Figure 42-8. Dural arteriovenous fistula of the cord. A. Sagittal T2-weighted MRI of the lower spinal cord of a 50-year-old man with progressive myelopathy. Cord edema (T2 hyperintensity at the conus medullaris) and multiple vascular flow voids surrounding the spinal cord and extending up to the mid-thoracic vertebral levels are seen, both the result of the arteriovenous fistula. B. Angiographic injection of the left T12 radicular artery from the patient whose MRI is shown in A, demonstrating abnormal early filling of veins surrounding the spinal cord, confirming the presence of an arteriovenous fistula. The fistula was repaired and the patient’s symptoms partially improved.
Figure 42-9. Sagittal T2 MRI in a patient with symptomatic cervical spondylosis. The spinal cord is severely compressed at the C5-C6 intervertebral disc space. Faint abnormal T2 hyperintensity of the spinal cord can be seen at the point of compression. Following surgical decompression, the patients myelopathic symptoms partially improved.
Figure 42-10. Sagittal (left) and axial (right) gadolinium-enhanced T1-weighted MRI of an intraspinal meningioma that displaced and compressed the spinal cord, causing incontinence and leg weakness. As in intracranial meningiomas, homogenous contrast enhancement and a dural attachment are seen.
Figure 42-11. Sagittal T2-weighted MRI of a primary glioma of the thoracic spinal cord in a middle-aged man. Note the expansion of the spinal cord.
Figure 42-12. Sagittal T1-weighted MRI showing multiple spinal metastases from carcinoma of the lung. The metastases exhibit low signal intensity due to tumor replacement of bone marrow, which is normally T1 hyperintense.
Figure 42-13. Sagittal T2 MRI of an intramedullary metastasis from breast cancer. The expansile lesion is at the T2 vertebral level (arrow) and the adjacent edema extends superiorly and inferiorly over a great length of the spinal cord.
Figure 42-14. Sagittal T2-weighted MRI showing a developmental syringomyelia without Chiari malformation. The cervical spinal cord is greatly expanded but there were only signs of spinothalamic sensory loss over the arms.
Chapter  42    Diseases of the Spinal Cord
Diseases of the Peripheral Nerves
In this single chapter, an attempt is made to provide an overview of the very large and difficult subject of peripheral nerve disease. Because the structure and function of the peripheral nervous system are relatively simple, one might suppose that our knowledge of its diseases would be fairly complete. Such is not the case. For example, when a group of patients with chronic polyneuropathy were investigated intensively in a highly specialized center for the study of peripheral nerve diseases several decades ago, a suitable explanation for their condition could not be found in 24 percent (Dyck et al, 1981) and equally discouraging figures prevail in our clinics today despite genetic testing. Moreover, the physiologic basis of many neuropathic symptoms continues to be elusive and in several of the neuropathies the pathologic changes have not been fully determined. However, rapidly advancing techniques in the fields of immunology and genetics are now clarifying entire categories of neuropathic disease. Also, effective forms of treatment for several peripheral neuropathies have been introduced, making accurate diagnosis imperative. For these reasons, clinicians now find the peripheral neuropathies among the most challenging and gratifying categories of neurologic disease.