Absent stapedial reflex: otosclerosis or middle ear tumor?

We present an unusual case in which a patient diagnosed as having otosclerosis on the basis of clinical and audiologic findings actually had a middle ear facial nerve schwannoma. To the best of our knowledge, this is the first reported case in English literature in which a facial nerve schwannoma presented with conductive deafness of gradual onset and absent stapedial reflex with a normally functioning facial nerve. We also include a review of the literature.

Vestibular schwannoma with absent vestibular evoked myogenic potentials to clicks but normal ABR, caloric responses and vestibular evoked myogenic potentials to 500 Hz tone bursts

We report a case of vestibular schwannoma with absent vestibular evoked myogenic potentials (VEMPs) to clicks but normal auditory brainstem responses, caloric responses, and vestibular evoked myogenic potentials to 500 Hz tone bursts. This patient visited our clinic with complaint of sudden right hearing loss. This was the third episode of hearing loss in his right ear. Due to atypical medical history, he underwent further neuro-otological and neuroradiological examinations. Among the neurophysiological tests, only VEMPs to clicks showed abnormal findings (absent responses on the right). MRI revealed a small vestibular schwannoma in the right internal auditory meatus, which was considered to be of inferior vestibular nerve origin. This case suggested that VEMPs to clicks should still be included in the test batteries for the diagnosis of vestibular schwannoma.

Mechanisms of morbid hearing loss associated with tumors of the endolymphatic sac in von Hippel-Lindau disease

CONTEXT

Endolymphatic sac tumors (ELSTs) are associated with von Hippel-Lindau disease and cause irreversible sensorineural hearing loss (SNHL) and vestibulopathy. The underlying mechanisms of audiovestibular morbidity remain unclear and optimal timing of treatment is not known.

OBJECTIVE

To define the mechanisms underlying audiovestibular pathophysiology associated with ELSTs.

DESIGN, SETTING, AND PATIENTS

Prospective and serial evaluation of patients with von Hippel-Lindau disease and ELSTs at the National Institutes of Health between May 1990 and December 2006.

MAIN OUTCOME MEASURES

Clinical findings and audiologic data were correlated with serial magnetic resonance imaging and computed tomography imaging studies to determine mechanisms underlying audiovestibular dysfunction.

RESULTS

Thirty-five patients with von Hippel-Lindau disease and ELSTs in 38 ears (3 bilateral ELSTs) were identified. Tumor invasion of the otic capsule was associated with larger tumors (P = .01) and occurred in 7 ears (18%) causing SNHL (100%). No evidence of otic capsule invasion was present in the remaining 31 ears (82%). SNHL developed in 27 of these 31 ears (87%) either suddenly (14 ears; 52%) or gradually (13 ears; 48%) and 4 ears had normal hearing. Intralabyrinthine hemorrhage was found in 11 of 14 ears with sudden SNHL (79%; P < .001) but occurred in none of the 17 ears with gradual SNHL or normal hearing. Tumor size was not related to SNHL (P = .23) or vestibulopathy (P = .83).

CONCLUSIONS

ELST-associated SNHL and vestibulopathy may occur suddenly due to tumor-associated intralabyrinthine hemorrhage, or insidiously, consistent with endolymphatic hydrops. Both of these pathophysiologic mechanisms occur with small tumors that are not associated with otic capsule invasion.

Tumors of the endolymphatic sac in patients with von Hippel-Lindau disease: implications for their natural history, diagnosis, and treatment

OBJECT

Endolymphatic sac tumors (ELSTs), which often are associated with von Hippel-Lindau (VHL) disease, cause irreversible hearing loss and vestibulopathy. Clinical and imaging surveillance protocols provide new insights into the natural history, mechanisms of symptom formation, and indications for the treatment of ELSTs. To clarify the uncertainties associated with the pathophysiology and treatment of ELSTs, the authors describe a series of patients with VHL disease in whom serial examinations recorded the development of ELSTs.

METHODS

Patients with VHL disease were included if serial clinical and imaging studies captured the development of ELSTs, and the patients underwent tumor resection. The patients' clinical, audiological, and imaging characteristics as well as their operative results were analyzed. Five consecutive patients (three men and two women) with a mean age at surgery of 34.8 years and a follow-up period of 6 to 18 months were included in this study. Audiovestibular symptoms were present in three patients before a tumor was evident on neuroimaging. Imaging evidence of an intralabyrinthine hemorrhage coincided with a loss of hearing in three patients. Successful resection of the ELSTs was accomplished by performing a retrolabyrinthine posterior petrosectomy (RLPP). Hearing stabilized and vestibular symptoms resolved after surgery in all patients. No patient has experienced a recurrence.

