Spinal Cord Compression



Fig. 7.1
Cervical spondylotic myelopathy: Sagittal T2-weighted MR image showing a multisegmental degenerative narrowing of the spinal canal at cervical level with depleted subarachnoid space and a hyperintense intramedullary signal reflecting myelopathy with maximum at level C4/C5 in a 50-year-old patient with tetraparesis C3 (AIS D)



The usual clinical course of spondylotic myelopathy is variable. Periods without clinical symptoms alternate with symptomatic periods, which complicate the treatment management. Conservative treatment options include physical therapy, analgesic drugs, and cervical orthoses. Nonoperative treatment strategies of cervical spondylotic myelopathy with regular reassessment represent the preferred option in cases with mild to moderate symptoms [5–7]. In contrast, results from a recent prospective multicenter cohort study suggest that the status of patients with cervical decompression may improve – even in patients with mild symptoms – in respect to function, participation, and quality-of-life at 1-year follow-up. In this study investigator-administered indices (mJOA scale and Nurick grade), which quantify the severity of functional and neurological impairment in patients with spondylotic myelopathy, and self-reported indices like the Neck Disability Index and Short Form-36 Version 2, were used for assessment [8]. In patients with progressive and moderate to severe neurological impairments, surgical decompression should be considered and can be performed anteriorly or posteriorly. The main goal is to remove compressing structures in order to provide sufficient space for the spinal cord. Furthermore stabilization of segments with increased mobility should be performed to prevent spine deformities. Discectomy and corporectomy and fusion are common techniques used in the anterior approach, while laminectomy with or without fusion is performed posteriorly [9].

In case of lumbar spinal stenosis, decompression by laminectomy is commonly performed [10] through removal of posterior spine structures like laminae, facets, ligaments, or osteophytes. After these procedures, an instability of the spine may develop over time requiring spinal fusion or implants. It has yet to be determined whether surgical or conservative treatment is superior in patients with lumbar spinal stenosis. Surgery-related complications have been reported in up to 24 % as opposed to a conservative regimen. Of course, noninvasive treatment programs including physical therapy, medication, exercise, manipulation, mobilization, acupuncture, and cognitive-behavioral therapy show little to no side effects [11].



7.1.2 Disk Herniation


Disk herniation in the thoracic spinal column represents a rare disease condition. The incidence of a symptomatic thoracic disk herniation is around one in 1,000,000 persons per year in the general population [12, 13]. In the midline of an intervertebral disk, the posterior longitudinal ligament strengthens the annulus fibrosus. As a consequence, a disk herniation usually occurs more laterally and rather compresses nerve roots. A medial disk herniation with consecutive cord compression causes a myelopathy or a compression of the cauda equina of the lower lumbar spinal cord [14].

The onset of clinical signs may be either acute within hours or slowly progressive over weeks or months. Typically patients suffer from neck or back pain followed by progressive numbness and weakness in the limbs. Bladder dysfunction may occur. In severe cases, painless urinary retention and overflow incontinence are common. In more incomplete conditions, an altered sensation of bladder filling, loss of urge to void, and voiding problems with associated residual urine in the bladderare early clinical signs. Furthermore, bowel and sexual dysfunction can be observed. Compression of the cauda equina by a lower lumbar disk herniation, prolapse, or sequestration mostly occurs at the L4/L5 or L5/S1 vertebral level and presents with severe lower back pain, bilateral sciatica, and sensory and motor deficits according to the affected lumbosacral roots. In particular, saddle and genital sensory disturbance are typical signs of cauda equina syndrome. Bladder, bowel, and sexual dysfunctions are found in severe cases. Both clinical courses with a rapid onset without a previous history of back pain or gradually progressing symptoms with chronic back pain and sciatica have been described [15].

Disk herniation is a space-occupying process, which depletes the ventrodorsal subarachnoid space typically found in sagittal or axial T2-weighted MR images. An intramedullary hyperintense signal caused by edema of the spinal cord indicates the myelopathy [16].

In case of neurological impairment caused by compression of the spinal cord or cauda equina, surgical decompression is recommended [16, 17]. Discectomy in combination with a ventral fusion is typically performed in patients with fast progressing neurological deficits caused by a cervical disk herniation [14]. In cauda equina compression caused by disk herniation, a dorsal decompression is performed by hemilaminectomy or laminectomy including a discectomy [18, 19].


