Arachnoid cyst is a rare benign cerebrospinal fluid-filled cyst that can develop anywhere in the brain along the arachnoid membrane and usually unaccompanied by the anomalous development of the brain structure. These cysts are usually located in the middle cranial fossa. However, they are also denoted in other regions. Arachnoid cysts are mostly asymptomatic and diagnosed incidentally. Spontaneous regression of arachnoid cysts in different anatomical regions of the brain has been reported in the literature. However, to the best of our knowledge, this is the first case reporting an unusual spontaneous regression of arachnoid cyst in the pineal region in a 3-year-old child presented to our hospital with hydrocephalus without alarming signs and was treated conservatively as the patient was stable, and the cyst showed spontaneous regression. A comprehensive review of the literature regarding spontaneous regression of arachnoid cysts has been collected and discussed in this article.

BackgroundMeningiomas are mostly benign and slow-growing neoplasms of the central nervous system. Spinal meningiomas account for up to 45% of all intradural spinal tumors in adults and up to 25%–45% of all spinal tumors. Spinal extradural meningiomas are rare and may be easily confused with malignant neoplasms.Case descriptionA 24-year-old woman was presented to our hospital with paraplegia and loss of sensation in the T7 dermatome and lower body. MRI findings showed T6-T7 right-sided intradural extramedullary and extradural lesion, measuring 1.4 cm × 1.5 cm × 3 cm, extending to the right foramen, compressing the spinal cord, and displacing it to the left. Hyperintense lesion on T2 and hypointense lesion on T1 were observed. The patient reported improvement after surgery and during follow-up. We recommend maximizing the decompression during surgery to achieve better clinical outcome. Extradural meningiomas represent 5% of all meningiomas; therefore, having an intradural on top of extradural meningioma with extraforaminal extensions makes this a unique and rare case.ConclusionMeningiomas can be easily missed in diagnosis depending on imaging and the pathognomonic pattern it represents, which can mimic other pathologies, such as schwannomas. Therefore, surgeons should always suspect their patient having a meningioma even if the pattern is not typical. Moreover, preoperative preparation, such as navigation and defect closure, must be taken in case it turns out be a meningioma instead of the presumed pathology.

Objectives: To assess the incidence of infection following various cerebrospinal fluid (CSF) shunt procedures among patients with hydrocephalus and related conditions, based on the age of the patient, and to determine the types of pathogens responsible for shunt infections. Methods: This retrospective single center study reviewed the records of patients with culture-confirmed CSF shunt infection diagnosed between January 2012 and December 2017. Cases without central nervous system imaging investigations were excluded. Results: The incidence rate of shunt-related infections was 32.2%. Among the 189 patients whose records were included, Staphylococcus epidermidis (47.5%) and Acinetobacter baumannii (18%) were the most common causative organisms. The incidence of postoperative infection was higher among those who underwent external ventricular drain procedures (65%) than among those who underwent ventriculoperitoneal shunt procedures (24%). There were no intraoperative deaths. However, the postoperative death rate was 12.2% during hospital stay (mean duration = 9 days); 2% of these deaths occurred after shunt removal. Conclusion: The incidence of infections after CSF shunt procedures was high in our tertiary academic hospital during the study period, compared to those reported in similar clinical settings and before developing a detailed standardized protocol for infection control. Although gram-negative organisms were the most prevalent cause of CSF infections, S. epidermidis (a gram-positive organism) was the most commonly encountered causative agent. Shunt protocols should be implemented to address perioperative shortcomings and to reduce overall mortality and morbidity.