CONCLUSIONS

Audiovestibular symptoms, including hearing loss, in patients with VHL disease can be the result of microscopic ELSTs. Once an ELST has been detected, it can be completely resected via an RLPP with preservation of hearing and amelioration of vestibular symptoms. Early detection and surgical treatment of small ELSTs, when hearing is still present, should reduce the incidence and severity of hearing loss, tinnitus, vertigo, and cranial nerve dysfunction, which are associated with these tumors.

Laser excision of glomus tympanicum tumours: long-term results

The purpose of this study was to evaluate the long-term results of laser excision of glomus tympanicum tumours in a series of patients who had been referred to the senior author (DAM) in a retrospective case review. Nine patients underwent complete excision of their glomus tympanicum tumours using a Diode or KTP laser. There were no cases of tumour recurrence. There were no complications during the peri- or postoperative period. Follow-up time was 31.8 months. In our experience, laser excision can be performed with minimal bleeding and morbidity, and it provides excellent tumour control in glomus tympanicum surgery.

Vertigo and hearing disturbance as the first sign of a glioblastoma (World Health Organization grade IV)

OBJECTIVE

To describe vertigo and hearing disturbance as a first sign of glioblastoma.

STUDY DESIGN

Case report.

SETTING

Ear, Nose, and Throat Department of the University of Regensberg, Germany. Primary Care Center.

PATIENTS

A patient with a left temporal glioblastoma.

RESULTS

A 67-year-old man presented with a 2-month history of vertigo and hearing disturbance. Radiological imaging revealed a left temporal tumor with dural inflation and erosion of the petrous bone and superior semicircular duct. The surgery involved total resection of the tumor and resurfacing of the gap in the superior canal. The histopathological examination revealed World Health Trade Organization IV glioblastoma. Postoperatively, the debilitating symptoms were relieved and the patient received radiation therapy. Tumor progression indicated a recraniotomy and a mastoidectomy. The tumor was only partially resected, and required chemotherapy. It subsequently developed otoliquorrhea and required a remastoidectomy. Histopathology of a pathological fracture of the X thoracic vertebra revealed a metastasis of the known glioblastoma. The patient died from respiratory distress syndrome.

CONCLUSION

To the best of our knowledge, we are presenting the first case with transdural infiltration of bony structures by a glioblastoma at the moment of diagnosis. The transdural spread could be via the sinus petrosus and along the nervous petrosus major in the petrosal bone. Superior canal dehiscence syndrome should be considered in the differential diagnosis of vertigo and hearing disturbance. Two different processes for the etiology of the superior canal dehiscence syndrome are discussed previously in the literature; however, we present a new entity with a tumor-cause dehiscence of the bone overlying the superior canal.

Primary ear and temporal bone meningiomas: a clinicopathologic study of 36 cases with a review of the literature

"Primary" ear and temporal bone meningiomas are tumors that are frequently misdiagnosed and unrecognized, resulting in inappropriate clinical management. To date, a large clinicopathologic study of meningiomas in this anatomic site has not been reported. Thirty-six cases of ear and temporal bone meningiomas diagnosed between 1970 and 1996 were retrieved from our files. Histologic features were reviewed, immunohistochemical analysis was performed (n = 19), and patient follow-up was obtained (n = 35). The patients included 24 females and 12 males, aged 10-80 years (mean, 49.6 years), with female patients presenting at an older age (mean, 52.0 years) than male patients (mean, 44.8 years). Patients presented clinically with hearing changes (n = 20), otitis (n = 7), pain (n = 5), and/or dizziness/vertigo (n = 3). Symptoms were present for an average of 24.6 months. The tumors affected the middle ear (n = 25), external auditory canal (n = 4), or a combination of temporal bone and middle ear (n = 7). The tumors ranged in size from 0.5 to 4.5 cm in greatest dimension (mean, 1.2 cm). Radiographic studies demonstrated a central nervous system connection in 2 patients. Histologically, the tumors demonstrated features similar to those of intracranial meningiomas, including meningothelial (n = 33), psammomatous (n = 2), and atypical (n = 1). An associated cholesteatoma was identified in 9 cases. Immunohistochemical studies confirmed the diagnosis of meningioma with positive reactions for epithelial membrane antigen (79%) and vimentin (100%). The differential diagnosis includes paraganglioma, schwannoma, carcinoma, melanoma, and middle ear adenoma. Surgical excision was used in all patients. Ten patients developed a recurrence from 5 months to 2 years later. Five patients died with recurrent disease (mean, 3.5 years), and the remaining 30 patients were alive (n = 25, mean: 19.0 years) or had died (n = 5, mean: 9.5 years) of unrelated causes without evidence of disease. We conclude that extracranial ear and temporal bone meningiomas are rare tumors histologically similar to their intracranial counterparts. They behave as slow-growing neoplasms with a good overall prognosis (raw 5-y survival, 83%). Extent of surgical excision is probably the most important factor in determining outlook because recurrences develop in 28% of cases.

