Related Experiment Video
Updated: Jul 11, 2026
06:59
Intrathecal Application of a Fluorescent Dye for the Identification of Cerebrospinal Fluid Leaks in Cochlear Malformation
Published on: February 29, 2020
Congenital inner ear malformations without sensorineural hearing loss
Kumiko Yukawa1, Satoshi Horiguchi, Mamoru Suzuki
1Department of Otolaryngology, Tokyo Medical University, 6-7-1, Nishishinnjyuku , Shinnjyuku, Tokyo 160-0023, Japan. entkumi@tokyo-med.ac.jp
Auris, Nasus, Larynx
|October 5, 2007
Summary
Normal hearing is rare in severe inner ear malformations. This case study highlights a patient with posterior and lateral semicircular canal dysplasia but normal hearing, experiencing temporary dizziness.
Area of Science:
- Otolaryngology
- Neuroscience
- Radiology
Background:
- Severe inner ear vestibular malformations are typically associated with hearing loss.
- Congenital malformations of the inner ear can affect semicircular canals and cochlea.
Observation:
- A 37-year-old woman presented with dizziness and bilateral posterior and lateral semicircular canal (PSCC, LSCC) dysplasia.
- High-resolution computed tomography (CT) and magnetic resonance imaging (MRI) revealed bony labyrinth hypogenesis and vestibular deformities.
- Despite absent caloric response in the left ear and reduced response in the right, horizontal vestibulo-ocular reflex (VOR) remained intact.
Findings:
- The patient exhibited combined PSCC and LSCC dysplasia with normal cochlear development and hearing.
- Dizziness resolved spontaneously within 3 months without intervention.
- The findings suggest a potential temporary breakdown of the peripheral vestibular system.
Implications:
- This case challenges the assumption of hearing loss in severe vestibular malformations.
- It underscores the complexity of vestibular system function and compensation mechanisms.
- Further research into the relationship between vestibular malformations and auditory function is warranted.
Related Concept Videos
01:16Anatomy of the Ear
Auditory sensation, commonly called hearing, involves the transformation of sonic waves into neural impulses facilitated by the structures of the auditory organ. The prominent, flesh-like structure on the side of the head, called the auricle, directs sound waves towards the auditory canal. The auricle is often mislabeled as the pinna, a term more aligned with mobile structures like a feline's external ear. The auditory canal penetrates the cranium via the external auditory meatus of the...
01:13The Cochlea
The cochlea is a coiled structure in the inner ear that contains hair cells—the sensory receptors of the auditory system. Sound waves are transmitted to the cochlea by small bones attached to the eardrum called the ossicles, which vibrate the oval window that leads to the inner ear. This causes fluid in the chambers of the cochlea to move, vibrating the basilar membrane.
01:17Auditory Perception
The auditory system is essential for sound perception, utilizing various critical structures. When sound waves enter the outer ear, they travel through the ear canal and cause the eardrum to vibrate. These vibrations are then transmitted to the middle ear, where three tiny bones – the malleus, incus, and stapes – amplify the sound. This amplification is crucial, as it ensures that the sound vibrations are strong enough to be conveyed to the inner ear. These vibrations then reach the cochlea, a...
00:50Unrenewable Cells
In humans, the photoreceptor cells of the eye and sensory hair cells of the ear lack stem cells. These cells are thus unrenewable and cannot be replaced when they are damaged or destroyed.
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
Photoreceptors
The retina is composed of several layers and contains specialized cells called photoreceptors. The photoreceptors (rods and cones) change their membrane potential when stimulated by light energy. There are two types of photoreceptors—rods and cones—which differ in the shape of their outer...
01:11The Auditory Ossicles
The auditory ossicles of the middle ear transmit sounds from the air as vibrations to the fluid-filled cochlea. The auditory ossicles consist of two malleus (hammer) bones, two incus (anvil) bones, and two stapes (stirrups), one on each side. These bones develop during the fetal stage and are the ones to ossify first. They are fully mature at birth and do not grow afterward.
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
The aptly named stapes look very much like a stirrup. The three ossicles are unique to mammals, and each plays a role in...
01:15Equilibrium and Balance
The inner ear assumes dual functionalities of auditory perception and equilibrium maintenance. The vestibule is the organ responsible for balance. This organ contains mechanoreceptors, specifically hair cells, endowed with stereocilia, which aid in deciphering information regarding the position and motion of our heads. Two intrinsic components, the utricle and saccule, help perceive head position, while the semicircular canals track head movement. Neurological messages initiated in the...