Pollock, Bruce E.

OBJECTIVEGeniculate neuralgia (GN) is an uncommon craniofacial pain syndrome attributable to nervus intermedius (NI) dysfunction. Diagnosis and treatment can be challenging, due to the complex nature of ear sensory innervation, resulting in clinical overlap with trigeminal neuralgia (TN) and glossopharyngeal neuralgia (GPN).METHODSA retrospective review of a prospective neurosurgical database at our institution was performed, 2000–2017, with a corresponding systematic literature review. Pain outcomes were dichotomized as unfavorable for unchanged/worsened symptoms versus favorable if improved/resolved. Eight formalin-fixed brains were examined to describe NI at the brainstem.RESULTSEleven patients were surgically treated for GN—9 primary, 2 reoperations. The median age was 48, 7 patients were female, and the median follow-up was 11 months (range 3–143). Seven had ≥ 2 probable cranial neuralgias. NI was sectioned in 9 and treated via microvascular decompression (MVD) in 2. Five patients underwent simultaneous treatment for TN (4 MVD; 1 rhizotomy) and 5 for GPN (3 MVD; 2 rhizotomy). Eleven reported symptomatic improvement (100%); 8 initially reported complete resolution (73%). Pain outcomes at last contact were favorable in 8 (73%)—all among the 9 primary operations (89% vs 0%, p = 0.054). Six prior series reported outcomes in 111 patients.CONCLUSIONSGN is rare, and diagnosis is confounded by symptomatic overlap with TN/GPN. Directed treatment of all possible neuralgias improved pain control in almost all primary operations. Repeat surgery seems a risk factor for an unfavorable outcome. NI is adherent to superomedial VIII at the brainstem; the intermediate/cisternal portion is optimal for visualization and sectioning.

Objectives: Catecholamine-secreting jugular paragangliomas (JPs) represent a rare subset of head and neck paragangliomas that may present with hypertension, arrhythmia, or syncopal episodes. Subtotal resection to protect critical neurovascular structures may result in persistent catecholamine excess from residual tumor. Herein, we report our experience with stereotactic radiosurgery (SRS) for salvage treatment of catecholamine-secreting JP following subtotal microsurgical resection. Patients: Adult patients treated with SRS after subtotal microsurgical resection of catecholamine-secreting JP. Interventions: SRS. Main Outcome Measures: Post-treatment catecholamine and metanephrine levels, clinical outcomes, and tumor control. Results: Of 85 patients with JPs treated with primary or salvage radiosurgery between 1990 and 2017, 2 (2%) harbored nonmalignant secreting tumors. Patient 1 developed catecholamine excess with elevated norepinephrine (NE) at 475 mcg/24 hours (normal < 80 mcg/24 h). Following subtotal resection, she developed catecholamine excess with radiographic evidence of tumor growth and therefore underwent SRS. Three years post-SRS and beyond, catecholamine levels remained normalized (NE 62 mcg/24 h at 10 yr) and tumor volume remained stable on serial MRI studies over the 17-year follow-up period. Patient 2 developed symptomatic arrhythmia and was found to have a JP. Urine norepinephrine (NE) was elevated at 213 mcg/24 hours. She underwent nerve-sparing subtotal resection and upfront SRS was used to treat residual tumor. Twenty months following SRS, the area of residual JP had not enlarged in size and catecholamine levels remained normal (NE 46 mcg/24 h). Conclusions: Radiosurgery can be used in salvage treatment of catecholamine-secreting JP, providing durable tumor control and resolution of catecholamine excess. For patients with large catecholamine-secreting JP and normal lower cranial nerve function, aggressive nerve-sparing subtotal resection with adjuvant radiosurgery may offer a low-morbidity alternative to gross total resection. Further study of this subset of patients is warranted to substantiate these promising, yet preliminary findings.

OBJECTIVE The morbidity of gross-total resection of jugular paraganglioma (JP) is often unacceptable due to the potential for irreversible lower cranial neuropathy. Stereotactic radiosurgery (SRS) has been used at the authors’ institution since 1990 for the treatment of JP and other benign intracranial tumors. Conventional means of assessing tumor progression using linear measurements or elliptical approximations are imprecise due to the irregular shape and insinuating growth pattern of JP. The objective of this study was to assess long-term tumor control in these patients by using slice-by-slice 3D volumetric segmentation of serial MRI data. METHODS Radiographic data and clinical records were reviewed retrospectively at a single, tertiary-care academic referral center for patients treated from 1990 to 2017. Volumetric analyses by integration of consecutive tumor cross-sectional areas (tumor segmentation) of serial MRI data were performed. Tumor progression was defined as volumetric growth of 15% or greater over the imaging interval. Primary outcomes analyzed included survival free of radiographic and clinical progression. Secondary outcomes included new or worsened cranial neuropathy. RESULTS A total of 85 patients were treated with Gamma Knife radiosurgery (GKRS) for JP at the authors’ institution over the last 27 years. Sixty patients had pretreatment and serial posttreatment contrast-enhanced MRI follow-up suitable for volumetric analysis. A total of 214 MR images were analyzed to segment tumor images in a slice-by-slice fashion to calculate integral tumor volume. The median follow-up duration was 66 months (range 7–202 months). At 5 years the tumor progression-free survival rate was 98%. Three tumors exhibited progression more than 10 years after GKRS. Estimated survival free of radiographic progression rates (95% confidence interval [CI]; n = number still at risk) at 5, 10, and 15 years following radiosurgery were 98% (95% CI 94%–100%; n = 34), 94% (95% CI 85%–100%; n = 16), and 74% (95% CI 56%–98%; n = 6), respectively. One patient with tumor progression required treatment intervention using external beam radiation therapy, constituting the only case of clinical progression. Two patients (3%) without preexisting lower cranial nerve dysfunction developed new ipsilateral vocal fold paralysis following radiosurgery. CONCLUSIONS SRS achieves excellent long-term tumor control for JP without a high risk for new or worsened cranial neuropathy when used in primary, combined modality, or recurrent settings. Long-term follow-up is critical due to the potential for late radiographic progression (i.e., more than 10 years after SRS). As none of the patients with late progression have required salvage therapy, the clinical implications of this degree of tumor growth have yet to be determined.