Ali Khalid, Nannapaneni Ravindra, Hamandi Khalid
Department of Neurology, Morriston Hospital, Swansea, UK.
BMJ Case Rep. 2013 Apr 3;2013:bcr2013008791. doi: 10.1136/bcr-2013-008791.
Isolated enlargement of the fourth ventricle, or 'encysted' fourth ventricle is a rare late complication following shunt insertion of the lateral ventricles for hydrocephalus. Caudal and rostral obstruction of the fourth ventricle and its subsequent dilation results in compression of adjacent cerebellum and brain stem structures; treatment with further shunt insertion directly to the fourth ventricle is invariably successful. There is potential for diagnostic delay, when clinical symptoms and signs of cerebellar and brain stem compromise are unrecognised or attributed to other factors, and attention on the CT is focused on the lateral ventricular system and the already existing ventriculoperitoneal shunt, which will appear unchanged from previous scans. We report two cases with isolated fourth ventricular obstruction and review the literature to highlight the importance of recognising this condition.
孤立性第四脑室扩大，即“包裹性”第四脑室，是脑积水行侧脑室分流术后一种罕见的晚期并发症。第四脑室的尾侧和头侧梗阻及其随后的扩张导致相邻小脑和脑干结构受压；直接向第四脑室进一步插入分流管进行治疗总是成功的。当小脑和脑干受损的临床症状和体征未被识别或归因于其他因素，且CT检查的注意力集中在侧脑室系统和已有的脑室腹腔分流管（其在先前扫描中看起来无变化）时，可能会出现诊断延迟。我们报告两例孤立性第四脑室梗阻病例，并回顾文献以强调认识这种情况的重要性。
