Cyrill Meuwly

Trigeminal Cardiac Reflex: New Thinking Model About the Definition Based on a Literature Review

AbstractTrigeminocardiac reflex (TCR) is a brainstem reflex that manifests as sudden onset of hemodynamic perturbation in blood pressure (MABP) and heart rate (HR), as apnea and as gastric hypermotility during stimulation of any branches of the trigeminal nerve. The molecular and clinical knowledge about the TCR is in a constant growth since 1999, what implies a current need of a review about its definition in this changing context.Relevant literature was identified through searching in PubMed (MEDLINE) and Google scholar database for the terms TCR, oculocardiac reflex, diving reflex, vasovagale response.The definition of the TCR varies in clinical as well as in research studies. The main difference applies the required change of MABP and sometimes also HR, which most varies between 10% and 20%. Due to this definition problem, we defined, related to actual literature, 2 major (plausibility, reversibility) and 2 minor criteria (repetition, prevention) for a more proper identification of the TCR in a clinical or research setting. Latest research implies that there is a need for a more extended classification with 2 additional subgroups, considering also the diving reflex and the brainstem reflex.In this review, we highlighted criteria for proper definition and classification of the TCR in the light of increased knowledge and present a thinking model to overcome this complexity. Further we separately discussed the role of HR and MABP and their variation in this context. As another subtopic we gave attention to is the chronic TCR; a variant that is rarely seen in clinical medicine.

Trigeminocardiac reflex: the current clinical and physiological knowledge.

The trigeminocardiac reflex (TCR) is defined as the sudden onset of parasympathetic dysrhythmia, sympathetic hypotension, apnea, or gastric hypermotility during stimulation of any of the sensory branches of the trigeminal nerve. Clinically, the TCR has been reported in all the surgical procedures in which a structure innervated by the trigeminal nerve is involved. Although, there is an abundant literature with reports of incidences and risk factors of the TCR; the physiological significance and function of this brainstem reflex has not yet been fully elucidated. In addition, there are complexities within the TCR that requires examination and clarification. There is also a growing need to discuss its cellular mechanism and functional consequences. Therefore, the current review provides an updated examination of the TCR with a particular focus on the mechanisms and diverse nature of the TCR.

Anesthetic Influence on Occurrence and Treatment of the Trigemino-Cardiac Reflex: A Systematic Literature Review

AbstractTrigeminocardiac reflex (TCR) is defined as sudden onset of parasympathetic dysrhythmia including hypotension, apnea, and gastric hypermotility during stimulation of any branches of the trigeminal nerve. Previous publications imply a relation between TCR and depth of anesthesia. To gain more detailed insights into this hypothesis, we performed a systematic literature review.Literature about occurrence of TCR was systematically identified through searching in Cochrane Central Register of Controlled Trials (CENTRAL), PubMed (MEDLINE), EMBASE (Ovid SP), and the Institute for Scientific Information (ISI Web of Sciences) databases until June 2013, as well as reference lists of articles for risk calculation. In this study, TCR was defined as drop in mean arterial blood pressure and heart rate, both >20% to baseline. We calculated intraoperative cerebral state index (CSI) of each TCR-case using a newly developed method. These data were further divided into 3 subgroups: CSI <40 (deep anesthesia), CSI 40–60 (regular anesthesia), and CSI >60 (slight anesthesia).Including 45 studies with 910 patients, 140 (15%) presented with TCR, and 770 (85%) without TCR during operation. TCR occurrence showed a 1.2-fold higher pooled risk slighter anesthesia (CSI <40: 13%, at CSI 40–60: 21%, and at CSI >60: 27%) compared with deeper anesthesia. In addition, we could discover a 1.3-fold higher pooled risk of higher MABP drop with a strong negative correlation (r = −0.935; r2 = 0.89) and a 4.5-fold higher pooled risk of asystole during TCR under slight anesthesia compared with deeper anesthesia.Our work is the first systematic review about TCR and demonstrates clear evidence for TCR occurrence and a more severe course of the TCR in slight anesthesia underlying the importance of skills in anesthesia management during skull base surgery. Furthermore, we have introduced a new standard method to calculate the depth of anesthesia.

Trigeminocardiac reflex: current trends.

Since the first introduction of the trigeminocardiac reflex (TCR) in 1999, substantial new knowledge about this brainstem reflex has been created. First, by different clinical case reports and case studies, and second, from basic research that gives inputs from bench to bedside. In the present work, the authors therefore introduce the molecular/anatomical knowledge of the TCR and show its different connections to clinical aspects. Special reference is given to prevention and treatment of the TCR; but always with a link to knowledge of the basis sciences. In such a context different topics of future interest are introduced.

