Foramen magnum decompression in adults with Chiari type 1 malformation: use of intraoperative ultrasound to guide extent of surgery.

BACKGROUND: Foramen magnum decompression (FMD) is an established technique for patients with Chiari-1 malformation. However, the extent of decompressive surgery is controversial, in particular whether dural opening is undertaken. OBJECTIVE: In this study, we report outcomes with our technique utilising intraoperative ultrasound (iOU) findings. Decision to proceed for further decompression was based on CSF flow around foramen magnum and visualisation of tip of tonsils. METHODS: Review of adults with CM-1 undergoing FMD 2013-2018. Patients underwent a suboccipital craniectomy ± partial C1 superior laminectomy ± duraplasty in a stepwise manner. Favourable iOU findings of CSF flow around the foramen magnum and pulsation of the tonsillar tips were sought at each step. Post-operative outcomes were assessed using the Chicago Chiari Outcome Score (CCOS). RESULTS: Fifty-seven patients were included. The mean age was 47 years (range 18-77 years). There was a strong female preponderance (48 females to nine males). The mean follow-up was 3.2 years (range 1-5 years). Surgery included: suboccipital craniectomy (52/57, 91%), plus partial C1 superior laminectomy (2/57, 4%), and plus duraplasty (3/57, 6%). Redo surgery was undertaken in 7/57 patients (12%). At final follow-up, 56/57 (98%) patients achieved a good (CCOS 13-16) or satisfactory (CCOS 9-12) outcome based on COSS. CONCLUSIONS: A patient centred approach to surgery utilising findings from iOU can achieve favourable outcomes. Dural opening is not routinely required.

Low-Grade Glioma with Foci of Early Transformation Does Not Necessarily Require Adjuvant Therapy After Radical Surgical Resection.

BACKGROUND: Low-grade glioma (LGG) is a slow-growing tumor often found in young adults with minimal or no symptoms. As opposed to true low-grade lesions such as dysembryoplastic neuroepithelial tumors, they are associated with continuous growth and inevitable malignant transformation. METHODS: Case series of patients who have had en bloc resection of LGG with foci of anaplasia found embedded within the tumor specimen and not at margins. Patients were offered and agreed to a conservative approach avoiding adjuvant therapy. RESULTS: In the current case series, we describe a small subset of LGG that have shown foci of high-grade glioma but have shown behavior and growth tendencies similar to LGG after radical surgical resection. No patient to date has shown recurrent disease requiring adjuvant therapy. CONCLUSIONS: This case series supports the use of early aggressive surgical treatment of grade II gliomas that are premalignant. It acts as proof of concept that after radical resection, the presence of small foci of transformation embedded within grade II tumor may be treated with close radiologic surveillance rather than immediate adjuvant therapy.

A suprasellar arachnoid cyst resulting from an intraventricular haemorrhage and showing complete resolution following endoscopic fenestration.

We present the case of a premature neonate who developed a large, acquired arachnoid cyst as a consequence of intraventricular haemorrhage. The child was managed with endoscopic fenestration and made an excellent recovery.

Spinal neuroschistosomiasis.

We report a 20-year-old woman with a diagnosis of spinal neuroschistosomiasis that was confirmed histologically. Magnetic resonance imaging demonstrated an expanded, oedematous conus with intrinsic heterogeneous enhancement, which was initially thought to be a neoplastic lesion. This case demonstrates an alternative diagnosis to oncological lesions of the spinal cord which should be considered in patients who have recently travelled to endemic areas.