Atypical trigeminocardiac reflex during intranasal dexmedetomidine sedation of a 6-month-old premature baby.

The trigeminocardiac reflex (TCR) is an established brainstem reflex leading to parasympathetic dysrhythmias-including haemodynamic irregularities, apnoea and gastric hypermotility-during stimulation of any sensory branches of the trigeminal nerve. Most of the clinical knowledge about TCR was gathered from general anaesthesia observations, not from procedural sedation.We present a case of a 6-month-old premature baby experiencing the reflex twice under dexmedetomidine-propofol-sedation while undergoing ophthalmic and ear examination. This was interpreted as cross-over sensitisation between the facial and trigeminal cranial nerve (N V and N VII).The present case demonstrates that different TCR subtypes can occur during the same anaesthetic procedure. Triggering TCR seems to be based on several factors and not just on a single stimulus as often presumed. Therefore, for premature babies, there is a risk for TCR under procedural sedation, and we recommend using glycopyrrolate as preventive treatment.

Perioperative Complications and Anesthesia Practices in Managing Patients With Quadriplegia Undergoing Surgery: A Systematic Review.

Quadriplegia is associated with a multitude of health complications affecting numerous organ systems. Complications during the perioperative periods are not uncommon in this patient population due to abnormal responses to surgical stressors. Such complications include autonomic dysreflexia, cardiac ischemia, and respiratory compromise. Currently, there is no clear consensus on the ideal technique for perioperative anesthesia management in this population. In addition, the relationship between the perioperative complications and anesthesia practices have not been explored in-depth. Therefore, we aimed to investigate perioperative complications in the context of anesthesia that are associated with patients with quadriplegia undergoing various surgical procedures. Our PRISMA compliant systematic review included 12 articles covering the literature from inception to January 12, 2021. The review showed complications being pulmonary, cerebral, but most importantly and commonly cardiac in nature, with many patients suffering hypertension, and many others hypotension. In addition, our review showed that autonomic dysreflexia is common and in majority of patients, it was managed successfully with good recovery. Based on our findings, the use of anesthesia, either general or spinal, can be considered. Future studies are needed to elucidate the exact mechanisms involved in perioperative complications and anesthetic management that are associated with patients with quadriplegia. This review will aid in developing general recommendations based on the information available in the literature to guide perioperative management of this vulnerable patient population.

Brain and Heart Crosstalk During Neurointerventional Procedures: The Role of the Trigeminocardiac Reflex: An Updated Systematic Review.

The trigeminocardiac reflex is a well-described brainstem reflex that clinically manifests as bradycardia, hypotension, or apnea. This physiological phenomenon is extensively reported during open neurosurgical procedures, but very few data exist for trigeminocardiac reflex occurrence during neurointerventional procedures. This systematic review aims to provide aggregated information related to the trigeminocardiac reflex during neurointerventional procedures and to improve understanding of the various mechanisms that can incite this unique brain-heart crosstalk.

Reappearance of Neurological Deficits in Pathologic Brain: Are Sedatives and Opioids Culprits? A Systematic Review.

Following a brain insult, focal neurological deficits may develop. Despite resolution of these deficits with time, the subsequent administration of sedative medications and opioids may lead to recrudescence of previous neurological deficits. Therefore, the present systematic review aims to explore the role of different sedatives and opioid analgesics at reproducing focal neurological deficits in patients with previous brain insults undergoing surgery. Our PRISMA compliant systematic review covering the literature from 1990 to 2020 showed a consistent reoccurrence of neurological deficits following administration of benzodiazepines and opioids across 12 studies. It appears that in all studies, the manifestations were transient and affected mostly middle-aged patients (45 to 67 y of age). In addition, benzodiazepines and opioid antagonism by naloxone and flumazenil reverses the unmasking of prior neurological deficits. In contrast, it is not clear based on our study whether the unmasking or worsening of neurological deficits occurs following recent injuries or an older brain insult, although for most patients it appears to be the former. Future studies are needed to elucidate the mechanisms involved in unmasking prior deficits and/or extension of prior injuries by sedative and opioid analgesics. This review will aid in developing prospective studies on individual sedative medications and their effects on unmasking neurological deficits in patients with multiple brain pathologies.

A Step Further-The Role of Trigeminocardiac Reflex in Therapeutic Implications: Hypothesis, Evidence, and Experimental Models.

