Intramedullary Cord Research Articles

Clinical profile and dynamic magnetic resonance imaging in Hirayama disease: a single-centered cross-sectional study in Nepal.

Eighteen patients were assessed for clinical and radiological Hirayama disease. Clinical criteria included insidious onset nonprogressive chronic upper limb weakness and atrophy in teens or early twenties without sensory deficits and coarse tremors. MRI was done in a neutral position followed by neck flexion to evaluate cord atrophy and flattening, abnormal cervical curvature, loss of attachment between the posterior dural sac and subjacent lamina, anterior shifting of the posterior wall of the cervical dural canal, posterior epidural flow voids, and an enhancing epidural component with its dorsal extension. The mean age was 20.33 years, and the majority, 17 (94.4%), were male. Neutral-position MRI revealed loss of cervical lordosis in 5 (27.8%) patients, cord flattening in all patients with asymmetry in 10 (55.5%), and cord atrophy was observed in 13 (72.2%) patients with localized cervical cord atrophy in only 2 (11.1%) and extension of atrophy to dorsal cord in 11 (61.1%) patients. Intramedullary cord signal change was seen in 7 (38.9%) patients. Loss of attachment of posterior dura and subjacent lamina and anterior displacement of dorsal dura was seen in all patients. A crescent-shaped epidural intense enhancement was noted along the posterior aspect of the distal cervical canal in all patients, with dorsal level extension in 16 (88.89%) patients. The mean thickness of this epidural space was 4.38±2.26 (mean±2SD), and the mean extension was 5.5±4.6 vertebral levels (mean±2SD). The high degree of clinical suspicion can guide additional contrast studies in flexion as a set MRI protocol for early detection and avoiding false negative diagnoses of HD.

Canal narrowing in adult patients with cervical spinal cord injury without computed tomography evidence of trauma

PurposeCervical spinal cord injury can be a particularly devastating sequela of trauma. The purpose of this study was to describe the imaging findings of adult patients with cervical spinal cord injury without computed tomography evidence of trauma (SCIWOCTET). MethodsAll adult patients (≥18 years) treated for acute cervical SCIWOCTET at a single Level I adult trauma center over an eight-year period were retrospectively identified. CT imaging was evaluated for degenerative changes narrowing the midsagittal canal diameter (SCD) of the cervical spine and relative congenital cervical stenosis (CCS; congenital narrowing of the SCD <13 mm). Magnetic resonance imaging (MRI) scans were evaluated for signal intensity change (SIC) suspicious for cord edema/contusion as well as ligamentous injury, hemorrhage, and epidural hematoma. ResultsNinety-six patients with cervical SCIWOCTET met inclusion criteria. The most common mechanism of injury was fall from standing (47.9%). On CT, 86 patients (89.6%) had CCS. Degenerative changes were present in 95 patients (99.0%). In 98/99 patients (99.0%), the point of narrowest cervical SCD was ≤8 mm. On MRI, 79 patients (82.3%) demonstrated signal intensity change (SIC) indicative of cord edema/contusion, while 16 (16.7%) had ligamentous injury. Intramedullary cord hemorrhage was seen in two patients (2.1%) and epidural hematoma in three (3.1%). ConclusionDegenerative changes or CCS may narrow the minimum cervical SCD beyond the threshold at which low-energy trauma results in C-SCI. Adult patients with cervical spinal stenosis, whether congenital and/or degenerative, and neurologic findings referable to the cervical spine should be assessed for C-SCI.

Idiopathic hypertrophic pachymeningitis as a rare cause of spinal cord compression

Idiopathic hypertrophic pachymeningitis (IHP) is a rare inflammatory disease characterized by inflammation and hypertrophy of the dura mater. Spinal form of IHP is extremely rare. We report an idiopathic hypertrophic spinal pachymeningitis case, a 67-year-old female who presented with neck and upper back pain with progressive paraparesis and sensory level. Her magnetic resonance imaging cervico-dorsal spine showed abnormal epidural hypointensity on T2-weighted images from C5 to T4 with significant cord compression and intramedullary cord signal changes at T2 and T3 levels. The lesional biopsy was done suggestive of chronic inflammatory changes. She was treated with steroids and was able to walk unaided.