[Nystagmus and vibration test research of mechanisms, theoretical methods: on 52 cases of unilateral vestibular lesions]

OBJECTIVE

The aim of the present study was to examine the characteristics of the Vibratory Nystagmus (VN) optimise the topography and the frequency of the stimulus, determine the origin of the VN and analyse its clinical implications.

MATERIAL AND METHOD

52 severe unilateral vestibular lesions (SUVL) (post-surgical vestibular areflexy) were studied. The vibratory nystagmus was measured by 2D and 3D videonystagmography (Synapsis, France). The stimulus was applied with a 3S vibrator at the vertex, both mastoïds, and posterior cervical muscles at frequencies ranging from 20 to 150 Hz. For topographic optimisation, stimulation was given with S vibrator (Synapsis, France) at 100 Hz. The interferences between the vibratory test (VT) and the caloric test (CT) were studied on the normal ear (in 11 subjects). The same study was carried with the optokinetic test.

RESULTS

The VT revealed a defective nystagmus at all frequencies of stimulation. Optimal response was obtained in a band frequency of 80-120 Hz. Stimulations at 100 Hz showed optimal responses for mastoïd topography (responses in 96% of the cases). Stimulation at the posterior cervical muscles and at the vertex indicated respectively a response in 90% and 60% of the cases. The efficiency of the mastoïd stimulation is not correlated with the side of stimulation (p = 0.9). The interference between the VT and caloric test (CT) at cold water (30 degrees et 20 degrees C) exhibited the inversion of the caloric nystagmus during the vibrator stimulation. The resulting nystagmus is respectively an algebric subtraction or addition between the pre-existing caloric nystagmus and the value of the vibratory nystagmus obtained before caloric test. Adaptation of the VN is moderate. The interference between the VT and the optokinetic test resulted in a subtraction or addition effect, according to the side of the lesion and the direction of the optokinetic stimulus.

CONCLUSION

The VT is an efficient stimulation in mastoïd topography. The vestibular contribution is bilateral by bony conduction of the vibration, it explores frequencies ranging from 30 to 120 Hz, with a maximum of response at 100 Hz. The VT interacts with the caloric test and the optokinetic test. The stimulation is very strong, and is able to inverse the caloric nystagmus at cold water stimulation (20 degrees C). In labyrinthine-defective subjects, the VN is always defective at all frequencies, whatever is the topographic location of the stimulus, and the position of the head.

Multichannel cochlear implantation in radical mastoidectomy cavities

OBJECTIVE

We report on our experience in cochlear implantation in patients with radical mastoidectomy cavities. Study Design, Setting, and Methods: Retrospectively, records of patients from the Department of Otolaryngology, University of Parma between December 1991 and March 2000 were reviewed, and 6 postlingually deafened adults who received a cochlear implant in a radical cavity were identified. Speech performances were evaluated in terms of bisyllabic word and sentence recognition and common phrase comprehension.

RESULTS

To date, with a follow-up of 1 to 9 years, no patient has experienced extrusion of electrodes or other local or intracranial complications. Mean bisyllabic word and sentence recognition scores were 74% and 80%, respectively. Mean comprehension score for common phrases was 86%.

CONCLUSION

By obliterating and isolating the radical mastoidectomy cavity from the outer environment, patients who previously had undergone radical surgery of the middle ear can be safely implanted with satisfactory hearing results.

Hearing preservation surgery for small endolymphatic sac tumors in patients with von Hippel-Lindau syndrome

OBJECTIVE

To determine the incidence of bilateral endolymphatic sac tumors in von Hippel-Lindau syndrome and to describe the technique and results of hearing preservation surgery for small endolymphatic sac tumors in a series of patients with von Hippel-Lindau syndrome.

STUDY DESIGN

Analysis of the literature to determine the incidence of bilateral endolymphatic sac tumors and a retrospective case review of hearing preservation surgery for removal of small endolymphatic sac tumors in four patients with von Hippel-Lindau syndrome.

SETTING

Tertiary care academic medical centers.

PATIENTS

Four patients with von Hippel-Lindau syndrome (three with bilateral endolymphatic sac tumors) and progressive sensorineural hearing loss in which preoperative imaging studies revealed in situ or small endolymphatic sac tumors without ipsilateral labyrinthine destruction.

INTERVENTION

All four patients had complete surgical excisions of the endolymphatic sac tumor via one of three surgical approaches with the goal of hearing preservation. One patient had bilateral surgery.

MAIN OUTCOME MEASURES

Audiometric and radiographic.

RESULTS

Nearly one-third (30.2%) of patients with von Hippel-Lindau syndrome and endolymphatic sac tumors have bilateral disease. All four patients (five ears) maintained serviceable hearing postoperatively after surgical excision of the endolymphatic sac tumor via a variety of approach options.

CONCLUSION

The discovery of a small or in situ endolymphatic sac tumor affords the patient the option of surgical removal with hearing preservation. This is critical in the patient with von Hippel-Lindau syndrome who is at risk for bilateral disease and complete bilateral anacusis if tumor growth progresses.

