Prognostic factors for hearing loss following the trigeminocardiac reflex

Photic sneeze reflex: another variant of the trigeminocardiac reflex?

The photic sneeze reflex (PSR) is a condition of uncontrollable sneezing episodes in response to bright light. This reflex often manifests as a mild phenomenon but may cause devastating consequences in some situations (aeroplane pilots, car drivers, etc.). Its exact mechanism is poorly understood. Interestingly, the roles of the fifth and tenth cranial nerves, brainstem nuclei and inciting patterns closely mimic a well-known brainstem reflex, known as the trigeminocardiac reflex (TCR). In this critical review, we hypothesize that the PSR can be a variant of the TCR. This concept will lead to a better understanding of the PSR and sharpens the TCR characteristics and open the doors for new research possibilities.

Key to Prevention of Bradycardia: Be Relax Postoperatively: A Case Report

Hypotension and bradycardia are commonly observed after the spinal anesthesia and various mechanisms have been postulated for these hemodynamic changes.A middle-aged otherwise healthy male Caucasian patient developed several episodes of bradycardia postoperatively after the umbilical hernia repair under subarachnoid block (SAB) while trying to lean forward and move his legs. Episodes were aborted when patient was advised to relax in supine position.The common mechanism of bradycardia and hypotension under SAB is postulated as sympathetic blockade, decrease venous return, and parasympathetic over-dominance leading to a decrease in right arterial pressure and pressure in the great veins as they enter the right atrium. But over time, the parasympathetic inhibition is usually withdrawn first, leading to the risk of severe bradycardia that is probably favored by the reverse Trendelenburg position as described in our case.Postoperative severe hemodynamic changes can occur even under stable spinal anesthesia; however, can be prevented by vigilant monitoring and simple maneuver which includes maintenance of relax posture on the bed.

How to apply case reports in clinical practice using surrogate models via example of the trigeminocardiac reflex

Case reports are an increasing source of evidence in clinical medicine. Until a few years ago, such case reports were emerged into systematic reviews and nowadays they are often fitted to the development of clinical (thinking) models. We describe this modern progress of knowledge creation by the example of the trigeminocardiac reflex that was first described in 1999 by a case series and was developed over the cause-and-effect relationship, triangulation to systematic reviews and finally to thinking models. Therefore, this editorial not only underlines the increasing and outstanding importance of (unique) case reports in current science, but also in current clinical decision-making and therefore also that of specific journals like the Journal of Medical Case Reports.

Functional Outcome Changes in Surgery for Pituitary Adenomas After Intraoperative Occurrence of the Trigeminocardiac Reflex: First Description in a Retrospective Observational Study

Trigeminocardiac reflex (TCR) represents now a nearly ubiquitary phenomenon in skull base surgery. Functional relevance of the intrainterventional TCR occurrence is hitherto only proven for vestibular schwannoma. In a retrospective observational study, 19 out of 338 (8%) enrolled adult patients demonstrated a TCR during transsphenoidal/transcranial surgery for pituitary adenomas. The 2 subgroups (TCR vs non-TCR) had similar patient's characteristics, risk factors, and histology. Preoperatively, there was a similar distribution of normal pituitary function in the TCR and non-TCR subgroups. In this TCR subgroup, there was a significant decrease of that normal pituitary function after operation (37%) compared to the non-TCR group (60%) (P < 0.03). The TCR subgroup therefore demonstrated a 3.15 times (95%CI 1.15-8.68) higher risk for non-normalizing of postoperative pituitary function compared with the non-TCR subgroup (P < 0.03). It is presented, for the first time, an impact of TCR on the functional hormonal outcome after pituitary surgery and strongly underline again the importance of the TCR in clinical daily practice. As a consequence, TCR should be considered as a negative prognostic factor of hormonal normalization after surgery for pituitary adenomas that should be included into routine practice.

Trigeminocardiac reflex during cerebellopontine angle surgery: anatomical location as a new risk factor

ABSTRACT 

Aim: Trigeminocardicac reflex (TCR), a brainstem reflex, can be manifested in almost all types of surgery in the head and neck region. Patients & methods: Retrospective review of 125 patients operated on cerebellopontine angle (CPA) tumors according to strict inclusion/exclusion criteria. Results: A total of 14 out of 125 patients showed TCR during CPA tumor operation. In total, 29% of those patients presented with a meningioma located exclusively premeatal, but not retromeatal in the CPA. There was significant relationship between meningiomas subgroups and TCR (Barnard test; p < 0.05). Conclusion: Anatomical location may represent an important, but not yet described risk factor for the TCR having therefore an important role in the understanding of the TCR.

