The feasibility and technical aspects of trigemino-cervical reflex elicitation in humans under general anesthesia.

OBJECTIVE: To analyze the feasibility, neurophysiological aspects, stimulation patterns, and topographic distribution of trigemino-cervical reflex (TCR) components in humans under general anesthesia. METHODS: This prospective observational study enrolled 20 participants who underwent posterior fossa surgery, surgical proceduresin thecraniovertebral junction,or spinal cord surgery. TCR responses were simultaneously recorded in the sternocleidomastoid (SCM) and trapezius muscles after electrical stimulation of the supraorbital and infraorbital nerves. TCR responses were recorded preoperatively and intraoperatively using single-pulse and multipulse (trains of 2-7 electrical stimuli) stimulation, respectively. Two stimulus duration patterns were evaluated: 0.2-0.5 ms and 0.5-1.0 ms. RESULTS: Intraoperatively, short- and long-latency TCR components were obtained in the SCM ipsilateral to the stimulation with variable recordability. Short-latency responses were the most commonly recorded components. A longer stimulus duration (0.5-1.0 ms) seems to favor the elicitation of TCR responses under general anesthesia. CONCLUSIONS: Short-latency components recorded in the SCM ipsilateral to the stimulation could be regularly elicited under general anesthesia when a larger stimulus duration (0.5-1.0 ms) was applied. SIGNIFICANCE: This is the first study to demonstrate the elicitation of TCR components in humans under general anesthesia. This neurophysiological technique can potentially optimize intraoperative neurophysiological monitoring during brainstem surgery.

Unstable bradycardia induced by posterior nasal packing: a rare activation of the Trigeminocardiacreflex.

A woman in her 40s presented to the emergency department with epistaxis. Anterior nasal packing was unsuccessful in achieving haemostasis. After the exchange of devices and insertion of a posterior nasal pack, the patient developed a junctional rhythm and progressively unstable bradycardia. The rhythm and bradycardia immediately improved following the removal of the posterior nasal pack. This case describes a rare occurrence of Trigeminocardiac reflex (TCR), following an insertion of a posterior nasal pack. Only one other such case has been reported and published. This case highlights the importance of raising awareness of this rare reflex and the need for prompt removal of the triggering cause in such scenarios. TCR can induce a junctional rhythm, which progresses to unstable bradycardia and may lead to asystole in susceptible individuals. The removal of the stimulus resolves the reflex and can result in prompt resolution of the bradycardia and hypotension induced via the TCR.

Trigeminocardiac Reflex: A Review and Key Implications to Dermatologic Surgery.

BACKGROUND: The trigeminocardiac reflex is a common but underreported occurrence that can vary from benign to life threatening. This reflex can be elicited by placing direct pressure on the globe of the eye or from traction of the extraocular muscles, stimulating the trigeminal nerve. OBJECTIVE: To provide a review of potential stimuli for the trigeminocardiac reflex within dermatologic surgery and to discuss management options for the treatment of the trigeminocardiac reflex. METHODS: PubMed and Cochrane were used to identify articles and case reports that established scenarios in which the trigeminocardiac reflex was provoked and subsequently how the reflex was managed. RESULTS: Within the field of dermatologic surgery, the trigeminocardiac reflex can be stimulated during biopsies, cryoablations, injections, laser treatments, Mohs micrographic surgery, and oculoplastic interventions, most often occurring in an office setting. The most common presentations include significant bradycardia, hypotension, gastric hypermobility, and lightheadedness. The most definitive treatment is cessation of the inciting stimulus, monitoring, and symptomatic management. Glycopyrrolate and atropine are common treatments for severe, intractable cases of the trigeminocardiac reflex. CONCLUSION: The trigeminocardiac reflex, while underreported and underrepresented in dermatologic literature and dermatologic surgery settings, should be considered in the setting of bradycardia and hypotension during dermatologic procedures.

Prolonged asystole induced by trigeminocardiac reflex accompanied with abnormal heart rate variability during percutaneous balloon compression: a case report.

