Hemangiomas of the spinal cord and epidural space of the spinal canal
Several types of hemangiomas can be observed in the epidural space of the spinal canal. These hemangiomas are classified according to the predominant type of vascular bed. The different types of hemangiomas include:
- cavernous hemangiomas
- capillary hemangiomas
- arteriovenous hemangiomas (malformations, AVMs)
- venous hemangiomas
The most common type of hemangioma of the epidural space of the spinal canal is the cavernous type. There is little information in the modern literature on capillary, arteriovenous, and venous hemangiomas. Arteriovenous and venous hemangiomas are often defined as small cystic masses, while cavernous and capillary types usually appear as solid masses with increased vasculature (vascularization).
Neurological manifestations (symptoms, syndromes) of arteriovenous malformation of the spinal cord
Arteriovenous malformation (AVM, angiomas, hemangiomas) of the spinal cord is the most difficult pathological process to diagnose, affecting the spinal vessels (arteries and veins). Clinical manifestations of arteriovenous malformations of the spinal cord are varied in patients. Neurological symptoms and syndromes may resemble multiple sclerosis, transverse myelitis, spinal stroke, and neoplastic compression.
Arteriovenous malformations are more often localized in the lower thoracic and lumbar spinal cord. This lesion of the spinal cord vessels is more often found in middle-aged men. In most cases, arteriovenous malformations begin to manifest as incomplete progressive spinal cord injury. This syndrome can occur in a patient sporadically and subacutely, resembling multiple sclerosis and accompanied by symptoms of bilateral involvement of the cortico-spinal, spinothalamic pathways, and posterior columns in various combinations. Almost all patients suffer from paraparesis and are unable to walk for several years.
Approximately 30% of patients may suddenly develop acute transverse myelopathy syndrome as a result of hemorrhage, which neurologically resembles acute myelitis. Other patients may have several severe exacerbations.
Approximately 50% of patients with arteriovenous malformations complain of back pain or radicular pain. These pains can cause intermittent claudication, as in lumbar stenosis. Sometimes patients describe the acute onset of their illness with sharp, localized back pain.
The development of myelopathy caused by arteriovenous malformations that did not bleed can be caused by a necrotic non-inflammatory process accompanied by spinal cord ischemia. Necrotizing myelopathy in arteriovenous malformations is accompanied by a syndrome of progressive intramedullary spinal cord injury.
Instrumental and laboratory diagnostics of arteriovenous malformation of the spinal cord
Changes in the intensity of pain and the severity of neurological symptoms during exercise, in certain body positions, and during menstruation (in women) help diagnose. Auscultatory murmurs over the area of arteriovenous malformation are rarely heard. An attempt should be made to detect them in the patient at rest and after exercise.
In most patients, the protein content in the cerebrospinal fluid (CSF, CSF) may be increased, with the possible presence of pleocytosis.
In patients with arteriovenous malformations with possible hemorrhages in the spinal cord and cerebrospinal fluid. When conducting diagnostic myelography and CT angiography with contrast, vascular lesions are found in the vast majority of cases. The study is carried out with the patient lying on his back. The anatomical structure of most spinal cord vascular malformations can be detected using selective spinal angiography. The procedure for selective spinal angiography requires a great deal of experience from the neurosurgeon physician to carry it out to the patient.
Cavernous hemangiomas of the spinal cord and epidural space of the spinal canal
Cavernous hemangiomas in the epidural space of the spinal canal are rare. Cavernous hemangiomas of the epidural space can be reliably diagnosed in a patient after histological examination of the obtained surgical material. Depending on the height of the location of the epidural cavernous hemangioma relative to the level of the spinal cord, the patient will complain of back pain, increasing weakness, and numbness in the arms and legs. MRI of the spinal cord will show a mass with a homogeneous intense signal, a homogeneous high-intensity signal, and a homogeneous uniform increase in signal after intravenous contrast enhancement, which is typical for epidural cavernous hemangioma.
