Lateral Supracerebellar Infratentorial Approach for Superior Oblique Myokymia: A Case Series

Trochlear Nerve Decompression by Endoscopic Suboccipital Supracerebellar Infratentorial Approach: A Technical Note: 2-Dimensional Operative Video

BACKGROUND AND IMPORTANCE

Superior oblique myokymia (SOM) is a rare, acquired aberration of the innervation of the superior oblique, resulting in episodic monocular contraction of the superior oblique muscle characterized by intermittent rotatory eye movement causing diplopia and oscillopsia. Several treatment modalities have been described to treat SOM, including medication and surgical interventions. There is a paucity of reports describing microvascular decompression (MVD) of the trochlear nerve near the root entry zone for the treatment of a neurovascular conflict. The authors describe a case report of a patient who presented with SOM by a supracerebellar infratentorial approach using microscopic and endoscopic visualization.

CLINICAL PRESENTATION

A 40-year-old woman presented with an 8-month history of rhythmic contractions of her right orbit with worsening double vision and occasional balance issues. Neuro-ophthalmological evaluation which revealed a right-sided SOM. MRI evaluation demonstrated a potential vascular compression by the superior cerebellar artery near the origin of the trochlear nerve. She underwent MVD by a supracerebellar infratentorial approach using microscopic and endoscopic visualization. The patient experienced resolution of her SOM in the immediate postoperative period and a Trochlear nerve palsy that resolved within 6 months.

CONCLUSION

The endoscopic supracerebellar infratentorial approach for MVD of the trochlear nerve is a safe and efficacious approach that provides superior visualization of the trochlear nerve at its origin and in the setting of SOM. This approach shows outcomes comparable with those used in previously described cases.

Ultrahigh-Definition-3-Dimensional Exoscope-Assisted Clipping of a Right Middle Cerebral Artery Unruptured Aneurysm with Indocyanine Green Video Angiography: Operative Video

Ultrahigh-definition 3-dimensional exoscopes represent an excellent technologic innovation in contemporary neurosurgery. They combine the advantages of operating microscopes and endoscopes, offering excellent magnification and lighting, maintaining a relatively small footprint and optimal ergonomic features.1-5 One of the most interesting employments of exoscopes in neurosurgery is represented by intracranial vascular surgery. Reports in this field are still limited, but recent experience has shown that ultrahigh definition 3-dimensional exoscopes for aneurysm surgery are noninferior to operating microscopes for surgery duration, complication rate, and patient outcomes.6 In addition, many intraoperative techniques such as the indocyanine green videoangiography (ICG-VA) have been successfully implemented to exoscope-based surgery.7 We present herein the case of a 66-year-old woman that came to our attention for the incidental finding of 3 unruptured brain aneurysms. After neurosurgical consultation, the one located at the right middle cerebral artery bifurcation was considered eligible for surgery.8,9 As shown in Video 1, ICG-VA was employed after permanent clipping to allow immediate quality assurance of occlusion and distal vessel integrity. Postoperative course was uneventful, and follow-up examinations demonstrated the complete occlusion of the aneurysm. This report highlights the feasibility of exoscopic-based ICG-VA in vascular neurosurgery, given its ease of use, ergonomics, and excellent quality of vision provided to both surgeons and operating staff.

Three-Dimensional Exoscopic Versus Microscopic Resection of Vestibular Schwannomas: A Comparative Series

BACKGROUND

Microsurgical resection of vestibular schwannoma (VS) is highly challenging, especially because surgical treatment nowadays is mainly reserved for larger (Koos grade 3 and 4) tumors.

OBJECTIVE

To assess the performance of three-dimensional exoscope use in VS resection in comparison with the operative microscope.

METHODS

Duration of surgery and clinical and radiological results were collected for 13 consecutive exoscopic schwannoma surgeries. Results were compared with 26 preceding microsurgical resections after acknowledging similar surgical complexity between groups by assessment of tumor size (maximum diameter and Koos grade), the presence of meatal extension or cystic components, and preoperative hearing and facial nerve function.

RESULTS

Total duration of surgery was comparable between microscopically and exoscopically operated patients (264 minutes ± 92 vs 231 minutes ± 84, respectively; P = .276). However, operative time gradually decreased in consecutive exoscopic cases and in a multiple regression model predicting duration of surgery, and exoscope use was associated with a reduction of 58.5 minutes (95% CI -106.3 to -10.6; P = .018). Tumor size was identified as the main determinant of duration of surgery (regression coefficient = 5.50, 95% CI 3.20-7.80) along meatal extension and the presence of cystic components. No differences in postoperative hearing preservation and facial nerve function were noted between the exoscope and the microscope.

CONCLUSION

Resection of VS using a foot switch-operated three-dimensional exoscope is safe and leads to comparable clinical and radiological results as resection with the operative microscope.

Microvascular Decompression for Concurrent Trigeminal Neuralgia and Hemi-Laryngopharyngeal Spasm: A Case Report

BACKGROUND AND IMPORTANCE

Hemi-laryngopharyngeal spasm (HeLPS) may result from vascular compression of the vagus nerve and can be treated using microvascular decompression. We describe the clinical characteristics and surgical treatment in a case of concurrent trigeminal neuralgia (TN) and HeLPS.

CLINICAL PRESENTATION

A 44-year-old man presented with a 12-month history of right TN and 8-month history of intermittent episodes of repeated throat contractions associated with a very distressing choking sensation. Preoperative 3-dimensional fusion imaging demonstrated compression of the trigeminal nerve by the superior cerebellar artery and petrosal vein and compression of the vagus nerve by the posterior inferior cerebellar artery and one of its branches. Microvascular decompression was performed by a right standard retrosigmoid approach with enlarged craniotomy. Initially, the compression of the trigeminal nerve was identified by visual inspection. All the offending vessels were wrapped in Teflon felt, transposed away from the trigeminal nerve, and adhered to the tentorial membrane and petrous bone using fibrin glue. Furthermore, observation of the caudal rootlets of the vagus nerve revealed that the posterior inferior cerebellar artery and its branch compressed the ventral side of the nerve. These vessels were displaced antero-caudally with Teflon felt and fibrin glue; no other vessels were found around the trigeminal and vagus nerves. Postoperatively, the patient had immediate and complete resolution of symptoms of TN and HeLPS without recurrence at the 18-month follow-up.

CONCLUSION

HeLPS may occur with TN, and neurosurgeons should identify the symptoms suspicious of this disease preoperatively.