Maximizing surgical resection in revision surgery for an intramedullary spinal cord tumour using DTI/tractography and direct spinal cord stimulation: A technical note

BackgroundIntramedullary spinal cord tumours are formidable lesions in spine surgery due to the high risk of postoperative deficits associated with surgical resection. Traditional MRI imaging fails to provide a 3-D rendering of the relationship between the tumour and spinal cord sensory and motor pathways; in contrast, DTI/tractography can show this relationship with the potential to reduce surgery-related morbidity. The use of intraoperative somatosensory evoked potentials (SSEP) and transcranial motor evoked potentials (MEP) have also been considered a standard of care to minimize neurologic complications of surgery. However, in situations where both baseline SSEPs and MEPs are unobtainable, D-wave and direct cord stimulation can become invaluable intra-operative tools. MethodsA 6 year old child presented with new growth from an incompletely resected thoracic intramedullary dermoid tumour. Pre-operative DTI/tractography images were obtained. During tumour resection, SSEP and MEP signals were unable to be obtained, however intraoperative monitoring of the spinal cord was undertaken with D-wave monitoring and direct cord stimulation. ResultsThis multimodal monitoring technique allowed identification of the corticospinal tracts intra-operatively and allowed safe tumour resection. Post-operative MRI revealed gross total resection and the patient returned to her pre-operative neurological baseline without incurring any further deficits. ConclusionsWe have presented a technical description of the clinical utility of DTI/tractography in surgical planning, and D-wave monitoring with direct cord stimulation as adjuncts in the resection of an intramedullary cord tumour. This is particularly useful in the scenario where TcMEP/SSEP signals cannot be obtained and in revision surgery for intramedullary spinal cord tumours.

LMD-11. Pure spinal cord invasion in recurrent classic Hodgkin’s Lymphoma - what is it?

We present the case of a 39-year-old male who initially presented in January 2017 with abdominal pain and weight loss. He was eventually diagnosed with stage IVB Classical Hodgkin’s Lymphoma. Brentuximab, Vinblastine, and Dacarbazine regimen was initiated with dose adjustments made due to cardiomyopathy and neuropathy. By cycle 5, good response was evident on systemic imaging. He was then lost to follow-up.He represented in December 2020 with near paraplegia, preceded by months of tingling, numbness in both legs, gait imbalance and low back pain. MRI spine in January 2021 demonstrated multifocal abnormal cord signal changes with scattered areas of intramedullary cord enhancement as well as extensive enhancement of the cauda equina (Figures 1,2,3). CNS angiitis as a paraneoplastic phenomenon, mimics a similar clinical and radiographic appearance. Unfortunately none of the cord lesions were amenable to biopsy.Full body PET CT showed florid disease concerning for recurrence. 2 lumbar punctures with limited CSF flow cytometry and cytology analyses were negative. Mediastinal lymph node biopsy revealed Classical Hodgkins Lymphoma. DHAP chemotherapy regimen was initiated, soon after. A 3rd time, high volume comprehensive CSF analysis performed later, was unremarkable. MRI spine, after 2 cycles demonstrated significant improvement(Figures 4,5,6)coinciding with systemic response and clinical improvement. This favored diagnosis of CNS Hodgkin lymphoma over secondary CNS angiitis.CNS Hodgkin’s Lymphoma is a rare occurrence1, let alone, pure spinal intramedullary and leptomeningeal metastases. Intramedullary metastases arise from direct hematogenous spread or by, centripetal growth of tumor along spinal nerve roots with secondary invasion of spinal cord2. Systemic Hodgkin’s Lymphoma rarely affects the spine with a prevalence of 0.2% - 0.5%3,4. In an analysis of a large cohort of Hodgkin’s patients comprising 14,868 individuals, a prevalence of less than 0.02%, indicating it had been overestimated in the past5.

