Temporal bone studies: findings with undecalcified sections in a 2,600-year-old Egyptian mummy.

Roentgenologic studies by polytomography of the temporal bones of a 2,600-year-old Egyptian mummy (PUM-II) revealed an increase in radiographic density throughout the left temporal bone. The superior portions of the petrous bones were removed with an electric saw for study by undecalcified techniques. For histological control, a similar specimen was removed from a cadaver immediately after autopsy. Light microscopy of sections showed excellent preservation of the Haversian systems. The vascular channels were clearly seen, and they were similar in appearance to those of the fresh specimen. The lacunae contained osteocytes with good preservation of the nucleus. Osteoid seams were identified and the osteon activity was described for the first time in an Egyptian mummy. There was a low turnover type of bone, but there was no evidence of metabolic bone disease. We postulate that the increased radiological density of the left temporal bone was due to a greater amount of resin infiltration in this bone as compared to the right. It appeared that the resin acted as a fixative preserving the bone cells and related elements.     

Otopathology of Egyptian mummy Pum II: final report

Otoscopic examination of the ears of Egyptian mummy PUM II with the operating microscope revealed a small oval perforation of the right tympanic membrane in the posteroinferior quadrant. The smooth and concise margins suggested an etiology of middle ear infection. A method which allows decalcification of ancient specimens without disintegration of the eardrum and other soft tissues within the temporal bone was described. There was evidence of histological repair at the margins of the perforation consistent with sequela of otitis media. No other abnormalities were observed in the temporal bones of this individual. There was no evidence of otosclerosis bilaterally. To our knowledge, this is the first time that a pathological tympanic membrane perforation has been histologically documented in an ancient temporal bone.     

原发性颞下窝肿瘤的诊断和治疗

目的：探讨原发性颞下窝肿瘤的诊断和治疗。方法：对2例原发性颞下窝肿瘤患者通过CT检查见颞下窝肿瘤，应用隐蔽的发际内侧切口进行手术。结果：切除肿瘤，保护了面神经，随访1～4年，无复发。结论：对原发于颞下窝的肿瘤应注意其早期症状，CT检查是诊断颞下窝肿瘤的有效手段，隐蔽于发迹内的侧切口是比较好的手术进路。     

Delayed endolymphatic hydrops as a clinical entity

Delayed endolymphatic hydrops (DEH) is a clinical entity that can be differentiated from Ménière's disease and is typically observed in patients who have been suffering from longstanding unilateral profound inner-ear hearing loss. DEH probably is caused by delayed atrophy or fibrous obliteration of the endolymphatic resorptive system of the membranous labyrinth. The time that elapses between the occurrence of hearing loss and the onset of DEH can range from 1 to 74 years. The most common cause of hearing loss preceding DEH is juvenile-onset unilateral profound deafness (early childhood unilateral profound sensorineural hearing loss of unknown etiology), followed by labyrinthitis from various causes and physical and acoustic traumas to the inner ear. Two types of DEH exist: the ipsilateral type, in which the ear with profound hearing loss suffers progressive endolymphatic hydrops, and the contralateral type, in which the formation of progressive endolymphatic hydrops takes place in the ear opposite to the previously deafened ear. The incidence of the ipsilateral type is higher than that of the contralateral type, and the contralateral type is more common in older patients. When recurrent episodic vertigo cannot be remedied through conservative treatment, labyrinthectomy and vestibular neurectomy on the deaf ear are curative for ipsilateral DEH. However, no such surgical treatment is available for the contralateral type.     

Delayed endolymphatic hydrops: a case study

Delayed endolymphatic hydrops (DEH) is an unusual variation of Ménière's disease characterized by episodic vertigo that develops some time after the onset of a profound, typically unilateral sensorineural hearing loss. This case study describes a 48-year-old male who presented with complaints of episodic vertigo and disequilibrium 15 years following the onset of unilateral sensorineural hearing loss. The patient's history, audiologic findings, and vestibular evaluation led to the diagnosis of DEH. The case highlights the diagnostic and treatment challenges associated with this condition and focuses attention on principles that guide the audiologist in collecting evidence that aids in solving these challenges.     

