TY - JOUR
T1 - Hypothyroidism and the ear
T2 - Electrophysiological, morphological, and chemical considerations
AU - Meyerhoff, W. L.
PY - 1979/10
Y1 - 1979/10
N2 - There is both clinical and laboratory evidence that hearing loss can result from congenital and acquired hypothyroidism. The reversibility of this process, however, and its incidence and pathophysiology are not universally agreed upon. Laboratory animals rendered hypothyroid with radioactive iodine 131 or propylthiouracil demonstrated normal perilymph sodium and potassium levels but increased auditory thresholds for N1N2 response and brain stem evoked audiometry as well as a crystallized consistency of the bone of the bullae and cochleae, ossicular abnormalities, obliteration of the oval and round window, large dark staining lipid accumulations in Hensen's cells, large intercellular spaces in the stria vascularis with degeneration of the marginal and intermediate cells, inner and outer hair cell degeneration, debris in the cochlear duct, and tectorial membrane irregularity. Otic capsule biochemical alterations were identified which may account for the osseous changes observed morphologically. The morphological, biochemical, and electrophysiological findings in this study support the hypothesis that the cochlea is a site of lesion for sensorineural hearing loss in hypothyroidism. Middle ear changes identified could be responsible for the conductive component.
AB - There is both clinical and laboratory evidence that hearing loss can result from congenital and acquired hypothyroidism. The reversibility of this process, however, and its incidence and pathophysiology are not universally agreed upon. Laboratory animals rendered hypothyroid with radioactive iodine 131 or propylthiouracil demonstrated normal perilymph sodium and potassium levels but increased auditory thresholds for N1N2 response and brain stem evoked audiometry as well as a crystallized consistency of the bone of the bullae and cochleae, ossicular abnormalities, obliteration of the oval and round window, large dark staining lipid accumulations in Hensen's cells, large intercellular spaces in the stria vascularis with degeneration of the marginal and intermediate cells, inner and outer hair cell degeneration, debris in the cochlear duct, and tectorial membrane irregularity. Otic capsule biochemical alterations were identified which may account for the osseous changes observed morphologically. The morphological, biochemical, and electrophysiological findings in this study support the hypothesis that the cochlea is a site of lesion for sensorineural hearing loss in hypothyroidism. Middle ear changes identified could be responsible for the conductive component.
UR - http://www.scopus.com/inward/record.url?scp=0018670468&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=0018670468&partnerID=8YFLogxK
U2 - 10.1002/lary.5540891501
DO - 10.1002/lary.5540891501
M3 - Article
C2 - 491810
AN - SCOPUS:0018670468
SN - 0023-852X
VL - 89
SP - 1
EP - 25
JO - Laryngoscope
JF - Laryngoscope
IS - 10
ER -