# Beyond the needle: how clinician expertise affects outcomes in the treatment of hemifacial spasm

## TL;DR

This study shows that supervised residents can safely administer botulinum toxin for hemifacial spasm with no more risks than experienced neurologists.

## Contribution

Demonstrates that supervised trainees can perform BoNT-A injections for HFS without compromising safety.

## Key findings

- Adverse event rates were similar between neurologists and supervised residents (12.3% vs. 12.7%).
- Structured training and supervision ensured safe BoNT-A administration by residents.
- Most adverse events were mild, such as facial paresis and eyelid ptosis.

## Abstract

•BoNT-A injections by supervised residents showed no increased risk of adverse events in HFS patients.•Adverse event rates were similar between neurologists (12.3%) and supervised residents (12.7%).•Structured training and supervision ensured safe BoNT-A administration by neurology residents.•Study supports supervised trainee involvement in HFS care without compromising patient safety.

BoNT-A injections by supervised residents showed no increased risk of adverse events in HFS patients.

Adverse event rates were similar between neurologists (12.3%) and supervised residents (12.7%).

Structured training and supervision ensured safe BoNT-A administration by neurology residents.

Study supports supervised trainee involvement in HFS care without compromising patient safety.

Hemifacial spasm (HFS) is characterized by abnormal contraction of the muscles innervated by the seventh cranial nerve. It is usually benign and diagnosed clinically. The effectiveness of botulinum toxin (BoNT) for its treatment has been well demonstrated. However, adverse events (AEs) resulting from its administration remain a concern, and some patients express reluctance to be treated by resident physicians, even when under expert supervision.

To determine the association between the level of expertise of the neurology professional and the presence of AEs following BoNT administration in patients with HFS.

A cross-sectional descriptive study with an analytical phase conducted at Hospital Occidente de Kennedy (Bogotá, Colombia). Out of 88 medical records reviewed, 73 met all inclusion criteria. Data analysis was performed using SPSS software version 22.

A predominance of female patients was observed, accounting for 74 % of the study population. The mean age of symptom onset was 54.5 ± 12.7 years, with a median symptom duration of 9 years. In most cases, the left side was affected (53.4 %). The average number of botulinum toxin applications per patient was 2.6 during the study period. Adverse events occurred in 12.6 % of cases, primarily mild facial paresis (7.9 %), hematoma (2.6 %), and eyelid ptosis (2.1 %)

The results did not show a statistically significant association between the level of expertise and the occurrence of adverse events. The frequency of observed adverse events was similar between the groups. This suggests that the occurrence of adverse events following BoNT administration was comparable regardless of whether the procedure was performed by a neurologist or a resident under supervision.