Raqeeb Haque, Teresa J. Wojtasiewicz, Paul R. Gigante, Mark A. Attiah, Brendan Huang, Steven R. Isaacson, and Michael B. Sisti
The goal of this article was to show that a combination of facial nerve–sparing microsurgical resection and Gamma Knife surgery (GKS) for expansion of any residual tumor can preserve good facial nerve function in patients with recurrent vestibular schwannoma (VS).
Records of individuals treated by a single surgeon with a facial nerve–sparing technique for a VS between 1998 and 2009 were retrospectively analyzed for tumor recurrence. Of the 383 patients treated for VS, 151 underwent microsurgical resection, and 20 (13.2%) of these patients required postoperative retreatment for a significant expansion of residual tumor after microsurgery. These 20 patients were re-treated with GKS.
The rate of preservation of good facial nerve function (Grade I or II on the House-Brackmann scale) in patients treated with microsurgery for VS was 97%. Both subtotal and gross-total resection had excellent facial nerve preservation rates (97% vs 96%), although subtotal resection carried a higher risk that patients would require retreatment. In patients re-treated with GKS after microsurgery, the rate of facial nerve preservation was 95%.
In patients with tumors that cannot be managed with radiosurgery alone, a facial nerve–sparing resection followed by GKS for any significant regrowth provides excellent facial nerve preservation rates.
David P. McMullen, Tessy M. Thomas, Matthew S. Fifer, Daniel N. Candrea, Francesco V. Tenore, Robert W. Nickl, Eric A. Pohlmeyer, Christopher Coogan, Luke E. Osborn, Adam Schiavi, Teresa Wojtasiewicz, Chad R. Gordon, Adam B. Cohen, Nick F. Ramsey, Wouter Schellekens, Sliman J. Bensmaia, Gabriela L. Cantarero, Pablo A. Celnik, Brock A. Wester, William S. Anderson, and Nathan E. Crone
Defining eloquent cortex intraoperatively, traditionally performed by neurosurgeons to preserve patient function, can now help target electrode implantation for restoring function. Brain-machine interfaces (BMIs) have the potential to restore upper-limb motor control to paralyzed patients but require accurate placement of recording and stimulating electrodes to enable functional control of a prosthetic limb. Beyond motor decoding from recording arrays, precise placement of stimulating electrodes in cortical areas associated with finger and fingertip sensations allows for the delivery of sensory feedback that could improve dexterous control of prosthetic hands. In this study, the authors demonstrated the use of a novel intraoperative online functional mapping (OFM) technique with high-density electrocorticography to localize finger representations in human primary somatosensory cortex. In conjunction with traditional pre- and intraoperative targeting approaches, this technique enabled accurate implantation of stimulating microelectrodes, which was confirmed by postimplantation intracortical stimulation of finger and fingertip sensations. This work demonstrates the utility of intraoperative OFM and will inform future studies of closed-loop BMIs in humans.