Intraoperative Neurophysiological Monitoring for Spinal Cord Tumor Surgery: Comparison of Motor and Somatosensory Evoked Potentials According to Tumor Types

OBJECTIVE: To identify which combination of motor evoked potentials (MEPs) and somatosensory evoked potentials (SEPs) is most reliable for postoperative motor deterioration during spinal cord tumor surgery, according to anatomical and pathologic type. METHODS: MEPs and SEPs were monitored in patients who underwent spinal cord tumor surgery between November 2012 and August 2016. Muscle strength was examined in all patients before surgery, within 48 hours postoperatively and 4 weeks later. We analyzed sensitivity, specificity, positive and negative predictive values of each significant change in SEPs and MEPs. RESULTS: The overall sensitivity and specificity of SEPs or MEPs were 100% and 61.3%, respectively. The intraoperative MEP monitoring alone showed both higher sensitivity (67.9%) and specificity (83.2%) than SEP monitoring alone for postoperative motor deterioration. Two patients with persistent motor deterioration had significant changes only in SEPs. There are no significant differences in reliabilities between anatomical types, except with hemangioma, where SEPs were more specific than MEPs for postoperative motor deterioration. Both overall positive and negative predictive values of MEPs were higher than the predictive values of SEPs. However, the positive predictive value was higher by the dual monitoring of MEPs and SEPs, compared to MEPs alone. CONCLUSION: For spinal cord tumor surgery, combined MEP and SEP monitoring showed the highest sensitivity for the postoperative motor deterioration. Although MEPs are more specific than SEPs in most types of spinal cord tumor surgery, SEPs should still be monitored, especially in hemangioma surgery.

Total Excision of a Giant Ventral Midline Cervical Spinal Intradural Schwannoma via Posterior Approach

Schwannomas are the most common intradural extramedullary tumors of the spine. They usually occupy a posterolateral or lateral position in relation to the cord. The ventral midline is a very rare location for the origin of a spinal schwannoma. A giant one in such a location causes technical difficulties in excision. Here, we present a giant cervical spinal schwannoma, located ventral to the cord, in a 38-year-old lady who presented with features of myelopathy and bladder involvement. Magnetic resonance imaging was suggestive of an intradural extramedullary lesion extending from cervico-medullary junction to the third dorsal vertebral level with severe cord compression. The same was excised totally via a posterior approach after midline suboccipital craniectomy and C2-C6 laminoplasty. Postoperatively, she made a good recovery and was ambulant without support. Postoperative magnetic resonance imaging showed complete excision of the tumor. Histopathology was suggestive of schwannoma.

Primary Spinal Cord Oligodendroglioma with Postoperative Adjuvant Radiotherapy: A Case Report

Primary spinal cord oligodendrogliomas are rare tumors comprising two percent of all spinal cord tumors. Although a treatment guideline has yet to be established, maximal surgical resection is primary in the treatment of spinal cord oligodendrogliomas. Adjuvant radiotherapy has remained controversial, and it is unclear whether chemotherapy adds any benefit. In this case report, the authors present a 24-year-old male who had a seven-year history of left leg weakness and a radiating pain in both legs. Magnetic resonance image (MRI) showed an intramedullary mass at the T4-T8 level. He underwent subtotal removal of the tumor and pathologic diagnosis revealed a WHO grade II oligodendroglioma. The patient was treated with radiotherapy postoperatively and followed up with MRI annually. Clinical and radiological status of the patient had been stationary for four years after the surgery. The five-year follow-up MRI showed an increase in the size and extent of the residual tumor. Despite radiological progression, considering that symptoms and the performance status of the patient had remained unchanged, further treatment has not been performed. Given the clinical outcome of this patient, close observation after subtotal removal with adjuvant radiotherapy is one of the acceptable treatment options for WHO grade II spinal cord oligodendrogliomas.

