Trigeminocardiac reflex: differential behavior and risk factors in the course of the trigeminal nerve

2014 ◽  
Vol 9 (1) ◽  
pp. 41-47 ◽  
Author(s):  
Tumul Chowdhury ◽  
Nora Sandu ◽  
Cyrill Meuwly ◽  
Ronald B Cappellani ◽  
Bernhard Schaller
Keyword(s):  
Risk Factors ◽  
Trigeminal Nerve ◽  
Trigeminocardiac Reflex ◽  
Differential Behavior

scholarly journals Prenatal nicotine exposure enhances the trigeminocardiac reflex via serotonin receptor facilitation in brainstem pathways

2013 ◽  
Vol 115 (4) ◽  
pp. 415-421 ◽  
Author(s):  
C. Gorini ◽  
H. Jameson ◽  
A. L. Woerman ◽  
D. C. Perry ◽  
D. Mendelowitz
Keyword(s):  
Receptor Antagonist ◽  
Trigeminal Nerve ◽  
Serotonin Receptor ◽  
Nucleus Ambiguus ◽  
Nicotine Exposure ◽  
Sprague Dawley ◽  
Trigeminocardiac Reflex ◽  
Brainstem Slice ◽  
Prenatal Nicotine Exposure ◽  
Prenatal Nicotine

In this study we used a rat model for prenatal nicotine exposure to test whether clinically relevant concentrations of brain nicotine and cotinine are passed from dams exposed to nicotine to her pups, whether this changes the trigeminocardiac reflex (TCR), and whether serotonergic function in the TCR brainstem circuitry is altered. Pregnant Sprague-Dawley dams were exposed to 6 mg·kg−1·day−1of nicotine via osmotic minipumps for the duration of pregnancy. Following birth dams and pups were killed, blood was collected, and brain nicotine and cotinine levels were measured. A separate group of prenatal nicotine-exposed pups was used for electrophysiological recordings. A horizontal brainstem slice was obtained by carefully preserving the trigeminal nerve with fluorescent identification of cardiac vagal neurons (CVNs) in the nucleus ambiguus. Stimulation of the trigeminal nerve evoked excitatory postsynaptic current in CVNs. Our data demonstrate that prenatal nicotine exposure significantly exaggerates both the TCR-evoked changes in heart rate in conscious unrestrained pups, and the excitatory neurotransmission to CVNs upon trigeminal afferent nerve stimulation within this brainstem reflex circuit. Application of the 5-HT1Areceptor antagonist WAY 100635 (100 μM) and 5-HT2A/Creceptor antagonist ketanserin (10 μM)significantly decreased neurotransmission, indicating an increased facilitation of 5-HT function in prenatal nicotine-exposed animals. Prenatal nicotine exposure enhances activation of 5-HT receptors and exaggerates the trigeminocardiac reflex.

scholarly journals Trigeminocardiac reflex during surgery in the cerebellopontine angle

1998 ◽  
Vol 5 (3) ◽  
pp. E9 ◽  
Author(s):  
Bernhard Schall ◽  
Rudolf Probst ◽  
Stephan Strebel ◽  
Peter Fuhr ◽  
Otmar Gratzl
Keyword(s):  
Blood Pressure ◽  
Trigeminal Nerve ◽  
Cerebellopontine Angle ◽  
Experimental Studies ◽  
Ocular Surgery ◽  
Trigeminocardiac Reflex ◽  
Arterial Blood ◽  
Nerve System ◽  
Central Stimulation ◽  
Stimulation Of

In different experimental studies authors have analyzed the autonomic responses elicited by the electrical, mechanical, or chemical stimulation of the trigeminal nerve system. The trigeminocardiac reflex (TCR) is a well-recognized phenomenon that consists of bradycardia, arterial hypotension, apnea, and gastric hypermotility. It occurs during ocular surgery and during other manipulations in and around the orbit. Thus far, it has not been shown that central stimulation of the trigeminal nerve can also cause this reflex. The TCR was defined as clinical hypotension with a drop in mean arterial blood pressure (MABP) of more than 20% and bradycardia lower than 60 beats/minute. Pre-, intra-, and postoperative heart rate (HR) and blood pressure were reviewed retrospectively in 125 patients who underwent surgery for tumors of the cerebellopontine angle (CPA), and they were divided into a TCR group and a non-TCR group. Of the 125 patients, 14 (11%) showed evidence of TCR during dissection of the tumor near the trigeminal nerve at the brainstem. Their HR fell 38% and their MABP fell 48% during operative procedures as compared with preoperative levels. After cessation of manipulation, the HR and the MABP returned to preoperative levels. Risk factors for the occurrence of TCR were compared with results from the literature. The authors' results show the possibility of occurrence of a TCR during manipulation of the central part of the trigeminal nerve when performing surgery in the CPA.

