Cerebro-oculo-facio-skeletal syndrome as a human example for accelerated cochlear nerve degeneration.
BACKGROUND
Cerebro-oculo-facio-skeletal (COFS) syndrome is a rare autosomal-recessive disorder that includes microcephaly, severe mental retardation, and multiple congenital anomalies. Otologic findings are usually limited to descriptions of the auricles.


METHODS
The authors report inner ear histopathologic findings of a deceased 13-year-old patient with COFS. A histologic study of the inner ear in COFS syndrome has not yet been described. This patient was documented as having a profound bilateral sensorineural hearing loss at the age of 2 years.


RESULTS
Histologic evaluation revealed accelerated neural and neuronal degeneration at the cochlear and retrocochlear levels. Remaining myelinated nerve fibers, counted in the spiral lamina, had degenerated by up to 97% when compared with normal innervation densities. Afferent nerve fibers innervating inner hair cells were completely absent, whereas medial efferent fibers to outer hair cells were found. Vestibular nerve fibers were less affected.


CONCLUSIONS
The authors report inner ear findings that differ from animal models of primary cochlear neural degeneration and that resemble the pattern of hereditary cochlear nerve degeneration reported in Friedreich's ataxia.
Fish
J H
JH
Department of Otolaryngology, University of Innsbruck, Austria.
Scholtz
A W
AW
Hussl
B
B
Kreczy
A
A
Schrott-Fischer
A
A
D000015:Abnormalities, Multiple / Q000473:pathology; D000293:Adolescent; D001369:Axons / Q000473:pathology; D001847:Bone Diseases / Q000150:complications*; D002648:Child; D003056:Cochlear Nerve / Q000473:pathology*; D005128:Eye Diseases / Q000150:complications*; D005145:Face / Q000002:abnormalities*; D005260:Female; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008607:Intellectual Disability / Q000150:complications; D008297:Male; D008831:Microcephaly / Q000150:complications*; D009410:Nerve Degeneration / Q000473:pathology*; D009413:Nerve Fibers, Myelinated / Q000473:pathology; D013136:Spiral Ganglion / Q000473:pathology; D013577:Syndrome