Diagnóstico de alterações neurológicas compressivas da medula espinal de cães com o uso da Tomografia Computadorizada (TC) Helicoidal / Diagnosis of neurologic compression of the spinal cord of dogs with use of Helical Computed Tomography (CT)

Alterações neurológicas em cães são comuns na rotina da clínica médica, sendo necessário identificar o sítio de lesão quando da ocorrência de neuropatias por compressão em estruturas do Sistema Nervoso Central (SNC). O objetivo deste trabalho foi realizar um estudo epidemiológico das alterações neurológicas compressivas em medula espinal de cães domiciliados em Salvador e região metropolitana: Discopatias, Neoplasias e Traumas identificadas através da Tomografia Computadorizada (TC). Foram avaliados 17 cães de diversas raças com idade entre 2 e 10 anos e de ambos os sexos, atendidos na rotina de dois serviços médicos-veterinários e encaminhados para realização do exame conforme indicação clínica. Imagens em cortes com espessura variando de 0,5 a 2mm em rotação foram produzidas com o Tomógrafo. Dos animais que apresentaram discopatia 12/17 (70,58 por cento), por mielopatia extradural 6/12 (50 por cento), foram da raça Dachshund com idade média 7,33±1,97 anos e para todos os outros a ocorrência foi pontual; 23,53 por cento de osteopatias vertebrais, neoplasias ósseas e fraturas, e 5,89 por cento correspondente a neoplasia de medula. Houve uma maior frequência de lesões nos segmentos C4-C6 3/12 (25 por cento), T12-T13 (25 por cento) e L2-L3 (25 por cento) dos casos.

Neurological disorders in dogs are common in veterinary medical practice routine, being necessary to identify the site of injury in the event of compression on structures of the central nervous system (CNS). The aim of this work was an epidemiological study of neurological changes in compressive spinal cord of pet dogs in Salvador and the metropolitan area. Discopathies, neoplasms and trauma were identified by Computed Tomography (CT). We evaluated 17 dogs of various breeds, aged between 2 and 10 years old and of both sexes, from two veterinary medical routine services and forwarded to the examination as clinically indicated. Slice images with a thickness ranging from 0.5 to 2mm were produced in rotation with the tomograph. Animals that showed disc disease (70.58 percent) for extradural myelopathy 6/12 (50 percent) were the breed Dachshund, mean age 7.33±1.97 years and for all other occurrence was timely; 23.53 percent of vertebral bone disease, bone tumors and fractures, and 5.89 percent corresponding to neoplasm marrow. There was a higher incidence of injuries segments L2-L3 (25 percent), followed by C4-C6 (16.67 percent), T12-T13 (16.67 percent), L7-S1 (16.67 percent) of cases.

Combined Muscle Motor and Somatosensory Evoked Potentials for Intramedullary Spinal Cord Tumour Surgery

PURPOSE: To evaluate whether intraoperative neurophysiologic monitoring (IONM) with combined muscle motor evoked potentials (mMEPs) and somatosensory evoked potentials is useful for more aggressive and safe resection in intramedullary spinal cord tumour (IMSCT) surgery. MATERIALS AND METHODS: We reviewed data from consecutive patients who underwent surgery for IMSCT between 1998 and April 2012. The patients were divided into two groups based on whether or not IONM was applied. In the monitored group, the procedures were performed under IONM using 75% muscle amplitude decline weaning criteria. The control group was comprised of patients who underwent IMSCT surgery without IONM. The primary outcome was the rate of gross total excision of the tumour on magnetic resonance imaging at one week after surgery. The secondary outcome was the neurologic outcome based on the McCormick Grade scale. RESULTS: The two groups had similar demographics. The total gross removal tended to increase when intraoperative neurophysiologic monitoring was used, but this tendency did not reach statistical significance (76% versus 58%; univariate analysis, p=0.049; multivariate regression model, p=0.119). The serial McCormick scale score was similar between the two groups (based on repeated measure ANOVA). CONCLUSION: Our study evaluated combined IONM of trans-cranial electrical (Tce)-mMEPs and SEPs for IMSCT. During IMSCT surgery, combined Tce-mMEPs and SEPs using 75% muscle amplitude weaning criteria did not result in significant improvement in the rate of gross total excision of the tumour or neurologic outcome.

Intramedullary Spinal Cord Metastasis in Renal Cell Carcinoma: A Case Report of the Surgical Experience

Intramedullary spinal cord metastasis (ISCM) from renal cell carcinoma (RCC) is rare manifestation and most of them are treated by adjuvant treatment modalities like radiotherapy. Despite the radio-resistance of RCC itself, focal radiotherapy has been preferred as the first-line treatment modality of ISCM from RCC and only a few cases underwent surgical treatment. We describe a case of ISCM from RCC, which underwent surgical excision and pathologically confirmed. A 44-yr-old man was presented with rapid deterioration of motor weakness during focal radiotherapy for ISCM from RCC. After the surgery for removal of the tumor mass and spinal cord decompression, his motor power was dramatically improved to ambulate by himself. We report the first published Korean case of ISCM from RCC confirmed pathologically and describe our surgical experience and his clinical characteristics.

