BASKIMUY'S IHSKASK 63 



that the protrusion of the eye-ball shows in many patients have led to this 

 assumption. The essential cause is, however, an abnormal tonus of the 

 Landstriim musculus palpebralis, which is innervated by the sympathetic. 

 The protrusion may be produced experimentally by electric stimulation of 

 the cervical sympathetic (Claude Bernard). The protrusion may be such 

 a high grade that the globe becomes displaced. In old Basedow's cases the 

 protrusion remains stationary, which may be explained through increased 

 deposition of retrobulbar fatty tissue. The gaping of the palpebral fissure 

 (Dalrymple-Slellivag's sign) on increased opening tension of the eye (L. 

 Bruns) is dependent on an abnormal tonus of the oculomotor nerve and 

 is, therefore, according to Eppinger and Hess, to be regarded as a sign of 

 autonomous irritation. 



The exophthalmus may also be unilateral. A confusion with unilateral 

 affection of the sympathetic may be avoided by attention to the width of 

 the pupils; the latter should show no differences in Basedow's disease; 

 Roasenda has described three Basedow's cases with unilateral eye symptoms, 

 and in one of these cases this symptom always remained limited to the one 

 side. The unilateral exophthalmus sometimes accompanies unilateral en- 

 largement of the thyroid gland, either with homolateral or with contra- 

 lateral enlargement. Worms and Hamant have issued a compilation of such 

 cases. 



?. Grafe's symptoms, i.e., the failure of the upper lid to follow, or only 

 retarded following of the upper lid when the vision' is turned slowly down- 

 ward, the white sclera thus becoming visible at the upper border of the 

 cornea, depends on an increased tonus of the levator palpebrae muscle. 

 v. Slellwag's symptom consists in a rarity and an incompleteness of the in- 

 voluntary blinking. Whereas in the normal individual the blinking move- 

 ment occurs three to five times in the minute, in Basedow's disease it may 

 not occur for minutes. 



The eye symptoms are very hard to reproduce experimentally, a fact 

 that for a long time stood in the way of the hypothesis that Basedow's dis- 

 ease was a hyperthyrosis; however, Kraus and Friedental and Honicke were 

 finally successful, through the administration of very large amounts of thy- 

 roidin in inducing a widening of the palpebral fissures and an exophthalmus, 

 although not to a very marked degree. Recently through the use of material 

 obtained by the removal of struma at operation on human beings it was 

 possible to induce typical exophthalmus in a dog (Lampe, Li esc gang, and 

 Klose, and Baruch). Worthy of mention here is also the case of Notlnijft, 

 in which an evident protrusion developed after an excessive use of thyroid- 

 gland tablets. 



Finally, Mobius's symptom consists in a weakness of convergence; by 

 fixation of the finger held near-by, the eye deviates without diplopia ; perhaps 

 this not common symptom is to be explained by a fatty degeneration of the 