7.1.3 Adjacent Segment Disease (ASD)


Adjacent segment disease includes various complications of spinal fusion including listhesis, herniated nucleus pulposus, facet joint degeneration, or vertebral compression fracture with instability of the spine. In severe cases, these conditions can cause a compression of the spinal cord or cauda equina. Adjacent segment disease is caused by biomechanical stress leading to degenerative processes in adjacent segments post fusion. Increased motion at adjacent segments causing increased intradiscal pressure is one reason for ASD. ASD only occurs in a certain population of patients after spinal fusion. Various risk factors have been identified, which can be categorized in preexisting conditions and surgery-related variables. One of the most important risk factors is age at the time of fusion, because of the ongoing disk degeneration in combination with an impaired ability of the spine to adapt to biomechanical alterations caused by a spinal fusion [20]. Furthermore, preexisting degenerated disks or facet joints in adjacent segments or osteoporosis are known as predisposing conditions. Nonphysiological sagittal alignment after surgery introduces biomechanical stress and can be another cause for ASD. After anterior cervical fusion with a plate, the distance between the plate and adjacent segments may influence the amount of ossification and degenerative changes at adjacent segments [21]. The number of fused segments does not necessarily correlate with increased incidence in ASD. Also the fusion method has no clear impact on ASD incidence [22]. Alterations confirmed by Radiographic changes in plain x-ray or CT scans of adjacent segments are common but do not correlate with clinical symptoms. Clinical symptoms are sustained back pain followed by sensory deficits, bladder and/or bowel dysfunction. The combination of clinical and radiological findings defines the treatment strategy. Treatment options for ASD include extension of the number of fused vertebrae and/or decompression [23].



7.2 Cord Compression by Neoplastic Diseases


Tumors compressing the spinal cord are commonly divided into epidural neoplastic diseases (primary neoplasms and metastases), intradural extramedullary malignancies, and intramedullary tumors.


7.2.1 Epidural Tumors and Metastases


Primary spinal benign and malign neoplasms originate from osteocytes, osteoblasts, chondrocytes, fibroblasts, and hematopoietic cells of the vertebral body and surrounding structures. Primary spinal tumors are rare. Only 0.5 % of all spinal neoplastic diseases are primary tumors and mostly affect patients older than 40 years.


7.2.1.1 Hemangioma


One of the most common benign tumors of the vertebral column is the vertebral hemangioma. This extremely vascularized and slowly growing neoplasm is characterized by vascular tissue proliferation of endothelial origin [24]. This tumor is predominantly located in the vertebral bodies of the thoracic spine. In most cases, vertebral hemangiomas are asymptomatic and therefore diagnosed incidentally [25]. Rarely, they may cause back pain or neurological impairments caused by spinal root and/or cord compression by a bony expansion or compression fracture of the vertebral body [26]. CT scans are mandatory to evaluate the grade of osteolytic destruction, which may lead to instability of the affected spine. MRI typically shows a hyperintense signal change in T1- and T2-weighted sequences within the vertebral body. Depending on the severity of the clinical symptoms, a number of treatment modalities exist including radiotherapy, vertebroplasty, embolization, and surgical decompression with spinal fusion. In instances, where a hemangioma does not cause clinical symptoms and does not lead to spine instability, no special treatment is required. In case of open surgery, a preoperative angiography with embolization should be considered to avoid a significant perioperative bleeding due to high grade of vascularization.


7.2.1.2 Osteoblastoma, Osteochondroma, Chondrosarcoma, Osteosarcoma, and Ewing Sarcoma


A variety of less common tumors originating in the spine can expand in the epidural space and cause spinal cord compression. Unremitting neck or back pain followed by neurological deficits depending on the localization of the tumor like radiculopathy, myelopathy, or cauda equina syndrome are typical clinical signs. Patients with more aggressive tumors like osteosarcoma and Ewing sarcoma will develop neurological dysfunctions more frequently and earlier in the clinical course.