Coronary Spasm in Neurosurgical Patients and Role of Trigeminocardiac Reflex

Background. Coronary artery spasm (CAS) is a rarely reported complication in neurosurgical patients and its main causative mechanism was attributed to vagal mediated responses. However, these may be the unusual manifestations of trigeminal cardiac reflex (TCR) which is a well established brain stem reflex observed in various neurosurgical patients. Methods and Results. In this review, we have searched for the case reports/papers related to intraoperative coronary spasm in neurosurgical patients and described the role of TCR in this regard. TCR is a possible mechanism in producing CAS in most of the cases in which stimulation occurred at or near the vicinity of trigeminal nerve. It is likely that TCR mediated coronary spasm may be a physiological mechanism and not related to actual myocardial insult apparent by cardiac enzymes or echocardiography studies in most of the cases. Some common risk factors may also exist related to occurrence of CAS as well as TCR. Conclusions. In conclusion, neurosurgical procedures occurring at the vicinity of trigeminal nerve may produce CAS even in previously healthy patients and may produce catastrophic consequences. There is a need for future reports and experimental studies on the interaction of TCR and pathophysiological mechanisms related to CAS.

Meta-areas of the Trigeminocardiac Reflex Within the Skull Base: A Neuroanatomic "Thinking" Model.

cardiac status was assessed. The mass was visualized (Fig. 1B). With all monitors in situ, the patient was turned prone. TEE assessment was performed again in the prone position, keeping a close watch on the left ventricular mass. Surgery lasted for 160 minutes. Throughout the surgery, TEE was monitored. No significant cardiac dysfunction or embolic shower of cardiac mass was noticed. A decision to ventilate the patient electively was made because of her poor neurological status. The patient’s trachea was extubated next day as she had good neurological recovery. Low–molecular-weight heparin, enoxaparin 0.6mg, was started subcutaneously twice a day after consultation with the neurosurgery team. She was discharged on the fifth postoperative day in satisfactory clinical condition on oral anticoagulation. Intracardiac mass can be either a tumor or an organized blood clot.3,4 Most common tumors are myxomas, which are generally located in the left atrium. In our patient, however, the mass was present in the left ventricle, which accounts for only 2.5% of cases.4 TEE monitoring is an established modality for monitoring intraoperative cardiac functions in various surgical positions and for detection of venous air embolism. In the present case, however, continuous TEE monitoring was of great help in keeping a close watch on the left ventricular mass lesion. To conclude, we recommend intraoperative TEE monitoring in patients with an intracardiac mass.

Peripheral trigeminocardiac reflex.

[1] Paydarfar JA, Birkmeyer NJ. Complications in head and neck surgery: a meta-analysis of postlaryngectomy pharyngocutaneous fistula. ArchOtolaryngol HeadNeck Surg 2006;132:67–72. [2] Delanian S, Lefaix JL. The radiation-induced fibroatrophic process: therapeutic perspective via the antioxidant pathway. Radiother Oncol 2004;73(2):119–31. [3] Bohannon IA, Carroll WR, Magnuson JS, et al. Closure of postlaryngectomy pharyngocutaneous fistulae. Head Neck Oncol 2011;3:29. [4] Roche NA, Houtmeyers P, Vermeersch HF, et al. The role of internal mammary vessels as recipient vessels in secondary and tertiary head and neck reconstruction. J Plast Reconstr Aesthet Surg 2012;65(7):885–92.

The Trigemino-cardiac Reflex: Is Treatment With Atropine Still Justified?

temporary clip in the operation room or balloon occlusion in the radiology suite may cause ischemia in the midbrain and the thalamus, especially in the corticospinal fibers, the occulomotor nerve nucleus. Both MEP and VEP monitoring will be very useful in detecting ischemia resulting from the P1 segment. Patients with PCA infarcts usually have hemianopia, hemiparesis, and sensory disturbances.4 As literature does not exist on this subject, we believe that in patients undergoing PCA aneurysm endovascular coiling or surgical clipping, the intraoperative evoked potential monitoring modality must take into consideration the location of the temporary clip/balloon occlusion; monitoring with both MEP and VEP was more effective in detecting ischemia.

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.

Trigeminocardiac reflex in cerebrovascular surgery: a review and an attempt of a predictive analysis

ABSTRACT Introduction: Trigemino-cardiac reflex (TCR) is a well-established neurogenic reflex that is primarily observed in many neurosurgical procedures, especially skull base surgery. Few management strategies have been highlighted in the literature; however, controversies still exist related to this topic. Areas covered: The authors present for the first time the results of a multivariable analysis to predict the TCR during cerebrovascular surgery. However, such first statistical results have not yet any impact on the treatment of the TCR, as correlation is not the cause. Therefore, there is highlighted different management options in such cases providing a better understanding of TCR and associated various facts that are important for anesthesiologist as well as the surgeon. Expert commentary: The TCR can be successfully managed by the cessation of the stimulus producing the TCR. Decision support tools are needed to make static predictive analysis dynamic and useful for a single patient and to make (skull base) surgery still safer.