Selective Microsurgical Vestibular Neurectomy: An Option in the Treatment of Intractable Vertigo and Related Microsurgical Landmarks

Selective microsurgical vestibular neurectomy (SMVN) is an accepted and effective means of treating patients with intractable vertigo, a resistant component of Meniere's syndrome. Meniere's syndrome is a condition characterized by fluctuating hearing loss, tinnitus and serious vertigo attacks. Vertigo is the most disabling symptom of the disease. There may be permanent hearing loss in untreated cases and vertigo may continue after deafness. Selective microsurgical vestibular neurectomy is an elite surgical procedure providing exact relief from vertigo while protecting the preoperative hearing level. In this report, clinical results of nine patients with intractable vertigo operated in the University of Ankara Medical Faculty, Department of Neurosurgery between 1999 and 2001 are discussed. Accordingly, we aimed to represent the landmarks often required for microsurgical exposure. From this study we conclude that SMVN is an effective neurosurgical procedure for those patients who are resistant for medical treatment and require hearing preservation.

Clinical and histopathological evaluation of sucralfate in prevention of oral mucositis induced by radiation therapy in patients with head and neck malignancies

Forty-four patients with head and neck malignancies were included in a prospective, randomized, double-blind, placebo-controlled study for evaluation of sucralfate in prevention of oral mucositis induced by radiation therapy. Patients were randomized to receive oral suspensions of either sucralfate (n = 23) or placebo (n = 21) in six daily doses of 1 g. The primary tumors were treated with portals covering at least one-third of the oral mucosa to a minimum dose of 60 Gy. Drug therapy was not associated with significant adverse effects and compliance was satisfactory. Daily inspection of the oral mucosa and questionnaires for oral mucositis-related items demonstrated reduction in oral mucositis scores and oral pain scores and biopsies obtained from the buccal mucosa demonstrated reduction in evidence of altered vascular calibration, altered vascular permeability and leukocyte emigration with sucralfate. Clinical and histopathological demonstration of reduction in oral mucositis with sucralfate suggests that sucralfate might be recommended in the prevention of oral mucositis induced by radiation therapy in patients with head and neck malignancies.

Evaluation of vocal cord function after thyroid surgery

OBJECTIVE

To compare clinical evaluation and indirect laryngoscopy with videolaryngostroboscopy (VLS), which is a new method of diagnosing abnormalities and dysfunction of the vocal folds.

DESIGN

Prospective study.

SETTING

Teaching hospital, Turkey.

SUBJECTS

218 patients who required thyroidectomy and who had no vocal abnormality preoperatively.

INTERVENTIONS

Clinical evaluation, indirect laryngoscopy, and VLS before operation and on the second postoperative day.

MAIN OUTCOME MEASURES

Sensitivity and specificity.

RESULTS

The specificity of all three investigations was 100%. The sensitivity of VLS was 100%, of clinical evaluation 81%, and of indirect laryngoscopy 67%.

CONCLUSIONS

Clinical evaluation and indirect laryngoscopy are safe ways of evaluating abnormalities of the vocal cords postoperatively. It would probably not be cost-effective to use VLS routinely, but for differential diagnosis and evaluation of prognosis of vocal abnormalities after thyroidectomy it is more accurate.

The three-dimensional fibrillar arrangement of the basilar membrane in the mouse cochlea

The three-dimensional fibrillar arrangement of the basilar membrane in the mouse cochlea was studied using scanning electron microscopy. Fibrils of the basilar membrane were exposed by removing cellular elements of the cochlea using a sodium hydroxide maceration technique. The arrangement of fibrils in the basilar membrane was different between the pars arcuata and pars pectinata. In the pars arcuata, fibrils were arranged in radial and spiral direction, showing a woven pattern. In the pars pectinata, most of the fibrils ran in the radial direction. These findings suggest that the vibration pattern of the pars arcuata and pars pectinata is different when the basilar membrane vibrates.

Spiral modiolar vein: its importance in viral load of the inner ear

Guinea pig-specific cytomegalovirus and Sendai virus were inoculated into the cochleas of seronegative guinea pigs to study the route of entry of cells participating in inner ear inflammation. Inflammatory cells accumulated around the spiral modiolar vein and appeared to be streaming from this vein into the scala tympani via a collecting venule. Inactivated virus inoculated into the cochlea and normal control cochlea failed to show inflammatory cell infiltrates. The spiral modiolar vein appears to play an important role in the movement of cells from the systemic circulation into the inner ear as part of the host's normal defense against invading pathogens such as viruses.