Osteoblastoma predominantly found in young men is in most cases a benign slowly growing neoplasm, which produces osteoid and is histologically characterized by a nidus comprising a vascularized bony matrix. The most common initial clinical sign is back pain. CT scan reveals multiple small calcifications in combination with a sclerotic rim. Bone destruction with matrix calcification and paravertebral expansion is typical for more aggressive types of osteoblastomas.

Osteochondroma is a benign neoplasm, predominantly of the cervical spine in male patients, defined as a cartilage-covered osseous excrescence of a parent bone. A marrow and cortical continuity to the parent bone is pathognomonic for osteochondromas revealed by thin-section CT [27]. MRI can visualize the hyaline cartilage cap. A thickness of more than 1.5 cm is suspicious for malignant transformation to a chrondrosarcoma. En-bloc-resection is considered the standard therapy for osteoblastoma and osteochondroma.

Chondrosarcoma is a common non-lymphoproliferative primary malignant neoplasm of the spine in adults and mainly found in the thoracic spine. Tumor cells produce a typical mineralized chondroid matrix forming a nodule pattern, which is a typical CT finding. MRI reveals the non-mineralized areas of the hyaline cartilage with low signal intensity on T1-weighted and high intensity on T2-weighted sequences. A septal and peripheral enhancement pattern is found after application of a contrast agent [28]. Total surgical resection is the therapy of choice, as chondrosarcomas tend to be resistant to chemotherapy and radiotherapy with a high rate of recurrence after incomplete resection [29].

Chordomas are rare and slow growing low-grade tumors derived from remnants of the notochord [30]. The sacral region and the base of the skull represent the mostly affected regions. Less frequent, this tumor is localized in the cervical spine. Bone destruction, sclerosis, and intratumoral calcification are morphological signs of chordomas. Low to intermediate signal intensity on T1-weighted and high intensity on T2-weighted sequences are found in MRI. Usually chordomas show a peripheral and septal contrast enhancement. En-bloc-resection is the preferred therapy since sensitivity to chemotherapy or radiation is low [31].

Osteosarcomas accounting for 3–5 % of all spinal neoplasms are aggressive malignant tumors of mesenchymal origin. Tumor cells produce an immature matrix and osteoid. The most common sites of metastasis are the lung, bones, and liver. Risk factors for osteosarcoma are the diagnosis of Paget disease and a previous radiation therapy. In CT scans, a heterogeneous morphology caused by ossified and non-ossified areas in combination with necrosis is found. MRI is the technique of choice to evaluate the extension of the tumor into the surrounding soft tissue and neural structures. On T1- and T2-weighted images, a hypointense signal represents the mineralized parts of the neoplasm. In contrast, hyperintense signal changes in T2-weighted sequences are found in non mineralized areas with inhomogeneous enhancement of contrast agent [28]. Patients with osteosarcoma may benefit from radical resection in combination with neoadjuvant chemotherapy. Protocols for neoadjuvant chemotherapy include doxorubicin, cisplatin, high-dose methotrexate, and ifosfamide [32]. Osteosarcomas, chondrosarcomas, and chordomas are relatively insensitive to radiation, but in case of incomplete resection or as a palliative treatment, postoperative radiotherapy may be a further treatment option.

Ewing sarcoma was originally described in 1921 and is a frequent highly malignant bone tumor in adolescents and young adults. James Ewing characterized a tumor of the diaphysis of long bones which is responsive to radiation therapy. Recent results discuss a mesenchymal stem cells origin of the neoplasm [33]. Primary sites of origin are the pelvic bones and femur although the vertebra, lungs, and bone marrow of long bones are usually involved in metastatic dissemination. A primary vertebral localization is reported with an incidence of 3.5–15 % of all cases [34]. In CT scans radiologic patterns of Ewing sarcoma are characterized by aggressive bone destruction and lysis. An extensive paraspinal soft tissue involvement is known and should be screened with MR imaging, which shows intermediate signal intensity on T1-weighted sequences and intermediate to high signal intensity on T2-weighted images [28]. The total resection of the tumor, preferably with a margin of surrounding normal tissue is the main aim of the surgical treatment. Additional neoadjuvant chemotherapy is considered as standard therapy [35, 36]. Ewing sarcoma is responsive to radiation therapy.


