When congenital, the syrinx develops most frequently in the cervical and upper thoracic segments. Serial sections of pathologic material show that it arises as a diverticulum from the central canal…

Subacute combined degeneration may also result from nitrous oxide abuse, which leads to inactivation of vitamin B12. A similar syndrome is also seen with copper deficiency, which may be a…

The two most common intramedullary tumors are astrocytomas and ependymomas. Astrocytomas are infiltrative, and total excision is not possible; however, there is frequently a well-demarcated plane around ependymomas, permitting their…

Transverse Myelitis. This syndrome of acute segmental spinal cord dysfunction results from inflammatory disease. Initial symptoms include limb weakness, loss of all sensation, and sphincter involvement. Nerve root pain and…

EXTRADURAL TUMORS Extradural tumors are usually metastases to the vertebrae that subsequently invade the epidural space (see Plate 2-21). Almost any neoplasm can spread to the spine, but spinal metastases…

The common mechanism in the patient with a potentially reversible condition is the presence of a mass lesion that has reached a critical size. Because the spinal cord lies within…

AUTONOMIC IMPAIRMENT In addition to its somatic components, the spinal cord also contains autonomic nerve fibers, carried in the intermediolateral columns. A lesion at any level may cause sphincter dysfunction….

The upper and lower visual fields are also topographically mapped onto the lateral geniculate body and visual cortex. The upper field is represented in the lateral parts of the lateral…

The medial and lateral rectus muscles move the eyeball horizontally, causing the cornea to look medially or laterally. The actions of the superior and inferior rectus muscles and those of…