The brachial plexus is the name given to the plexus of nerves formed by the lower four ventral cervical roots (C5-C8) and the first thoracic ventral root (T1) as they emerge from the spinal cord, intermingle, realign, and emerge from the plexus as defined distal nerves. C4 and T2 may contribute axons to the plexus with little effect on the clinical location of the lesion. The…
Successful surgery for spondylosis and disc disease relieves the initial symptoms and, for cases in which stabilization is performed, provides solid fusion at the operative site. Complications of surgery can include failure to relieve the symptoms, failure of fusion, and any new problem resulting from the surgery itself. General complications of surgery include thrombophlebitis (2%-3%), pulmonary embolism (1%), and death (0.1%-0.3%). Risks of spinal surgery include…
Compression fractures of vertebral bodies affect approximately 750,000 people each year in the United States and up to 25% of postmenopausal women. The leading cause of vertebral compression fractures is osteoporosis, a disease that affects 44 million Americans. Younger patients taking corticosteroids for medical problems such as lupus, asthma, and rheumatoid arthritis may also suffer from osteoporotic compression fractures. Other, less common causes of vertebral body…
First described more than 40 years ago, intraoperative neurophysiologic monitoring (IONM) is now used routinely in many surgical procedures that carry risk to the brain, spinal cord, and peripheral nervous system. These include closure of intracranial aneurysms and arteriovenous malformations; resections of intracranial tumors; repair of carotid artery disease; relief of spinal compressions caused by degenerative spondylosis, tumor, or trauma; and treatment of spinal vascular malformations.…
The spine and the peripheral nervous system remain diagnostically challenging to image owing to the extensive bony canal, relatively small size of the neural elements, and multiplicity of clinical symptoms. A wide variety of techniques are available for imaging the spine. MRI is the procedure of choice for evaluation of many of the musculoskeletal and neurologic diseases of the spine. The musculoskeletal system includes the vertebral…
Noninfectious inflammatory spinal cord lesions include multiple sclerosis (MS), acute transverse myelitis (ATM), neuromyelitis optica (NMO), neurosarcoidosis, and Guillain-Barré syndrome (GBS). Except for MS, these entities are rare. The disease etiologies are incompletely understood but seem to involve immune system activation as a significant event. Recent discoveries, such as the recognition of a serum autoantibody to the membrane protein aquaporin-4 in patients with NMO, have led…
Noninfective inflammations of the vertebral spine can be caused by seronegative spondyloarthropathies or by seropositive rheumatoid arthritis. The seronegative spondyloarthropathies include ankylosing spondylitis, psoriatic arthritis, reactive arthritis, arthritis associated with inflammatory bowel diseases, and undifferentiated arthritis. ANYLOSING SPONDYLITIS Epidemiology Ankylosing spondylitis is the most frequent seronegative inflammatory spinal disease in adults and the prototype for other members of the spondyloarthropathies. The prevalence of this disorder is…
SPINAL MENINGITIS Spinal meningitis is infection of the spinal cord, leptomeninges, and subarachnoid space by various pathogens. It is also called infectious arachnoiditis. Epidemiology The incidence of bacterial meningitis is 2 to 3 per 100,000. It occurs most commonly in newborns, in infants aged 3 to 8 months, and in adults at the second and sixth decades. Spinal meningitis occurs less frequently than intracranial meningitis. Clinical…
Spinal infection frequently injures the vertebral bodies, intervertebral discs, paraspinal soft tissues, epidural space, meninges, and spinal cord. Clinically, it is notoriously difficult to differentiate spinal infection from degenerative processes, noninfective inflammatory disorders, and spinal neoplasms. Spinal infections are a common cause of morbidity and mortality, especially in immunocompromised patients. Epidural and intradural extramedullary infections are most often caused by pyrogens. Intramedullary infections are usually caused…
Metabolic disorders of the spinal cord are less common than metabolic disorders of the brain and peripheral nerves. Such metabolic myelopathies can be secondary to nutritional deficiencies, especially vitamin B 12 deficiency, or to systemic metabolic disorders. VITAMIN B 12 DEFICIENCY Subacute combined degeneration (SCD) of the spinal cord is a symmetric spongy vacuolation and degeneration of myelin that results from deficiency of vitamin B 12…