7.2.1.3 Solitary Plasmacytoma


Solitary plasmacytoma, which occurs in 5 % of patients with plasma cell disorders, refers to an uncommon type of plasma cell dyscrasia. The entity is caused by a localized proliferation of neoplastic monoclonal plasma cells and can be subdivided into solitary bone plasmacytomas and solitary extramedullary plasmacytomas. Solitary bone plasmacytomas affect the axial skeleton or the vertebral bodies with subsequent pathologic fractures causing spinal cord compression. Extramedullary plasmacytomas originate from soft tissue and may compress the spinal cord when they arise from the dura mater [37]. The neoplasm affects middle-aged adults (male to female ratio of 2:1) with a peak occurrence between 55 and 60 years [38]. In case of more than one affected locus or a systemic involvement, the term multiple myeloma is used. According to the guidelines on diagnosis and management of solitary plasmacytoma, the investigations should include a complete radiological staging of the skeleton as a whole, bone marrow biopsy, blood/urine tests, and MRI of the thoracic and lumbar spine [39]. MRI represents the first diagnostic choice to evaluate the osseous and extraosseous extension of plasmacytomas. In patients with a solitary bone lesion, MRI of the complete spine helps to reveal unanticipated lesions. The MR pattern is characterized by a bright signal in T2-weighted images and a hypointense signal in T1-weighted images. Postcontrast images show an enhancement of the focal lesions [40]. Radical radiotherapy is the primary treatment for patients with solitary bone plasmacytoma. Surgery may be indicated in case of structural or neurological compromise. The role of adjuvant chemotherapy is not clear, it may have a benefit in cases at high risk of treatment failure [39].


7.2.1.4 Epidural Metastases


Spinal cord compression caused by epidural metastases is a common complication affecting almost 5 % of cancer patients [41]. Approximately 10 patients per 100,000 persons per year are diagnosed with this condition [42]. Most of the metastases expand from the spine into the epidural space. In 60 % of all cases, prostate, breast, or lung cancers are the primary neoplasms followed by non-Hodgkin lymphoma, renal cell cancer, and multiple myeloma, which represent 5–10 % of all cases; colorectal cancers and metastases of sarcomas are less common [41]. It is known that carcinoma of the lung, cancer of unknown primary origin, and hematologic neoplasms manifest in 20 % initially as spinal epidural metastases [43].

Increasing back pain represents an early and the most common clinical sign. Over time patients may develop radicular pain, if metastases invade or compress nerve roots. Weakness and gait dysfunction are also frequent. Sensory deficits and bowel or bladder dysfunction follow later on in the clinical course.

MR and CT imaging of the entire spine are recommended to identify additional metastases, which may cause instability of the spine or cord compression. Up to one third of patients have more than one site of spinal cord compression. Usually T1- and T2-weighted sequences (Fig. 7.2) give sufficient information to detect the tumor [44]. However postcontrast images should be routinely added. CT scans are crucial to assess bone structure and osteolytic lesions of the affected spine. Metastases of renal cell and thyroid tumors are highly vascularized lesions, which can complicate surgery with extensive bleeding. In these cases a preoperative angiography with embolization should be considered.

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Fig. 7.2
A 74-year-old patient with primary lung carcinoma developed a paraparesis Th4 (AIS C). (a) In a sagittal T2-weighted MRI, osteolytic destruction of the vertebral body and a tumor mass expanding into the epidural space at level Th 6. (b) Ventral compression of the spinal cord. T2-weighted axial image

Decompressive laminectomy was once a treatment of choice, but metastases are often located anterior to the spinal cord. Alternative surgical strategies are developed to remove or debulk the tumor followed by subsequent spine stabilization. Radiotherapy or radiosurgery alone or in combination with chemotherapy, hormone therapy, or surgical treatment is a further treatment option for metastatic spinal cord compression [41, 45]. The so-called Tokuhashi scoring system helps to select the appropriate treatment modality based on the overall tumor-related prognosis [46, 47]. A curative treatment may be achieved with a radical en-bloc- resection of a singular metastasis. In most cases, a palliative treatment concept is realistic aiming for prevention of progressing neurological deficits, prevention of pathological fractures, and pain reduction. Early surgical decompression as opposed to delayed surgery post-48 h appears to promote superior neurological outcome in patients with metastatic spinal cord compression [48]. Cord compression due to leukemia or lymphoma-derived metastases responds to steroids, which are considered first-line treatment to provide pressure relief for the affected spinal cord [41].