Tumor growth and audiometric change in vestibular schwannomas managed conservatively

OBJECTIVE

To prospectively define the correlation between changes in tumor volume and audiometric function in vestibular schwannomas managed conservatively.

STUDY DESIGN

Prospective longitudinal study.

METHODS

Twenty-one patients (age range, 15-84 y; mean age, 63.3 y) with newly diagnosed vestibular schwannomas were enrolled between 1994 and 1999 in a protocol at The Ohio State University Hospital (Columbus, OH) to evaluate the correlation between tumor volume and audiometric change during a period of observation. Patients were evaluated yearly by clinical examination, a standardized internal auditory canal magnetic resonance imaging scan with gadolinium contrast for volumetric analysis, and audiometric function testing. Demographic data, historical features, neurofibromatosis type 2 (NF2) status, initial testing results, and serial testing results were recorded.

RESULTS

An increase in tumor volume occurred in 14 of the 21 patients (66%). The pattern of volumetric change was found to be extremely variable. Multiple regression analysis revealed significant correlations of changes in tumor volume with changes in pure-tone average and speech discrimination score (P < .0001 and P = .0021, respectively). Change in tumor volume had greater effect on pure-tone average and speech discrimination score in patients initially with class D audiometric function when compared with those initially in class A (P = .0083 and P = .0245, respectively). The presence of NF2 had an independent protective effect against deterioration of the pure-tone average when compared with patients without NF2 (P = .0125).

CONCLUSIONS

This study demonstrated a significant correlation between a change in volume and auditory deterioration in vestibular schwannomas being managed with a trial of observation. A given change in tumor volume appeared to have a greater effect on pure-tone average and speech discrimination score as initial auditory classification declined.

Vestibular schwannoma growth: the continuing controversy

OBJECTIVE

To investigate the growth of vestibular schwannoma (VS) in a series of 123 patients with 127 tumors allocated to the "wait and scan" group in the period 1973-1999.

STUDY DESIGN

Retrospective review of prospectively registered data on all patients with VSIE from the entire country who were allocated to the wait and scan group.

METHOD

Clinical charts, audiometric data, and neuroradiological images were reviewed and tabulated for age, hearing level expressed as speech reception threshold (SRT) and speech discrimination score (SDS), maximum extra-canalicular tumor extension, and possible changes in tumor diameter. The material was updated three times (in June 1993, June 1996, and June 1999). Via the Danish national register, data on whether the included patients were alive or dead were collected in 1999.

RESULTS

The tumor growth, growth rate, and growth patterns were calculated in three periods 1973 to 1993 (mean observation period, 3.4 y), 1973 to 1996 (mean observation period, 3.8 y), and from 1973 to 1999 (mean observation period, 4.2 y). By termination of the first period, 94 tumors (74%) exhibited measurable growth, 23 tumors (18%) no measurable growth, and 10 tumors (8%) revealed negative growth. By the end of the extended observation period, tumor growth was observed in 104 tumors (82%), no tumor growth in 15 tumors (12%), and negative growth in 8 tumors (6%). Subsequent to the third observation period, growth was observed in 108 tumors (85%), no growth in 11 tumors (9%) and negative growth in 8 tumors (6%). However, the results may also be interpreted in another way: 52 patients (42%) were alive at the time of writing, tumor growth did not demand any intervention, 23 patients (19%) died as a result of non-tumor-related causes, and 35 patients (28%) were previously treated and alive by the termination of the third observation period.

CONCLUSION

Depending on the observation period, three sets of growth results were obtained. The long observation period, updating and re-updating the results, gave us the opportunity for a de novo interpretation of the results and the long-term consequences of the wait and scan policy. Combined with other factors, the achieved results should be considered when timing of surgery is to be decided.

Vestibular disorders and impaired path integration along a linear trajectory

The goal of this study was to determine if people use vestibular information to keep track of their positions while walking through a simple course. Subjects were normals and patients with chronic peripheral vestibulopathies-- each of whom were tested once--and patients with acoustic neuromas tested pre-operatively and one and three weeks post-operatively. Subjects walked over a straight course, 7.62 m, with their eyes open and then with their eyes closed. The time needed for task performance, the forward distance subjects walked before veering, and the lateral distance subjects veered from the straight ahead were recorded. The angle of veering was then calculated. Normals were able to perform this task easily with eyes open or closed. With eyes closed pre-operative acoustic neuroma subjects walked significantly shorter distances before veering than normals but did not veer significantly more than normals or take longer than normals to perform the task. Chronic vestibulopathy subjects, by contrast, were significantly impaired compared to normals on all measures. With eyes open within a week after acoustic neuroma resection subjects could perform the task as well as normals. With eyes closed, however, post-operative subjects were impaired compared to their own pre- operative levels, but they had returned to their pre-operative levels at the second post-operative test. Ataxia was only weakly correlated to any measures and tumor size was not related to performance. These findings support the hypothesis that vestibular input is used for spatial orientation during active motion.

