Question 2257
{"accessible":false,"alternatives":[{"id":11181,"text":"communicating non-obstructive hydrocephalus"},{"id":11182,"text":"communicating obstructive hydrocephalus"},{"id":11183,"text":"non-communicating non-obstructive hydrocephalus"},{"id":11184,"text":"non-communicating obstructive hydrocephalus"}],"archived":false,"correctAlternativeId":11184,"explanation":"\u003cp\u003eAlthough hydrocephalus is typically referred to as either being \"obstructive\" or \"communicating\", this can lead to confusion as to the underlying cause of ventriculomegaly as the terms are referring to different aspects of the underlying pathophysiology (namely \"why\" and \"where\").\u003c/p\u003e\u003cp\u003eFor example, acute\u0026nbsp;subarachnoid hemorrhage\u0026nbsp;confined to the basal cisterns can result in ventriculomegaly by obstructing the normal flow of CSF through the basal cisterns, and by filling the arachnoid granulations. Given that this is mechanistically an obstruction to CSF flow outside of the ventricular system should it be considered communicating or obstructive hydrocephalus? The correct answer is that it is actually communicating obstructive hydrocephalus.\u003c/p\u003e\u003cp\u003eAs such a more precise terminology is to divide hydrocephalus into:\u003c/p\u003e\u003col\u003e\n\u003cli\u003ecommunicating and non-communicating:\u0026nbsp;addressing \"where\" the obstruction is located\u003c/li\u003e\n\u003cli\u003eobstructive and non-obstructive:\u0026nbsp;on the grounds of whether or not there is obstruction of CSF pathways in the ventricles or the subarachnoid space\u0026nbsp;\u003c/li\u003e\n\u003c/ol\u003e\u003cp\u003eAn aqueduct stenosis therefore is both obstructive and non-communicating.\u0026nbsp;\u003c/p\u003e","id":2257,"imageUrl":null,"imageAttribution":null,"imageAttributionCaseInfo":null,"firstQuestionPath":"/questions/2258","nextQuestionPath":"/articles/aqueduct-stenosis/questions/1468","relatedArticles":[{"id":19487,"title":"Hydrocephalus","link":"/articles/hydrocephalus?lang=us"}],"alsoUsedIn":[{"id":1171,"kind":"Course","title":"Adult Neuroradiology Review Course - page 1171","link":"https://radiopaedia.org/courses/adult-neuroradiology-review-course/pages/1171"},{"id":1171,"kind":"Course","title":"Adult Neuroradiology Review Course - page 1171","link":"https://radiopaedia.org/courses/adult-brain-mri-review-course-2015-online-video/pages/1171"}],"stem":"\u003cp\u003eAqueduct stenosis causes...\u0026nbsp;\u003c/p\u003e","menuLinks":[{"text":"Report problem with question","url":"https://docs.google.com/forms/d/e/1FAIpQLSfO3soWYhOjJ7yErSysyCe5V4A1CqW7WK3rDA7MtAkecMGqNw/viewform?entry.1624461248\u0026entry.553583435=https://radiopaedia.org/questions/2257"}],"attemptsPercentages":[{"alternativeId":"11181","percentage":2},{"alternativeId":"11182","percentage":10},{"alternativeId":"11184","percentage":85},{"alternativeId":"11183","percentage":3}],"promptToLogin":false,"questionManager":false,"articleId":"aqueduct-stenosis"}