7.2.2 Intradural Extramedullary Tumors and Leptomeningeal Carcinomatosis


Intradural extramedullary neoplasms are located in the subarachnoid space and represent 80 % of all intradural tumors [49].


7.2.2.1 Meningioma


Meningiomas represent benign tumors and accordingly are mostly classified as WHO grade I [50]. The slowly growing tumor arises from arachnoid cells and is usually located next to the cervical and thoracic spinal cord. The incidence is estimated about 0.3 per 100,000 persons per year. Meningiomas contribute more than 25 % of primary spinal cord tumors and are more frequent in females [51]. The occurrence of clinical signs is delayed because meningiomas grow rather slowly. Therefore, patients are asymptomatic over months or years. Local neck or back pain are common initial signs. Over time radicular pain sensory deficits, gait ataxia, and weakness as signs of a spinal cord compression may develop. MRI detects meningiomas with an isointense signal in relation to the spinal cord in T1- and T2-weighted images. Contrast agent is homogenously enhanced in the tumor. Complete surgical removal is the primary curative treatment option. In many cases a dorsal approach with laminectomy or hemilaminectomy can be performed without compromising spine stability. Recurrence rates of spinal meningioma after surgical resection have been described in the range of 1.3–15 % [52].


7.2.2.2 Schwannoma


Schwannomas originate from Schwann cells of the spinal roots with a preference for the dorsal roots. They are mostly intradurally located next to the intervertebral foramina and frequently found at cervical and lumbar level. Intramedullary location is rarely described [53]. Schwannomas are classified as WHO grade I tumors. They represent 30 % of all primary intradural and extramedullary tumors. The occurrence (0.3–0.4 cases per 100,000 persons per year) is mostly sporadic, but an association with neurofibromatosis type 2 is known [54]. In these cases, multiple manifestations are possible. Patients develop segmental pain followed by motor deficits, but clinical signs are vague in the beginning similar to meningiomas reflecting the slow tumor progression. MRI reveals typical findings, which help to differentiate these two benign spinal tumors. Besides remodeling of the adjacent bony structures in terms of expansion of the neural foramen, focal cystic changes within the benign tumor are typical for schwannomas. T1-weighted images of this tumor reveal an iso- to hyperintense signal and T2-weighted images a hyperintense signal. As described for meningiomas, complete surgical resection represents the first-line treatment. Tumor recurrence may occur several years after resection with a recurrence rate of approximately 5 % [55].


7.2.2.3 Neurofibroma


Neurofibromas are derivates from mesenchymal stem cell lines and are associated with neurofibromatosis type 1. This peripheral nerve sheet tumor is also categorized as WHO grade I and shows a fusiform shape and encloses the spinal nerve root. MR imaging shows an iso- to hypointense signal on T1-weighted sequences and hyperintensity on T2-weighted sequences. Total surgical resection is the primary treatment. Recurrence after total resection of spinal neurofibroma is rare [56].


7.2.2.4 Leptomeningeal Carcinomatosis


Leptomeningeal carcinomatosis – spreading of tumor cells in the cerebrospinal fluid – is rare in adults, but a common intradural extramedullary lesion in children, and mostly affects the lumbosacral spine with an overall poor prognosis. Lung and breast cancer, melanoma, and hematological neoplasms represent common non-CNS tumors causing leptomeningeal carcinomatosis. Primary CNS tumors such as glioblastoma, gliosarcoma, and ependymoma can also cause leptomeningeal dissemination. Patients develop multifocal neurological signs reflecting radiculopathy or myelopathy. Leptomeningeal carcinomatosis is confirmed after detection of tumor cells in the cerebrospinal fluid (CSF). However, in 10–15 % of patients, the cytology is negative [57]. MRI typically shows nodular dural contrast enhancement along the spinal cord and spinal nerve roots. Therapeutic options should be carefully balanced against the patient’s clinical condition, systemic disease status, and individual preferences. Often patients are treated with a combination of radiation therapy to sites of bulky or symptomatic disease, systemic chemotherapy, and intrathecal chemotherapy. Methotrexate, thiotepa, cytarabine, liposomal cytarabine, topotecan, and etoposide represent standard chemotherapy drugs for treatment of neoplastic meningitis [57].


