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Visish M. Srinivasan, Patrick J. Karas, Anish N. Sen, and Jared S. Fridley

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Brian J. Williams, Patrick J. Karas, Ganesh Rao, Laurence D. Rhines, and Claudio E. Tatsui

The authors present the first report of laser interstitial thermal therapy (LITT) ablation of a recurrent chordoma metastasis to the cervical spine. This patient was a 75-year-old woman who was diagnosed and treated for a sacral chordoma, and then developed metastases to the lung and upper thoracic spine. Unfortunately she experienced symptomatic recurrence at the C-7 spinous process. She underwent an uncomplicated LITT to the lesion. The patient convalesced without incident and was discharged on postoperative Day 1. She received stereotactic spinal radiosurgery to the lesion at a dose of 24 Gy in 1 fraction. At the 3-month follow-up evaluation she had radiographic response and improvement in her symptoms.

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Patrick J. Karas, Charles B. Mikell, Eisha Christian, Mark A. Liker, and Sameer A. Sheth

Deep brain stimulation (DBS), the practice of placing electrodes deep into the brain to stimulate subcortical structures with electrical current, has been increasing as a neurosurgical procedure over the past 15 years. Originally a treatment for essential tremor, DBS is now used and under investigation across a wide spectrum of neurological and psychiatric disorders. In addition to applying electrical stimulation for clinical symptomatic relief, the electrodes implanted can also be used to record local electrical activity in the brain, making DBS a useful research tool. Human single-neuron recordings and local field potentials are now often recorded intraoperatively as electrodes are implanted. Thus, the increasing scope of DBS clinical applications is being matched by an increase in investigational use, leading to a rapidly evolving understanding of cortical and subcortical neurocircuitry. In this review, the authors discuss recent innovations in the clinical use of DBS, both in approved indications as well as in indications under investigation. Deep brain stimulation as an investigational tool is also reviewed, paying special attention to evolving models of basal ganglia and cortical function in health and disease. Finally, the authors look to the future across several indications, highlighting gaps in knowledge and possible future directions of DBS treatment.

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Patrick J. Karas, Robert Y. North, Visish M. Srinivasan, Nathan R. Lindquist, K. Kelly Gallagher, Jan-Karl Burkhardt, Daniel Yoshor, and Peter Kan

The classic presentation of a carotid-cavernous fistula (CCF) is unilateral painful proptosis, chemosis, and vision loss. Just as the goal of treatment for a dural arteriovenous fistula (dAVF) is obliteration of the entire fistulous connection and the proximal draining vein, the modern treatment of CCF is endovascular occlusion of the cavernous sinus via a transvenous or transarterial route. Here, the authors present the case of a woman with a paracavernous dAVF mimicking the clinical and radiographic presentation of a CCF. Without any endovascular route available to access the fistulous connection and venous drainage, the authors devised a novel direct hybrid approach by performing an endoscopic endonasal transsphenoidal direct puncture and Onyx embolization of the fistula.