844: PETEE BASSOE 



kind. We are glad to note that Peritz(a) takes a similar view. In some 

 cases the psychosis clearly is dependent on compression or direct invasion 

 of the brain by tumor, or on hydrocephalus, as is frequently seen in tumor 

 of any portion of the brain. 



Secondary Symptoms and Lesions 



Ocular Symptoms. These are practically always produced mechani- 

 cally by the pressure of the hypophyseal tumor on the chiasma, nerves and 

 tracts and by deformity of the orbits. Thus Dr. Mark's chief ocular dis- 

 turbance was caused by constant change in the character of his astigma- 

 tism ascribed to pressure on the eyeball by hyperostosis of the orbits. Op- 

 penheim(&) (1914) makes the interesting suggestion that in exceptional 

 instances optic nerve degeneration, analogous to the rarely observed spinal 

 cord degeneration, may be produced by a toxic substance furnished by the 

 hypophysis. With this possible exception the explanation for the eye symp- 

 toms must be found in the complicated mechanical conditions created by a 

 growing hypophysis and a changing sella in the immediate vicinity of the 

 optic chiasma. (Fig. 18.) As a result of the sellar widening the optic 

 foramina become farther separated, necessitating additional readjustment. 

 The usual sequence of events was stated by Holdeii in 1899 : "First, the 

 posterior portion of the chiasma is compressed by the pituitary body. 

 Following this, the posterior and middle portions of the chiasma are 

 flattened and forced upward, and thus separated from the anterior portion 

 which is protected by the bone beneath it. (Fig. 19.) Later, with this 

 tilting upward of the chiasma posteriorly and the forcing forward of the 

 anterior wall of the pituitary fossa, the anterior portion of the chiasma is 

 encroached upon by the pituitary body and arched directly forward. 

 Finally the chiasma may be severed completely." With the pressure 

 mainly exerted on the chiasma the decussating fibers going to the nasal 

 sides of the retina suffer most, and consequently bitemporal hemianopsia 

 constitutes the commonest visual defect. The types of field encountered 

 have been worked out most carefully, among others by Arnold Josefson, 

 Gushing and Walker, and de Schweinitz. 



Optic atrophy and its resulting visual impairment are said to be much 

 less frequent in acromegaly than in other forms of hypophyseal disease. 

 Uhthoff (a) found amblyopia and amaurosis in 7 per cent of the acromegaly 

 cases and in 28.5 per cent of cases of other hypophyseal affections. 



De Schweinitz classified the eye symptoms as follows: 



1. Impairment of vision, varying from blurred sight to amaurosis 

 or complete blindness. 



2. Intraocular optic nerve alterations varying from partial or 

 general pallor of the nerve head to partial or complete atrophy; less 