7.2.3 Intramedullary Spinal Cord Tumors


Only 20 % of all intradural tumors are located inside the spinal cord parenchyma (intramedullary location) [49].


7.2.3.1 Ependymoma


The most frequent intramedullary tumors are ependymomas with 60–70 % of all intramedullary neoplasms and occurring in approximately 0.21 cases per 100,000 persons per year [51]. Ependymomas belong to neuroepithelial tumors and originate from ependymal cells within the CNS. According to the WHO classification [50], four different subtypes can be distinguished: subependymoma (WHO grade I), myxopapillary ependymoma (WHO grade I), cellular ependymoma (WHO grade II), and anaplastic ependymoma (WHO grade III). Subependymomas mostly grow in the fourth ventricle followed by the lateral ventricles and are not common in the spinal cord [58]. Anaplastic ependymomas which develop more rapidly are rare and have a poor prognosis. Myxopapillary ependymomas arising from the filum terminale are located extramedullary in the lumbar cistern. The cellular ependymoma (WHO grade II) represents the most common type and is histologically characterized by ependymal rosettes and perivascular pseudorosettes. Spinal ependymomas can be associated with neurofibromatosis type 2 and are most commonly located in the cervical, cervicothoracic, and thoracic spinal cord and show a typical cystic enlargement over three to four vertebral bodies. Frequently syrinx formation is located at the interface between tumor and spinal cord [59].

Back or neck pain is typically the first clinical sign followed by sensorimotor deficits and bladder/bowel dysfunction; however, radicular and central neuropathic pain has been described. Myxopapillary ependymomas often cause compression of conus or cauda equina due to the location in the lumbar cistern.

MRI shows frequently a mostly centrally located fusiform structure over multiple vertebral segments with hypointense T1-signal and hyperintense T2-signal changes. Usually ependymomas show a diffuse heterogeneous contrast enhancement, which is not present in all subtypes (Fig. 7.3). In subependymomas (WHO grade I), contrast enhancement is weak or completely absent [60].

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Fig. 7.3
A 57-year-old patient with paraparesis Th5 (AIS D). (a) Ependymoma (WHO grade II) at level Th6 extending over multiple spinal cord segments. T2-weighted image shows hyperintense signal change rostral and caudal to the tumor suggesting edema. (b) Contrast-enhanced T1-weighted image reveals the well-defined tumor border

Evoked potential-guided microsurgical total resection is recommended and represents a curative treatment option in the majority of patients [61–63]. Leptomeningeal spread of ependymoma cells is uncommon. Cytologic examination of CSF remains clinically useful, when dissemination is suspected [64]. Surgical treatment is considered the first-line therapy. Whenever possible, a maximal resection is recommended. After resection of an ependymoma WHO grade II, MRI should be followed within 72 h to detect tumor residues. In case of a known or suspected residual lesion, postoperative radiation therapy should be considered to avoid a tumor relapse. After surgery of an ependymoma WHO grade III, radiotherapy should be performed in any case. At this point there is no known added value for additional chemotherapy. In case of tumor dissemination into the CSF craniospinal irradiation as a palliative concept should be considered. Adjuvant chemotherapy is available, which may be a treatment option for patients with recurrent malignancy. Long-term follow-up is recommended for all patients with ependymomas [65].


7.2.3.2 Astrocytoma


Astrocytomas belong to the group of gliomas and are of neuroepithelial origin, but only 3 % are located in the spinal cord. In adults they represent the second most common intramedullary malignancy (30 %) and occur in approximately 0.03 cases per 100,000 persons per year [51]. Astrocytomas are predominantly found in the cervical spinal cord and extend over multiple segmental levels and can be associated with syrinx formation [59]. Based on the histological pattern, astrocytomas can be distinguished in pilocytic astrocytoma (WHO grad I), diffuse astrocytoma (WHO grad II), anaplastic astrocytoma (WHO grade III), and glioblastoma (WHO grade IV) [50]. In adults high-grade tumors are more common. Astrocytomas can be associated with neurofibromatosis type 1.

