TUMORS OF THE SPINAL CORD.
Tumors of the spinal cord may be classified as follows (Krauss):
1. Tumors springing primarily from the envelopes of the cord: (a) Tumors of the vertebral column, and (b) tumors of the meninges, the latter including those arising from the external surface of the dura, or from the periosteum of the spinal canal, i. e., extradural tumors, and those from the inner surface of the dura and the other membranes, that is, intradural tumors.
2. Tumors developing in the cord proper, intramedullary. These are generally gliomas and do not present so much the symptoms of cord tumors as of syringomyelia.
Vertebral tumors may be carcinoma (secondary), endothelioma, sarcoma, osteosarcoma, as well as the non-malignant and cartilaginous or osseous tumors, and parasitic cysts, i. e., echinococcus. The sarcomas are the most common of all.
Symptoms.
—The symptoms of tumor of the spinal cord depend upon the part involved and differ according as it involves the cervical, thoracic, or lumbar portions or the cauda equina. They are to be classed as root symptoms and cord symptoms. Root symptoms include pain, paresthesia, and hyperesthesia. The pain is usually persistent, burning, and severe, affecting one side or the other, if the tumor be laterally placed, or both sides if central. The pain follows the distribution of the spinal roots rather than the course of the intercostal nerves, i. e., is more horizontal and less oblique. These pains persist and have the characteristic feature of not presenting painful points on pressure. They are commonly referred to the abdomen, and may thus give rise to serious mistakes in diagnosis, e. g., they have been regarded as due to hepatic colic, dry pleurisy, appendicitis, etc. Pain may assume the girdle character, which is usually accentuated by movement, and is frequently accompanied by herpes zoster. The greater the involvement of the posterior roots the more painful the condition. When the anterior sensory roots are involved pain may be wanting and the disturbance assume a type of paresthesia, with final anesthesia, in which case the patient would at first complain of numbness and prickling sensations. There is sometimes noted a zone of hyperesthesia on the proximal side of the anesthetic area, or this zone, if not hyperesthetic, may be replaced by a condition of uncertainty of sensation.
The cord symptoms are the reliable ones, varying according to the segment involved. The portions of the cord where lesions can be best localized are, for instance, the third to the fifth cervical, including the origin of the phrenic nerve; the fifth to the seventh cervical, where the posterior thoracic nerve comes off; the seventh to the eighth cervical and first thoracic segments, where originate the dilator nerves of the pupil. The upper border of the anesthetic area points to a lesion of the next or second higher spinal segment than the level really represents. The lowest level of the lesion corresponds to the highest level of the sensory disturbance. The level of the segment area of the skin of the back does not correspond to the level of the spinal segment involved, the latter being higher up. The point of greatest sensitiveness over the spine is in many cases a good guide to the segment involved, but is applicable only where the lesion is posteriorly placed. The absence of pain or tenderness along the spine means little or nothing, but their presence has great significance.
Diagnosis.
—The diagnosis of a cord tumor covers, according to Krauss, a first or subjective period, indicative of irritation along the posterior roots, and is characterized by pain and paresthesia. This is followed in time by a second or objective period which points to invasion of the spinal cord, characterized mainly by weakness and later by paralysis, with disturbed tendon reflexes. Diagnosis early is extremely difficult, for pain and disturbances of sensation are produced in many ways.