Thoraco-lumbar high grade spinal cord astrocytoma: first documented case in a tertiary medical center and review of literature

&lt;p class="abstract"&gt;This presents the first documented case of high grade spinal cord astrocytoma in a pediatric patient treated at a tertiary medical center and gives a comprehensive review of literature on the most current modes of diagnosis, treatment, and prognosis. We report the case of a 7-year-old male with complaints of inability to ambulate and associated low back pain, which rapidly deteriorated to complete paraplegia. Magnetic resonance imaging (MRI) of his spine revealed an intradural intramedullary spinal cord lesion extending from T11 to L5 vertebra, with considerations of spinal astrocytoma and ependymoma. The patient underwent en bloc laminectomy on T9-L3, partial resection of the intramedullary cord tumor, and subsequent laminoplasty with mini plates and screws. Histopathologic studies showed spinal cord astrocytoma, World Health Organization (WHO) grade 3 (anaplastic type). The patient’s neurologic status did not improve after the surgery and was advised to undergo chemo-radiation therapy but was lost to follow up. Ten months post-operation, patient sought consult due to severe back pain, generalized body weakness, and difficulty of breathing and was then admitted. Patient’s condition worsened that eventually resulted to his demise.&lt;/p&gt;&lt;p class="abstract"&gt; &lt;/p&gt;

Hirayama disease – Early MRI diagnosis of subacute medullary ischemia: A case report

Background: Hirayama disease (HD) is a rare, benign, and self-limiting motor neuron disorder that results in selective motor impairment of the C7-T1 myotomes. It is characterized by progressive, unilateral, or bilateral asymmetric muscle atrophy of the distal upper extremities and myelopathy.Case Description: A 23-year-old male presented with bilateral atrophy of the thenar/hypothenar eminences/ interosseous muscles, plus left-hand weakness. The cervical MRI documented subacute ischemic damage of the distal cervical cord. To rule out a tumor and reduce questionable cord compression, the patient underwent a C5–C6 anterior cervical discectomy and fusion (ACDF) immediately followed by a laminectomy with durotomy and to obtain a spinal cord biopsy. When the histology confirmed focal cord ischemia consistent with HD, it was clear that both operations were unnecessary.Conclusion: Establishing the diagnosis of HD is based on clinical findings and MRI/flexion MR features which include the demonstration of an increased T2-weighted intramedullary cord signal, enlargement of the posterior epidural space, and segmental spinal cord atrophy. The presence of HD should be recognized as a “nonsurgical entity,” and conservative nonsurgical management should be employed.

The Central Dot Sign : ASpecific Post-gadolinium Enhancement Feature of Intramedullary Spinal Cord Metastases.

Peripheral enhancement characteristics on magnetic resonance imaging (MRI), namely the rim and flame signs, are specific for intramedullary spinal cord metastases (ISCM) compared to primary cord masses. The study compared the frequency of anovel finding-the central dot sign-in ISCMs versus primary intramedullary masses. In this study 45 patients with 64ISCMs and 64control patients with 64primary intramedullary cord masses were investigated and 2 radiologists blinded to lesion type independently evaluated MR images for the presence of acentral dot sign: apunctate focus of enhancement in/near the center of an enhancing intramedullary mass. The frequency of this sign in the two patient groups was compared. A total of 63 enhancing ISCMs in 44patients and 54enhancing primary cord masses in 54patients were included. The central dot sign was identified in 6% (4/63) of enhancing ISCMs in 9% (4/44) of patients and in none (0/54) of the enhancing primary cord masses (p = 0.038, per patient). The specificity for diagnosing ISCMs among spinal cord masses was 100%. The central dot sign was present in the axial plane only in two ISCMs and in the axial and sagittal planes in two ISCMs. The two ISCMs harboring the central dot sign also demonstrated both the previously described rim and flame signs, and two also demonstrated the rim sign alone. The central dot sign is not sensitive but highly specific for ISCMs compared to primary spinal cord masses. The rim and/or flame signs may or may not be concurrently present in ISCMs.

