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Variations in the Spinothalamic Tract in Man

1957; American Association of Neurological Surgeons; Volume: 14; Issue: 1 Linguagem: Inglês

10.3171/jns.1957.14.1.0055

1933-0693

Harold C. Voris,

Neurology and Historical Studies

T UlS is a report of two cases that illustrate the variability of the pain pathways in the spinal cord of some individuals. Standard textbooks of neuroanatomy 3,5,6 give descriptions and present diagrams indicating that the pain pathway in the spinal cord in man is a discrete bundle of fibers, known as the spinothalamic tract, located in the anterolateral funiculus and consisting of afferent neurons of the second order. Finely myelinated or unmyelinated dorsal root fibers that serve as pain conductors terminate in the gray matter almost at once after entering the cord. From cells in the posterior column of the gray matter fibers arise which, in man, cross to the opposite side of the cord in the anterior white commissure and ascend in the lateral spinothalamic tract to end in the thalamus. Unilateral section of this tract produces complete loss of pain and temperature sensations on the opposite side of the body, extending upward to a level one segment below the level of the lesion, because of the oblique crossing of the spinothalamic fibers. These and similar statements are the result of piecing together fragmentary bits of clinical and experimental facts obtained over a period of many years. Unfortunately, our knowledge of the pain pathways in the spinal cord is still far from exact and the dogmatic statements and diagrams to be found in most textbooks cannot be substantiated by clinical observations. White and Sweet 9 in their extensive monograph on pain have reviewed the knowledge accumulated to date on the pain pathways in man.