Auditory brain-stem evoked potentials in patients with thyroid and parathyroid dysfunction: adaptation to chronic hormonal dysequilibrium.
Auditory Brainstem Evoked Potentials (ABEPs) and pure tone audiograms were obtained from 24 patients with parathyroid dysfunction (17 hypercalcemia and 7 hypocalcemia) and 12 patients with thyroid dysfunction (6 hyperthyroid and 6 hypothyroid) and from 10 control subjects. ABEPs were characterized by I-V interpeak latency difference at 10/sec click rate and by the effect of increasing stimulus rate to 55/sec. None of the ABEP measures were significantly affected by levels of serum calcium, thyroid hormones or their interactions. Moreover no correlation was found between biochemical and electrophysiological measures. This stability of ABEP measures contrasts with earlier reports on acute effects of calcium and thyroid hormonal levels on auditory brainstem evoked potentials. We propose that chronic calcium or thyroid hormonal homeostatic changes are associated with adaptive mechanisms resulting in normal function of the auditory brainstem.
Luboshitzky
R
R
Endocrine Institute, Haemek Medical Center, Afula, Israel.
Bleich
N
N
Ishay
A
A
Pratt
H
H
D000220:Adaptation, Biological; D000328:Adult; D016022:Case-Control Studies; D016057:Evoked Potentials, Auditory, Brain Stem; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D010279:Parathyroid Diseases / Q000503:physiopathology*; D013959:Thyroid Diseases / Q000503:physiopathology*