Vestibulo-ocular dysfunction in mTBI: Utility of the VOMS for evaluation and management - A review.

BACKGROUND: Individuals who have suffered a concussion/mild traumatic brain injury (mTBI) frequently report symptoms associated with vestibular and/or oculomotor dysfunction (VOD) like dizziness, nausea, fatigue, brain fog, headache, gait and neurocognitive impairments which are associated with the development of chronic symptoms. The Vestibular/Ocular Motor Screening (VOMS) tool has been established as a reliable and clinically relevant complement to use alongside a battery of post-concussion tests to improve screening and referral for further evaluation and treatment of VOD. OBJECTIVES: This paper will review the pathoanatomy and symptomatology of common vestibular and oculomotor disorders after concussion, as well as the utility of the VOMS to assist in diagnosis, referral, and management. METHODS: Primary articles were identified using a search via PubMed, Google Scholar, OneSearch, and CINAHL. Search key terms were combinations of "mild traumatic brain injury" or "concussion" or "pursuit" or "accommodation" or "vergence" or "convergence insufficiency" or "saccades" or "vestibulo-ocular reflex" or "vestibular ocular motor screen" or "vestibular rehabilitation", or "vision rehabilitation" including adult and pediatric populations that were published in print or electronically from 1989 to 2021 in English. Classic papers on anatomy of eye movements, vestibular system and pathological changes in mTBI were also included, regardless of publication date. RESULTS: Objective impairments are commonly found during testing of smooth pursuit, saccades, vergence, accommodation, vestibular ocular reflex, and visual motion sensitivity after mTBI. These deficits can be actively treated with vestibular physical therapy and oculomotor/neuro-optometric vision therapy. VOMS is an efficient and reliable tool that can be used by all healthcare and rehabilitation providers to aid in diagnosis of post-concussion VOD, to help facilitate the decision to refer for further evaluation and treatment to expedite symptomatic post-concussion recovery. CONCLUSIONS: VOD is common after concussion in acute, post-acute, and chronic phases. Once areas of impairments are identified through proper assessment, clinicians can maximize recovery by referring to vestibular physical therapy and/or neuro-optometry to design a targeted treatment program to address individual deficits.

Oncological and Functional Outcomes of Transoral Robotic Surgery and Endoscopic Laryngopharyngeal Surgery for Hypopharyngeal Cancer: A Systematic Review.

Objectives: Hypopharyngeal carcinoma (HPC) is a head and neck carcinoma with poor prognosis. Traditional laryngopharyngectomy offered promising oncological outcomes at the cost of functional outcomes. The recent advent in transoral robotic surgery (TORS), an organ-preserving surgery, has opened up new perspectives in the treatment for HPC. Here, we evaluate minimally invasive organ preservation surgery [TORS and endoscopic laryngopharyngeal surgery (ELPS)] for HPC in terms of feasibility and oncological and functional outcomes. Methods: This is a systematic review. Six databases [CUHK Full-Text Journals, Embase 1910 to 2021, Ovid Emcare, Ovid MEDLINE (R), CINAHL, PubMed] were searched for articles and primary studies for TORS and ELPS for HPC. Screening was completed using predefined inclusion or exclusion criteria. Results: A total of 8 studies on TORS and 3 studies on ELPS were eventually chosen after full-text review. For studies on TORS, 61.3% of patients (84 out of 137) still survived at the last follow-up with a mean follow-up time of 23.20 months (range: 12.8-37.21 months). Severe intraoperative and postoperative complications have not been reported. No cases of TORS required a conversion to open surgery. Swallowing function was optimal postoperatively with only 6 patients eventually required a percutaneous endoscopic gastrostomy (PEG) for feeding. Disease-specific survival was taken as the parameter for the measurement of oncological outcomes. A total of 2 studies reported a disease-specific survival of 100% within their follow-up period of 1 and 1.5 years, respectively. Another 2 studies reported a 2-year DSS of 89 and 98%, respectively. A 5-year DSS of 100% in early stage and 74% in late stage were achieved in one study. Another study also reported a 5-year DSS of 91.7%. For studies of ELPS, a 5- and 3-year disease-specific survival of 100% were achieved in 2 studies. Patients who underwent ELPS had good postoperative swallowing function with no PEG placement. There were also no other fatal complications. Conclusions: Both TORS and ELPS for HPC provide satisfactory long-term oncological and functional outcomes improving postoperative quality of life of patients.

Post-cardiac arrest therapeutic hypothermia: overcoming the barrier of workplace culture and other implementation lessons.

