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Classification of cochlear anomalies

Dr Frank Gaillard et al.

The cochlea is prone to a variety of congenital anomalies, depending on the exact time at which an insult occurs during embryogenesis. Terminology is often used imprecisely leading to confusion not only among clinicians but also in the literature.

A classification first propsed in 1987 by Jackler et al ²has become widely accepted (with various modification), which divides congenital cochlear anomalies according to the timing of developmental arrest.

Conveniently starting from the 3^rd week of gestation, an insult during each subsequent week results in a distinct inner ear abnormality.

3^rd week : complete labyrinthine aplasia (or Michel deformity)
4^thweek : common cavity to the cochlea and vestibule
5^thweek : cochlear aplasia
6^th week : cochlear hypoplasia
7^thweek : incomplete partition and dilatational defects (including Mondini dysplasia)

References

Synonyms & Alternative Spellings

Synonyms or Alternative Spelling	Include in Listings?
Jackler's classification of cochlear anomalies	✗
Jackler classification of cochlear anomalies	✗
Classification of cochlear abnormalities	✗
Classification of congenital cochlear abnormalities	✗