Table 2:

Patients with cochlear hypoplasia^a

Patient	Age (yr) Sex	L CH (mm)	R CH (mm)	TYPE HL	Diagnosis	CT Findings
1	6.3 Female	2.8	2.5	SNHL, bilaterally	Bilateral vestibulocochlear dysplasia, L Mondini malformation	Bilateral vestibulocochlear dysplasia
						R common chamber malformation, absent vestibular aqueduct, aplastic modiolus
						L Mondini malformation (hypoplastic cochlea with partition defect)
2	1.9 Male	3.4	3.6	Mixed HL	BOR syndrome	Bilateral dilated vestibular aqueduct with small modiolus, trumpet-shaped IAC, small mass in R middle ear (possible congenital cholesteatoma)
3	0.8 Female	3.7	3.5	Mixed HL	BOR syndrome	Bilateral tympanostomy tubes, hypoplasia of modiolus, vestibular ectasia, dilated vestibular aqueducts, Mondini deformities (cochlear ectasia with partition defects), question of ossicular fusion
						R middle ear and mastoid air cell opacification; absent vs hypoplastic stapes
						L hypoplastic mastoid with soft tissue thickening at L mesotympanum
4	6.7 Female	3.6	4.3	Mixed HL, bilaterally	CHARGE syndrome	Bilateral hypoplastic SCCs, prominent EAC, vestibular dysplasia, cochlear ectasia with partition defects, hypoplastic stapes
						R sclerosis of ossicles, poorly visualized oval window, L poorly defined modiolus
5	0.1 Male	4.2	3.8	Mixed HL, bilaterally	CHARGE syndrome	Bilateral absent SCCs, middle ear/mastoid air cell congestion or inflammation, normal middle ear morphology
6	6.6 Male	4.0	4.5	SNHL, bilaterally	EVA syndrome	Bilateral enlarged vestibular aqueducts, R cochlear implant, L hypoplastic modiolus
7	7.1 Male	4.2	4.3	CHL, bilaterally	Bilateral class II microtia and EAC atresia	R malformed IAC, partially formed middle ear cavity, poorly defined ossicles, narrow EAC, normal SCCs/vestibule
						L absent lateral SCC, vestibular dysplasia, ossicular dysplasia, absent membranous EAC, normal cochlea

Note:—R indicates right; L, left; IAC, internal auditory canal; SCC, semicircular canals; BOR, branchio-oto-renal; EVA, enlarged vestibular aqueduct; EAC, external auditory canal..
↵a CHs >2 SDs below the mean CH.