Evidences in Neurological Surgery and a Cutting Edge Classification of the Trigeminocardiac Reflex: A Systematic Review.

BACKGROUND: The trigeminocardiac reflex (TCR) is characterized by bradycardia, decrease of mean arterial blood pressure, and sometimes, asystole during surgery. We critically reviewed TCR studies and devised a novel classification scheme for assessing the reflex. METHODS: A comprehensive systematic literature review was performed using PubMed, MEDLINE, Web of Science, EMBASE, and Scielo databases. Eligible studies were extracted based on stringent inclusion and exclusion criteria. Statistical analyses were used to assess cardiovascular variables. TCR was classified according to morphophysiologic aspects involved with reflex elicitation. RESULTS: A total of 575 patients were included in this study. TCR was found in 8.9% of patients. The reflex was more often triggered by interventions made within the anterior cranial fossa. The maxillary branch (type II in the new classification) was the most prevalent nerve branch found to trigger the TCR. Heart rate and mean arterial blood pressure were similarly altered (P = 0.06; F = 0.3912809), covaried with age (P = 0.012; F = 9.302), and inversely correlated to each other (r = -0.27). CONCLUSIONS: TCR is a critical cardiovascular phenomenon that must be quickly identified and efficiently classified and should trigger vigilance. Prompt therapeutic measures during neurosurgical procedures should be carefully addressed to avoid unwanted complications. Accurate categorization using the new classification scheme will help to improve understanding and guide the management of TCR in the perioperative period.

Key Aspects in Foramen Magnum Meningiomas: From Old Neuroanatomical Conceptions to Current Far Lateral Neurosurgical Intervention.

Foramen magnum meningiomas represent a challenge for neurosurgeons. These tumors require careful surgical manipulation as they are often located in proximity to critical neurovascular structures and the cranial nerves. The far lateral approach is considered the safest neurosurgical approach for excising foramen magnum lesions. It facilitates the access to the anterior foramen magnum and reduces the retraction of vital structures. We describe key historical, epidemiological, genetic, epigenetic, clinical, and neurosurgical aspects of foramen magnum meningiomas. We emphasize the far lateral approach for lesions arising in the foramen magnum, as well as the most appropriate patient positioning for such approach. Caring for these aspects will be rewarded with the best perioperative neurosurgical outcomes.