Intradural Extramedullary Metastasis of Small Cell Lung Cancer: A Case Report

A 60-year-old man presented with para-anesthesia and a tingling sensation in the saddle area. Intradural extramedullary (IDEM) tumors in conus medullaris were observed by radiologic studies. The patient underwent laminoplastic laminotomy at the T12-L2 level and subtotal removal of the tumor because of the ill-defined margin. Postoperatively, hypesthesia was improved up to 50%. The IDEM tumor revealed a metastatic cancer originated from small cell lung cancer (SCLC) by histologic examination, and additional studies showed multiple metastases including adrenal gland, brain, and bone. Clinicians need to consider IDEM metastasis when SCLC patients were complained of neurologic symptoms mimic paraneoplastic syndrome. The pathophysioloigy of IDEM metastasis may be not only tertiary drop metastasis, but also faster mechanisms such as direct invasion.

Intradural Extramedullary and Subcutaneous Tumors in Neonate : Atypical Myxoid Spindle Cell Neoplasm

Tumors of the central nervous system are common in the pediatric population and constitute the second most prevalent tumor type in children. Within this group, spinal cord tumors are relatively rare and account for 1 to 10% of all pediatric central nervous system tumors. We describe a very rare case of an intradural extramedullary spinal cord tumor with a subcutaneous mass and discuss its clinical presentation, pathogenesis, and treatment. A male infant was delivered normally, with uneventful development. At 16 days post-delivery, his family took him to a pediatrician because of a mass on his upper back. Magnetic resonance imaging of the thoracic spine revealed a well-demarcated soft-tissue mass with central cystic change or necrosis at the subcutaneous layer of the posterior back (T2-7 level). Another mass was found with a fat component at the spinal canal of the T1-3 level, which was intradural extramedullary space. After six weeks, the spinal cord tumor and subcutaneous mass were grossly total resected; pathologic findings indicated an atypical myxoid spindle cell neoplasm, possibly nerve sheath in type. The final diagnosis of the mass was an atypical myxoid spindle cell neoplasm. The postoperative course was uneventful, and the patient was discharged after nine days without any neurological deficit. We report a rare case of an intradural extramedullary spinal tumor with subcutaneous mass in a neonate. It is necessary to monitor the patient's status by examining consecutive radiologic images, and the symptoms and neurological changes should be observed strictly during long-term follow-up.

Thoracic Intramedullary Schwannoma Accompanying by Extramedullary Beads-Like Daughter Schwanommas

Thoracic intramedullary schwannomas are rare spinal cord tumors. Most of these tumors have been reported as a single lesion in the spinal cord. The authors report the first case of intramedullary schwannoma accompanying by extramedullary beads-like daughter masses of the thoracic spine. A 68-year-old male presented with walking disturbance and decreased sensation below T10 dermatome. Imaging workup revealed an intramedullary mass at T6 and T7. T6 and T7 laminectomy and mass removal were performed. Intraoperatively, extramedullary beads-like daughter masses along the nerve roots adjacent to intramedullary mass were identified. Total removal of intramedullary lesion and partial resection of extramedullary masses were done. Histological analysis confirmed the diagnosis of schwannoma. The patient could ambulate independently at postoperative 1 month without any neurological sequelae. The authors experienced a surgical case of intramedullary schwannoma accompanying by extramedullary beads-like same pathologies in the thoracic spine.

