Hoxworth, Joseph M.

OBJECTIVE Although it is still early in its application, laser interstitial thermal therapy (LiTT) has increasingly been employed as a surgical option for patients with mesial temporal lobe epilepsy. This study aimed to describe mesial temporal lobe ablation volumes and seizure outcomes following LiTT across the Mayo Clinic’s 3 epilepsy surgery centers. METHODS This was a multi-site, single-institution, retrospective review of seizure outcomes and ablation volumes following LiTT for medically intractable mesial temporal lobe epilepsy between October 2011 and October 2015. Pre-ablation and post-ablation follow-up volumes of the hippocampus were measured using FreeSurfer, and the volume of ablated tissue was also measured on intraoperative MRI using a supervised spline-based edge detection algorithm. To determine seizure outcomes, results were compared between those patients who were seizure free and those who continued to experience seizures. RESULTS There were 23 patients who underwent mesial temporal LiTT within the study period. Fifteen patients (65%) had left-sided procedures. The median follow-up was 34 months (range 12–70 months). The mean ablation volume was 6888 mm 3 . Median hippocampal ablation was 65%, with a median amygdala ablation of 43%. At last follow-up, 11 (48%) of these patients were seizure free. There was no correlation between ablation volume and seizure freedom (p = 0.69). There was also no correlation between percent ablation of the amygdala (p = 0.28) or hippocampus (p = 0.82) and seizure outcomes. Twelve patients underwent formal testing with computational visual fields. Visual field changes were seen in 67% of patients who underwent testing. Comparing the 5 patients with clinically noticeable visual field deficits to the rest of the cohort showed no significant difference in ablation volume between those patients with visual field deficits and those without (p = 0.94). There were 11 patients with follow-up neuropsychological testing. Within this group, verbal learning retention was 76% in the patients with left-sided procedures and 89% in those with right-sided procedures. CONCLUSIONS In this study, there was no significant correlation between the ablation volume after LiTT and seizure outcomes. Visual field deficits were common in formally tested patients, much as in patients treated with open temporal lobectomy. Further studies are required to determine the role of amygdalohippocampal ablation.

Introduction: Rheumatoid meningitis (RM) is a rare complication of rheumatoid arthritis (RA) and has a high mortality rate. It can present as a first diagnosis of RA, in long-standing disease, or in active or well-controlled disease. Neurological manifestations vary widely. Case Report: A patient with a 30-year history of RA, well controlled with methotrexate therapy, presented with new-onset seizures. Magnetic resonance imaging showed leptomeningeal and pachymeningeal enhancement. A de novo workup resulted in diagnosis of RM. Conclusions: Cerebrospinal fluid findings for RM are nonspecific, typically lymphocytic pleocytosis; however, they can be neutrophilic, as in this case. Magnetic resonance imaging findings consist of leptomeningeal and pachymeningeal enhancement but can also involve the parenchyma. The diagnosis is typically confirmed with meningeal biopsy. Treatment involves high-dose corticosteroids or immunomodulatory therapy, or both. Long-term follow-up with radiologic surveillance typically ranges from improvement to resolution.

Background Recurrence of inverted papilloma (IP) is a problem in 12–17% of tumors. Controversy exists regarding benefits of intraoperative frozen section histopathology (IFSH) for IP resection; however, to our knowledge, no study has specifically investigated this. IFSH for IP resection is the standard of care in our practice. We, therefore, reviewed our outcomes of using IFSH for IP resection. A secondary goal was to assess the reliability of IFSH. Methods Patients with IP who underwent surgical resection (2010–2016) with minimum 9–month follow-up were included. Results Twenty-two adults with IP met inclusion criteria. All underwent surgery via endoscopic techniques, supplemented by external ports in five patients. At the time of presentation, 36% IPs were recurrent tumors; 68% were graded as Krouse stage 3. Resection was conducted until “clear” (negative) mucosal margins were achieved on IFSH. In 6 (27%), a “positive” IFSH result dictated additional resection to clear margins. Final negative margins were achieved in all the patients. Both positive and negative predictive values for IFSH were 100% (concordance with final pathology results). Surveillance was performed every 1–6 months with nasal endoscopy by using imaging when necessary. No recurrences were noted (0%) at mean follow-up of 40 months (range, 10 -73 months). Conclusions Positive IFSH results led to increased resection in 27% of the patients, with a 0% recurrence rate in this cohort. The reliability of IFSH for IP is very high. No recurrence of IP was noted in any patient at a mean follow-up of 3.3 years. IFSH may help reduce recurrence rates of IP, but additional studies with longer follow-up are warranted.

ObjectiveTo determine whether machine learning can accurately classify human papillomavirus (HPV) status of oropharyngeal squamous cell carcinoma (OPSCC) using computed tomography (CT)-based texture analysis.MethodsTexture analyses were retrospectively applied to regions of interest from OPSCC primary tumors on contrast-enhanced neck CT, and machine learning was used to create a model that classified HPV status with the highest accuracy. Results were compared against the blinded review of 2 neuroradiologists.ResultsThe HPV-positive (n = 92) and -negative (n = 15) cohorts were well matched clinically. Neuroradiologist classification accuracies for HPV status (44.9%, 55.1%) were not significantly different (P= 0.13), and there was a lack of agreement between the 2 neuroradiologists (κ = −0.145). The best machine learning model had an accuracy of 75.7%, which was greater than either neuroradiologist (P< 0.001,P= 0.002).ConclusionsUseful diagnostic information regarding HPV infection can be extracted from the CT appearance of OPSCC beyond what is apparent to the trained human eye.

Objectives: To compare the diagnostic yield of high-resolution volumetric T2-weighted MRI (HRT2-MRI) with high-resolution computed tomography (HRCT) for diagnosis of large vestibular aqueduct (LVA). Study Design: Three board-certified neuroradiologists performed an independent, blinded radiological review for diagnosing LVA with 2:1 age-matched controls on patients with both HRCT and HRT2-MRI imaging. Setting: Tertiary referral center. Patients: All patients between 2002 and 2016 with hearing loss who underwent both HRCT and HRT2-MRI and were diagnosed with LVA on either modality. Main Outcome Measures: Concordance rate for LVA between HRCT and HRT2-MRI. Results: Concordance rate for HRCT and HRT2-MRI for diagnosing LVA was 88% (124/141) when assessing both the midpoint and external aperture diameters. Fifteen ears had LVA on computed tomography (CT), but not on magnetic resonance imaging (MRI); in comparison, two ears had LVA on MRI, but not on CT (p = 0.002). Excellent inter-rater reliability among the three radiologists was demonstrated. Conclusion: Historically, HRCT has been the imaging modality of choice for diagnosing LVA. Although a higher concordance rate of HRT2-MRI was found compared with previous studies utilizing earlier MRI technology, HRCT still detected a larger number of patients with clinically significant hearing loss compared with MRI. Given the high concordance rate and efficacy of both modalities in diagnosing LVA, the ultimate decision of which modality to choose may depend on other patient-specific and clinical factors.