Surgery of the endolymphatic sac and preservation of hearing in endolymphatic hydrops

Vertigo is the most important symptom of Ménière's disease both from the standpoint of follow-up and indication for surgery. But although vertigo is an alerting symptom for both the patient and the physician, we believe that the hearing level is the most reliable and even the single sign in determining the recent status of the disease. Between 1983-1989, 42 patients with various types of Ménière's disease (MD) (34 typical MD, 3 cochlear MD and 3 vestibular MD) underwent endolymphatic sac surgery at ENT department of Gazi University School of Medicine. In the typical MD group, patients with a duration of symptoms of less than one year prior to surgery revealed better postoperative results; 91% fell into class A and B, whereas this rate was found to be lower (40%) in patients with symptomatology lasting for more than one year. In conclusion, especially in bilateral cases, given the importance of the hearing, early sac surgery is thoroughly recommended for the conservation of hearing.     

The vestibular aqueduct and endolymphatic sac and duct in endolymphatic hydrops.

The histologic features of the endolymphatic sac and duct in 23 serially sectioned temporal bones with idiopathic or secondary endolymphatic hydrops were blindly compared with 22 randomly selected, normal temporal bones. In idiopathic hydrops, the pars rugosa of the endolymphatic sac extended out of the vestibular aqueduct into the dura in 29% of bones, compared with none of normal bones (P less than .01). In the other 71%, the pars rugosa in the vestibular aqueduct was surrounded by dura more commonly than normal. Functional studies are required to assess the relationship of these findings to hydrops. In secondary hydrops (eg, due to labyrinthitis), the endolymphatic duct was obliterated in the isthmus of the vestibular aqueduct by bone or fibrosis in seven of nine bones. Because of similar ossification and fibrosis elsewhere in the vestibular labyrinth, a direct relationship with hydrops cannot be assumed.     

Change in endolymphatic hydrops 2 years after endolymphatic sac surgery evaluated by MRI

Objective

This study was performed to determine whether endolymphatic sac surgery improves vestibular and cochlear endolymphatic hydrops 2 years after sac surgery and to elucidate the relationship between the degree of improvement of endolymphatic hydrops and the changes in vertigo symptoms, the hearing level, and the summating potential/action potential ratio (?SP/AP ratio) by electrocochleography (ECochG) in patients with Ménière’s disease (MD).

Saccular and cochlear endolymphatic potentials in experimentally induced endolymphatic hydrops of guinea pigs

Saccular and cochlear endolymphatic potentials (SEP and CEP) were recorded in 33 normal animals. We confirmed that SEP is not produced in the saccule per se, but is a potential leak from the cochlea. CEP was reduced to one-tenth of the original value when it reached the saccule. Endolymphatic hydrops was provoked in 32 animals, and CEP and SEP were successfully recorded in 29 and 20 cases, respectively. The measurements were performed in the 2nd, 4th and 12th postoperative week. Both CEP and SEP decreased in magnitude as time elapsed after the surgery. This reduction is attributed to the strial dysfunction. In advanced hydrops, CEP transmission to the saccule is greatly inhibited. It is concluded that the saccular dysfunction can occur in the hydropic ear.     

Ultrastructure of the endolymphatic sac in two-phase endolymphatic hydrops in the guinea pig.