Microstructures of the osseous spiral laminae in the bat cochlea: a scanning electron microscopic study

The architecture and surface structures of the primary and secondary osseous spiral laminae in the cochlea of the bat, an animal able to hear high frequency sounds, were examined by scanning electron microscopy to understand the micromechanical adaptations of the bony supportive elements in the inner ear to the specific hearing function. The bat used was Myotis frater kaguyae. The myotis bat cochlea was seen to consist of a hook and a spiral portion with one and three-quarter turns and was characterized by: 1) a distinct ridge-like projection running spirally along the middle line on the vestibular leaf of the primary osseous spiral lamina; 2) a wide secondary osseous spiral lamina; and 3) a narrow spiral fissure between the primary and secondary osseous spiral laminae. The ridge on the primary osseous spiral lamina was 150 microns high in the hook and basal turn, then lowered toward apex, and flattened before the apical end. The surface structures appeared to provide a firm anchorage of the auditory teeth. The secondary osseous spiral lamina, which anchors the fibers of the basilar membrane, was sharply projected and measured 150 microns in width in the hook, and then narrowed gradually toward apex to disappear in the helicotrema. The spiral fissure for the basilar membrane was about 40 microns in width in the hook and about 120 microns in the apical turn. The findings suggest the presence of a narrow and rigid basilar membrane with a high amount of fibers and a strong bony support to the auditory teeth for scaffolding the tectorial membrane during intense vibration in response to high frequency sounds.(ABSTRACT TRUNCATED AT 250 WORDS)

Scanning electron microscopy of the auditory teeth along the mouse cochlear duct

The auditory teeth in the spiral limbus of the cochlear duct are located under the limbal portion of the tectorial membrane and separated by furrows lodging the interdental cells. In this study, the shape, arrangement and distribution of the auditory teeth in the cochlear duct of adult mice were examined by scanning electron microscopy after removing the tectorial membrane and the interdental cells with chemical maceration methods. The auditory teeth appeared on the top face of the spiral limbus between the edge of the vestibular lip and the Reissner membrane. The teeth on the vestibular lip side possessed elongated upper plates and formed a continuous row resembling the keyboard of a piano; the teeth were separated by radially oriented parallel slits. The elongated teeth decreased in length from the base to the apex of the cochlear duct. The teeth on the Reissner membrane side showed star-shaped upper plates separated by slits and gaps. The population density of the star-shaped teeth decreased from the base to the apex, widening the gaps to hold the interdental cells. The upper plates of the teeth occupied about 75% of an extent of the tooth zone in the hook and first basal half turn, and about 55% in the apical turn. The regional differences of the auditory teeth are considered to be closely related to local functions of the tectorial membrane and the interdental cells.

Scanning electron microscopy of the connective tissue along the lateral wall of the mouse cochlear duct with special reference to the external sulcus cells

The external sulcus cells in the lateral wall of the cochlear duct insert cell cords into the connective tissue. To examine the shape, arrangement, and distribution of the sulcus cell cords in the cochlear duct in adult mice, the external sulcus cells were removed by chemical maceration methods, and the connective tissue exposed. The holes for the insertion of the sulcus cell cords along the entire course of the cochlear duct could thus be observed by scanning electron microscopy. A zone perforated with the holes was seen in the lateral region of the area between the stria vascularis and the lateral edge of the basilar membrane, this zone extending from the basal end of the hook to the helicotrema. In the hook and basal half turn, the holes possessed large fusiform openings and branched in the connective tissue toward the outer bony wall. In the apical turn, the holes displayed small round openings and were shallow, having a small number of branchings. The width of the perforated zone, the population density of the openings of the holes and the area proportion of the openings per unit surface area in the lateral wall decreased from the base to the apex of the cochlear duct. The regional differences in the organization of the sulcus cell cords suggest that the external sulcus cells function in close relation to regional auditory functions in the cochlear duct.

Microanatomy of the mouse osseous cochlea: a scanning electron microscopic study

This is the first scanning electron microscopic demonstration of the three-dimensional architecture and detailed surface structures of the entire osseous labyrinth of the cochlea. Mouse cochleae were observed after dissolving the soft tissues with KOH and NaOCl solutions. The precise shapes, surface structures, and orientations of the primary osseous spiral lamina and secondary osseous spiral lamina in the cochlea were observed along their entire course from the hook at the base to the helicotrema at the apex. The primary osseous spiral lamina showed three half turns after the hook; the lengths of the hook and each half turn and the slope angle of the spiral were obtained. The widths of the primary and secondary spiral laminae and the spiral fissure for the basilar membrane between the free edges of the two spiral laminae were measured along the course of the cochlear duct. The surface of the lateral wall under the stria vascularis was also viewed. Scanning electron microscopy can provide more precise microanatomical data than has been previously available for the osseous cochlea, giving a better understanding of hearing mechanisms with regard to the width, support, and movement of the basilar membrane and the functions of various components of the cochlea.