Trigeminocardiac reflex (TCR) can result in bradycardia and even cardiac arrest, and is reversible with elimination of the stimulus. Here, we report the case of a 68-year-old man who experienced cardiac arrest during percutaneous balloon compression for the treatment of trigeminal neuralgia. In this patient, sinus rhythm did not recover after stimulation removal, causing us to successfully perform cardiopulmonary resuscitation (CPR). The patient regained a sinus rhythm and was pretreated with atropine 0.5 mg, allowing the operation to be started again. The operation was completed successfully and the patient experienced no complications. Subsequent heart rate variability (HRV) analysis showed that parasympathetic activity predominated before anesthesia induction and after tracheal intubation. It further elevated during foramen ovale puncture, leading to prolonged asystole. Fortunately, sympathetic activity predominated after atropine was administered, which manifested as an increase in sympathetic activity and a decrease in parasympathetic activity. This could be beneficial for patients with TCR. This case indicates that TCR-related cardiac arrest might not be reversed with stimulus cessation, and atropine played a key role in preventing TCR. Moreover, HRV analysis might be essential for preoperative screening for high-risk patients. We also reviewed the literature for cases of TCR with prolonged asystole.

The Influence of Trigeminocardiac Reflex on Postoperative Cardiac Adverse Events in Patients Undergoing Cerebellopontine Angle Tumor Resections: A Case-Control Study.

OBJECTIVE: To assess the potential impact of the trigeminocardiac reflex (TCR) on postoperative adverse cardiac events and to identify predictors of the TCR in cerebellopontine angle surgery. METHODS: Patients undergoing elective cerebellopontine angle surgery from October 1, 2015, to September 30, 2020, were recruited consecutively for this retrospective case-control study. The TCR was evaluated by reviewing electronic anesthesia records and defined as a drop in heart rate was >20%. Controls were identified from the same retrospective cohort and matched by age, sex, and similar (±5 days) surgery date in the ratio of 1:2. RESULTS: Of 2446 patients, 68 (2.78%) experienced TCR episodes. A total of 97 TCR episodes occurred among the 68 patients. In 2 TCR episodes, severe cardiac complications developed after surgery-myocardial injury in one case and cardiac arrest in the other case. The prevalence of adverse cardiovascular events was higher in the TCR group (60.3% vs. 36.0%, P = 0.001) than in the control group. The independent risk factor for the TCR in the multivariate condition logistic regression was tumor compression of the brainstem (odds ratio = 2.36, 95% confidence interval 1.40-3.95; P = 0.001). CONCLUSIONS: Intraoperative TCR episodes seemed to be associated with postoperative adverse cardiac events in patients undergoing cerebellopontine angle surgery. Moreover, tumor compression of the brainstem might be a risk factor for TCR episodes.

Prophylactic intra-arterial injection of lidocaine: a novel strategy to prevent endovascular embolization-induced trigeminocardiac reflex.

BACKGROUND: Trigeminocardiac reflex (TCR) is a brainstem reflex that can lead to hemodynamic instability manifested as bradycardia, decrease/increase of mean arterial pressure (MAP) and, in the worst case scenario, asystole during surgery. The effective intraoperative management of recurrent and profound TCR has yet to be established. This randomized paired study was performed to identify the effect of a prophylactic intra-arterial injection of lidocaine to prevent TCR caused by Onyx embolization during cerebrovascular intervention surgery. METHODS: A total of 136 patients who received Onyx embolization under general anesthesia were assigned to a control group pretreated with intra-arterial saline injection or a lidocaine group pretreated with an intra-arterial injection of 20 mg lidocaine. Heart rate (HR) and MAP were closely monitored during the embolization procedures and the incidence of TCR, mainly characterized by a decrease in HR of ≥20%, and perioperative adverse events was recorded. RESULTS: During dimethyl sulfoxide (DMSO)/Onyx injection, HR was much slower in the control group than in the lidocaine group (p<0.05). TCR occurred in 12 patients (17.6%) in the control group (cardiac arrest in 3 patients) with decreased (7 cases) or increased (5 cases) MAP, whereas no TCR was observed in the lidocaine group. Notably, most TCR episodes occurred in patients with dural arteriovenous fistula and middle meningeal artery being affected. The composite adverse events were significantly higher in the control group than in the lidocaine group (p<0.05). CONCLUSION: This prospective study shows that a prophylactic intra-arterial injection of 20 mg lidocaine could be recommended as a novel strategy to effectively and safely prevent TCR during endovascular embolization.

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.

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.

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.

Physiological responses to facemask application in newborns immediately after birth.

