On the Nature of Hearing Loss in Méniere's Disease.

Objective: To explain the pathophysiology of the hearing loss in Ménière's disease (MD).

Background: In a previous report, we described a dramatic recovery of hearing in 12/31 patients with MD using antiviral (AV) drugs. The hearing loss in the remaining 19 patients with a longer history of MD remained unchanged or else worsened.

A Novel Molecular Test to Diagnose Canine Visceral Leishmaniasis at the Point of Care.

Dogs are the principal reservoir hosts of zoonotic visceral leishmaniasis (VL) but current serological methods are not sensitive enough to detect all subclinically infected animals, which is crucial to VL control programs. Polymerase chain reaction (PCR) methods have greater sensitivity but require expensive equipment and trained personnel, impairing its implementation in endemic areas. We developed a diagnostic test that uses isothermal recombinase polymerase amplification (RPA) to detect Leishmania infantum.

Recovery of Hearing in Meniere's Disease after Antiviral Treatment.

Objective: Determine the outcome of hearing in Meniere's Disease (MD) after antiviral treatment.

Study Design: Prospective study.

Setting: University Hospital.

A perspective on recurrent vertigo.

The recurrent nature of the 3 most common vestibulopathies suggests a recurrent cause. Histopathology in temporal bones from patients with these syndromes - vestibular neuronitis (VN, n = 7), Ménière's disease (MD, n = 8) and benign paroxysmal positional vertigo (BPPV, n = 5) - shows focal degeneration of vestibular nerve axons and degenerated nearby facial nerve meatal ganglion cells. Transmission electron microscopic confirmation of intracytoplasmic viral particles in surgically excised vestibular nerves from patients with VN and MD support a viral etiology in these vestibulopathies.

Clustering is a feature of the spiral ganglion in the basal turn.

Objective: To demonstrate the organization of the spiral ganglion in the mammalian species.

Methods: Temporal bone (TB) specimens from man (n = 2), monkey (n = 2), lion (n = 2) and cat (n = 20) were stained, decalcified and dissected according to the Sudan black B method of Rasmussen. These TB specimens were examined under a Zeiss operating microscope and photographed with a Canon 100 camera interfaced with the microscope.

Fusion as an evolutionary principle of the vertebrate labyrinth.

Objectives: This study was undertaken to demonstrate changes in the innervation of vestibular and auditory sense organs with the evolutionary ascent of the vertebrate labyrinth.

Methods: Dissected labyrinths and their nerve supply prepared by the Sudan black B technique of Rasmussen were examined and photographed with a Canon A100 camera interfaced with a Zeiss operating microscope.

Results: In lizards and alligators, the utricular sense organ is represented by 2 small maculae, each with a separate nerve branching off the ampullary nerves to the anterior and lateral canal cristae.

Evidence of a gustatory-vestibular pathway for protein transport.

Objective: To demonstrate anatomically a pathway for protein transport from the palate to the vestibular system.

Method: The vestibulofacial anastomosis and associated ganglion cells were identified in a collection of 160 horizontally sectioned human temporal bones that had been stained with hematoxylin and eosin. Wheat germ agglutinin-horseradish peroxidase (HRP) was applied to the greater superficial petrosal nerve in 4 Sprague-Dawley rats.

Ménière's disease is a viral neuropathy.

Morphological and clinical evidence supports a viral neuropathy in Ménière's disease (MD). Quantitative examination of 11 sectioned temporal bones (TBs) from 8 patients with a history of MD revealed a significant loss of vestibular ganglion cells in both the endolymph hydropic (EH) and non-EH ears. Transmission electron microscopy of vestibular ganglion cells excised from a patient with MD revealed viral particles enclosed in transport vesicles.

Evidence for a viral neuropathy in recurrent vertigo.

The concept that reactivation of latent neurotropic viruses (i.e. Herpesviridae group) in the vestibular ganglion is responsible for recurrent vestibulopathies is presented.

A place principle for vertigo.

Objective: To provide a road map of the vestibular labyrinth and its innervation leading to a place principle for different forms of vertigo.

Method: The literature describing the anatomy and physiology of the vestibular system was reviewed.

Results: Different forms of vertigo may be determined by the type of sense organ, type of ganglion cell and location in the vestibular nerve.

Aneurysmal bone cyst of the temporal bone associated with reversible hemifacial paralysis.

Aneurysmal bone cyst (ABC) is an uncommon lesion of the temporal bone (TB), with only 20 cases reported. Facial paralysis is a rare complication (2 cases); however, no cases have been reported with preoperative reversal of paralysis. We report a 60-year-old man with a history of remote head trauma, who presented with serious otitis media and right hemifacial paralysis, which resolved with nonsurgical therapeutic measures.

Efferent system degeneration in the human temporal bone.

Sense organ deposits have been described in temporal bones from patients with vestibular neuronitis, Meniere's disease, and benign paroxysmal positional vertigo that are not found in a comparable series of temporal bones without vestibulopathy. Because the recurrent vestibulopathies are caused by vestibular ganglionitis and the vestibulocochlear anastomosis was degenerated in these temporal bones, the deposits may represent the end buds of regenerating efferent axons injured in passage through the vestibular ganglion. Such neural buds have been described with transmission electron microscopy in animals after vestibular nerve transection and in a human temporal bone with endolymphatic hydrops.

Pathology of benign paroxysmal positional vertigo revisited.

The pathophysiology of benign paroxysmal positional vertigo (BPPV) is not completely understood. Although the concept of degenerated otoconia transforming the posterior canal (PC) crista into a gravity-sensitive sense organ has gained popular support, several temporal bone (TB) series have revealed similar deposits in normal TBs, suggesting they are a normal change in the aging labyrinth. Furthermore, some TBs from patients with BPPV do not contain particles in the posterior canal.

Results of singular neurectomy in the posterior ampullary recess.

Objective: To determine the effect on hearing and balance symptoms following singular neurectomy (SN) for benign paroxysmal positional vertigo (BPPV) in the ampullary recess of the posterior semicircular canal.

Research Design: The charts of 242 patients with chronic disabling BPPV who were treated with SN over a 29-year period (1972-2001) were reviewed. The results on relief of BPPV and hearing function were recorded.