A child with severe inner ear malformations with favorable.
Fig 4.—Temporal bone section demonstrating typical findings of Mondini malformation. For this to occur, two abnormalities must exist. On the medial aspect of the labyrinth, CSF must flow quickly from the subarachnoid space into the peri- lymphatic space. On the lateral aspect of the labyrinth, it must then escape into the middle ear through a defect in the otic capsule. The cochlear aqueduct.
Mondini dysplasia, described in 1791 by Carlo Mondini, is one of the most commonly diagnosed inner ear malformations. 10 Morphologically, it is characterized by a helical cavitation of the otic mesenchyme, which leads to the abnormal development of the cochlea in which only the basal turn is clearly identified, while the remaining turns show variable degrees of development but never reach.
Abstract. Mondini dysplasia, also known as Mondini malformation, is a developmental abnormality of the inner and middle ears that can cause hearing loss, cerebrospinal fluid (CSF) leakage, and recurrent bacterial meningitis (RBM), which is defined as two or more episodes of meningitis separated by a period of convalescence and the complete resolution of all signs and symptoms.
In membranous malformations, this classification is based on histopathologic changes in the inner ear; in combined osseous-membranous deformities, radiographic appearance is used to distinguish among the various entities. 3 Correct use of the terminology of pathoembryology is important, although these terms frequently are applied imprecisely in the earlier literature.
Remember: In a classification essay, the writer organizes, or sorts, things into categories. There are three steps to remember when writing an effective classification essay: organize things into useful categories, use a single organizing principle, and give examples of things that fit into each category.
Mondini deformity represents a later malformation, so the amount of dysplasia is much less than in type II. Therefore, it is more accurate and useful for clinical purposes to classify these malformations (in descending order of severity) as follows: Michel deformity, cochlear aplasia, common cavity, IP-I (cystic cochleovestibular malformation), cochlear hypoplasia, and IP-II (Mondini deformity).
Inner ear malformations are one of the most challenging and confusing topics in all of neuroradiology (and radiology for that matter). The topic has “haunted” radiology residents for years, and I remember being a petrified fourth-year resident in the spring of 1992 (last century!), preparing for the oral boards and being completely flummoxed by the temporal bone.