Trigeminal Nerve Repair: Is the Trigeminocardiac Reflex a Concern?

PURPOSE

Our hypothesis is that direct manipulation of the third and second divisions of the trigeminal nerve during microneurosurgery does not affect the incidence of trigeminocardiac reflex (TCR). The purpose of this paper was to analyze the incidence of TCR events during microneurosurgery involving the second and third divisions of the trigeminal nerve.

MATERIALS AND METHODS

This was a retrospective cohort study of 94 patients who underwent nerve repair of the second and third divisions of the trigeminal nerve, between July 2014 and February 2021 by a single surgeon (J. Z.). The independent variables were the trigeminal nerve branch injured, the laterality of the trigeminal nerve injury, the Sunderland classification, the ASA classification, the intraoperative narcotic(s) used, and the depth of anesthesia. The dependent variables included the occurrence of intraoperative hypercapnia, hypoxia, and TCR event. Since the data was retrospective and categorical in nature, χ² analysis was performed initially.

RESULTS

None of the patients in this retrospective cohort demonstrated intraoperative hypercapnia, hypoxia or TCR events. Initial χ² calculation was performed for the dependent variables with the trigeminal nerve groups (IAN, LN, and ION). The χ² calculation [χ² (1, n = 101)] was 0.2235. The P-value was .6364. Since there was no statistical significance found, there was no further analysis of surgical and anesthesia independent variables in the data collection.

CONCLUSIONS

The zero incidence of TCR in a large number of patients provides strong evidence supporting the rejection of the hypothesis that TCR can occur during the surgical repair of peripheral trigeminal nerves.

An in vivo functional genomics screen of nuclear receptors and their co-regulators identifies FOXA1 as an essential gene in lung tumorigenesis

Using a mini-library of 1062 lentiviral shRNAs targeting 40 nuclear hormone receptors and 70 of their co-regulators, we searched for potential therapeutic targets that would be important during in vivo tumor growth using a parallel in vitro and in vivo shRNA screening strategy in the non-small cell lung cancer (NSCLC) line NCI-H1819. We identified 21 genes essential for in vitro growth, and nine genes specifically required for tumor survival in vivo, but not in vitro: NCOR2, FOXA1, HDAC1, RXRA, RORB, RARB, MTA2, ETV4, and NR1H2. We focused on FOXA1, since it lies within the most frequently amplified genomic region in lung adenocarcinomas. We found that 14q-amplification in NSCLC cell lines was a biomarker for FOXA1 dependency for both in vivo xenograft growth and colony formation, but not mass culture growth in vitro. FOXA1 knockdown identified genes involved in electron transport among the most differentially regulated, indicating FOXA1 loss may lead to a decrease in cellular respiration. In support of this, FOXA1 amplification was correlated with increased sensitivity to the complex I inhibitor phenformin. Integrative ChipSeq analyses reveal that FOXA1 functions in this genetic context may be at least partially independent of NKX2-1. Our findings are consistent with a neomorphic function for amplified FOXA1, driving an oncogenic transcriptional program. These data provide new insight into the functional consequences of FOXA1 amplification in lung adenocarcinomas, and identify new transcriptional networks for exploration of therapeutic vulnerabilities in this patient population.

Primary Gastrointestinal Stromal Tumor Presenting as an Isolated Lung Mass

Gastrointestinal stromal tumors (GISTs) are rare gastrointestinal (GI) tumors, representing a small portion of soft tissue tumors of the abdominal cavity. Extraintestinal gastrointestinal stromal tumors (EGISTs) are uncommon forms of GISTs that present outside the GI tract. There have only been a rare number of reported cases of EGIST presenting above the diaphragm. We present the case of a 50-year-old female with shortness of breath, and found to have bilateral pleural effusions and left-sided lung mass. The initial lung mass aspiration was negative for malignancy; yet, pleural fluid was suggestive of malignancy, and repeat biopsy and immunohistochemical stain were diagnostic for GIST. Ultimately, the patient underwent video-assisted thoracoscopic surgery, pleurodesis with doxycycline, and adjuvant therapy with imatinib. This is a report of primary EGIST presenting as an isolated lung lesion with no involvement of the GI tract. In patients with suspected malignancy, it is of paramount importance to obtain a detailed history, including remote signs and symptoms, while performing a thorough work-up. Especially in the lung where initial biopsies can be skewed due to inflammation and atelectasis, repeat biopsies may be necessary to obtain an accurate diagnosis.

Retrospective Analysis of Population Demographic Characteristics, Medical Interventions, and Resource Use at a Medical Student-Run Clinic on the Texas-Mexico Border

PURPOSE

The study's purpose was to assess population demographics and resource utilization of the Medical Student Run Clinic, which provides primary care services to patients in El Paso, Texas along the Texas-Mexico border.

METHODS

A retrospective cross-sectional chart review was performed on 760 patients evaluated at the medical student-run clinic between 2013 and 2016. Data included demographic characteristics, chief complaints, diagnoses, and interventions, which were analyzed with calculations of means, standard deviations, and percentages.

RESULTS

Most (79.7%) patients were female; average age was 38.43 years; 91% of patients were Hispanic, and 66.8% spoke Spanish. Average BMI was 30.9 kg/m2. Less than 1% of patients presented with a psychiatric complaint; however, 17.9% screened positive for anxiety, and 16.5% screened positive for depression.

CONCLUSIONS

This study shows that diabetes, hypertension, obesity, anxiety, and depression represent avenues for future patient-centered interventions and provide insight into challenges patients face along the border.

MRI evaluation of mediastinal and thoracic inlet venous obstruction

Fourteen patients with clinical and/or radiographic evidence of mediastinal or thoracic inlet venous obstruction were studied with magnetic resonance imaging (MRI) on a 0.35-T superconducting system using multislice spin-echo technique. The MRI examinations were retrospectively evaluated for their ability to provide information about the presence, level, and cause of venous obstruction, local extent of disease causing obstruction, and presence of collateral venous pathways. The results were compared to the information available from correlative studies including CT (11) and venography (four). In each instance, MRI provided detailed information about the precise site and extent of venous obstruction. The specific cause of the obstruction was suggested by MRI findings in one case of teratoma and in one case of postradiation fibrosis. Otherwise, all masses had relatively prolonged T1 T1 and T2 relaxation times and could not be differentiated on the basis of their and T2 relaxation times and could not be differentiated on the basis of their MRI appearances. Transaxial images most clearly and unequivocally depicted patent and obstructed superior vena cava (SVC). Enlarged venous collateral pathways were apparent in four cases. CT scans with intravenous contrast material in general provided information similar to that available with MRI, except in two cases where there was a discrepancy between CT and MRI concerning complete versus partial occlusion of the SVC. This initial study indicates that MRI can provide information about the presence, cause, and precise level of mediastinal and thoracic inlet venous obstruction.