Diagnostic Approach to Intrinsic Abnormality of Spinal Cord Signal Intensity.

Intramedullary cord hyperintensity at T2-weighted MRI is a common imaging feature of disease in the spinal cord, but it is nonspecific. Radiologists play a valuable role in helping narrow the differential diagnosis by integrating patient history and laboratory test results with key imaging characteristics. The authors present an algorithmic approach to evaluating intrinsic abnormality of spinal cord signal intensity (SI), which incorporates clinical evaluation results, time of onset (acute vs nonacute), cord expansion, and pattern of T2 SI abnormality. This diagnostic approach provides a practical framework to aid both trainees and practicing radiologists in workup of myelopathy.©RSNA, 2019.

S122. Intraoperative electrical stimulation to identify the corticospinal tract and dorsal column during spinal cord tumor surgery

Introduction Anatomical identification of the corticospinal tract (CT) and the dorsal column (DC) of the exposed spinal cord is difficult when anatomical landmarks are distorted by tumour growth. Intraoperative neurophysiological identification is complicated by the fact that direct stimulation of the DC may result in muscle motor responses due to the centrally activated H-reflex. This study aimed to provide a technique for intraoperative neurophysiological differentiation between CT and DC in the surgical exposed spinal cord. Methods Recordings were obtained from 32 consecutive patients undergoing intramedullary or intradural-extramedullary spinal cord tumour surgery from 07/2015 to 03/2017. A double train stimulation paradigm with an intertrain interval of 60 ms was devised by a hand held probe with simultaneous recording of responses from limb muscles. Results In non spastic patients (55% of cohort) an identical second response was noted following the first response after CT stimulation, but the second response was absent after DC stimulation. In patients with preexisting spasticity (45%), CT stimulation again resulted in two identical responses, whereas DC stimulation generated a second response that differed substantially from the first one. The recovery times of interneurons in the spinal cord grey matter for the CT were much shorter than those for the DC. Therefore, when a second stimulus train was applied 60 ms after the first, the CT-fibre interneurons had already recovered ready to generate a second response, whereas the DC interneurons were still in the refractory period. Conclusion Intraoperative mapping of the surgical exposed spinal cord using double-train stimulation paradigm allows neurophysiological distinction of CT from DC pathways during spinal cord surgery in patients with and without preexisting spasticity.

Neurosyphilis as a Cause of Transverse Myelitis in a Teenage Girl

BackgroundSyphilis is a sexually transmitted infection that was nearly eradicated in 2001 but is now making a resurgence. It has a wide range of clinical manifestations depending on disease stage. Neurosyphilis is an infrequently seen infectious disease with central nervous system involvement that can occur in either early- or late-stage syphilis. The diagnosis of neurosyphilis is challenging, primarily because Treponema pallidum, the infecting organism, cannot be cultured in vitro. This article describes a patient with neurosyphilis and reviews the epidemiology and clinical manifestations, diagnostics, and treatment of neurosyphilis. Case ReportIn compliance with the request of the Privacy Board of our institution, the numerical age of this patient has been omitted. A sexually active teenage girl who was treated for primary syphilis 2 years earlier presented to a tertiary children's hospital with paresthesia and weakness of her right leg, left arm, and neck. Magnetic resonance imaging revealed cervical intramedullary cord edema consistent with transverse myelitis. Serum studies showed positive syphilis enzyme immunoassay, T. pallidum particle agglutination assay, and fluorescent treponemal antibody absorption. A serum rapid plasma reagin test was negative. A lumbar puncture was performed with normal cell count and protein. A cerebrospinal fluid Venereal Disease Research Laboratory test was negative. She was diagnosed with neurosyphilis and treated with intravenous steroids and penicillin G, with near complete resolution of symptoms. Why should an Emergency Physician Be Aware of This?The Centers for Disease Control and prevention has noted a steady rise of the incidence of syphilis since 2002. Emergency physicians should be familiar with the spectrum of the clinical manifestations of syphilis, challenges in diagnostics, and appropriate treatment course.