OBJECTIVE: Application of a face mask may induce apnoea and bradycardia, possibly via the trigeminocardiac reflex (TCR). We aimed to describe rates of apnoea and bradycardia in term and late-preterm infants following facemask application during neonatal stabilisation and compare the effects of first facemask application with subsequent applications. DESIGN: Subgroup analysis of a prospective, randomised trial comparing two face masks. SETTING: Single-centre study in the delivery room PATIENTS: Infants>34 weeks gestational age at birth METHODS: Resuscitations were video recorded. Airway flow and pressure were measured using a flow sensor. The effect of first and subsequent facemask applications on spontaneously breathing infants were noted. When available, flow waveforms as well as heart rate (HR) were assessed 20 s before and 30 s after each facemask application. RESULTS: In total, 128 facemask applications were evaluated. In eleven percent of facemask applications infants stopped breathing. The first application was associated with a higher rate of apnoea than subsequent applications (29% vs 8%, OR (95% CI)=4.76 (1.41-16.67), p=0.012). On aggregate, there was no change in median HR over time. In the interventions associated with apnoea, HR dropped by 38bpm [median (IQR) at time of facemask application: 134bpm (134-150) vs 96bpm (94-102) 20 s after application; p=0.25] and recovered within 30 s. CONCLUSIONS: Facemask applications in term and late-preterm infants during neonatal stabilisation are associated with apnoea and this effect is more pronounced after the first compared with subsequent applications. Healthcare providers should be aware of the TCR and vigilant when applying a face mask to newborn infants. TRIAL REGISTRATION NUMBER: ACTRN12616000768493.

Recurrent trigeminocardiac reflex in percutaneous balloon compression for trigeminal neuralgia: A case report.

RATIONALE: Trigeminocardiac reflex (TCR) sometimes occurs during the percutaneous balloon compression (PBC) procedure to treat trigeminal neuralgia (TN), and it manifests as transient bradycardia or sinus arrest. However, recurrent intraoperative TCR cases are rarely reported. Meanwhile, the treatment for recurrent TCR is still unclear. PATIENT CONCERNS: A 74-year-old male with a 2-year TN history could no longer tolerate the side effects of carbamazepine and came to seek PBC treatment. DIAGNOSES: Bradycardia or sinus arrest occurred repeatedly during the operation, and the heart rate (HR) rapidly returned to normal when the operation was suspended. The C-arm image showed the puncture needle entering the foramen ovale. INTERVENTIONS: First, 0.5 mg atropine was administered twice, and then 1 mL of 2% lidocaine was injected locally at the puncture site. Finally, isoproterenol was continuously pumped and dynamically adjusted to maintain the HR above 90 bpm. OUTCOMES: The use of atropine and lidocaine did not prevent the recurrence of TCR. The use of isoproterenol to maintain the HR enabled the successful completion of the operation. The patient recovered quickly after the operation and was discharged 2 days later. No complaints of discomfort were reported during the sixth-month follow-up. LESSONS: The elimination of intraoperative TCR may be difficult. Maintaining a high HR intraoperatively by continuous isoproterenol infusion is effective for preventing or mitigating the onset of TCR.

Asystole due to stimulation of the supraorbital nerve: abrupt and potentially fatal presentation of the trigeminocardiac reflex.

We present a case of sudden asystole that was elicited via the trigeminocardiac reflex in a patient undergoing surgery for a frontal sinus fracture. Asystole occurred after mild stimulation of the supraorbital nerve during dissection along the superior orbital rim. Anticholinergics were administered and lidocaine-soaked gauze was applied to the exposed wound. The patient was an athlete and had pre-existing sinus bradycardia. We hypothesise that the severe reflex response was associated with his underlying increased vagal tone. When performing surgery in patients with increased vagal tone, preventative measures to diminish the trigeminocardiac reflex are recommended. Further studies are needed.

Asystole during Le Fort 1 osteotomy: the trigeminovagal reflex.

The trigeminovagal reflex is a phenomenon that occurs rarely during maxillofacial surgery. Previously described as the oculocardiac reflex, this reflex can occur during ocular and periocular surgery. To be more anatomically precise, it was renamed the trigeminocardiac or trigeminovagal reflex, since stimulation of any part of the trigeminal nerve can elicit this reflex arc. We describe a case of asystole during mobilization of a maxilla following a Le Fort 1 osteotomy.

Sudden arrhythmia followed by bradycardia during sagittal split ramus osteotomy: trigeminocardiac reflex.