The skeletal manifestations of metabolic disease are a heterogeneous group of conditions resulting from endocrinopathy, vitamin deficiency, renal tubular dysfunction, and disorders of endogenous metabolism. As a group, they are characterized by altered function of the osteoblasts and osteoclasts or abnormal rates of mineralization. Consequently, there are pathologic changes in the bone mass, the collagen framework of the bone, the degree of bone mineralization, and the…
Spinal tumors comprise a large spectrum of distinct histologic entities that may arise primarily from the spinal cord (intra-axial or intramedullary space), the surrounding leptomeninges (intradural extramedullary space), or the extradural soft tissues and bony structures (extradural space). All three anatomic compartments may also be secondarily affected by metastatic disease from a known or unknown distant primary neoplasm. The same category also includes primary and metastatic…
Cystic lesions of the spine are a diverse group of infectious, post-traumatic, postinterventional, and degenerative abnormalities with the common feature of a fluid collection with a wall. The cellular linings of the walls may be squamous epithelium, columnar epithelium, arachnoid cap cells, ependymal cells, or collagenous fibrous tissue. The cyst may contain simple low protein fluid similar to cerebrospinal fluid (CSF), highly proteinaceous fluid, hemorrhagic fluid,…
Spinal vascular malformations are developmental derangements of the interconnections between arteries and veins, with secondary features of vascular enlargement, aneurysm and varix formation, mass effect from the enlarged vessels, excessively high flow with vascular steal and potential cardiac failure, and/or elevated venous pressure with low blood flow and backpressure ischemia due to venous congestion. Multiple schemes have been proposed to classify spinal vascular malformations. Genetically, spinal…
Spinal cord trauma is the application of excess force to the spinal cord and the consequences of that force for the cord. Traumatic spinal cord injury (SCI) may result from an acute blow to the spine, resulting in fracture or dislocation of the vertebrae, rupture of intervertebral discs and ligaments, occlusion or rupture of blood vessels of the spine or the spinal cord, and/or formation of…
Traumatic injuries of the spinal column reflect the mechanisms that produced them. The patterns of these injuries on imaging studies, therefore, help to predict the underlying mechanisms of trauma and lead, in turn, to more complete description of the pathologic process, more thorough search for associated abnormalities, and better patient prognostication. Differences in the anatomy and mobility of each spinal segment influence the pathologic process suffered.…
Spinal epidural hematoma and spinal subdural hematoma are accumulations of blood within the epidural or subdural spaces of the spinal canal or both. They may appear “spontaneously,” result from trauma, or arise secondary to coagulopathy, vascular malformation, neoplasm, or another cause. The clinical symptoms are similar in both spinal epidural and spinal subdural hematomas and include local pain, extremity weakness, sensory loss, and bladder or bowel…
Spinal cord ischemia is caused by deficient spinal arterial blood flow secondary to occlusion of intercostal/lumbar arteries or to involvement of the intrinsic arteries of the cord. It is also referred to as ischemic myelomalacia of the spinal cord. Epidemiology The precise epidemiology of spinal cord arterial ischemia is unknown. In our experience, men and women are affected equally and age range is highly variable: 0.5…
The normal vascular anatomy of the spine and spinal cord is described in this chapter as it follows the blood flow from large arteries to smaller arterial trunks and through the capillaries to venous drainage channels of progressively larger size. The application of this anatomy to the imaging of spinal cord pathology is reviewed elsewhere. ARTERIES Segmental Arteries and Their Anastomoses In the segmented spine, the…
Degeneration of the spine should be distinguished from normal aging of the spine. Normal aging retains the biomechanical and biochemical functions of the spine, whereas degeneration does not. The claim that disc degeneration begins in the first decade of life and affects many children suggests misconceptions in the use of the term degeneration . In this chapter a description is provided of the biochemical and biomechanical…