Major risks and complications of cervical epidural steroid injections: An updated review.

Background:Too many patients, with or without significant cervical disease, unnecessarily undergo cervical epidural steroid injections (CESIs). These include interlaminar (ICESI) and transforaminal ESI (TF-CESI) injections that are not Food and Drug Administration (FDA) approved, have no documented long-term efficacy, and carry severe risks and complications.Methods:Here we reviewed recent reports of morbidity and mortality attributed to the various types of CESIS. Major complications included; epidural hematomas, infection (abscess/meningitis), increased neurological deficits due to intramedullary (quadriparesis/quadriplegia), and intravascular injections (e.g., vertebral artery injections leading to cord, brain stem, and cerebellar strokes). The latter injections leading to strokes were typically attributed to the particulate steroid matter (e.g., within the methylprednisolone injection solution) that embolized into the distal arterial branches.Results:Complications of cervical CESI/TF-CESI injections producing epidural hematoma, new neurological deficits (intramedullary injections), or intravascular injections resulting in strokes to the cord, brain stem, and cerebellum are often underreported. Interestingly, several other cases involving adverse events of CESI/TF-CESI may now be found in the medicolegal literature.Conclusions:Cervical epidural injecions (e.g., CESI, ICESI, and TF-CESI) which are not FDA approved, provide no long-term benefit, and are being performed for minimal to no indications. They contribute to significant morbidity and mortality, including; epidural hematomas, infection, inadvertent intramedullary cord injections or cord, brain stem, and cerebellar strokes. Furthermore, these injections are increasingly required by insurance carriers prior to granting permission for definitive surgery, thus significantly delaying in some cases necessary operative intervention, while also subjecting patients at the hands of the insurance companies, to the additional hazards of these procedures.

Correlation between Preoperative Magnetic Resonance Imaging Signal Intensity Changes and Clinical Outcomes in Patients Surgically Treated for Cervical Myeloradiculopathy.

Study DesignThis was a single surgeon, single center-based retrospective study with prospective data collection.PurposeTo assess the correlation between T2-weighted magnetic resonance imaging (MRI) signal intensity (SI) changes and factors such as age, duration of symptoms, baseline modified Japanese Orthopedic Association (mJOA) score and to determine its prognostic value in predicting recovery after surgery.Overview of LiteratureWhether intramedullary cord T2-weighted MRI SI changes can predict operative outcomes of cervical myeloradiculopathy remains debatable, with only a few prospective studies analyzing the same.MethodsForty-six consecutive patients who underwent cervical myeloradiculopathy were included and were followed up for an average of 1 year. Preoperative T2-weighted MRI SI grading was performed for all patients. The correlation between MRI SI changes and age, duration of symptoms, preoperative mJOA score, and mJOA score at 1-year follow-up were analyzed.ResultsFifteen patients had single-level (21.73%) or double-level (10.86%) prolapsed discs; 54.34% had degenerative cervical spondylosis with canal stenosis or multilevel disc prolapse and 13.07% had ossified posterior longitudinal ligaments. The mean age was 56.17±9.53 years (range, 35–81 years). The mean baseline mJOA score was 10.83±2.58 (range, 6–16), which postoperatively improved to 13.59±2.28 (range, 8–17; p<0.001). There was a statistically significant correlation between mJOA score at 1 year and MRI T2 SI grading (p=0.017).ConclusionsPatients with longer symptom durations had high grades of intramedullary cord T2-weighted MRI SI changes. Age and preoperative neurological status were not significantly correlated with the existence of intramedullary cord SI changes. However, patients without or with mild and diffuse intramedullary cord T2-weighted MRI SI changes had better postoperative neurological recovery than those with sharp and focal SI changes.