Hearing preservation in solitary vestibular schwannoma surgery using the retrosigmoid approach

The results of 50 cases of vestibular schwannoma surgery with hearing preservation performed by the retrosigmoid approach at Addenbrooke's Hospital, Cambridge, during a 10-year period are presented. The hearing-preservation rate, using audiometric criteria set by others as "serviceable hearing" (Wade PJ, House W. Otolaryngol Head Neck Surg 1984;92:1184-93; Silverstein H, et al. Otolaryngol Head Neck Surg 1986;95:285-91; Cohen NL, et al. Am J Otol 1993;14:423-33) was 8% (4 of 50 cases). When the more stringent selection criteria of near-normal hearing and reporting criteria of socially useful hearing preservation (pure-tone average < 30 dB/speech discrimination score > 70%) is used, the hearing-preservation rate is 4.8% (1 of 21 cases). The only preoperative factor that may predict a favorable hearing-preservation outcome is normal auditory brain stem response morphology (Fisher's exact 2-tailed test, P < 0.001). The number of suitable candidates for hearing-preservation surgery are few. Reasonable indications for attempted vestibular schwannoma surgery with hearing preservation are discussed.

The prognostic value of intraoperative BAEP patterns in acoustic neurinoma surgery

Based on a consecutive series of 70 hearing patients with unilateral acoustic neurinomas and intraoperative monitoring of brain-stem auditory evoked potentials (BAEP), 4 dynamic BAEP patterns could be characterized. These patterns correspond with early and late postoperative hearing outcome. All patients with stable wave V (pattern 1) showed definite hearing preservation, all patients with irreversible abrupt loss of BAEP (pattern 2) lost their hearing, despite early hearing preservation in two cases. All patients with irreversible progressive loss of either wave I or wave V (pattern 3) eventually suffered from definite postoperative hearing loss, despite early hearing preservation in two cases. Those cases with intraoperative reversible loss of BAEP (pattern 4) showed variable short and long term hearing outcome. In 34% hearing was preserved, 44% suffered from postoperative hearing loss, the remaining 22% showed postoperative hearing fluctuation, either as a delayed hearing loss or as reversible hearing loss. Postoperative hearing fluctuation indicates anatomical and functional preservation of the cochlear nerve during surgery and is suggestive of a pathophysiological mechanism initiated during the surgical procedure and continuing thereafter. Patients at risk for delayed hearing loss can be identified during surgery by a characteristic BAEP pattern and may benefit from vasoactive treatment.

Carcinoid tumor of the middle ear in a 28-year-old patient

Carcinoid tumor of the middle ear is an extremely rare condition. The origin of the tumor cells is still speculative and the closeness of relationship to adenomas of the middle ear has been a matter of discussion since the first description of this tumor entity in 1980. In this study we report a case of a 28-year-old male patient with a carcinoid tumor of the middle ear. We present the results of histomorphological, immunohistochemical and electron microscopic examinations and compare our findings to those of previously published cases.

Passive drainage versus primary closure after total ear canal ablation-lateral bulla osteotomy in dogs: 59 dogs (1985-1995)

OBJECTIVE

Compare passive wound drainage to primary closure of total ear canal ablation-lateral bulla osteotomy (TECA-LBO) in dogs.

STUDY DESIGN

Retrospective analysis of medical records.

SAMPLE POPULATION

Fifty-nine dogs with end-stage otitis externa or neoplasia of the external and middle ear.

METHODS

Medical records of dogs with TECA-LBO were reviewed. Dogs were divided into postoperative drain and primary closure groups. Statistical analyses were performed to identify differences in data for signalment, preoperative treatment, duration of hospitalization, immediate complications, and long-term complications between groups.

RESULTS

No significant differences were detected in signalment, diagnosis, and duration of medical management between groups (P > .05). Duration of hospitalization was greater for dogs in the drain group (P < .05). Immediate postoperative complications occurred in 26 of 59 dogs and included ipsilateral facial palsy, incision swelling, vestibular signs, premature drain removal, and one dog died of aspiration pneumonia. Long-term (> 6 months) complications were identified in 12 of 50 dogs and included dermatitis of the medial aspect of the pinna, chronic fistula formation, and permanent facial paralysis. No association between immediate or long term complications and method of closure was identified.

CONCLUSIONS

Primary closure is an acceptable alternative in dogs undergoing TECA-LBO when surgical wound dead space can be managed with meticulous hemostasis, complete debridement of devitalized tissue, and accurate apposition of tissue planes.

