Premenstrual exacerbation of Meniere's disease revisited.

Some women with Meniere disease demonstrate exacerbation of symptoms during the premenstrual period. It is believed that the hormonal stress of the premenstrual period acts on the volatile inner ear with Meniere disease to result in dysfunction. Migraine, Meniere disease, and the premenstrual period may be a complex interaction leading to exacerbation of symptoms.

Theoretical models for the mechanisms of benign paroxysmal positional vertigo.

Benign paroxysmal positional vertigo (BPPV) is a common vestibular disorder resulting from a malfunction of the semicircular canal. Prior studies attempting to elucidate the mechanics of BPPV have focused on clinical and laboratory findings, and have discussed theoretical aspects only in qualitative terms. The goal of this study is to create a mathematical description of BPPV mechanics based on biophysical principles, in order to improve the physiopathological understanding of the most common varieties of the disorder, canalithiasis and cupulolithiasis.

Synaptophysin immunohistochemistry during vestibular hair cell recovery after gentamicin treatment.

In the present study, morphometric and immunohistochemical techniques were used to evaluate the degree of synaptic recovery in the chinchilla crista sensory epithelia during various post-gentamicin-treatment periods of hair cell loss and recovery. For this purpose, two groups of animals were treated with Gelfoam pellets impregnated with 50 micro g of gentamicin implanted in the perilymphatic space within the otic capsule of the superior semicircular canal. Animals were sacrificed 1, 2 and 4 weeks after treatment.

Fiber diameter distributions in the chinchilla's ampullary nerves.

A morphometric study of the chinchilla's ampullary nerves was conducted to produce an unbiased accounting of the diameter distribution of their constituent fibers. Diameter analyses were determined from 1 microm plastic-embedded nerve sections taken at a plane immediately proximal to the sensory epithelium. We found these nerves to be composed of 2094+/-573 fibers, having diameters that ranged from 0.

In vivo and in vitro localization of brain-derived neurotrophic factor, fibroblast growth factor-2 and their receptors in the bullfrog vestibular end organs.

The inner ear sensory epithelia of vertebrates are composed mainly of supporting cells and hair cells (HCs). Brain-derived neurotrophic factor (BDNF) and fibroblast growth factor-2 (FGF-2) are trophins that are believed to play an essential role in the development and innervation of inner ear epithelia. Both trophins also may play a crucial role in the maintenance and regeneration of hair cells in the adult vertebrate ear.