Peripheral vestibular dysfunction in patients with primary ciliary dyskinesia: abnormal otoconial development?

Area of Science:

• Otolaryngology
• Genetics
• Neuroscience

Background:

• Primary ciliary dyskinesia (PCD) is a congenital disorder affecting ciliary structure and function.
• Cilia are crucial for otolith organ development in animal models, but human data is lacking.
• This study investigates otoconial function in human patients with PCD.

Purpose of the Study:

• To evaluate otoconial function in patients with primary ciliary dyskinesia (PCD).
• To determine if PCD patients exhibit reduced or absent otoconial function compared to controls.
• To explore the relationship between ciliary defects and otoconia development.

Main Methods:

• Vestibular function tests including utricular centrifugation (UCF) and vestibular evoked myogenic potentials (VEMPs) were performed on five PCD patients.
• Electronystagmography and validated questionnaires on balance and symptoms were also utilized.
• Assessment of the vestibulo-ocular reflex (VOR) was conducted.

Main Results:

• Three out of five PCD patients had markedly reduced or unobtainable VEMPs bilaterally; the remaining two had unilateral reductions.
• No pathological UCF asymmetry was observed, but three subjects displayed utricular abnormalities.
• The vestibulo-ocular reflex (VOR) remained normal in all participants, and no subjective balance issues were reported.

Conclusions:

• Reduced saccular and utricular function in PCD patients suggests a link between ciliary structure/motility and otoconia seeding/positioning.
• This pilot study highlights a potential connection between ciliary defects and otolith development in humans.
• Further research is warranted to confirm these findings and elucidate the underlying mechanisms.