Effectiveness and Toxicity of Fractionated Proton Beam Radiotherapy for Cranial Nerve Schwannoma Unsuitable for Stereotactic Radiosurgery

PurposeIn this benign tumor entity, preservation of cranial nerve function is of special importance. Due to its advantageous physical properties, proton beam radiotherapy (PRT) is a promising approach that spares healthy tissue. Could PRT go along with satisfactory preservation rates for cranial nerve function without compromising tumor control in patients with cranial nerve schwannoma unsuitable for stereotactic radiosurgery?MethodsWe analyzed 45 patients with cranial nerve schwannomas who underwent PRT between 2012 and 2020 at our institution. Response assessment was performed by MRI according to RECIST 1.1, and toxicity was graded following CTCAE 5.0.ResultsThe most common schwannoma origin was the vestibulocochlear nerve with 82.2%, followed by the trigeminal nerve with 8.9% and the glossopharyngeal nerve as well as the vagal nerve, both with each 4.4%. At radiotherapy start, 58% of cranial nerve schwannomas were progressive and 95.6% were symptomatic. Patients were treated with a median total dose of 54 Gy RBE in 1.8 Gy RBE per fraction. MRI during the median follow-up period of 42 months (IQR 26–61) revealed stable disease in 93.3% of the patients and partial regression in 6.7%. There was no case of progressive disease. New or worsening cranial nerve dysfunction was found in 20.0% of all patients, but always graded as CTCAE °I-II. In seven cases (16%), radiation-induced contrast enhancements (RICE) were detected after a median time of 14 months (range 2–26 months). RICE were asymptomatic (71%) or transient symptomatic (CTCAE °II; 29%). No CTCAE °III/IV toxicities were observed. Lesions regressed during the follow-up period in three of the seven cases, and no lesion progressed during the follow-up period.ConclusionThese data demonstrate excellent effectiveness with 100% local control in a median follow-up period of 3.6 years with a promising cranial nerve functional protection rate of 80%. RICE occurred in 16% of the patients after PRT and were not or only mildly symptomatic.

Metachronous Skull Base Paraganglioma Surgical Management: 2-Dimensional Operative Video

Paragangliomas (PGLs) are benign hypervascular tumors that can develop in head and neck at different locations, primarily in the carotid bifurcation, jugular bulb, tympanic plexus, and vagal ganglia.1 Different gene mutations have been linked to the familial inherited forms, which can represent approximately 30% of all PGLs.1,2 These are classified into 5 different clinical syndromes: PGL 1 to 5.1 These patients have increased risk for synchronous and metachronous lesions requiring an extensive work-up for hormone secretion and other associated neoplasms, as well as attentive follow-up for lifelong management.1,3 Surgical resection is the best treatment option as it can be curative when the resection is total.2-4 Preservation of the lower cranial nerve function is central to the management of head and neck PGLs, given the gravity of bilateral injuries.3 Irradiation therapy should be considered if the risk for bilateral lower cranial nerve injuries is high.5 Surgically, intrabulbar resection with preservation of the medial wall of the jugular bulb protects the lower cranial nerve function.3 Other technical finesses, including maintaining the facial nerve in its bony fallopian canal (facial bridge), avoiding carotid artery sacrifice, preservation of the ear canal, and preoperative embolization, contributed markedly to outcome improvement.2,3 We report a case of a 34-yr-old male with PGL 3 with a left glomus jugulare tumor that recurred and a right carotid body tumor. Patient consented to surgery and photography. Image at 3:44 republished from Al-Mefty and Teixeira,3 with permission from JSNPG.

Preoperative embolization of jugular paraganglioma tumors using particles is safe and effective

