Obscurations and further time-related paroxysmal disorders in intracranial tumors; syndrome of initial herniation of parts of the brain through the tentorial incisure.

Abstract

SUDDEN and rapidly transient attacks of blurred vision affecting both eyes are not an uncommon occurrence. In some instances the condition may progress to complete blindness, followed by immediate and complete recovery of vision. In the present paper, these various types of blurring and dimming of vision and black-out will be denoted by the common term obscurations. Such attacks have repeatedly been described in cases of intracranial tumor. Their prevalence in cases in which the tumor is located below the tentorium has been pointed out by a number of writers,1usually with comments on the genesis of the attacks. Spasm of the retinal arteries, for example, has been assumed to be the causal factor. In cases of intracranial tumors the attacks have tentatively been accounted for by the pressure exerted upon the optic nerve in the optic canal, or by the pressure on the intracranial portion of the nerve