Nervous and mental diseases . aand entering the cord by the poste-rior roots has been demonstratedin a series of cases. ^ To understand the distributionof the cord-lesions it is necessary torecall that tlie posterior root fur-nishes three sets of fibers, whichenter the posterior horn by difierentroutes and at different levels. Thefibers of the first group, almost assoon as they reach the cord, enterthe posterior gray to the inner sideof the horn at its posterior third bya short route through the tract ofLissauer. Those of the second grouppass to the inner side of the first inBurdachs colunni,
Nervous and mental diseases . aand entering the cord by the poste-rior roots has been demonstratedin a series of cases. ^ To understand the distributionof the cord-lesions it is necessary torecall that tlie posterior root fur-nishes three sets of fibers, whichenter the posterior horn by difierentroutes and at different levels. Thefibers of the first group, almost assoon as they reach the cord, enterthe posterior gray to the inner sideof the horn at its posterior third bya short route through the tract ofLissauer. Those of the second grouppass to the inner side of the first inBurdachs colunni, and enter themiddle third of the horns innerborder at a level considerably abovetheir point of entrance to the of them reach Clarkescolumn. The third group, arisingmainly from the lower limbs, enterstill nearer the median line and pass up nearly the entire length of the 1 Berlin, klin. Oct. 18. 1897. ^ Xenrolooc. Centralbl., Feb. 15, ^ Roux, Lesions of the Sympathetic System in Tabes, Paris, Fig. 183.—Schematic representation of thecourses pursued by the sensory root-fibers enter-ing the cord from the root-ganglion (Marie). 434 DISEASES OF THE CORD PROPER. cord, constituting the columns of Goll, and terminate in the bulbargray. The tract of Lissauer lying between the head of the posteriorhorn and the periphery of the cord among the entering posterior-rootfibers, is made up of fine fibers arising from the posterior roots eitheras collaterals or as direct continuations of the numerous finer fibers ofthe root. These fibers of Lissauers tract, after ascending a shortdistance, enter the gelatinous substance of Rolando, which caps theposterior horn, and some of them penetrate the posterior horn tract also degenerates in tabes. Embryologically, the posterior columns of the cord, includingLissauers tracts, are an accession to the cord. They arise in the lateralneural plaques, which are finally represented by the posterior-rootganglia, a
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Keywords: ., bookcentury1900, booksubjectmentalillness, booksubjectnervoussys
