, and 351 responses (15%) were received. The survey included questions on the number of myelography examinations performed and the number of seizures and other complications observed in myelography patients; questions on screening for potentially epileptogenic drugs, metformin, and aspirin or other NSAIDs; and a question on checking PT and PTT. Most responding ASNR members (88%) reported no postmyelography seizures, and 82% observed no other significant complications in the past 5 years. A majority of practitioners (63%) screens patients for potentially epileptogenic drugs, 63% of respondents do not advise patients to discontinue metformin use after myelography, 58% do not advise patients to discontinue aspirin or other NSAIDs, and 73% do not routinely check PT and PTT. Myelography is generally safe, with a low risk of seizures, contrast reactions, and other significant complications. The results of this study show that a majority of practitioners screens patients for use of potentially epileptogenic drugs, but a majority does not require patients to discontinue use of metformin and aspirin or other NSAIDs, nor do they routinely check PT and PTT before the procedure. These common practice patterns are considered to be appropriate for the safe and efficient performance of myelography.

Magnetic resonance myelography evaluation of the lumbar spine end plates and intervertebral disks

To evaluate the value of magnetic resonance (MR) myelography in the evaluation of intervertebral disk and end-plate degenerative changes in the lumbar spine. Conventional MR and MR myelography examinations were performed in 150 consecutive patients (69 F and 81 M, mean age 45+/-15 years, range 18 89). Sagittal T1 and T2-weighted TSE images were compared to MR myelography obtained with a multishot-TSE-T2-weighted sequence (4000/250/fat suppression). Coronal, sagittal, and both oblique MR myelography projections were obtained. Image analysis was carried out independently by two radiologists who categorized lumbar disks into normal, degenerated, or edematous; and vertebral end plates into normal, edematous, or with fatty changes. The proportions were statistically compared at every lumbar intervertebral level. There was good agreement in the classification of disk disease (Kappa: 0.8-0.9). MRI detected a larger number of disk degeneration and end-plate fatty metamorphosis, while the MR myelography technique depicted a larger number of edematous disks and end plates. MR myelography was of limited value in detecting the same vertebral end-plate changes observed in MRI, although with similar findings in disk disease. However, the higher detection of edema changes by MR myelography should be analyzed prospectively, as it could be more sensitive than conventional MR sequences.

Spinal cord astrocytoma in a cat

A nine-year-old neutered male domestic shorthaired cat with a history of spinal pain and progressive hindlimb dysfunction was presented to the Norwegian School of Veterinary Science. Following neurological and myelographic examination, an intramedullary mass affecting several lumbar spinal cord segments was diagnosed. A neoplastic lesion was suspected and a poor prognosis was given. On postmortem examination, the spinal cord was found to be dorsally flattened from the 12th thoracic vertebra to the fifth lumbar vertebra and severely thickened with a dorsal cleft from the fifth to the seventh lumbar vertebra. Histologically, the tumour was diagnosed as an anaplastic astrocytoma.