Brainstem death due to intracranial hypertension with hydrocephalus, produced by a third ventricular colloid cyst.

We describe the clinical presentation and CT findings of a 10-year-old female patient about half an hour prior to cardiorespiratory arrest and subsequent death, resulting from brainstem compression and herniation caused by hydrocephalus and intracranial hypertension, produced by a previously undetected colloid cyst occluding foramina of Monro on both sides. While third ventricular colloid cysts are rare lesions, sudden unpredicted deaths have been attributed to undetected colloid cysts in many case reports, with some authors even considering that 10% of colloid cyst patients suffer such ends. However, there is still no conclusive or comprehensive guideline regarding how to prevent such situations. We make a short literature review and put forward a few recommendations or learning points to that end.

Bilateral Occipital Lobe Herniations Due to Asymmetric Tentorial Defects: Incidental Computed Tomography (CT) Findings & Literature Review.

Congenital defects in the tentorium cerebelli are quite rare occurrences and are often too small and asymptomatic. This is a case report of a female patient aged 11 years, complaining of headache, vertigo, and vomiting. Her computed tomography (CT) images show transtentorial herniation of occipital gyri across a developmental defect involving the anterior free margin of the tentorium cerebelli. Similar cases have been reported in the past as "incidental" and "potentially symptomatic" findings, and in at least one case as a proven pathological findings. Our case is unique in terms of the asymmetric bilateral configuration and comparatively larger size of the defect. We have included a review of the existing medical literature in order to derive learning points for the betterment of our understanding of a rare entity that can have significant implications.

Tarlov cysts in back pain patients: prevalence, measurement method and reporting points.

OBJECTIVE: Determining the prevalence of Tarlov cysts in low back pain patients. METHODS AND MATERIALS: The picture archiving & communication system (PACS) & hospital information system (HIS) of a corporate hospital were retrospectively analyzed to determine the percentage of Tarlov cysts among patients undergoing spinal MRI for back pain over 3 years (January 2017 to December 2019). RESULTS: 384 patients had undergone spinal MRI for back pain over the study period, and 25 of them (6.51%) had Tarlov cysts. Vast majority (15 cases) showed cysts located at S2/S3 level, and few were found at S1/S2 and other levels. Single cysts were found in most (=18) of the cases, while 7 cases of multiple / bilateral cysts were found. Cyst dimensions were higher in craniocaudal than anteroposterior or transverse directions. In case of multiple cysts, one or two cysts were noted as dominant, having higher dimensions than the others. The study data revealed no gender or age predilection. CONCLUSIONS: We conclude that including the entire sacrum with a T2 sagittal sequence in all MRI for low back pain can increase detection of Tarlov cysts, and thereby provide more data for further analysis. ADVANCES IN KNOWLEDGE: We propose the concept of one "dominant" cyst when there are multiple Tarlov cysts. We recommend that diameter or size of Tarlov cysts be specified to their craniocaudal dimension. We also suggest reporting points for contextual structured reporting, viz. presence or absence of bony scalloping, neural foraminal narrowing, nerve root compression or extraforaminal extension.