Acute airway obstruction requiring nasotracheal intubation following hypoglossal neuromonitoring: a case report.

BACKGROUND: Intraoperative neurophysiological monitoring (IONM) is utilized for both the localization of critical structures and for real time detection and prevention of intraoperative neurological injury. Use of IONM to monitor the hypoglossal nerve is performed during neurosurgical, otolaryngological, and vascular procedures to improve surgical outcomes. There is a paucity of literature describing potential complications of IONM of the hypoglossal nerve, especially with respect to airway compromise. Here we present our findings regarding a case of acute airway obstruction following hypoglossal nerve monitoring. CASE PRESENTATION: A 54-year-old male was admitted for left far-lateral craniotomy and microsurgical clipping of a left posterior inferior cerebellar artery (PICA) aneurysm. Following induction and intubation but prior to the procedure start, the patient was placed in the ¾ prone position with the left side up and his neck was flexed approximately 10 degrees. He then underwent placement of subdermal needle electrodes into the facial muscles, trapezius muscles, soft palate, and tongue for IONM. The procedure lasted 523 minutes and was completed without complication. However, approximately one hour after emergence from general anesthesia, the patient experienced progressive difficulty breathing secondary to severe lingual swelling. He required emergent placement of a nasotracheal tube guided by a fiberoptic bronchoscope. He remained intubated for 3 days and was treated with dexamethasone, after which the swelling resolved, and the patient was successfully extubated. CONCLUSIONS: Acute lingual edema is a potentially life-threatening phenomenon that can lead to rapid airway compromise. Generally, causes of acute lingual swelling include hemorrhage, edema, infarction, and infection. In the case described above, we suspect traumatic injury to the tongue's vascular supply caused a deep tissue hematoma leading to postoperative acute lingual swelling and airway obstruction. With the widespread use of IONM, it becomes essential for providers to be aware that perioperative airway compromise is a potentially life-threatening complication, especially with respect to monitoring of the hypoglossal nerve. Awake fiberoptic nasotracheal intubation can successfully be employed to establish an emergency airway in such situations.

The RNA-binding protein IGF2BP3 is critical for MLL-AF4-mediated leukemogenesis.

Despite recent advances in therapeutic approaches, patients with MLL-rearranged leukemia still have poor outcomes. Here, we find that the RNA-binding protein IGF2BP3, which is overexpressed in MLL-translocated leukemia, strongly amplifies MLL-Af4-mediated leukemogenesis. Deletion of Igf2bp3 significantly increases the survival of mice with MLL-Af4-driven leukemia and greatly attenuates disease, with a minimal impact on baseline hematopoiesis. At the cellular level, MLL-Af4 leukemia-initiating cells require Igf2bp3 for their function in leukemogenesis. At the molecular level, IGF2BP3 regulates a complex posttranscriptional operon governing leukemia cell survival and proliferation. IGF2BP3-targeted mRNA transcripts include important MLL-Af4-induced genes, such as those in the Hoxa locus, and the Ras signaling pathway. Targeting of transcripts by IGF2BP3 regulates both steady-state mRNA levels and, unexpectedly, pre-mRNA splicing. Together, our findings show that IGF2BP3 represents an attractive therapeutic target in this disease, providing important insights into mechanisms of posttranscriptional regulation in leukemia.