The trigeminocardiac reflex (TCR) is a well-recognized brainstem reflex that represents a unique interaction between the brain and the heart through the Vth and Xth cranial nerves and brainstem nuclei. The TCR has mainly been reported as an intraoperative phenomenon causing cardiovascular changes during skull-base surgeries. However, it is now appreciated that the TCR is implicated during non-neurosurgical procedures and in nonsurgical conditions, and its complex reflex pathways have been explored as potential therapeutic options in various neurological and cardiovascular diseases. This narrative review presents an in-depth overview of hypothetical and experimental models of the TCR phenomenon in relation to the Vth and Xth cranial nerves. In addition, primitive interactions between these 2 cranial nerves and their significance are highlighted. Finally, therapeutic models of the complex interactions of the TCR and areas for further research will be considered.

Single-use device endoscopy for the diagnosis of acute bacterial rhinosinusitis in primary care: A pilot and feasibility study.

OBJECTIVE: Antibiotics are largely overprescribed for acute rhinosinusitis in primary care, mainly due to the lack of diagnostic tests to confirm or rule out bacterial infection. The study objective was to assess the on-site applicability and safety of the newly developed JGG endoscope® for the diagnosis of acute bacterial rhinosinusitis in primary care. DESIGN: Five Swiss primary care centres and one university-affiliated ENT unit participated in this single-arm pilot study. PARTICIPANTS: Adults with acute suspected bacterial rhinosinusitis. The newly developed JGG endoscope® , which is attached to a pocket otoscope, was used to inspect after local anaesthesia the nasal cavity and middle meatus and to gain material for bacterial culture from paranasal sinuses draining ostium. MAIN OUTCOME MEASURES: Applicability and safety. RESULTS: The visualisation of the middle meatus was successful in 16 of 21 patients (13 in both sides and three in one side), and unclear or unsuccessful in five patients. Sample collection from the middle meatus was successful in 10 patients (six on both and four on one side) and unclear or unsuccessful in the remaining patients. Only one culture-confirmed bacterial rhinosinusitis and 11 PCR-confirmed viral infections were identified from collected samples. After a 2-week follow-up, no serious adverse events were observed. CONCLUSIONS: The on-site use of the JGG endoscope® in daily primary care routine is feasible and safe and was well accepted by the trial physicians and patients (assessed with structured questionnaires). The JGG endoscope® may support general practitioners to differentiate between bacterial and viral rhinosinusitis.

Molecular Imaging and Tracking Stem Cells in Neurosciences.

Stem cell transplantation is a promising new therapeutic option in different neurological diseases. However, it is not yet possible to translate its potential from animal models to clinical application. One of the main problems of applying stem cell transplantation in clinical medium is the difficulty of detection, localization, and examination of the stem cells in vivo at both cellular and molecular levels. State-of-the-art molecular imaging techniques provide new and better means for noninvasive, repeated, and quantitative tracking of stem cell implant or transplant. From initial deposition to the survival, migration, and differentiation of the transplant/implanted stem cells, current molecular imaging methods allow monitoring of the infused cells in the same live recipient over time. The present review briefly summarizes and compares these molecular imaging methods for cell labeling and imaging in animal models as well as in clinical application and sheds light on consecutive new therapeutic options if appropriate.

The Role of Intraoperative MRI in Awake Neurosurgical Procedures: A Systematic Review.

Background: Awake craniotomy for brain tumors remains an important tool in the arsenal of the treating neurosurgeon working in eloquent areas of the brain. Furthermore, with the implementation of intraoperative magnetic resonance imaging (I-MRI), one can afford the luxury of imaging to assess surgical resection of the underlying gross imaging defined neuropathology and the surrounding eloquent areas. Ideally, the combination of I-MRI and awake craniotomy could provide the maximal lesion resection with the least morbidity and mortality. However, more resection with the aid of real time imaging and awake craniotomy techniques might give opposite outcome results. The goal of this systematic review.is to identify the available literature on combined I-MRI and awake craniotomy techniques, to better understand the potential morbidity and mortality associated. Methods: MEDLINE, EMBASE, and CENTRAL were searched from inception up to December 2016. A total of 10 articles met inclusion in to the review, with a total of 324 adult patients. Results: All studies showed transient neurological deficits between 2.9 to 76.4%. In regards to persistent morbidity, the mean was ~10% (ranges from zero to 35.3%) with a follow up period between 5 days and 6 months. Conclusion: The preliminary results of this review also suggest this combined technique may impose acceptable post-operative complication profiles and morbidity. However, this is based on low quality evidence, and is therefore questionable. Further, well-designed future trials with the long-term follow-up are needed to provide various aspects of feasibility and outcome data for this approach.

