Vocal Cord Palsy in Hypoxic Brain Injury: A Qualitative Systematic Review

Area of Science:

• Neurology
• Otolaryngology
• Pathophysiology

Background:

• Vocal cord palsy (VCP) is a known complication of various neurological insults.
• The precise link between hypoxic brain injury and VCP, including its underlying pathophysiology and topographical correlations, requires further elucidation.

Purpose of the Study:

• To consolidate existing evidence on the association between vocal cord palsy and hypoxic brain injury.
• To explore the pathophysiology and topographical representations of VCP resulting from hypoxic injury along the laryngeal innervation pathway.

Main Methods:

• A systematic review was conducted adhering to PRISMA guidelines.
• Searches were performed on PubMed, Embase, and Scopus for case series or reports published before December 6, 2023.
• Studies documenting VCP from hypoxic injury with imaging confirmation of lesion level were included.

Main Results:

• Eleven papers involving 12 patients (6 male, 6 female) were included.
• Hypoxic injuries primarily stemmed from stroke (11 cases) and perinatal asphyxia (1 case), affecting various brain regions including the medulla, pons, and basal ganglia.
• Vocal cord involvement was unilateral (8 cases) or bilateral (4 cases), with patterns correlating to the location and extent of brain injury.

Conclusions:

• Hypoxic brain injury is a demonstrable cause of vocal cord palsy.
• The study highlights the correlation between the topographical location of hypoxic brain lesions and the clinical presentation of VCP, implicating neuronal pathways from the motor cortex to medullary motor neurons.