Dorsal Intramedullary Lipoma without Spinal Dysraphism: A Rare Case Report and Review of Literature

Study Design Case report. Objective The study aims to report a rare case of dorsal intramedullary lipoma, its management, and outcome. Background We are reporting the rare case of a 23-year-old man with dorsal intramedullary lipoma without spinal dysraphism. The clinical presentation, diagnosis, and management are discussed with relevant review of literature. Conclusion Intramedullary cord lipoma without spinal dysraphism can be a cause of myelopathy, and proper diagnosis with MRI and subtotal excision preserving the vital cord parenchyma should be the goal, which can give a better outcome.

RARE-23TWO CASES OF RARE INTRASPINAL POORLY DIFFERENTIATED NEUROENDOCRINE TUMOR WITH EXCELLENT RESPONSES TO RADIATION THERAPY

We describe two unusual cases of poorly differentiated neuroendocrine tumor of the spinal cord and leptomeninges. A 61-year-old woman developed rapidly progressive lower extremity paraparesis and sensory deficits. MRI revealed an intradural extramedullary mass levels arising from the conus extending from T12-S3, in multiple foramina, with extensive craniospinal leptomeningeal dissemination. Debulking revealed a poorly differentiated neoplasm characterized by nuclear molding and a high mitotic rate with immunohistochemical positivity for neuroendocrine markers (CD56, chromogranin, synaptophysin). Hematopoietic markers, keratin, GFAP, S100, and CD99/MIC2 were negative, and EWSR1 gene was intact by FISH. She received craniospinal irradiation of 39.6Gy in 22 fractions with a 5.4Gy boost followed by temozolomide. She remains clinically stable nineteen months since presentation, and MRI shows dramatic improvement with small remnants of enhancement at the cauda equina and thoracic thecal sac. The second case is a 65-year-old man with two months of progressive lower extremity paraparesis. He became non-ambulatory with a KPS of 40. MRI revealed an expansile intramedullary cervical cord lesion and diffuse neuroaxial leptomeningeal enhancement. Biopsy revealed a small round blue cell tumor with a markedly elevated proliferative index. Immunostaining showed diffuse positivity for CD56 and CD99/MIC2, while stains for CD45 and keratin were negative. EWSR1 and FUS genes were intact. He received craniospinal irradiation with a boost to bulky disease. His exam improved greatly and he was ambulatory four weeks after radiation with a KPS of 90. One year after radiation, he has little residual radiographic disease with an unchanged examination. For both cases, no alternative primary source was identified. Cauda equine paragangliomas have been the principal intraspinal neuroendocrine tumors described to date; we have been unable to identify other reports of primary intraspinal high grade poorly differentiated neuroendocrine tumors. Remarkably, despite extensive disease and poor performance status both our patients had excellent responses to radiation.

Currarino syndrome with intramedullary spinal cord abscess related communication between the tethered cord and a presacral mass: A case report

Abstract We herein report the case of a 21-day-old boy in which the detection of an intramedullary spinal cord abscess led to the diagnosis of Currarino syndrome (CS). He had a complete phenotype of CS, including sacral agenesis, an anorectal malformation, a presacral mass, and spinal cord malformations. In addition, he had an intramedullary spinal cord abscess. Intramedullary spinal cord abscess is rare in CS and is thought to require immediate intervention. Therefore, we additionally reviewed the available literature and discussed the therapeutic approach for CS with an intramedullary cord abscess.

Intraoperative neurophysiological monitoring in spinal surgery.