Trigeminocardiac reflex (TCR) is a brainstem reflex triggered by the stimulation of any branch of the fifth cranial nerve along its course, presenting as a reduction in heart rate and blood pressure. Oculocardiac reflex is a well-known subtype of TCR. In the case reported here, remarkable arrhythmia followed by bradycardia occurred suddenly in a healthy patient undergoing orthognathic surgery. The heart rhythm recovered when the surgical manipulation ceased, but bradycardia was reproduced when the surgery resumed. This case of TCR is unique in that remarkable arrhythmia first appeared and led to bradycardia; accordingly, intravenous lidocaine and an anticholinergic agent were administered simultaneously instead of anticholinergic agents alone, and were protective. Although TCR rarely occurs during orthognathic surgery, clinicians should be aware of its possibility and able to judge and manage it promptly.

The effect of a face mask for respiratory support on breathing in preterm infants at birth.

OBJECTIVE: Applying a mask on the face for respiratory support could induce a trigeminocardiac reflex leading to apnoea and bradycardia. We have examined the effect of applying a face mask on breathing and heart rate in preterm infants at birth. METHODS: Resuscitation videos of infants ≤ 32 weeks gestation recorded from 2010 until 2018 at the Leiden University Medical Centre and the General University Hospital in Prague were reviewed. All infants received respiratory support via face mask. Breathing and heart rate were noted before and after application of the face mask and over the first 5 min. RESULTS: Recordings of 429 infants were included (median (IQR) gestational age of 28+6 (27+1-30+4) weeks). In 368/429 (86%) infants breathing was observed before application of the face mask and 197/368 (54%) of these infants stopped breathing following application of the face mask. Apnoea occurred at a median of 5 (3-17) seconds after application of the face mask with a duration of 28 (22-34) seconds of the first minute. In a logistic regression model, the occurrence of apnoea after face mask application was inversely associated with gestational age (OR = 1.424 (1.281-1.583), p < 0.001). Infants who stopped breathing had a significantly lower heart rate 82 (66-123) vs 134 (97-151) bpm, p < 0.001) and oxygen saturation (49% (33-59) vs 66% (50-82), p < 0.001) over the first minute after face mask application, compared to infants who continued breathing. CONCLUSION: Applying a face mask for respiratory support affects breathing in a large proportion (54%) of preterm infants and this effect is gestational age dependent.

Delayed trigeminocardiac reflex after maxillofacial surgery: case report / Reflexo trigêmino-cardíaco tardio após cirurgia buco-maxilo-facial: relato de caso

Abstract Background: Trigeminocardiac reflex is a physiological phenomenon that may occur in head and neck surgery, and is usually benign. However, it may present with exaggerated responses with severe morbidity. Case report: Male patient, 26 years old, candidate for surgical treatment of zygomatic-orbital complex fracture. The surgery with bilateral nasal packing placed at the end of the procedure was uneventful. After being admitted to the post-anesthesia care unity, the patient complained of shortness of breath and nausea. Pulse oximetry fell below 90% in ambient air, and 100% O2 was then offered through a Hudson mask. He showed no improvement in oximetry and presented with worsening dyspnea, diffuse wheezing, reduced heart rate, and blood pressure. Atropine was given, which raised the heart rate, but without resolution of hypotension and bronchospasm. Our suspicion was of a trigeminal-cardiac reflex, and then the removal of the nasal packing was done with complete remission of the signs and symptoms. Discussion: Florian Kratschmer (1870) was the first to describe the influences of nasal mucosal reflexes on respiration and circulation, which became known as Kratschmer's reflex. It is a reflex arc whose afferent originates in the nerve endings of the trigeminal nerve. The clinical presentation of trigeminocardiac reflex is the occurrence of sudden bradycardia, hypotension, apnea, and gastric hypermotility. Conclusion: Trigeminocardiac reflex may be a protective neurogenic, oxygen-conserving response with low morbidity, however, exacerbated in certain situations. The interaction between surgeon and anesthesiologist, together with a careful monitoring of blood pressure and heart rate are fundamental for diagnosis and treatment.

