A treatise on the diseases of the nervous system . pheres. Very often thephenomenon is due to a restricted lesion in the vicinity of the corpusstriatum and peduncular expansion. M. Prevost* has endeavored tolay down a general law to the effect that, in a case of cerebral lesion,the conjugate deviation of the eyes is always from the affected a case reported by Duplay, and four others by Eichorst, demon-1 De la deviation conjuguie des yeux. These de Paris, 1868. 24 370 DISEASES OF THE BRAIN. strate that the contrary direction may exist, and that consequently therule enunciated by Prevos
A treatise on the diseases of the nervous system . pheres. Very often thephenomenon is due to a restricted lesion in the vicinity of the corpusstriatum and peduncular expansion. M. Prevost* has endeavored tolay down a general law to the effect that, in a case of cerebral lesion,the conjugate deviation of the eyes is always from the affected a case reported by Duplay, and four others by Eichorst, demon-1 De la deviation conjuguie des yeux. These de Paris, 1868. 24 370 DISEASES OF THE BRAIN. strate that the contrary direction may exist, and that consequently therule enunciated by Prevost is too absolute. IV. LESIOXS OF THE OPTIC TRACTS. Lateral Hemiopia.—As we have seen, according to the theorygenerally admitted, the nerve-fibres which form the optic nerves onlypartially decussate in the chiasma. Those which cross over from oneside to the other are, of course, the nearest to the median line, andoccupy the most internal part of the nerve and optic tract of eachside. On the other hand, those fibres which do not cross occupy the. Diagram explaining the phenomena of lateral hemiopia and of crossed amhlyopia, according to M. Char-cot. (Leeons sur les localisations cerebrales. 1S76, p. 124.) C, semi-decussation in the chiasma;H, decussation posterior to the corpora genieulata; C G-. C G. corpora genicuata: 0. left eye:O, right eye; X O. N O. optic nerves; B O, B O, optic tracts; A. lesion of the left optic nerve,producing amaurosis of the corresponding side ; B. le-ion of the left optic tract, producing right lat-eral hemiopia ; E. lesion producing right crossed amblyopia; 0, a lesion at this point will producetemporal hemiopia. most external part of the nerve and tract. An examination of thedrawing (Fig. 33) will be sufficient to make these statements clear,and to establish the fact that the nerve-fibres which form each tractpass to the corresponding half of each retina. Thus the fibres of theleft optic tract pass to the left half of each retina, and those of th
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Keywords: ., bookcentury1800, bookdecade1880, booksubjectnervoussystem, bookye