Sinus arrest with prolonged asystole due to the trigeminocardiac reflex during application of local anaesthetic in the nasal mucosa.

The trigeminocardiac reflex (TCR) is defined as a sudden onset of parasympathetic dysrhythmias during stimulation of the trigeminal nerve. We describe a peripheral variation of TCR during manipulation of the nasal mucosa. A 42-year-old patient suffering from severe obstructive sleep apnoea was scheduled for surgical treatment. After inducted anaesthesia, the surgeon infiltrated the nasal mucosa with a local anaesthetic. The patient immediately showed an asystole and was treated with ephedrine and five chest compressions, despite spontaneous sinus rhythm return after ceasing of manipulation. Treatment with atropine established this TCR episode and ensured an event-free surgery.The authors present here, for the first time, a prolonged asystole caused by the TCR, triggered by minimal manipulation of the nasal mucosa. This severe manifestation of peripheral TCR demonstrates its importance in daily clinical business. This case was treated according to a modified treatment algorithm for all subtypes of TCR which is presented here.

Breve reseña del reflejo trigémino cardíaco / Trigeminocardiac Reflex: an Overview

RESUMEN El reflejo trigémino cardíaco es un reflejo único del tallo cerebral que se manifiesta como perturbaciones cardiorespiratorias, y ocurre principalmente en cirugías o intervenciones de la base del cráneo. Sin embargo, recientemente se lo ha vinculado a muchos procedimientos de neurocirugía e intervenciones neurológicas y condiciones no relacionadas a neurocirugía y no quirúrgicas. Este reflejo presenta muchas alteraciones cardiovasculares que pueden provocar complicaciones adversas, empeorar la evolución y producir problemas diagnósticos. Esta reseña intenta profundizar su definición, mecanismos, fisiopatología, manifestaciones, diagnóstico y manejo.

ABSTRACT Trigemino-cardiac reflex is a unique brain stem reflex that manifests as negative cardio-respiratory perturbations. This reflex is largely reported in skull base surgeries/interventions; however, in recent times, it has been also linked with many neurosurgical, neurointerventional procedures, non-neurosurgical and non-surgical conditions. This reflex presents with many cardiovascular changes that can create catastrophic complications, worse outcome as well as diagnostic dilemmas. Therefore, this narrative review intends to elaborate on its mechanisms, definition, pathophysiology, manifestations, diagnosis and management.

The clinical surrogate definition of the trigeminocardiac reflex: Development of an optimized model according to a PRISMA-compliant systematic review.

BACKGROUND: The trigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmias including hemodynamic irregularities, apnea, and gastric hypermotility during stimulation of sensory branches of the trigeminal nerve. Since the first description of the TCR 1999, there is an ongoing discussion about a more flexible than the existing clinical definition. Aim of this work was to create a clinical surrogate definition through a systematic review of the literature. METHODS: In this meta-analysis study, literature about TCR occurrences was, according to the Preferred Reporting Items for Systematic Reviews and Meta-Analysis statement, systematically identified through various search engines including PubMed (Medline), Embase (Ovid SP), and ISI Web of Sciences databases from January 2005 to August 2015. TCR was defined as a drop of heart rate (HR) below 60 bpm or 20% to the baseline. We extracted detailed data about hemodynamic changes and searched for connections between arterial blood pressure (BP) and HR changes during such episodes. RESULTS: Overall 45 studies harboring 57 patients were included in the study but only 32 patients showed sufficient data for final analyze. HR showed a nonlinear behavior with a "tipping point" phenomena that differs in variance from the central/peripheral (20-30% drop) to ganglion (40-49% drop). BP showed a linear behavior with a "central limit" phenomena not differing in variance in the whole subgroup (30-39% drop). An analyzation of the correlation between BP and HR showed a trend to a linear correlation. CONCLUSIONS: We can show for the first time that HR is the dominant variable in the TCR and present a new surrogate definition model. This model and the role of BP must be better investigated in further studies.

Definition and Diagnosis of the Trigeminocardiac Reflex: A Grounded Theory Approach for an Update.