Epidural cavernous hemangioma in its pure form is rare. It accounts for only 4% of all epidural tumors and 12% of all intracerebral (intramedullary) hemangiomas of the spinal cord. Cavernous hemangioma is a conglomerate of tightly packed, dilated, thin-walled vessels with no elastic layer (elastic membrane). The tumor is not malignant, but due to its volume, it causes secondary problems, compressing the spinal cord or nerve roots.
Manifestations of spinal epidural cavernous hemangioma include spinal cord compression and radiculopathy syndromes. The damage to the spinal cord will depend on where and at what level the tumor is located in the spinal canal. These tumors can be found in the cervical, thoracic and lumbar spinal canal. In the spinal canal, they can grow along the anterior and posterior surfaces of the spinal cord or in the lateral part of the epidural space, squeezing the intervertebral foramen with the nerve root passing through it. Cavernous hemangiomas tend to bleed. With a large amount of bleeding, compression of the spinal cord can occur with an acute onset of neurological symptoms. The patient may have chronic neurological symptoms if the cavernous hemangioma grows slowly and is not accompanied by bleeding. Patients may also suffer from bladder dysfunction. But it is less common than pain syndromes or muscle paresis with impaired sensitivity.
Differential diagnosis of epidural cavernous hemangioma includes:
- herniated discs
- synovial cyst
- granulomatous infection
- true epidural hematoma
- extramedullary hemorrhage
A combination of a patient's medical history, neurologic examination findings, laboratory findings, and MRI can be used to narrow the differential diagnosis. Medical history can help distinguish cavernous epidural hemangioma from certain other spinal cord lesions. For example, with trauma, surgery on the structures of the spine, or coagulopathies, a true epidural hematoma can be assumed. If the patient complains of pain during lifting or physical exertion, a herniated disc is more likely to be diagnosed. Examination of the patient helps diagnose an epidural infection (bacterial epiduritis), which manifests itself as fever, neck muscle tension, and tenderness on palpation of the spinous processes. Patients with sickle cell disease may be prone to the development of extramedullary hematopoiesis. This disease should be associated with abnormalities found in the bone marrow of adjacent vertebrae on MRI of the spine.
MRI of the spinal cord is the best diagnostic method for examining the epidural cavernous hemangioma. The classic finding on MRI of the spinal cord is a mass located in the epidural space. This mass is usually pressed into the contour of the spinal cord and can also spread to adjacent nerve exit points in the intervertebral foramen. On T1-weighted images, these masses, as a rule, give a signal similar to the adjacent intervertebral discs, or isointense with foci of a hyperintense signal. T2-weighted images most often show homogeneous or heterogeneous signal amplification. Post-contrast images usually produce a noticeable signal enhancement from the detected mass of cavernous hemangioma. Some cavernous hemangiomas on MRI of the spinal cord may also have a low signal on T1-weighted images, T2-weighted images, and after-image contrast. Low signal in T2-weighted images is most common.
Some cavernous hemangiomas may also have connections to the dura mater (dural tail). A dural tail is considered true if there is a thin thickening of the dura mater of the spinal cord near a wide-angle hemangioma mass. If the cavernous hemangioma is located in the lateral part of the epidural space of the spinal canal, it can lead to the expansion of the intervertebral foramen (the point of exit of the nerve root).
Intramedullary cavernous hemangiomas of the spinal cord are more common than epidural (extramedullary) hemangiomas.
Surgical removal of hemangioma is currently recommended only if other methods of treatment are ineffective (embolization, radiation therapy). the risk of bleeding with such an intervention is about 1.4% -4.5% per year. If the patient has already had an episode of hemorrhage from a hemangioma, the risk of re-bleeding is estimated at 66% per year.
Even in the absence of bleeding from intramedullary and extramedullary cavernous hemangiomas, they cause a progressive deterioration in the clinical picture. This is due to the growing volume of the hemangioma itself, which is observed in most cases. In the postoperative period, the best clinical results were obtained in patients with extramedullary localization of cavernous hemangiomas, rather than intramedullary. Intramedullary cavernous hemangiomas grow within the spinal cord, which must be dissected to allow access to the tumor (62% improvement after surgery). Extramedullary cavernous hemangioma lies outside the spinal cord and can be removed while leaving the spinal cord intact (90% improvement after surgery).