Resumo Justificativa: O reflexo trigêmino-cardíaco é um fenômeno fisiológico passível de ocorrer em cirurgias da cabeça e pescoço, e normalmente é benigno. Contudo, pode apresentar respostas exageradas, com grave morbidade. Relato de caso: Paciente masculino, 26 anos, candidato a tratamento cirúrgico de fratura do complexo zigomático-orbitário. Ato cirúrgico sem intercorrências com tamponamento nasal bilateral ao final. Após admitido na sala de recuperação pós-anestésica, queixou-se de "falta de ar" e náusea. A oximetria de pulso caiu abaixo 90% em ar ambiente e foi ofertado então O2 a 100% sob máscara de Hudson. Não houve melhora da oximetria e apresentou piora da dispneia, com sibilos difusos, redução da frequência cardíaca e da pressão arterial. Administrada atropina, que elevou a frequência cardíaca, mas sem resolução da hipotensão arterial e broncoespasmo. Aventamos a hipótese de reflexo trigêmino-cardíaco e então foi feita a remoção do tamponamento nasal com remissão completa dos sinais e sintomas. Discussão: Florian Kratschmer (1870) foi o primeiro a descrever as influências de reflexos da mucosa nasal na respiração e na circulação, o que ficou conhecido como reflexo de Kratschmer. Trata-se de um arco reflexo cuja aferência é originária nas terminações nervosas do nervo trigêmeo. A apresentação clínica do reflexo trigêmino-cardíaco é a ocorrência de súbita bradicardia, hipotensão, apneia e hipermotilidade gástrica. Conclusão: O reflexo trigêmino-cardíaco pode ser uma resposta neurogênica protetora, oxigênio-conservadora, de baixa morbidade, contudo exacerbada em determinadas situações. A interação entre cirurgião e anestesiologista, aliada à monitoração criteriosa da pressão arterial e do ritmo cardíaco, é fundamental para o diagnóstico e o tratamento.

[Delayed trigeminocardiac reflex after maxillofacial surgery: case report]. / Reflexo trigêmino­cardíaco tardio após cirurgia buco­maxilo­facial: relato de caso.

BACKGROUND: Trigeminocardiac reflex is a physiological phenomenon that may occur in head and neck surgery, and is usually benign. However, it may present with exaggerated responses with severe morbidity. CASE REPORT: Male patient, 26 years old, candidate for surgical treatment of zygomatic-orbital complex fracture. The surgery with bilateral nasal packing placed at the end of the procedure was uneventful. After being admitted to the post-anesthesia care unity, the patient complained of shortness of breath and nausea. Pulse oximetry fell below 90% in ambient air, and 100% O2 was then offered through a Hudson mask. He showed no improvement in oximetry and developed a worsening dyspnea, diffuse wheezing, reduced heart rate, and blood pressure. Atropine was given, which raised the heart rate, but without resolution of hypotension and bronchospasm. Our suspicion was of a trigeminal-cardiac reflex, and then the removal of the nasal packing was done with complete remission of the signs and symptoms. DISCUSSION: Florian Kratschmer (1870) was the first to describe the influences of nasal mucosal reflexes on respiration and circulation, which became known as Kratschmer's reflex. It is a reflex arc whose afferent originates in the nerve endings of the trigeminal nerve. The clinical presentation of trigeminocardiac reflex is the occurrence of sudden bradycardia, hypotension, apnea, and gastric hypermotility. CONCLUSION: Trigeminocardiac reflex may be a protective neurogenic, oxygen-conserving response with low morbidity, however, exacerbated in certain situations. The interaction between surgeon and anesthesiologist, together with a careful monitoring of blood pressure and heart rate are fundamental for diagnosis and treatment.

Trigeminocardiac Reflex: Case Report and Literature Review of Intraoperative Asystole in Response to Manipulation of the Temporalis Muscle.

BACKGROUND: The trigeminocardiac reflex is a sudden onset of bradycardia, hypotension, apnea, or gastric hypermotility in response to stimulation of the trigeminal nerve. CASE DESCRIPTION: A 60-year-old female underwent a left orbitozygomatic craniotomy to debulk a large skull base epidermoid cyst compressing the brainstem and cranial nerves. Intraoperatively, retraction of the temporalis muscle consistently produced asystole. Cessation of retraction resulted in prompt return of sinus rhythm. CONCLUSIONS: Our report describes an unusual and extreme example of the trigeminocardiac reflex and explores possible etiologies. This is the third reported surgical case in which manipulation of the temporalis muscle alone was sufficient to elicit bradycardia and asystole, and the first such case within the context of neurosurgery. We emphasize the importance of surgical teams to be cognizant of such extreme examples of this reflex.