MRI shows a heterogenous tumor morphology with cystic formations and inconsistent contrast enhancement with an eccentric location of the lesion in the spinal cord (Fig. 7.4).

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Fig. 7.4
A 41-year-old patient with paraparesis Th2 (AIS D) caused by an astrocytoma (WHO grade II) in the thoracic spinal cord. Sagittal T2-weighted image shows heterogenous signal changes and cyst formation rostral to the solid tumor

Only in pilocytic astrocytomas total resection may be attempted. In most cases, a total resection via microsurgery is not possible because a clear border between the intact spinal cord and diffuse astrocytoma, anaplastic astrocytoma, and glioblastoma is absent. However maximal resection is recommended in patients with neurological deficits or tumor progression. In case of WHO grade II astrocytoma after complete resection, radiotherapy may be deferred until clinical or radiological disease progression occurs. Postsurgical radiation therapy should follow after incomplete resection. Additional chemotherapy should not be routinely administered. When disease progression occurs, repeated surgical resection followed by radiation therapy represents a standard treatment regimen. Chemotherapy with temozolomide is a treatment option in patients with a combined chromosome 1p/19q loss of heterozygosity in the state of progressive disease [66]. In patients with anaplastic astrocytomas, postoperative radiotherapy should be administered, and participation in clinical trials with postoperative adjuvant chemotherapy should be considered. Combination of radiotherapy with temozolomide is a further treatment option. Particularly for patients that harbor a combined chromosome 1p/19q loss of heterozygosity, treatment with temozolomide should be considered [66, 67]. In the future, stereotactic radiosurgery may play a role in the management of high-grade lesions.


7.2.3.3 Hemangioblastoma


Hemangioblastoma are rare benign highly vascularized neoplasms (WHO grade I) mostly located in the cerebellum (80 %) but can also be found in the spinal cord (20 %), predominantly in the dorsal part of the cervical or thoracic segments. They represent 2 % of all intramedullary tumors and are the third most common intramedullary lesion after ependymomas and astrocytomas occurring in 0.02 cases per 100,000 persons per year. Cyst formation is commonly seen. If associated with von Hippel–Lindau syndrome, multiple manifestations can be observed [68], which require repeated MRI follow-ups. Histologically, hemangioblastomas show a compact capillary network consisting of stromal cells, pericytes, and endothelial cells [69] with a well-defined border to the intact spinal cord. Pain and sensory deficits are common complaints. Because of the dorsal location in the spinal cord, a slowly progressing impairment of proprioception is described. The tumor usually appears as a nodule. However, it can also expand diffusely into the spinal cord. Homogenous contrast enhancement of the nodular structures is typically seen due to the intense vascularization. On T1-weighted images iso- to hypointense and on T2-weighted images iso- to hyperintense signal changes – the latter reflecting cyst or syrinx formation – are common [54]. Treatment of choice is to completely resect the well-demarcated tumor. Spinal angiography in combination with endovascular embolization may be considered before surgery to reveal the nidus with prominent dilated arteries and draining veins in order to reduce intraoperative uncontrolled bleeding.


7.2.3.4 Intramedullary Spinal Cord Metastasis


Metastases within the spinal cord parenchyma are rare and less frequent (5 % of all spinal metastases) compared to leptomeningeal metastases. Only 1–3 % of all intramedullary neoplasms are caused by intramedullary metastases. Most frequently spinal cord metastases are derived from lung cancer (50 %) followed by breast cancer with 16 %. Less frequently, melanoma, renal cell cancer, colorectal cancer, lymphoma, and CNS tumors cause intramedullary metastases [70]. A clear preference of a certain spinal cord segment is not described. Pain and sensory deficits followed by weakness and bowel and bladder dysfunction are typically clinical manifestations. Multilocular manifestation in some instances requires complete spinal cord and brain MRI workup. Typically, hyperintense signal changes on T2- and T1-weighted images with contrast enhancement are observed within the spinal cord parenchyma. CSF analysis is rarely indicating meningeosis. The treatment strategy should be individualized based on the type and stage of the primary cancer. Radiotherapy in combination with steroids is commonly applied in radiosensitive lesions such as metastases derived from breast cancer or small cell lung carcinoma as a palliative concept [71, 72]. Chemotherapy may be an option in chemosensitive tumors mostly in combination with radiation or surgery. Only in selected cases, subtotal resection in order to preserve neurological function may be a treatment option. Overall prognosis of patients with intramedullary metastases is poor. The median survival from the time of diagnosis is less than 1 year [70, 73, 74].