Hemangioblastoma espinal: presentación de un caso / Spinal hemangioblastoma: a case presentation

Los hemangioblastomas son unos de los tumores más comunes en la fosa posterior de los pacientes adultos. Esta lesión es de rara ocurrencia en la medula espinal y corresponde a un rango de entre 1 y 5% de los tumores medulares espinales. Los hemangioblastomas tienen una asociación importante con la enfermedad de von Hippel-Lindau, son tumores histológicamente benignos y se asemejan mucho a los astrocitomas. Dependiendo de su localización, pueden presentar sintomatología neurológica importante y afectar en gran manera la funcionalidad de los pacientes. La resonancia magnética es el estudio de imagen de elección para diagnosticarlos. El tratamiento es quirúrgico y, gracias a los avances de la las técnicas microquirúrgicas, el pronóstico de los pacientes que los sufren ha mejorado. En este artículo presentamos un caso clínico de una paciente de 58 años que comenzó con un cuadro subagudo de parestesias en miembros superiores, le fue diagnosticado un tumor intramedular y fue llevada a cirugía para la resección de la lesión. La patología reportó un hemangioblastoma.

Hemangioblastoma is one of the most common tumors of the posterior fossa in the adult. These lesions are rare in the spine and they represent between 1 to 5% of the spinal intramedullary tumors.Hemangioblastomas are histologically benign tumors that may be difficult to differentiate from astrocytomas. Depending on their localization in the spinal cord, these lesions may present important neurological symptoms and may compromise functionally these patients. Magnetic resonance imaging is the gold standard for diagnosis. Treatment is surgical and due to the advancement in microsurgical techniques there has been an improvement in the prognosis of these patients. In this article we will present a case of a 58 year old patient who presented with pain of the upper limbs.An intramedullary tumor was diagnosed and she was taken to surgery. The pathological studies reported an hemangioblastoma. We will review the literature concerning this rare pathology of the spine.

Syringomyelia Associated with a Spinal Arachnoid Cyst

While syringomyelia is not a rare spinal disorder, syringomyelia associated with a spinal arachnoid cyst is very unusual. Here, we report a 62-year-old man who suffered from gait disturbance and numbness of bilateral lower extremities. Spinal magnetic resonance imaging (MRI) showed the presence of a spinal arachnoid cyst between the 7th cervical and 3rd thoracic vertebral segment and syringomyelia extending between the 6th cervical and 1st thoracic vertebral segment. The cyst had compressed the spinal cord anteriorly. Syringomyelia usually results from lesions that partially obstruct cerebrospinal fluid flow. Therefore, we concluded that the spinal arachnoid cyst was causing the syringomyelia. After simple excision of the arachnoid cyst, the symptoms were relieved. A follow-up MRI demonstrated that the syringomyelia had significantly decreased in size after removal of the arachnoid cyst. This report presents an unusual case of gait disturbance caused by syringomyelia associated with a spinal arachnoid cyst.

Spinal Intradural Extramedullary Mature Cystic Teratoma in an Adult

Spinal intradural extramedullary teratoma is a rare condition that develops more commonly in children than in adults and may be associated with spinal dysraphism. We report a rare case of adult-onset intradural extramedullary teratoma in the thoracolumbar spinal cord with no evidence of spinal dysraphism and without the history of prior spinal surgery. The patient was a 38-year-old male whose chief complaint was urinary incontinence. X-ray images of the thoracolumbar spine showed the widening of the interpedicular distance and posterior marginal erosion of the vertebral bodies and pedicles at the T11, T12, and L1 level. Magnetic resonance imagings of the lumbar spine showed a lobulated inhomogeneous high signal intradural mass (87x29x20 mm) between T11 and L1 and a high signal fluid collection at the T11 level. Laminectomy of the T11-L1 region was performed, and the mass was subtotally excised. The resected tumor was histopathologically diagnosed as a mature cystic teratoma. The patient's symptom of urinary incontinence was improved following the surgery.

A Dumbbell-Shaped Solitary Fibrous Tumor of the Cervical Spinal Cord

A 40-year-old Asian female presented with a 2-month history of right shoulder pain and right triceps weakness. MRI revealed an extramedullary, extradural, dumbbell-shaped spinal cord tumor with C6 to C7 iso- and hyperintensity on T1 and T2 weighted imaging, respectively. Histological examination revealed monomorphous spindle cells with a storiform pattern. Immunohistochemistry was positive for CD34, CD99, and negative for EMA, SMA, and S100; solitary fibrous tumor (SFT) was confirmed.

