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The majority of vestibular schwannomas have a stable evolution or a progression of size. Some publications report cases of spontaneous involution. We report here the clinical and radiological characteristics of this type of tumor observed in 14 patients showing a spontaneous tumor involution of their vestibular schwannoma. The results showed an incidence of 8 % with an average tumor regression of 50 %. Functionally, a hearing loss was found in all patients, without correlation with the duration of the observational follow-up. There are spontaneously involutive vestibular schwannomas, but tumor regression does not prevent the deterioration of hearing. Patients should be considered as a subset of those receiving observational management., Competing Interests: Les auteurs n’ont déclaré aucun conflit d’intérêts en relation avec cet article.

Introduction: Dental pain may have another origin than teeth. It may be caused by myofascial, neurovascular, cardiac, neurological, sinusal or psychological factors. We will discuss 2 rare cases of patients who presented with a cerebellopontine tumor, who initially manifested with symptoms of dental pain., Observation: The first patient, male, 44 years of age presented to his dentist with toothache (47), which led to its extraction. Five months later, a second painful episode, more characteristic, revealed the presence of a vestibular schwannoma, which was successfully treated and led to the disappearance of the pain. The second case, a 43-year-old female presented to her dentist with toothache (46), which lead the dentist perform a root filling. Two years later, with a 3rd episode of dental pain, more relevant of a trigeminal neuralgia, a epidermoid cyst of the right cerebellopontine angle was identified and successfully treated leading to the disappearance of the pain., Discussion: Cerebellopontine tumors of this type may lead, in exceptional cases to symptoms of dental pain. Therefore, in face of atypical tooth or facial pain, both a detailed medical history and a detailed examination are necessary, in order to investigate any neurological signs and symptoms, before undertaking any non-essential dental treatment, which may be detrimental for the patients., (Copyright © 2015 Elsevier Masson SAS. All rights reserved.)

Objectives: To present a unique case of unilateral widening of the internal auditory canal (IAC) with no significant contact with an ipsilateral intracanalicular vestibular schwannoma (VS), raising the issue of the cause(s) of this IAC widening., Methods: The medical record and radiologic data were reviewed of a patient presenting an enlarged unilateral IAC, which led to the diagnosis of an intracanalicular VS that could not account for the dilation., Results: The patient had a unilateral dilation of the IAC that did not match the ipsilateral VS he had. As a result, this case motivated discussion of whether such dilation of the IAC was congenitally asymmetrical or the result of the mechanisms involved in the widening of the IAC., Conclusions: Although asymmetry of IAC is a current notion, this case demonstrates a contrario that increased pressure exerted on the walls of the IAC cannot be the only mechanism in such widening.

Objectives: To summarize the indications and evaluate the Auditory Brainstem Implant (ABI) performances in neurofibromatosis type 2 (NF2) and other otologics indications, as postmeningitis ossified cochlea., Material and Methods: Main and first indication of ABI is NF2. Emergent indications are bilateral total ossified cochlea, vestibular schwannoma with controlateral lesions, cochlear nerve aplasia or inner ear's malformations. The pre-operative evaluation includes clinical, radiological, lipreading, and psychological status. A translabyrinthine or retrosigmoid approach is performed, depending on tumoral or not tumoral status. The auditory perception with the ABI is evaluated by testing, the words recognition in open-set lists, and the speech understanding with usual sentences., Results: In NF2 patients, best results are obtained in cases of smaller vestibular schwannoma and none, or short term, auditory deprivation. Negative prognostic factors are duration of total hearing loss (>10 years), tumor size (>30 mm), difficulties in electrode array placement, complications during post-operative course and number of active electrodes (<10). In cases of postmeningitis total deafness with totally ossified cochlea, results demonstrate a good benefit reaching these obtained with cochlear implant in post-meningitis deafness., Conclusion: These results show a clear benefit of ABI in NF2 patients, with or without previous tumor removal, in case of small tumor with a short duration of hearing loss. In case of postmeningitis ossified cochlea, results potentially reach those of cochlear implants.

