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Marcus F. Keep, Lois Mastrofrancesco, Daniel Erdman, Brent Murphy and Lynn S. Ashby

✓ The authors present the neuroimaging, treatment planning, and radiosurgical technique for the first reported case of unilateral radiosurgical subthalamotomy, which was performed to control motor symptoms associated with advanced Parkinson disease (PD) in a patient who had undergone previous contralateral radiofrequency (RF) pallidotomy.

A 73-year-old woman with end-stage PD had undergone RF pallidotomy of the right globus pallidus with resolution of symptoms. Two years following this procedure, due to the natural progression of her disease, she suffered recurrent motor fluctuations, dyskinesia, and worsening bradykinesia of the right side. Her Parkinson's Disease Disability Rating (PDDR) score was 28. Computerized tomography and magnetic resonance (MR) imaging were used to localize the left subthalamic nucleus (STN). The patient underwent gamma knife radiosurgery—a single shot of 120 Gy was administered using the 4-mm collimator helmet.

The patient was evaluated up to 42 months after the procedure. The dyskinesia became minimal. Right-sided motor control improved as did her balance. At 3 months after treatment MR imaging demonstrated the radiosurgical lesion in the left STN. At 3.5 years postradiosurgery, she experienced minimal focal (oral) dyskinesia, no bradykinesia or rigidity, and her PDDR score was 11.

Radiosurgery of the STN in this case was safe and effective. The STN is a readily localized anatomical target with neuroimaging. Radiosurgery avoids the risks of open procedures.

Open access

Rafael Martínez-Pérez, Marcus Zachariah, Ruychen Li, Giuliano Silveira-Bertazzo, Ricardo L. Carrau and Daniel M. Prevedello

Atypical trigeminal schwannomas (ATSs) are notorious for their ability to invade the skull base. An expanded endoscopic endonasal approach (eEEA) provides direct access to the tumor with no need for cerebral retraction or manipulation of neurovascular structures. Herein, we present a case of a large temporal fossa extradural lesion with secondary invasion of the sella, clivus, and temporal and infratemporal fossae in a 49-year-old male with severe vision loss. A transpterygoid transmaxillary approach was performed. Gross-total removal was achieved and pathology revealed the diagnosis of ATS. Visual function fully recovered in the right side and the patient has been uneventfully followed since surgery.

The video can be found here: https://youtu.be/6pSwdYsN9hk.

Open access

Mostafa Shahein, Thiago Albonette-Felicio, Giuliano Silveira-Bertazzo, Rafael Martinez-Perez, Marcus Zachariah, Ricardo L. Carrau and Daniel M. Prevedello

Chordomas are rare tumors that occur at an incidence rate of 0.8 per 100,000. Thirty-five percent of chordomas occur in the spheno-occipital region. We present a case of a clival chordoma that had severe brainstem compression. The patient had a 1-year history of slurred speech and left facial weakness (House-Brackmann 3). The endoscopic endonasal transclival approach gave a panoramic view of the region without the necessity of brain retraction or manipulation of the surrounding cranial nerves. Gross-total resection was achieved and no CSF leak was encountered postoperatively. The left facial weakness improved to House-Brackmann 1.

The video can be found here: https://youtu.be/DzW9Q6ckTHw.