116 DIABETES INSIPIDUS 



the other hand, a great number of observations show that every one of the 

 previously mentioned areas may be affected without polyuria appearing. 



We must, therefore, admit that although we can find cases which are in 

 accord with Claude Bernard's celebrated experiments, and although the eases 

 of diabetes mellitus occurring in connection with cerebral disease have turned 

 out to be associated with a lesion of the very area in the floor of the fourth 

 ventricle which was discovered in Bernard's experiments, nevertheless we 

 cannot speak of diabetes insipidus in the same sense that we do of aphasia 

 as a focal symptom, meaning that it occurs invariably in lesions of this 

 area. 



In the majority of cases, diabetes insipidus first appears at a relatively 

 advanced stage of the cerebral disease, i. e., after other cerebral symptoms have 

 developed. In some cases, on the other hand, polyuria has been the only 

 symptom for months. This has been observed several times in tubercular 

 meningitis, in tumors of the brain, and in cerebral softening. 



A similar polyuria has been noted after trauma to the head, usually asso- 

 ciated with other cerebral symptoms. Almost always the injuries are severe 

 and are followed by complete loss of consciousness for several days. The in- 

 crease of urine usually appeared for the first time after consciousness had 

 returned ; comparatively often the signs that the seat of the cranial lesion was 

 in the posterior brain were paralyses of the muscles of the eye. Such a poljniria 

 arising after injuries to the head sometimes disappears with the other cere- 

 bral symptoms, while in other eases it persists as the only morbid phenomenon 

 for a varying period of time, even for many years. 



The form of diabetes insipidus which occurs in connection with cerebral 

 affections usually leads only to a moderate increase in the amount of the urine. 

 In the traumatic cases the daily excretion of urine amounts to from 5 to 20 

 liters; in the form occurring in non-traumatic cranial disease, from 5 to 10 

 liters are excreted. There are no peculiarities in the behavior of the polyuria 

 which distinguish these cerebral cases from other types of polyuria. Variations 

 in the intensity of the urinary disturbances occur, but are for the most part 

 slight ; it is but little influenced by drugs or other therapeutic measures. The 

 general health appears but slightly affected by the polyuria itself, apart from 

 the influence of the cerebral disease. 



There is only one peculiarity of the cerebral form, and this is its relation 

 to diabetes mellitus, which, as we have already mentioned, is apparently more 

 distinctive than in other forms of the affection. 



Among the functional neuroses in which diabetes insipidus is frequently 

 observed, two are of importance : epilepsy and hysteria. 



In epilepsy, polyuria usually develops gradually, after the underlying dis- 

 ease has existed for years; more rarely it appears suddenly in connection 

 with the attack. Usually it reaches but a moderate grade, and as a rule it 

 IS more susceptible to treatment than the cerebral form. 



The manner in which epilepsy develops and its different stages are without 

 any discernible influence on the polyuria. That diabetes insipidus occurs in 

 connection with a particular form of epilepsy (e. g., one suspected to depend 