Clear Cell Meningioma of Cauda Equina without Dural Attachment

We report a 17-year-old woman presented with a one-month history of lower back pain and radiating pain in the left leg. Examination revealed Lasegues sign in left leg with mild weakness of the plantar flexion of the left big toe. Magnetic resonance image revealed a well enhanced intradural lesion at the S1-2 level. Following a subtotal laminectomy of S1 and an intradural exposure, the roots of the cauda equina draped the tumor loosely without any attachment to the dura or cauda equina. The tumor was removed en bloc. The patient's recovery was uneventful. Histological examination confirmed a clear cell meningioma.

The MRI diagnosis of lung cancer intramedullary spinal cord metastasis / 中华放射学杂志

Objective To discuss the MRI features and pathogenic mechanisms of lung cancer intramedullary spinal cord metastasis (ISCM). Methods Four cases with clinically and 3 cases pathologically proved lung cancer ISCM were analyzed retrospectively. Turbo spin-echo sequence T 1 and T 2 weighted images were acquired in all patients. T 1 weighted images were obtained after intravenous administration of Gd-DTPA in all patients. Results A total of 7 ISCM were displayed by MR studies. The tumor occurred in thoracic cord (3/7) and in medullary cone (4/7). The tumor involved the central aspect of the cord. The lung cancer ISCM showed hypointensity (n=1) or isointensity (n=6) on T 1WI and hyperintensity on T 2WI. The extensive cord enlargement with cyst formation or syringomyelia was common. On contrast study, all tumors showed marked homogenous enhancement with clear borders. Conclusion The lung cancer ISCM usually presented as solitary lesions with marked contrast enhancement. The extensive cord enlargement was common in all patients. Because of the limitation in the evaluation of lung cancer ISCM on MRI, definite diagnosis of lung cancer ISCM depended on combination of clinical and MRI data.

Posterolateral Approach in Ventral or Ventrolateral Thoracic Tumor

There were many surgical approaches for the ventral or ventrolateral thoracic spinal cord tumor. Six ventrally or ventrolaterally located thoracic spinal tumors were successfully resected through the posterolateral approach. This approach allows direct visualization of the ventral and dorsal boundaries of the tumor with minimal manipulation of the spinal cord. Compared to the traditional laminectomy, visualization of the tumor and spinal cord can be shown to markedly improved. Also, when compared to the transthoracic approach, this approach has be associated with fewer potential complications, such as violation of pleural space and mediastinum, and eliminates the necessity of vertebrectomy. Neurological improvement was obtained in all six patients. It is believed that this approach offers significant advantages for the treatment of ventrally or ventrolaterally located thoracic tumors, and should be considered an to alternative the transthoracic approach.

MR Imaging of Intramedullary Tumors of the Spinal Cord

PURPOSE: The purpose of this study was to evaluate the characteristic MR findings of intramedullary spinal cord tumors according to histologic diagnosis. MATERIALS AND METHODS: MR images of 34 patients with surgically-proven intramedullary spinal cord tumor were retrospectively reviewed. Histologic diagnosis revealed 15 ependymomas, ten astrocytomas, three hemangioblastomas, two oligidendrogliomas, one malignant schwannoma, one glioblastoma multiforme, one neuroblastoma and one ganglioglioma. MR images were analyzed for location, size, shape, signal intensity, and degree and pattern of contrast enhancement of the tumors. RESULTS: All tumors showed cord expansion and a varying extent of involvement ranging from 1.5 to 30cm. Variable degrees of contrast enhancement were seen in all cases. Cervical, cervico-thoracic, thoracic, and thoraco-lumbar spinal ependymomas accounted for three, two, six, and four cases, respectively, while four, two, and four cases of cervical, cervico-thoracic, and thoracic spinal astrocytomas respectively, were seen. Other tumors were located most commonly in the thoracic spinal cord. A sharply-defined tumor margin was seen in 13 of 15 ependymomas, in all three hemangioblastomas, one neuroblastoma and one ganglioglioma. Tumors usually showed slightly low- or iso-signal intensity on T1-weighted images and high signal intensity on T2-weighted images. Peritumoral cysts were seen in nine ependymomas, one hemangioblastoma, and one astrocytoma, while peritumoral hemorrhage was seen only in three ependymomas. Relatively homogeneous enhancement was seen in nine of 13 ependymomas, all hemangioblastomas and one neuroblastoma. All ten astrocytomas showed a poorly defined tumor margin and heterogeneous enhancement. CONCLUSION: On the basis of characteristic MR findings, intramedullary cord tumors may be histopathologically diagnosed.