Neurosurgery
-
Hearing loss after removal of vestibular schwannomas with preservation of the cochlear nerve can result from labyrinthine injury of the posterior semicircular canal and/or common crus during drilling of the posterior wall of the internal auditory meatus. Indeed, there are no anatomic landmarks that intraoperatively identify the position of the posterior semicircular canal or of the common crus. We investigated the usefulness of image guidance and endoscopy for exposure of the internal auditory canal (IAC) and its fundus without labyrinthine injury during a retrosigmoid approach. ⋯ Frameless navigation using high-resolution computed tomographic scans and bone-implanted reference markers can provide a "roadmap" to maximize safe surgical exposure of the IAC without violating the labyrinth and leaving a small segment of the lateral IAC unexposed. Further exposure and surgical manipulation of this segment, including the fundus without additional cerebellar retraction and labyrinthine injury, can be achieved using an endoscope. Use of image guidance and an endoscope can help in exposing the entire posterior aspect of the IAC including its fundus without violating the labyrinth through a retrosigmoid approach. This technique could improve hearing preservation in vestibular schwannoma surgery.
-
En plaque sphenoid wing meningiomas are complex tumors involving the sphenoid wing, the orbit, and sometimes the cavernous sinus. Complete removal is difficult, so these tumors have high rates of recurrence and postoperative morbidity. The authors report a series of 71 patients with sphenoid wing meningiomas that were managed surgically. ⋯ Surgical management of patients with sphenoid wing meningiomas cannot be uniform; it must be tailored on a case-by-case basis. Successful resection requires extensive intra- and extradural surgery. We recommend optic canal decompression in all patients to ameliorate and/or preserve visual function.
-
We sought to determine the frequency, risk factors, and impact on functional outcome and quality of life (QOL) of global cognitive impairment 1 year after subarachnoid hemorrhage. ⋯ Global cognitive impairment affects more than 20% of subarachnoid hemorrhage survivors at 1 year, is predicted by fever, anemia treated with transfusion, and delayed cerebral ischemia, and adversely affects functional recovery and QOL.
-
To describe initial experience with resting-state correlation mapping as a potential aid for presurgical planning of brain tumor resection. ⋯ Resting-state correlation mapping is a promising tool for reliable functional localization of eloquent cortex. This method compares well with "gold standard" cortical stimulation mapping and offers several advantages compared with conventional motor mapping fMRI.
-
Transcranial magnetic stimulation (TMS) is a noninvasive method for analyzing cortical function. To utilize TMS for presurgical functional diagnostics, the magnetic impulse must be precisely targeted by stereotactically positioning the coil. The aim of this study was to evaluate the usefulness of TMS for operation planning when combined with a sensor-based electromagnetic navigation system (nTMS). ⋯ nTMS allowed for reliable, precise application of the magnetic impulse, and the peritumoral somatotopy corresponded well between the 2 modalities in all 10 cases. nTMS is a promising method for preoperative functional mapping in motor cortex tumor surgery.