BACKGROUND: The trigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmias including hemodynamic irregularities, apnea, and gastric hypermotility during stimulation of sensory branches of the trigeminal nerve. Since the first description of the TCR in 1999, there is an ongoing discussion about a more emergent clinical definition. In this work, the author worked out an approach to such an improved definition. METHODS: In this study, a grounded theory approach was used. Literature about TCR was systematically identified through PubMed (MEDLINE), EMBASE (Ovid SP), and ISI Web of Sciences databases from 1/2005 until 8/2015. TCR was defined as a drop of heart rate (HR) below 60 bpm or 20% to the baseline. A grounded theory approach was used to analyze and interpret the data through a synthesis by the researcher's perspectives, values, and positions. RESULTS: Out of the included studies, the authors formed available data to an update of the understanding of changes in hemodynamic parameters (HR and blood pressure) in a TCR. According to this update, an HR deceleration should be a constant observation to identify a TCR episode while a drop in blood pressure should probably not being fixed to a certain percentage of decrease. CONCLUSION: The here presented working definition improves our understanding of the TCR. It leads the way to a new understanding of the TCR for a proper clinical definition.

Rhinitis and sleep disorders: The trigeminocardiac reflex link?

Rhinitis, allergic or non-allergic, is an inflammatory condition of the nose. It is associated with a wide range of sleep disorders that are generally attributed to nasal congestion and presence of inflammatory mediators like cytokines and interleukins. However, the pathophysiological mechanisms behind these sleep disorders remain unclear. On the other hand, the trigeminocardiac reflex (TCR) has recently been linked to various sleep disorders like obstructive sleep apnea, sleep bruxism and rapid eye movement (REM) sleep apnea. TCR can be incited by stimulation of the trigeminal nerve or the area innervated by its branches including the nasal mucosa. Trigeminal nasal afferents can be activated on exposure to noxious stimuli (mechanical or chemical) like ammonia vapors, carbon-dioxide, nicotine, hypertonic saline, air-puffs and smoke. In rhinitis, there is associated neuronal hyper-responsiveness of sensory nasal afferents due to inflammation (which can be suppressed by steroids). This may further lead to increased occurrence of TCR in rhinitis. Moreover, there is involvement of autonomic nervous system both in rhinitis and TCR. In TCR, parasympathetic over activity and sympathetic inhibition leads to sudden onset bradycardia, hypotension, apnea and gastric motility. Also, the autonomic imbalance reportedly plays a significant role in the pathophysiology of rhinitis. Thus, considering these facts we hypothesize that the TCR could be the link between rhinitis and sleep disorders and we believe that further research in this direction may yield significant development in our understanding of sleep disorders in rhinitis.

Sleep Disorders: Is the Trigemino-Cardiac Reflex a Missing Link?

Trigeminal innervated areas in face, nasolacrimal, and nasal mucosa can produce a wide array of cardiorespiratory manifestations that include apnea, bradypnea, bradycardia, hypotension, and arrhythmias. This reflex is a well-known entity called "trigemino-cardiac reflex" (TCR). The role of TCR is investigated in various pathophysiological conditions especially in neurosurgical, but also skull base surgery procedures. Additionally, its significance in various sleep-related disorders has also been highlighted recently. Though, the role of diving reflex, a subtype of TCR, has been extensively investigated in sudden infant death syndrome. The data related to other sleep disorders including obstructive sleep apnea, bruxism is very limited and thus, this mini review aims to investigate the possible role and correlation of TCR in causing such sleep abnormalities.

Perioperative Factors Contributing the Post-Craniotomy Pain: A Synthesis of Concepts.

The perioperative management of post-craniotomy pain is controversial. Although the concept of pain control in non-neurosurgical fields has grown substantially, the understanding of neurosurgical pain and its causative factors in such a population is inconclusive. In fact, the organ that is the center of pain and its related mechanisms receives little attention to alleviate distress during neurosurgical procedures. In contrast to the old belief that pain following intracranial surgery is minimal, recent data suggest the exact opposite. Despite the evolution of various multimodal analgesic techniques for optimal pain control, the concern of post-craniotomy pain remains. This paradox could be due to the lack of thorough understanding of different perioperative factors that can influence the incidence and intensity of pain in post-craniotomy population. Therefore, this review aims to give an in-depth insight into the various aspects of pain and its related factors in adult neurosurgical patients.