BACKGROUND: Therapeutic hypothermia (TH) is associated with improved neurologically intact survival after out-of-hospital cardiopulmonary arrest. Because of its complex multidisciplinary nature, many hospitals in the United States have resisted implementing TH. A post-cardiac arrest (post-arrest) TH program was implemented at a major urban academic medical center. IMPLEMENTING THE THERAPEUTIC HYPOTHERMIA PROGRAM: After initial efforts at TH at the University of Alabama at Birmingham Hospital nearly failed, the leaders restructured the TH program. Key elements included frequent multidisciplinary meetings involving all stakeholders, development of TH protocols and techniques consistent with customary institutional practices, introduction of cooling technology, and implementation of a TH physician rapid response system. RESULTS: During its first 21 months, the program initiated TH on 93 post-arrest patients. Of the 83 patients who achieved goal hypothermia temperature, 30 (36%; 95% confidence interval [CI]: 26%-47%) survived to hospital discharge. Care teams successfully managed expected complications. Of two patients with TH-associated coagulopathy, one required TH termination. CONCLUSIONS: The program illustrates key lessons for successful TH program implementation, such as the difficulty of organizing and coordinating complex interventions in complex institutions, the importance of overcoming workplace culture, the value of technology, the need for mid-course corrections, and the advantages of a physician-based rapid response system. Many of these lessons are applicable to any quality improvement intervention.

Effect of vitamin A depletion on nonvisual phototransduction pathways in cryptochromeless mice.

Mice exhibit multiple nonvisual responses to light, including 1) photoentrainment of circadian rhythm; 2) "masking," which refers to the acute effect of light on behavior, either negative (activity suppressing) or positive (activity inducing); and 3) pupillary constriction. In mammals, the eye is the sole photosensory organ for these responses, and it contains only 2 known classes of pigments: opsins and cryptochromes. No individual opsin or cryptochrome gene is essential for circadian photoreception, gene photoinduction, or masking. Previously, the authors found that mice lacking retinol-binding protein, in which dietary depletion of ocular retinaldehyde can be achieved, had normal light signaling to the SCN, as determined by per gene photoinduction. In the present study, the authors analyzed phototransduction to the SCN in vitamin A-replete and vitamin A-depleted rbp-/- and rbp-/-cry1-/-cry2-/- mice using molecular and behavioral end points. They found that vitamin A-depleted rbp-/- mice exhibit either normal photoentrainment or become diurnal. In contrast, while vitamin A-replete rbp-/-cry1-/-cry2-/- mice are light responsive (with reduced sensitivity), vitamin A-depleted rbp-/-cry1-/-cry2-/- mice, which presumably lack functional opsins and cryptochromes, lose most behavioral and molecular responses to light. These data demonstrate that both cryptochromes and opsins regulate nonvisual photoresponses.

Vitamin A: overlapping delivery pathways to tissues from the circulation.

Although retinol bound to retinol-binding protein (RBP) is the most abundant retinoid form present in the circulations of humans and most mammals, other retinoid and proretinoid forms are also present in the blood. We are interested in understanding to what extent each of these circulating retinoid forms contributes towards retinoid actions within cells and tissues. Here we report two studies focused on this question. First, we examined retinoid transport and storage in RBP-deficient mice that lack circulating RBP. These mice under normal laboratory conditions are phenotypically normal except for a visual impairment early in life that is corrected if the mice are maintained on a vitamin A-sufficient diet throughout life. The RBP-deficient mice take up vitamin A from the diet into most tissues at least as well as wild type mice. Compared to wild type mice, mice lacking RBP accumulate excess vitamin A in the liver, since there is no RBP to facilitate mobilization of stored retinol from hepatic stores. In a second study, we explored in vitro the actions of carotene cleavage enzyme (CCE) in facilitating beta-carotene cleavage to retinoid in the testis. CCE is most highly expressed in the testis. Pull-down experiments coupled with MALDI-MS analysis showed that mouse testis CCE is able to interact with the testis-specific lactate dehydrogenase-C (LDH-C) isoform. This may suggest that CCE and LDH-C act in concert to catalyze beta-carotene cleavage.

Targeted disruption of the mouse cis-retinol dehydrogenase gene: visual and nonvisual functions.

It has been proposed that cis-retinol dehydrogenase (cRDH) acts within the body to catalyze the oxidation of 9-cis-retinol, an oxidative step needed for 9-cis-retinoic acid synthesis, the oxidation of 11-cis-retinol [an oxidative step needed for 11-cis-retinal (visual chromophore) synthesis], and 3 alpha-hydroxysteroid transformations. To assess in vivo the physiological importance of each of these proposed actions of cRDH, we generated cRDH-deficient (cRDH-/-) mice. The cRDH-/- mice reproduce normally and appear to be normal. However, the mutant mice do have a mild visual phenotype of impaired dark adaptation. This phenotype is evidenced by electroretinagram analysis of the mice and by biochemical measures of eye levels of retinoid intermediates during recovery from an intense photobleach. Although it is thought that cRDH is expressed in the eye almost solely in retinal pigment epithelial cells, we detected cRDH expression in other retinal cells, including ganglion cells, amacrine cells, horizontal cells, and the inner segments of the rod photoreceptor cells. Aside from the eye, there are no marked differences in retinoid levels in other tissues throughout the body for cRDH-/- compared with cRDH+/+ mice. Moreover, we did not detect any non-visual phenotypic changes for cRDH-/- mice, suggesting that these mice do not have problems in metabolizing 3 alpha-hydroxysteroids.Thus, cRDH may act essentially in the visual cycle but is redundant for catalyzing 9-cis-retinoic acid formation and 3 alpha-hydroxysteroid metabolism.