Two-phase endolymphatic hydrops is a subtle experimental model for Meniere's disease. Chronic dysfunction of the endolymphatic sac, induced by dissection of the most distal part without causing damage to the intermediate part, is combined with increased endolymph production induced by administration of aldosterone which stimulates the N/K-ATPase in the stria vascularis. A transmission electron microscopic study was performed on the endolymphatic sacs of four groups of guinea pig cochleas: controls: non-operated aldosterone-treated cochleas; operated (dissection of the endolymphatic sac) cochleas; operated and aldosterone-treated cochleas. Light and electron microscopy showed a normal morphology in the controls. Aldosterone treatment had no visible effect. Dissected ears revealed severe deviations. The epithelium of the intermediate sac was low, showed dilated lateral intercellular spaces indicating elevated fluid transport and displayed serious degenerative processes. Distally, the endolymphatic sac was completely blocked by newly formed bone. Additional aldosterone treatment had no cumulative effect on the dissected ears.     

Verification of a new test of endolymphatic hydrops

A new objective test of endolymphatic hydrops has been described previously. The test uses auditory brain-stem response (ABR) techniques to estimate the basilar membrane travelling wave velocity (TWV). The underlying hypothesis is that raised pressure in the scala media will lead to an increase in the stiffness of the basilar membrane and that this will give rise to a travelling wave velocity that is greater than normal. It was considered that verification of the technique could be obtained by carrying out the new test before and during a glycerol dehydration procedure. Patients who required this procedure for verification of the diagnosis or as a prognostic indicator for sacculotomy, underwent the following tests. Prior to dehydration an audiogram, the ABR TWV test and a blood sample (for plasma osmolality) were taken. The patient was then given the appropriate amount of glycerol mixed with lemon juice and laid on a bed in a test room. The audiogram and a blood sample were repeated every hour and the ABR TWV test was repeatedly carried out every twenty minutes between the other tests. Six of these procedures have been carried out. In five of them the 0.5 and 1 kHz average threshold improved by at least 10dB and in all those cases the ABR TWV test showed an abnormal pre-dehydration result which moved towards the normal value following dehydration. One patient gave ABR TWV results that were within normal limits before and during the procedure and gave an audiometric change of only 5dB.(ABSTRACT TRUNCATED AT 250 WORDS)     

Morphology of the endolymphatic sac in the guinea pig after an acute endolymphatic hydrops

The role of the endolymphatic sac (ES) in endolymph volume homeostasis is speculative. The present study investigates changes of the ES's epithelia and luminal filling after induction of an acute endolymphatic hydrops. After microinjection of 1.1 mul artificial endolymph into scala media of the cochlea, guinea pigs were terminated immediately (n = 6) or after different time intervals ; 1/2 h (n = 3), 1 h (n = 4) and 2 h (n = 4). Inner ear specimens were processed for light and/or transmission electron microscopy. The non-injected contralateral ear served as a histological control. Correct injection was confirmed by detection of microspheres in the endolymphatic compartment after the same microinjection procedure. In all specimens, ribosome rich cells and intraluminal macrophages appeared to be actively involved in degradation of homogeneous substance (HS) by secreting lytic enzymes and digestion, respectively. Amazingly, in our study no ES differences were found between injected and non-injected ears and no distinct changes were observed in guinea pigs terminated after different time intervals. The ES's luminal HS was always present and often to a large extent. This is in contrast with [Hear. Res. 138, 81] dramatic changes were observed. Endolymph volume homeostasis is a complex mechanism, in which the role of HS remains obscure.     

Study by radiolabelling of the residual time of a therapeutic gel in the nasal fossae

The residence times in the nose of the liquid and gel forms of the same therapeutic preparation were compared in 7 healthy subjects. A 50 microliters drop of the preparation, labelled with Tc99m, was placed down the head of the inferior turbinate, and the kinetics of its clearance from the site of deposition was monotired using a gamma camera, during 60 minutes for the liquid and 120 minutes for the gel. The average times for removal of 50% of the labelled material from the site of deposition were 10.3 minutes and 28.6 minutes for the liquid and gel forms respectively. The slower removal of the gel form is probably due to a mechanical effect, and seems to affect the whole nasal passage. The contact time between the preparation and the mucosa is increased in this galenic form and this should improve the efficiency of the preparation.     

