Histopathology of the vestibular end organs after intratympanic gentamicin failure for Meniere's disease.
CONCLUSIONS
To our knowledge, this is the first report of the histopathology of the vestibular end organs following intratympanic gentamicin for intractable Meniere's disease. There was relative sparing of the utricular macula, compared with the cristae ampullares. However, the utricular macula exhibited severe hair cell loss. Clinically, the patient has been free from vertigo spells for 3 years following labyrinthectomy.


OBJECTIVE
To describe the histopathology and morphometry of the vestibular end organs from a 59-year-old Meniere's patient who underwent transmastoid labyrinthectomy for recurrent vertigo after failed intratympanic gentamicin.


METHODS
Light and transmission electron microscopy were utilized; with unbiased stereology-physical fractionator for type I, type II hair cell, and supporting cell counts. Comparison with end organ histopathology in a 56-year-old with Meniere's disease without gentamicin treatment was carried out.


RESULTS
Histopathological analysis of the semicircular canal cristae ampullares showed severe atrophy of the neuroepithelium with undifferentiated cells, and fibrosis and edema of the stroma. The utricular macula had some remaining type I and type II vestibular hair cells, and nerve fibers and terminals within the underlying stroma. Morphometric measures were obtained from the utricular macula: 2000 type I and 500 type II hair cells, representing 7.3% of type I hair cells and 4.9% of type II hair cells compared with normative controls, and 24 000 supporting cells were obtained.
Ishiyama
Gail
G
Department of Neurology, University of California School of Medicine, Los Angeles, CA 90095, USA. ishiyama@ucla.edu
Lopez
Ivan
I
Baloh
Robert W
RW
Ishiyama
Akira
A
D000287:Administration, Topical; D000900:Anti-Bacterial Agents / Q000009:adverse effects* / Q000627:therapeutic use; D001284:Atrophy / Q000139:chemically induced / Q000473:pathology; D007758:Ear, Inner / Q000601:surgery; D005839:Gentamicins / Q000009:adverse effects* / Q000627:therapeutic use; D006198:Hair Cells, Auditory / Q000187:drug effects* / Q000648:ultrastructure*; D006319:Hearing Loss, Sensorineural / Q000175:diagnosis / Q000209:etiology; D006801:Humans; D008297:Male; D008416:Mastoid / Q000601:surgery; D008575:Meniere Disease / Q000150:complications / Q000188:drug therapy* / Q000473:pathology*; D046529:Microscopy, Electron, Transmission; D008875:Middle Aged; D013506:Otologic Surgical Procedures / Q000379:methods; D012008:Recurrence; D012665:Semicircular Canals / Q000187:drug effects / Q000648:ultrastructure*; D012720:Severity of Illness Index; D017211:Treatment Failure; D014432:Tympanic Membrane; D014717:Vertigo / Q000209:etiology / Q000601:surgery; D014722:Vestibule, Labyrinth / Q000187:drug effects* / Q000648:ultrastructure*
D000900:Anti-Bacterial Agents; D005839:Gentamicins