# Ansa cervicalis or ansa hypoglossi? A systematic review

## TL;DR

This paper clarifies the correct anatomical term for a nerve loop, showing that 'ansa cervicalis' is more accurate than 'ansa hypoglossi'.

## Contribution

The study resolves terminology confusion by proving 'ansa cervicalis' aligns better with anatomical origins.

## Key findings

- The term 'ansa cervicalis' is anatomically accurate as its fibers arise from the cervical cord.
- The term 'ansa hypoglossi' should be avoided as it is structurally incorrect.
- Classic textbooks and literature support the use of 'ansa cervicalis' over 'ansa hypoglossi'.

## Abstract

•There is a disparity of terminology in the literature between ansa cervicallis and ansa hypoglossi.•This systematic review of 3731 articles proved that the term that best suits anatomical reality is “ansa cervicalis”.•This conclusion is based on the fact that the nerve fibers arise only from the cervical cord.•The authors also demonstrated that the term “ansa hypoglossi” should be avoided, in scientific research and clinical/surgical practice.

There is a disparity of terminology in the literature between ansa cervicallis and ansa hypoglossi.

This systematic review of 3731 articles proved that the term that best suits anatomical reality is “ansa cervicalis”.

This conclusion is based on the fact that the nerve fibers arise only from the cervical cord.

The authors also demonstrated that the term “ansa hypoglossi” should be avoided, in scientific research and clinical/surgical practice.

To conduct a literature review on the relationship between the ansa cervicalis (or ansa hypoglossi) and the hypoglossal nerve, discussing this disparity in terminology, and determine which of these terms is the most suitable to identify this important nerve structure.

This is a systematic review of the literature based on studies found through a standardized search performed at the LILACS and MEDLINE/PUBMED databases; classic anatomy textbooks were also consulted.

Forty-five of the 3731 articles found in the scientific research databases were selected and six classic anatomy textbooks were included in the study. Controversies involving the ansa cervicalis were analyzed and the results clearly showed that most textbooks describe its relationship with the hypoglossal nerve as a temporal junction, with no exchange of nerve fibers. The ansa cervicalis contains fibers arising from the cervical cord, and not from the hypoglossal nerve.

The term ansa cervicalis should be chosen to name this loop of nerves. The term ansa hypoglossi is not structurally correct, and should be abandoned in medical practice, the teaching of anatomy, and in scientific publications.

Level II.