Prolonged Dyspnea after Interscalene Block: Attributed to Undiagnosed Addison's Disease and Myasthenia Gravis

This report describes a patient who had a series of daily interscalene nerve blocks to treat pain following a shoulder manipulation for postsurgical stiffness. She experienced acute respiratory compromise that persisted for many weeks. All typical and unusual causes of these symptoms were ruled out. Her treating pulmonologist theorized that the ipsilateral carotid body had been injured. However, it was subsequently determined that the constellation of symptoms and their prolonged duration were best explained by a poor stress response from Addison's disease coupled with exacerbation of early onset myasthenia gravis. This patient's case is not a typical reaction to interscalene nerve blocks, and thus preoperative testing would not be recommended for myasthenia gravis or Addison's disease without underlying suspicion. We describe this report to inform physicians to consider a workup for these diagnoses if a typical workup rules out all usual causes of complications from an interscalene block

Artery-Only Ear Replantation in a Child: A Case Report With Daily Photographic Documentation

Objective: Ear replantation poses a significant technical challenge even for the skilled microsurgeon. Many ear amputations result from avulsion and thus have damaged and often diminutive vessels with a paucity of veins. Artery-only replantation is an option for ear salvage, but little is published on the clinical course and appearance after this procedure. Methods: A subtotal ear replantation was performed on a 10-year-old boy without a venous anastomosis. Leech therapy was used to manage venous congestion postoperatively, and daily photography was performed to document the clinical course. Results: Postoperative venous congestion was successfully managed with leech therapy. Four days after the replantation, arterial thrombosis occurred that required a take back and salvage with an interposition vein graft for arterial repair. Native venous drainage and arterial revascularization from skin edges were evident by postoperative day 12, and leeches were discontinued on day 14. The patient required debridement of the posterior ear and superior helix necrotic skin, with burying of the upper portion of the ear in a superior auricular skin flap. The ear was subsequently released from the head, and the exposed portions were covered successfully with a full-thickness skin graft. Conclusions: While arterial and venous anastomoses should always be attempted, arterial-only ear replantation can provide excellent results when venous congestion is properly managed. Daily photography can be a useful tool to monitor subtle skin color changes that may indicate native venous drainage and arterial revascularization

Expanding Indications of the Medial Femoral Condyle Free Flap: Systematic Review in Head and Neck Reconstruction

Background:. The medial femoral condyle free flap serves as an attractive reconstructive option for small- to intermediate-sized bony defects. It is commonly applied in the extremities with limited reports in the head and neck. Methods:. A systematic review of the literature was performed using the Preferred Reporting Items for Systematic Reviews and Meta-Analyses guidelines. Results:. Seventeen articles met inclusion criteria, yielding 166 cases for analysis, with a majority of the cohort from a single study (n = 107; 64.4%). However, all included studies represented novel reconstructive sites and surgical indications. Flap components were described in 157 cases; periosteum was used only in four cases (2.5%), whereas all others are composed of cortical bone combined with periosteum, cancellous bone, and/or cartilage (97.5%). Additionally, a skin island was used in 43 cases (25.9%). Flap measurements were reported in 51 cases, averaging 4.5 ± 2.7 cm in length. Seven cases listed skin island dimensions, averaging 20.2 ± 12.8 cm2. The descending genicular artery was the primary pedicle employed (n = 162; 97.6%), while the superior medial genicular was used in the descending genicular artery’s absence (n = 4; 2.4%). Descending genicular artery pedicle length from 15 reporting cases averaged 6.4 ± 1.2 cm. Successful reconstructions totaled 160 cases (96.4%). Recipient complications were seen in 16 cases (9.6%) with six constituting flap failures (3.6%). Donor site complications were minimal (n = 6; 3.6%); however, this included one major complication of femoral shaft fracture. Conclusion:. The medial femoral condyle free flap is an effective reconstructive option for the head and neck due to its versatile nature, low complication profile at both recipient and donor site, ease of harvest, and two-team approach

Identification of Specific Ligand–Receptor Interactions That Govern Binding and Cooperativity of Diverse Modulators to a Common Metabotropic Glutamate Receptor 5 Allosteric Site

A common metabotropic glutamate receptor 5 (mGlu₅) allosteric site is known to accommodate diverse chemotypes. However, the structural relationship between compounds from different scaffolds and mGlu₅ is not well understood. In an effort to better understand the molecular determinants that govern allosteric modulator interactions with mGlu₅, we employed a combination of site-directed mutagenesis and computational modeling. With few exceptions, six residues (P654, Y658, T780, W784, S808, and A809) were identified as key affinity determinants across all seven allosteric modulator scaffolds. To improve our interpretation of how diverse allosteric modulators occupy the common allosteric site, we sampled the wealth of mGlu₅ structure–activity relationship (SAR) data available by docking 60 ligands (actives and inactives) representing seven chemical scaffolds into our mGlu₅ comparative model. To spatially and chemically compare binding modes of ligands from diverse scaffolds, the ChargeRMSD measure was developed. We found a common binding mode for the modulators that placed the long axes of the ligands parallel to the transmembrane helices 3 and 7. W784 in TM6 not only was identified as a key NAM cooperativity determinant across multiple scaffolds, but also caused a NAM to PAM switch for two different scaffolds. Moreover, a single point mutation in TM5, G747V, altered the architecture of the common allosteric site such that 4-nitro-<i>N</i>-(1,3-diphenyl-1<i>H</i>-pyrazol-5-yl)­benzamide (VU29) was noncompetitive with the common allosteric site. Our findings highlight the subtleties of allosteric modulator binding to mGlu₅ and demonstrate the utility in incorporating SAR information to strengthen the interpretation and analyses of docking and mutational data