Sudden asystole due to trigeminocardiac reflex during transsphenoidal surgery for pituitary tumor

BACKGROUND

A sudden attack of an asystolic phenomenon is an extremely rare event during transsphenoidal surgery (TSS). It may be caused by an extreme type of trigeminocardiac reflex (TCR) during the manipulation of the trigeminal nerve or its innervated structures.

CASE DESCRIPTION

We report two cases of sudden asystole and a case of severe bradycardia due to TCR during TSS. All patients were managed successfully by cessation of the surgical manipulation or with the injection of an anticholinergic agent.

CONCLUSIONS

Although TCR occurs rarely and usually is self-limiting, surgeons should be cautious of its occurrence, especially when manipulating the cavernous sinus during TSS. This allows the early detection and appropriate treatment of this manifestation. Stopping the surgical procedure as soon as TCR occurs is likely to normalize the vital parameters. In addition, if further manipulations are inevitable, the administration of anticholinergic medication should be considered cautiously to improve surgical outcomes.

The first 50s: can we achieve acceptable results in vestibular schwannoma surgery from the beginning?

OBJECTIVE

Vestibular schwannoma surgery requires a profound knowledge of anatomy and long-standing experience of surgical skull base techniques, as patients nowadays requests high-quality results from any surgeon. This educes a dilemma for the young neurosurgeon as she/he is at the beginning of a learning curve. The presented series should prove if surgical results of young skull base surgeons are comparable respecting carefully planned educational steps.

METHODS

The first 50 vestibular schwannomas of the first author were retrospectively evaluated concerning morbidity and mortality with an emphasis on functional cranial nerve preservation. The results were embedded in a timeline of educational steps starting with the internship in 1999.

RESULTS

Fifty vestibular schwannomas were consecutively operated from July 2007 to January 2010. According to the Hannover Classification, 14% were rated as T1, 18% as T2, 46% as T3, and 21% as T4. The overall facial nerve preservation rate was 96%. Seventy-nine percent of patients with T1-T3 tumours had no facial palsy at all and 15% had an excellent recovery of an initial palsy grade 3 according to the House & Brackman scale within the first 3 months after surgery. Hearing preservation in T1/2 schwannomas was achieved in 66%, in patients with T3 tumours in 56%, and in large T4 tumours in 25%. Three patients suffered a cerebrospinal fluid fistula (6%), and one patient died during the perioperative period due to cardiopulmonary problems (2%).

CONCLUSIONS

The results demonstrate that with careful established educational plans in skull base surgery, excellent clinical and functional results can be achieved even by young neurosurgeons.

The incidence of trigeminocardiac reflex in endovascular treatment of dural arteriovenous fistula with onyx

This paper reports the incidence of tri-geminocardiac reflex (TCR) in endovascular treatment of dural arteriovenous fistulas (DAVFs) with Onyx. The consecutive case histories of 45 patients with DAVFs, treated with Onyx transarterially and transvenously, from February 2005 to February 2008 at Beijing Tiantan Hospital, China, were retrospectively reviewed. The time period was limited as the anesthetic and intravascular procedure was performed under the same standardized anesthetic protocol and by the same team. The TCR rate was subsequently calculated. Of the 45 patients, five showed evidence of TCR during transarterial Onyx injection and transvenous DMSO injection. Their HR fell 50% during intravascular procedures compared with levels immediately before the stimulus. However, blood pressure values were stable in all cases. The TCR rate for all patients was 11.1% (95% CI, 4 to 24%), 7.7% (95% CI, 2 to 21%) in patients treated intraarterially and 33.3% (4 to 78%) in patients treated intravenously. Once HR has fallen, intravenous atropine is indicated to block the depressor response and prevention further TCR episodes. TCR may occur due to chemical stimulus of DMSO and Onyx cast formation under a standardized anesthetic protocol and should be blunted by atropine.