Recently, many surgeons have been using intraoperative neurophysiological monitoring (IOM) in spinal surgery to reduce the incidence of postoperative neurological complications, including level of the spinal cord, cauda equina and nerve root. Several established technologies are available and combined motor and somatosensory evoked potentials are considered mandatory for practical and successful IOM. Spinal cord evoked potentials are elicited compound potentials recorded over the spinal cord. Electrical stimulation is provoked on the dorsal spinal cord from an epidural electrode. Somatosensory evoked potentials assess the functional integrity of sensory pathways from the peripheral nerve through the dorsal column and to the sensory cortex. For identification of the physiological midline, the dorsal column mapping technique can be used. It is helpful for reducing the postoperative morbidity associated with dorsal column dysfunction when distortion of the normal spinal cord anatomy caused by an intramedullary cord lesion results in confusion in localizing the midline for the myelotomy. Motor evoked potentials (MEPs) consist of spinal, neurogenic and muscle MEPs. MEPs allow selective and specific assessment of the functional integrity of descending motor pathways, from the motor cortex to peripheral muscles. Spinal surgeons should understand the concept of the monitoring techniques and interpret monitoring records adequately to use IOM for the decision making during the surgery for safe surgery and a favorable surgical outcome.

Spinal dural arteriovenous fistula with intramedullary cord hemorrhage

Spinal dural arteriovenous fistula (SDAVF) consists of an acquired arteriovenous shunt between a dural artery and perimedullary veins.1 This results in arterialization of radicular veins, venous hypertension, and decreased spinal cord perfusion.1 The condition has a male predominance and presents as a myelopathy in the fifth or sixth decade. Initial misdiagnosis is common.1–3 We present a man with a SDAVF and associated intramedullary cord hemorrhage.

Posterior atlantoaxial dislocation complicating odontoid fracture without neurologic deficit: a case report and review of the literature

Traumatic posterior atlantoaxial dislocation associated with odontoid fracture is extremely rare, with only eight cases reported thus far in the English literature. This report concerns a 47-year-old female who presented with considerable pain and stiffness in the neck without a neurologic deficit after injury due to a fall. Radiographs, computed tomography, and magnetic resonance imaging demonstrated a posterior dislocation of the atlas with respect to the axis with an odontoid fracture. No cord compression or intramedullary cord signal abnormalities were detected at the level of the atlantoaxial dislocation. A pedicle screw fixation/fusion was performed via a posterior approach following successful closed reduction.

Rim and Flame Signs: Postgadolinium MRI Findings Specific for Non-CNS Intramedullary Spinal Cord Metastases

No highly specific MR imaging features distinguishing ISCMs from primary cord masses have been described. Our purpose was to retrospectively compare peripheral enhancement features on postgadolinium MR imaging of ISCMs with primary intramedullary cord masses. A consecutive group of patients with firmly diagnosed ISCM (45 patients with 64 ISCMs) and a comparison group with consecutive pathologically proved primary intramedullary spinal cord masses (64 patients with 64 primary spinal cord masses: ependymoma, astrocytoma, hemangioblastoma, ganglioglioma, and cavernous malformation) were included. MR images were evaluated for 2 specific signs on postgadolinium images: a "rim" sign (more intense thin rim of peripheral enhancement around an enhancing lesion) and "flame" sign (ill-defined flame-shaped region of enhancement at the superior/inferior lesion margins). The frequency of rim and/or flame signs in ISCMs and primary cord masses was compared (χ2 test). For ISCMs, the maximal dimension of the enhancing lesion was correlated with the presence of rim or flame signs (t test). Rim and flame signs, alone and in combination, were seen more frequently in ISCMs than in primary cord masses (P<.0001 for each). Specificity and sensitivity, respectively, for diagnosing ISCMs among spinal cord masses on a per-patient basis were the following: rim sign, 97%, 47%; flame sign, 97%, 40%; at least 1 sign, 94%, 60%; and both signs concurrently, 100%, 27%. In the ISCM group, the presence of either a rim or flame sign correlated with a larger measured maximum enhancing lesion size (P=.0065 and P=.0012, respectively). The rim and flame signs are common in and specific for ISCM and are rare in primary spinal cord masses.