scholarly journals Penanganan Trigeminocardiac Reflex (TCR) selama Anestesi untuk Bedah Saraf

2021 ◽  
Vol 10 (3) ◽  
pp. 214-227
Author(s):  
Dewi Yulianti Bisri ◽  
Keyword(s):  
Risk Factor ◽  
Trigeminal Nerve ◽  
Sudden Onset ◽  
Cardiovascular Monitoring ◽  
Trigeminocardiac Reflex ◽  
Brainstem Reflex ◽  
Surgical Conditions ◽  
And Function ◽  
Neurointerventional Procedures ◽  
Brain Stem Reflex

Trigeminocardiac reflex (TCR) is a unique brain stem reflex that manifests as negative cardio-respiratory perturbations. 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. 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. 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. If a CTR occurs, it can risk factor identification and modification, depth of anesthesia assessment, prophylactic treatment with either vagolytic agents or peripheral nerve block in case of peripheral manipulations of the nerve, careful cardiovascular monitoring during anesthesia, especially in those with a risk factor for TCR, treatment of the condition when it occurs: cessation of the manipulation, and administration of vagolytic agents and adrenaline. Therefore, this narrative review intends to elaborate on its mechanisms, definition, pathophysiology, manifestations, diagnosis and management.

scholarly journals Coronary Spasm in Neurosurgical Patients and Role of Trigeminocardiac Reflex

2014 ◽  
Vol 2014 ◽  
pp. 1-5 ◽  
Author(s):  
Tumul Chowdhury ◽  
Cyrill Meuwly ◽  
Nora Sandu ◽  
Ronald B. Cappellani ◽  
Bernhard Schaller
Keyword(s):  
Trigeminal Nerve ◽  
Case Reports ◽  
Coronary Artery Spasm ◽  
Coronary Spasm ◽  
Experimental Studies ◽  
Physiological Mechanism ◽  
Neurosurgical Procedures ◽  
Trigeminocardiac Reflex ◽  
Neurosurgical Patients

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.

scholarly journals Brain and heart connections: The trigeminocardiac reflex!

2017 ◽  
Vol 04 (02) ◽  
pp. 071-077 ◽  
Author(s):  
Gyaninder Singh ◽  
Tumul Chowdhury
Keyword(s):  
Clinical Significance ◽  
Clinical Manifestation ◽  
Trigeminal Nerve ◽  
Warning Signs ◽  
Central Nucleus ◽  
Physiological Adaptation ◽  
Protective Function ◽  
Trigeminocardiac Reflex ◽  
Face Region ◽  
Head Neck

AbstractTrigeminocardiac reflex (TCR) is a well-established neurogenic reflex although its exact mechanism and clinical significance remain unclear. This reflex may be incited by stimulation of the trigeminal nerve anywhere along its course starting from the peripheral distribution to the central nucleus. It usually manifests as bradycardia, asystole, hypotension, apnoea and gastric hypermotility; though other clinical manifestation such as tachycardia and hypertension may also occur. Diving reflex (DR) shares many similarities with TCR in both clinical manifestation and mechanism of action and is often considered as a modified or subtype of TCR. DR is an important physiological adaptation to withstand hypoxia during apnoea in many animal species including humans and thus belongs to a group of oxygen-conserving reflexes. Although TCR is a physiological reflex having protective function, an exaggerated response may have fatal consequences. Surgeries or stimulation involving head, neck and face region (area supplied by trigeminal nerve) are particularly prone to provoke this reflex. Vigilant and continuous monitoring for early identification of warning signs and communication with surgeon to interrupt the stimulus immediately is enough to cease the reflex in most of the cases. However, failure to identify and treat in time may have deleterious consequences and thus TCR has gained much attention and awareness in recent years. Over the last two decades, our knowledge on TCR has expanded but we still remain far from complete elucidation of pathophysiology, mechanism and clinical significance of this unique ‘brain and heart connection’ called TCR.

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