7.3 Spinal Hematoma


The exact incidence of spinal hematoma is not known but appears to be low. Frequently a spinal hematoma becomes apparent with a sudden onset of clinical signs requiring urgent diagnostic evaluation and immediate surgical spinal cord decompression in case of relevant neurological deficits. Most commonly, an epidural location (about 75 % of all spinal hematomas), followed by subarachnoid (16 %) and subdural manifestation (4 %), is observed. In less than 1 %, the hemorrhage occurs within the spinal cord parenchyma. Spinal hematomas overall peak between 15 and 20 years and between 45 and 75 years of age. A similar age distribution is found for epidural hematomas, whereas subarachnoid hematoma occurs predominantly between 15 and 20 years of age [75].


7.3.1 Spinal Epidural Hematoma


In the majority of patients, the etiology of the spinal hematoma cannot be determined (40–50 %) [76]. Epidural hematomas without adequate trauma are classified as spontaneous spinal epidural hematoma. Spontaneous spinal hematomas can be associated with a trivial trauma, coughing, defecation, or a prolonged Valsalva maneuver [77] leading to a rupture of the internal vertebral venous plexus [78]. The incidence of spontaneous spinal hematomas is estimated at 0.1 cases per 100,000 persons per year [79]. Alternatively, spinal epidural hematomas can be associated with anticoagulants, platelet aggregation inhibitors or non-drug-induced coagulopathies [80–82], epidural tumors, and underlying spinal vascular malformations [83, 84]. Respective hematomas are predominantly located around the level C6 or T12 [85]. Trauma-associated spinal hematomas occur less frequently and are often associated with degenerative spine disease in the elderly patient [86]. Furthermore a spinal hematoma can be a complication of an invasive medical procedure. The incidence of epidural hematoma in the course of spine surgery is estimated to be less than 1 % [87]. A spinal hematoma can occur as a complication of spinal anesthesia.

Injections of a local anesthetic into the subarachnoid space (spinal anesthesia) and epidural space (epidural anesthesia) represent well-established procedures. The incidence of spinal hematoma due to spinal anesthesia has been reported between 1:480,000 and 1:750,000, whereas epidural anesthesia causes spinal hematoma in 1:10,300–1:26,400 [88, 89]. As expected, concomitant oral anticoagulants or low-molecular-weight heparins increase the risk for a spinal hematoma. Concomitant application of acetylsalicylic acid and other nonsteroidal anti-inflammatory drugs further enhance the risk of a spinal hematoma [90].

Typically, patients present with acute onset neck or back pain radiating to the corresponding dermatome followed by signs and symptoms of spinal cord and/or nerve root compression. Acute hemiparesis as initial manifestation of spinal epidural hematoma is not uncommon. Therefore, patients with acute hemiparesis have to be carefully examined for signs of Brown-Sequard syndrome (dissociated sensory dysfunction; see chapter 3) to distinguish them from an acute ischemic cerebrovascular event [91]. Sometimes patients can present with subacutely progressive or remitting-relapsing neurological symptoms; sometimes the chief complaint is centered around persistent neck or back pain with relatively minor neurological symptoms. Once suspected appropriate diagnostic workup – in particular MRI – has to be performed immediately. Typically, dorsal convex lens-shaped structures can be observed as iso- to hyperintense signals on T1-weighted images and hyperintense signals on T2-weighted images (Fig. 7.5). Respective findings may extend over multiple spinal levels [92].
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Aug 25, 2017 | Posted by in NEUROLOGY | Comments Off on Spinal Cord Compression

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