Different aspects of hearing preservation in surgery of vestibular schwannoma in women and men

Pre-operative and postoperative auditory function was reviewed retrospectively in 98 patients with vestibular schwannomas. According to their hormonal status, women were categorized as "premenopausal" and "postmenopausal". Before surgery, 48% of the women (65% premenopausal) and 16% of the men presented with sudden hearing loss. The degree of auditory function before operation was similar for women and men. Preservation of pre-operative hearing was possible for 41% of the women (21% premenopausal) and 59% of the men. Further details of the surgery and the results of histopathological examination were also compared for women and men. Our results support substantial evidence that hearing preservation after surgery of vestibular schwannoma is easier to accomplish for men than for women. The finding of significantly more sudden hearing loss in premenopausal women may suggest a hormonal influence on tumour growth, which may also be partially responsible for the difference in hearing prognosis between women and men.

Audiometric findings in children with chronic suppurative otitis media without cholesteatoma

Chronic suppurative otitis media without cholesteatoma (CSOMWC) is usually associated with an increase in air conduction thresholds. However, only a few investigations reported on loss of cochlear function in the pediatric population. We undertook a prospective study in order to further delineate air and bone conduction levels in children with CSOMWC and the possible relationship between sensorineural hearing loss (SNHL) and other clinical characteristics that might reflect the extent of disease. Eighty-seven children were enrolled, 40 of which had bilateral disease. Hence, the total number of diseased ears tested was 127. Audiometric studies were performed three days after achieving a 'dry' ear following medical treatment. We found no statistically significant differences between the bone conduction threshold tested in ears with CSOMWC and control ears. This was also the case in 47 children with unilateral disease when cochlear function was investigated in the diseased and uninvolved ear in the same patient. Clinical correlation showed no association between age, sex, duration of otorrhea and presence of granulation or polyps and the degree of cochlear loss. Our study shows that CSOMWC in children has little effect on cochlear function.

Recurrent adult myofibromatosis. A case report

Myofibromatosis generally is regarded as a fibrous proliferative disease of neonates and children that, even when multicentric, has an excellent prognosis and a propensity for spontaneous involution. Reported is a case of solitary, locally recurrent myofibromatosis in the ear canal of an adult patient. It was initially thought to be a leiomyoma. The diagnosis of myofibromatosis was made on the basis of its histologic appearance and corroborated by immunohistochemical stains. Clinicians and pathologists should be aware that myofibromatosis may occur in adults in unusual locations, with a potential for local recurrence. Furthermore, its histologic appearance may mimic that of other mesenchymal neoplasms.

Intraoperative facial nerve monitoring: prognostic aspects during acoustic tumor removal

Intraoperative facial nerve monitoring with electrical stimulation (IFNMES) has become an integral part of acoustic tumor surgery. We reviewed the records of fifty-six patients who underwent translabyrinthine acoustic tumor removal with IFNMES. There was excellent correlation between intraoperative facial nerve activity and immediate postoperative facial nerve function (24 hours after surgery and at hospital discharge). Our data would suggest that patients who exhibit less than 500 microvolts of ongoing EMG activity during surgery, and who yield at least a 500-microvolt contraction when stimulated with 0.05 milliamps at the brainstem after tumor removal, can expect an excellent immediate facial nerve result (grade I or II).

Delayed spontaneous return of hearing after acoustic tumor surgery: evidence for cochlear nerve conduction block

Unlike the eventual resolution of facial paralysis in most patients with intact facial nerves, delayed hearing return after acoustic tumor resection is rare. This discrepancy in recovery has been ascribed to the inherent resilience of the facial nerve (a special visceral efferent nerve) to injury versus the cochlear nerve (a special somatic afferent nerve). In the presence of an intact cochlear nerve, hearing loss has been attributed to transection or spasm of the internal auditory artery or to direct mechanical trauma to the cochlear nerve during manipulation of the tumor. The possibility of a reversible conduction block in the cochlear nerve has not been considered. A review of three instances of delayed spontaneous hearing recovery several months after acoustic tumor resection suggests that a conduction block phenomenon can exist. This report describes the pathophysiology and the possible intraoperative predisposing features of this condition.

[Value of dynamic recording of short-latency auditory evoked potentials in the diagnosis and pathogenetic characteristics of hearing loss in acoustic neuroma]

Short-latency acoustic evoked potentials (SAEP) were recorded in 40 patients with vestibulocochlear neurinoma and 15 patients with unilateral cochlear hypoacusis. The results were compared with their psychophysical audiometric parameters. In the case of neurinoma, electric responses typically showed elongation of single waves and intervals between two peaks. In addition, they also displayed two other features. One of them was horizontal or ascending configuration of the curve reflecting the latency/intensity function. This indicates the absence of an electrophysiological equivalent of the phenomenon of loudness increment acceleration and, in more general terms, the stability of responses: lack of SAEP wave shortening and enhancement of acoustic stimulation level. The second feature was deterioration of the pattern and disintegration of individual complexes with a greater number of realizations. This can be attributed to the lability of nervous structures, in the case of neurinoma. This feature may also be responsible for the generally recognized concept that in neurinoma primary SAEP waves are not detectable when the routine method of recording responses to a large number of stimuli is used. These parameters are pathognomonic of neurinoma of the vestibulocochlear nerve and are never identified in the case of unilateral hypoacusis caused by cochlear lesions.