Calcium transport in the endolymphatic sac

Ca++ activity and DC potential were measured in vivo in the endolymphatic sac (ES) of guinea pigs by means of double-barrelled ion-sensitive microelectrodes. We found a positive DC potential of 14 mV and a Ca++ activity of 4.7 X 10(-4) M. Anoxia induced a decrease in the DC potential and an increase in Ca++ activity; however, no negative DC potential was measured during permanent anoxia. The Ca++ activity measured was in agreement with the Ca++ value calculated with the Nernst equation, assuming a positive DC potential. On the basis of these data, it was suggested that the Ca++ in the ES is in electrochemical equilibrium with the surrounding fluid and no active Ca++ transport is necessary in the ES of guinea pigs.     

Cochlear blood flow in endolymphatic hydrops

There is no animal model for Meniere's disease but by obliteration of the endolymphatic duct, endolymphatic hydrops may be achieved in several animal species. In order to measure the cochlear blood flow in ears with endolymphatic hydrops the endolymphatic duct was obliterated in 9 guinea pigs. The blood flow was measured with the microsphere method and the cochlear histology was studied. The regional and total blood flow was determined in the serially sectioned cochleas 2, 4 and 8 months after obliteration of the endolymphatic duct. No change in regional or total cochlear blood flow was observed in the hydropic ears.     

Intratympanic injection in delayed endolymphatic hydrops

Conclusions: The present study showed that intratympanic dexamethasone injection (ITD) is a promising approach for the treatment of contralateral and ipsilateral delayed endolymphatic hydrops (DEH). Moreover, intratympanic gentamicin injection (ITG), as a chemical labyrinthectomy, is a simple alternative for controlling vertigo in patients with ipsilateral DEH. Objective: This study examined the effect of ITD or ITG on DEH. Methods: Fourteen patients with DEH completed the clinical and audio-vestibular evaluation. Among them, 10 cases (ipsilateral type: nine cases, contralateral type: one case) were treated with intratympanic injection. Four patients with ipsilateral DEH underwent ITG, five patients with ipsilateral type and one patient with contralateral type received ITD. All 10 cases were followed up for 8–48 months. Results: Complete and substantial vertigo control was achieved in four of nine ipsilateral DEH patients treated with ITG. In the other five ipsilateral cases who received ITD, two accomplished complete vertigo control and two had substantial control. In one case, the vertigo was not effectively controlled. One case of contralateral DEH underwent ITD and this case had complete vertigo control. The vertigo intensity, vertigo frequency, vertigo duration and the functional level scale after intratympanic injection was decreased significantly.     

Ultrastructural evidence of a merocrine secretion in the human endolymphatic sac

The results of a light and transmission electron microscopic analysis of an endolymphatic sac (ES) from a patient suffering from episodic vertigo, tinnitus, and hearing loss are presented. A biopsy of the intraosseous portion of the ES was obtained during a translabyrinthine approach to section the vestibular nerve in the internal acoustic meatus. The material consisted mainly of tubular epithelial structures filled with heavily stained material. Pathologically dilated and degranulated rough endoplasmic reticuli and disaggregation of polyribosomes with accumulation of solitary ribosomes in the cytosol and endoplasmic reticulum suggested a disturbed epithelial cell protein synthesis. Ultrastructural evidence of an increased merocrine secretion of glycoprotein conjugates into the ES was noted. This made it possible to analyze the presumed intracellular secretory pathways. An increased number of intraepithelial lymphocytes and monocytes was observed. Since the inner ear had been subjected to surgical intervention before the vestibular nerve section, no conclusions can be drawn as to whether the patient's symptoms were related to the disturbed protein metabolism and hypersecretion of glycoprotein conjugates into the ES. The findings support earlier experimental results that indicate that the ES has not only a resorptive function but also a secretory one.