Histopathological correlation of brain tumor recurrence vs. radiation effect post-radiosurgery as detected by MRI contrast clearance analysis: a validation study.

PURPOSE: The differentiation between adverse radiation effects (ARE) and tumor recurrence or progression (TRP) is a major decision-making point in the follow-up of patients with brain tumors. The advent of immunotherapy, targeted therapy and radiosurgery has made this distinction difficult to achieve in several clinical situations. Contrast clearance analysis (CCA) is a useful technique that can inform clinical decisions but has so far only been histologically validated in the context of high-grade gliomas. METHODS: This is a series of 7 patients, treated between 2018 and 2023, for various brain pathologies including brain metastasis, atypical meningioma, and high-grade glioma. MRI with contrast clearance analysis was used to inform clinical decisions and patients underwent surgical resection as indicated. The histopathology findings were compared with the CCA findings in all cases. RESULTS: All seven patients had been treated with gamma knife radiosurgery and were followed up with periodic MR imaging. All patients underwent CCA when the necessity to distinguish tumor recurrence from radiation necrosis arose, and subsequently underwent surgery as indicated. Concordance of CCA findings with histological findings was found in all cases (100%). CONCLUSIONS: Based on prior studies on GBM and the surgical findings in our series, delayed contrast extravasation MRI findings correlate well with histopathology across a wide spectrum of brain tumor pathologies. CCA can provide a quick diagnosis and have a direct impact on patients' treatment and outcomes.

A survey of surveys: an evaluation of the quality of published surveys in neurosurgery.

PURPOSE: Surveys generate valuable data in epidemiologic and qualitative clinical research. The quality of a survey depends on its design, the number of responses it receives, and the reporting of the results. In this study, we aimed to assess the quality of surveys in neurosurgery. METHODS: Neurosurgical surveys published between 2000 and 2020 (inclusive) were identified from PubMed. Various datapoints regarding the surveys were collated. The number of citations received by the papers was determined from Google Scholar. A 6-dimensional quality assessment tool was applied to the surveys. Parameters from this tool were combined with the number of responses received to create the survey quality score (SQS). RESULTS: A total of 618 surveys were included for analysis. The target sample size correlated with the number of responses received. The response rate correlated positively with the target sample size and the number of reminders sent and negatively with the number of questions in the survey. The median number of authors on neurosurgery survey papers was 6. The number of authors correlated with the SQS and the number of citations received by published survey papers. The median normalized SQS for neurosurgical surveys was 65%. The nSQS independently predicted the citations received per year by surveys. CONCLUSIONS: The modifiable factors that correlated with improvements in survey design were optimizing the number of questions, maximizing the target sample size, and incorporating reminders in the survey design. Increasing the number of contributing authors led to improvements in survey quality. The SQS was validated and correlated well with the citations received by surveys.

Trigeminal schwannoma of the sphenoid sinus--report of a rare entity.

Schwannomas are common slow growing benign tumors. About 25-45% of all schwannomas arise in the head and neck region. Less than 4% of these tumors are found in sinonasal regions and usually affect nasal ethmoid. There are very few case reports of a schwannoma arising from the sphenoid sinus. We report a case of sphenoid sinus schwannoma treated by microscopic decompression and review the relevant literature.

Acute pyogenic necrotizing encephalomyelitis: a fulminant and fatal infection.

In this report the authors describe a rare case of a fulminant, pyogenic, necrotizing infection of the spinal cord and brain. Necrotizing lesions of the brain and spinal cord are usually infectious in origin and are associated with high rates of morbidity and death. Although the pathogens responsible have been identified in a few instances, the causal factors remain unknown in many cases. An 11-year-old girl developed acute, rapidly progressive paraplegia with bladder involvement and sensory loss below T-10. She had been treated recently for a Staphylococcus aureus infection of the knee joint precipitated by a penetrating injury with organic matter in the aftermath of a cyclone. Although appropriate antibiotic therapy was instituted, the spinal cord infection progressed to involve the entire spinal cord, brainstem, and brain. This fulminant course was marked by a rapid deterioration in the patient's clinical condition, ultimately leading to her death. Magnetic resonance imaging demonstrated a previously undescribed pattern of longitudinal enhancement along the spinal cord, as well as the white matter tracts in the brainstem and brain. The possible route of spread of infection along the neuraxis is postulated to be the potential space along the white matter tracts. Treatment is not standardized due to the rarity of the condition.