[Management of acoustic neurinoma with preserved hearing]

Six cases of acoustic neurinoma (AT) with preoperatively preserved hearing are presented. Their clinical features and surgical management for hearing preservation are discussed. Presenting symptoms were hearing decrease in 3 cases (#1, #2, #6), trigeminal neuralgia in 3 cases (#4, #5, #6), and hemifacial spasm in case #2. Case #3 was an incidentally diagnosed case by CT scan. Preoperative decrease of hearing in the affected ears ranged from 10 dB to 60 dB. In all cases except for case #1, CT scans revealed CP angle tumors sized 1 - 4 cm in diameter. A small intracanalicular tumor was detected in case #1 by metrizamide CT scan. Enlargement of the internal auditory meatus was detected in two cases (#4, #6). Through a lateral suboccipital transmeatal approach, all cases underwent radical total resection of tumor with anatomical preservation of both facial and cochlear nerves. Postoperatively, in spite of good morphological preservation of cochlear nerve, useful hearing function was noted in only one case (#3) who had excellent preoperative hearing (10 dB) and whose tumor was very small (1 cm). Facial nerve function was satisfactory in all patients. According to the previous reports, the level of hearing decrease in AT is related to the origin of tumor, direction of its growth, invasions or involvement to cochlear nerve and extension toward the labyrinth. Major factors to achieve preservation of useful hearing in AT surgery are 1) size of the tumor and 2) preoperative hearing acuity. Early detection of small tumor is extremely important and surgery must be precise to preserve cochlear nerve, internal auditory artery and labyrinth.(ABSTRACT TRUNCATED AT 250 WORDS)

Stapedial muscle electromyography in various diseases

Stapedial muscle electromyograms (SEMGs), obtained by an averaging technique of electrocochleography, were studied in patients with various diseases. The latency of SEMG was prolonged in incomplete facial palsy (Bell's palsy and cerebellopontine angle tumor), with stapedial reflex (SR) of a small amplitude or without SR. In otitis media with effusion, in which SR could not be obtained, SEMGs were clearly observed and showed normal waveforms and latencies. In Meniere's disease and sensorineural hearing loss, SEMG waves had normal waveforms and latencies. These results indicate that the SEMG shows a normal waveform and latency when facial nerve function is intact, and that its latency is prolonged in incomplete paralysis of the facial nerve.

Tissue culture of human cholesteatomatous keratinocytes

The aim of this study was to culture keratinocytes from migratory skin and from cholesteatomatous matrix. At operation, cholesteatomatous matrix, normal drumhead and non-migratory stratifying skin from the extrameatal incision were obtained. Successful cultures of keratinocytes were produced in 4 out of 5 attempts. The cholesteatomatous keratinocytes produced slower growing colonies with an abnormal pattern of keratinization, whereas the drumhead produced rapidly growing colonies with a more regular pattern of keratinization, similar to those obtained from a vertically stratifying epidermis. This method may offer new fields of study in the investigation of cholesteatoma.

Differential facial nerve function in tumors of the internal auditory meatus

Fifty-five consecutive cases of neoplastic involvement of the internal auditory meatus resulting in ipsilateral retrocochlear auditory dysfunction were reviewed. The majority of these tumors (89%) were solitary schwannomas of the eighth nerve. Eleven percent were other tumors. Preoperative facial paralysis was unusual in eighth nerve schwannomas (6.1%) and much more common in other tumors (66.6%). These data tend to suggest that facial paralysis preoperatively increases the probability that the tumor is other than an eighth nerve schwannoma. Furthermore, facial paralysis resulting from an eighth nerve schwannoma indicates a poorer prognosis for ultimate facial nerve function. The small numbers in this series, though far from conclusive, suggest that normally functioning facial nerves may be infiltrated by eighth nerve schwannomas. Failure of eventual recovery of facial nerve function in the postoperative period may suggest tumor infiltration.

Quantitation of tumor growth in the ears of mice

Transplantation of ascitic P-815 mastocytoma cells intradermally in the ears of syngeneic DBA/2J mice allows a simple and precise quantitation of tumor growth by ear swelling. Tumor growth was retarded and then arrested in allogeneic DBA/1J mice, whereas syngeneic hosts died as a result of tumor dissemination in draining lymph nodes, liver and spleen.

