# Comparison between rigid telescopic and flexible fiberoptic laryngostroboscopy

## TL;DR

This study compares rigid and flexible fiberoptic laryngostroboscopy methods for evaluating vocal issues in Parkinson's Disease patients.

## Contribution

The study provides a direct comparison of rigid and fiberoptic stroboscopic techniques in Parkinson's Disease patients.

## Key findings

- Tremor, open phase closure, and vocal fold bowing were most commonly observed in PD patients.
- Rigid telescope is preferable when technically feasible due to better anatomical detail.
- Both methods revealed similar vibratory source characteristics in all cases.

## Abstract

•The use of rigid and fiberoptic telescopic laryngostroboscopy is well established and each one presents advantages.•Seventy to 92% of patients with Parkinson's Disease present tongue, larynx, and pharynx disorders.•Patients unable to maintain regular voice production under the rigid approach can be evaluated using fiberoptic stroboscopy.•When both methods are technically feasible, the rigid telescope approach is preferrable due to providing greater anatomical detail.

The use of rigid and fiberoptic telescopic laryngostroboscopy is well established and each one presents advantages.

Seventy to 92% of patients with Parkinson's Disease present tongue, larynx, and pharynx disorders.

Patients unable to maintain regular voice production under the rigid approach can be evaluated using fiberoptic stroboscopy.

When both methods are technically feasible, the rigid telescope approach is preferrable due to providing greater anatomical detail.

Stroboscopy can uncover significant laryngeal abnormalities in patients with Parkinson’s Disease (PD). Rigid telescope and flexible fiberscopy present differing advantages. Objective: To compare the stroboscopic findings observed using rigid telescopy to those obtained through fiberoptic examination.

A prospective study was conducted in order to evaluate 36 patients with PD from January 2018 to December 2019. The HY – Degree of Disability Scale was adopted in order to assess individual patients’ levels of impairment. The patients included in this study were grouped- higher than 1.5 on the scale. There were 22 men and 14 women, with ages varying from 41 to 78. Three observers analyzed the recording data, with a protocol for stroboscopic evaluation being adopted.

Tremor, open phase closure and vocal fold bowing were the most common findings among patients. Aperiodic voice in 4 cases recommended against stroboscopic analysis. Strong gag reflex in another 3 cases, made evaluation with rigid telescope impossible. The irregularity of the edge, glottic closure, prevalence of the glottic cycle phase, amplitude; mucosal wave; vibratory behavior; phase symmetry, periodicity and movement extension were evaluated by both methods. The vibratory source was exclusively glottic in all cases.

Videolaryngostroboscopy can be performed by means of both methods – rigid and fiberoptic examination.

Level III.