Background Jugular paragangliomas represent a surgical challenge due to their vascularity and proximity to vital neurovascular structures. Preoperative embolization aids in reducing intraoperative blood loss, transfusion requirements, and improves surgical visualization. Several embolization agents have been used. Objective The aim of this study is to evaluate the safety and efficacy of PVA in pre-operative embolization of jugular paragangliomas. Methods A retrospective review of all patients who underwent jugular paraganglioma resection with pre-operative embolization between 2000 and 2020 was performed. Pre-operative data including baseline patient and tumor characteristics were documented. Outcomes of preoperative embolization including extent of devascularization and post-embolization complications were recorded. Early and long-term postoperative outcomes were reported. Results Twenty-nine patients met study criteria with a median age of 38 years. Average tumor size was 3.4±1.8 cm. The most commonly encountered arterial feeder was the ascending pharyngeal artery followed by the posterior auricular artery. More than 50% reduction in tumor blush was achieved in 25 patients (86.2%). None of the patients experienced new or worsening cranial neuropathy following embolization. Gross total or Near total resection was achieved in 13 patients (44.8%). A STR or NTR was chosen in these patients to preserve cranial nerve function or large vessel integrity. Average intraoperative estimated blood loss was 888 ml, 9 patients (31%) required intra-operative transfusion of blood products. Extent of resection and post-operative complications did not correlate with extent of devascularization. Conclusion Pre-operative embolization of jugular paraganglioma tumors with PVA particles is an effective strategy with a high safety profile.

Abducens nerve schwannoma of the cavernous sinus: A case report and literature review

Background: Schwannomas of the abducens nerve are a rare pathology and are encountered less within the cavernous sinus. We describe a case of sixth cranial nerve schwannoma, in the cavernous sinus. Case Description: A 50-year-old lady, presented with 2 years history of double vision and left facial numbness that started 6 months before presentation, found to have hyperintense lobulated mass at the left cavernous sinus extending into Meckel’s cave with bony remodeling on magnetic resonance imaging. She underwent left frontotemporal craniotomy, combined extra-intradural approach, gross total resection. She had a gradual recovery of the sixth cranial nerve function. Conclusion: Abducens nerve schwannoma of the cavernous sinus is a rare and challenging tumor. However amenable to surgical intervention with favorable neurological outcome.

Severe Locked-In-Like Guillain–Barré's Syndrome: Dilemmas in Diagnosis and Treatment

Guillain–Barré's syndrome in childhood can follow an atypical course, increasing the challenges in diagnosis and decisions regarding immunomodulatory treatment. Here, we report the case of on a 13-year-old boy with acute onset Guillain–Barré's syndrome progressing over 40 days to a very severe, locked-in-like syndrome despite intensive immunomodulatory treatment. After a plateau phase lasting 3 months and characterized by fluctuating signs of ongoing inflammatory disease activity, we were prompted to perform repeated and maintenance immunomodulatory treatment, which resulted in a continuous and nearly complete recovery of function. Atypical features at disease onset, the severe “total” loss of all peripheral and cranial nerve function, and an apparent late response to treatment give rise to reviewing the dilemmas of diagnosis and treatment in such severe and protracted courses of Guillain–Barré syndrome.

Neurological assessment

The neurological assessment incorporates the assessment of the patient’s level of consciousness, cognition, cranial nerve function, and motor, sensory, and cerebellar function. A comprehensive, good-quality neurological assessment is able to detect early changes and deterioration in neurological status. It enables to practitioner to establish a baseline for later comparison to judge the patient’s response to specific medical and nursing interventions.

Conquering the Rock—A Retrospective Single-Center Experience of the Transapical Petrosal Transtentorial (Kawase) Approach: Operative Technique and Impact on Cranial Nerve Function

Since its description in 1985, the transapical petrosal transtentorial or Kawase approach has become a viable option of approaching lesions located in and around the apex of the petrous bone, Meckel's cave, and the anterolateral surface of the brain stem while preserving cranial nerve function. At the Brain Tumor Center, Erasmus MC, 25 patients were treated using the Kawase approach between 2004 and 2018 for various indications, including petroclival meningiomas, chondrosarcomas, pontine cavernomas, trigeminal schwannomas, and posterior circulation aneurysms. Hearing preservation was achieved in all patients; new abducens nerve and trochlear nerve palsies were present in three and six patients, respectively, of which a total of eight required ophthalmological correction. Seven patients experienced a cerebrospinal fluid fistula postoperatively, but this complication appeared self-limiting in all cases, with one patient experiencing secondary meningitis. After modifying our closure technique, the rate of fistulas dropped to zero. The observed direct postoperative mortality was 4% (one patient), although not related to the approach itself. In conclusion, the Kawase approach is a highly complex, but essential middle fossa approach, extremely robust, and able to serve a wide array of pathologies together with its extensions. It is very accurate for performing hearing preservation surgery, but not without caveats and inherent risk of complications.