Intracranial ceruminous gland adenocarcinoma

Patients with adenocarcinoma of the ceruminous gland arising in the middle ear have a typical syndrome consisting of unilateral hearing loss, otalgia, facial paresis, and a middle-ear mass. Adjacent cranial nerves also may be affected. Some patients may have an ipsilateral cerebellar ataxia if the lesion extends into the cerebellopontine angle and compresses the cerebellar hemisphere. Obstructive hydrocephalus may occur secondary to obstruction of the aqueduct or fourth ventricle. The initial clinical findings may be those of a jugular foramen syndrome. These lesions are usually slow-growing and may be associated with a very prolonged clinical course. Although the tumors are rare, the physician should be aware of their existence if proper care is to be given.

Vestibular findings in patients with acoustic neurinoma

We studied the vestibular system of 30 patients with eighth nerve schwannoma. Preoperatively, cold and warm calorizations were performed. At operation, the utriculus and the ampulla of the horizontal semicircular canal as well as the eighth nerve were identified and removed for study. The sensory epithelium of utricular macula and ampullar crista appeared fairly normal in most cases. In one, there was tumor invasion to the labyrinth and in another patchy necrosis of the sensory epithelium. The number and quality of sensory cells varied from case to case. In cases with intact superior vestibular nerve, on light microscopy the histopathologic features of sensory epithelia did not differentiate between groups and symmetrical caloric reactions and with reduced or absent caloric reactions.

The negative acoustic reflex in retrocochlear disorders

The most frequent impedance abnormality of an acoustic tumor is an absent reflex. However, this finding also occurs with middle ear disorders and is therefore nonspecific. This study recorded the contralateral acoustic reflex of human subjects suspected of having an acoustic tumor. Many tumor subjects, by visual inspection of the impedance bridge balance meter, appeared to have an absent reflex. Most of these subjects, in fact, had small amplitude negative reflexes by offline analysis on an averaging computer. Recognition of these negative reflexes increases the specificity and sensitivity of the reflex test for acoustic tumors. We recommend reflex testing with averaging computer monitoring to ensure their recognition.

The contralateral effects of large tumors on brain stem auditory evoked potentials

Brain stem auditory evoked potential (BAEP) testing has been demonstrated to be a useful diagnostic tool in the presence of severe or complete sensorineural hearing loss. From a series of 38 patients with tumors in the vicinity of the VIIIth nerve, 13 patients with tumors larger than 2 cm had abnormal BAEP results contralateral to the involved side. The abnormalities observed on the noninvolved side included prolonged peak latencies, reduced amplitudes, poor wave shape and poor response stability. The significance of these findings is twofold: 1. Large tumors may disrupt BAEP test results on the side contralateral to the lesions, 2. Important information may be obtained on patients having complete sensorineural hearing loss on the involved side.

Pulse volume recordings in outer ear canal in pulse synchronous tinnitus. A comparison between ears with Glomus tumour, serous otitis media, and normal ears

With the aid of a volume flowmeter it is possible to record pulse synchromous volumetric changes in the outer ear canal. In 7 ears with glomus tumour in the tympanic cavity and in 5 with serous otitis media, such changes were larger than in 125 persons with a normal middle ear. By changing the ambient pressure in a pressure chamber and instructing the patients not to swallow, the drum can be pushed inward or outward. In all the cases of glomus tumour studied the pulse volumetric change was considerably affected when the drum was pushed inward or outward. In the normal patients the change was no change at all. This means that the pulse volume changes in normals are generated mainly by the vessels in the outer ear canal.

Acoustic tumor detection with brain stem electric response audiometry

Tumors that press on the audiotry nerve can cause a latency increase that is detectable from the scalp by electric response audiometry (BERA). The response delay is best seen by comparing the Jewett wave V, or P5, latencies for the two ears. This interaural latency difference is normally less than 0.2 msec, but was 0.4 msec or greater for 35 acoustic tumor cases and for seven of ten other temporal bone tumors. Acoustic tumor size can be estimated from the amount of latency delay.

Hemangiomas of the internal auditory canal

Three patients who presented with symptoms and signs of acoustic tumors are described: one of them had an arteriovenous malformation and the other two had cavernous hemangiomas. The common feature in all these patients was the presence of marked facial weakness with or without fasciculations and a complete loss of hearing in the presence of a small tumor. The cerebrospinal fluid protein was normal in these patients. Polytomography and Pantopaque cisternograms were used to make the diagnosis. Since these lesions are circumscribed, they are suitable for removal using microneurosurgical techniques.

In defense of SISIs. The short increment sensitivity index

We review the Short Increment Sensitivity Index (SISI) in terms of its performance with a variety of sites of lesion and its likely physiologic basis. We conclude that its original schema can be broadened to extend its clinical application if changes are made in the parameters of its routine use. The two major changes involve (1) a presentation level of no less than 90 dB hearing threshold level (HTL) and (2) a bimodal interpretation of results based on the premise that high scores indicate normal cochlear function and low scores indicate extensive cochlear damage or neural dysfunction. We suggest that routine use of the modifications suggested here can provide useful diagnostic information and bring to light a group of neurally impaired patients that has been relatively ignored.