The superior sagittal sinus (SSS) is a midline structure of the superficial cerebral venous system that drains the anterior cerebral hemispheres. Hypoplasia of the rostral SSS is a known variant, although associated complications are rare. A woman in her 30s presented for evaluation of a symptomatic left-sided acoustic neuroma and was found to have an incidental chronic subdural haematoma (SDH) over the left frontoparietal convexity without trauma or precipitating event. The SDH expanded on serial imaging and the patient eventually underwent left-sided frontoparietal craniotomy for haematoma evacuation. Haematological evaluation was benign, but angiography revealed absence of the anterior half of the SSS. We report the first case of spontaneous SDH in the setting of hypoplastic rostral SSS.

The natural history of neurofibromatosis type 2 (NF2) is profound bilateral hearing loss. The decision to pursue microsurgery may be more complicated in NF2 than with sporadic tumors. Schwannomas in NF2 often occur with other skull base tumors. Treatment should be tailored to preserve auditory perception for as long as possible. The authors present the case of a man with NF2 and a vestibular schwannoma who has poor hearing on the same side as a large petrous apex meningioma, both opposite to a well-hearing ear. This case highlights surgical decision-making and technical nuances during resection of collision tumors in NF2. The video can be found here: https://stream.cadmore.media/r10.3171/2021.7.FOCVID21130

Background/Objectives: For patients with profound deafness resulting from auditory nerve pathology, as in Neurofibromatosis type 2, auditory brainstem implantation (ABI) can restore meaningful acoustic input. The literature reporting real-world results for ABI users is limited, especially regarding patients with bilateral implants. Here, we provide an updated report on the audiologic outcomes among all ABI patients treated at a tertiary institution, including high-performing bilateral ABI users. Methods: In this updated and expanded retrospective case series, audiologic outcomes were reviewed in sixteen consecutive patients who underwent ABI placement by a single neurosurgeon-neurotologist team at our center since 2018. Implantation in four of these patients was on their second side after having undergone first side implantation prior to receiving care at our hospital. Main outcome measures were sound awareness (sound-field threshold testing) and speech understanding (pattern perception, spondee, open-set speech testing). Results: Sound awareness was achieved in 100% of patients (16/16) using an average of 12 electrodes (range 7–20). Persistent non-auditory sensations were reported by 12.5% (2/16). Postoperative speech differentiation (with or without lip-reading) was experienced in 87.5% (14/16). Two second-sided ABI recipients experienced exceptional outcomes as high-performing outliers: one achieved 57% audio only and 86% audio + visual hearing in noise test (HINT) sentence scores; the second bilateral user scored 92% with auditory-only input. Conclusions: ABI represents a viable option for patients who are at risk of developing bilateral profound deafness resulting from auditory nerve disruption. Second sided device implantation is safe and has the potential to significantly improve auditory outcomes.