Objectives: To determine the results and sensitivity of a comprehensive audiological and vestibular work-up in patients presenting with vestibular schwannoma (VS)., Material and Methods: One hundred consecutive cases of VS diagnosed from January 2004 to May 2005 were prospectively studied. The tumour size was classified according to Koos classification and hearing was assessed according to the five-stage classification from the Tokyo consensus. A comprehensive work-up was conducted in all patients, including pure tone and speech audiometry, Brainstem Evoked Audiologic Potentials (BEAP) assessment, Vestibular Evoked Myogenic Potentials (VEMP) examination and bithermal caloric testing using videonystagmography, on both sides. BEAP responses were considered as normal or endocochlear when interwave intervals were normal, absent because of poor hearing or retrocochlear when wave 1 to 5 interval > 4.3 ms and/or when this interval was greater than > 0.25 ms between sides, or when no response was recorded when hearing was preserved. VEMP were considered as normal absent or diminished (amplitude < 50%, as compared with contralateral). Caloric responses were considered normal, reduced (reduced by > or = 30%) absent (reduced by > 80%)., Results: Fifty-six women and 44 men were examined (mean age 57.8 years). Left and right side were equally affected. Vertigo, tinnitus and hearing loss were the main presenting symptom in 21%, 32% and 68% of the cases, respectively. Eighty-two per cent were operated, 17% simply monitored and 1% irradiated. The tumours were Stage 1, 2, 3 and 4 in 14%, 28%, 21% and 37%, respectively. Hearing was class A in 9%, Class B in 34%, Class C in 14% and Class E-D in 43% of the cases. Globally, BEAP showed a retrocochlear pattern in 64% of the cases and no response in 30%. Abnormal responses of VEMP were observed in 94% of the cases. Caloric testing was abnormal in 61% and normal in 11%. Responses could not be analyzed in 28% of patients. Only one patient showed normal responses to the whole work-up (99% sensitivity). This patient had a small intrameatal tumour and actually complained of contralateral symptoms., Conclusion: The results suggest that a full audiovestibular assessment can help diagnose VS of all sizes. But false-negative results remain possible in small intrameatal tumours (1%). In addition it can give useful postoperative prognostic information.

Non-surgical stereotactic gamma ionizing irradiation was developed in order to produce a lethal effect on unilateral acoustic neurinomas (vestibular schvannomas). We present a study of postural vestibular dependent performances in 218 patients before and after curative irradiation. Subjects were asked to stand at ease on a static dynamometric foot-plate, gazing at a fixed point in front of them (EO condition) or to stand eyes closed (EC condition). Statokinesigrams were registered during two consecutive sessions of 51.2 sec, under EO and EC conditions. These sessions were first managed the days before (d-1), and after (d+1) irradiation; others were performed later (d+1 to 5 Years; n=37). Center of pressure (CofP) mediolateral (X) and sagittal (Y) positions were quantified every 100 msec. Mean Xm session value (with SD) was taken as a personal parameter for left or right body inclination. Area S for 90% of the XY successive placements of the CofP observed during a session was taken as an index for 2D postural way. Before irradiation the overall average of the 218 personal Xm mean values demonstrated a statistically significant body inclination toward the affected side, however under EC condition only. The day after irradiation, a significant reduction of the overall mean value of body inclination was observed. Paired Xm statistics of confirmed this trend toward usual symmetry. The day after stereo-irradiation, averaging areas S of ellipses indicated a shift of instability toward normality. For the two parameters, the pseudo-Romberg ratios (performance EC/performance EO) indicated that a special visual contribution to balance control is present in patients with a neurinoma tumor (here I and II grades). The relative importance of this visual support declined shortly after ionizing treatment. Because the radiation is neither noxious nor excitatory we think such a rapid recovery is due to some recovery of vestibular nerve afferent conduction, and a rapid neural reprogramming of the balance control. These attractive results call for deeper investigations of both vestibular and auditory functions.

Intraoperative auditory monitoring in acoustic neuroma surgery is used to improve residual hearing. Three techniques are available: monitoring of brainstem auditory evoked potentials, of electrocochleography or of direct eighth nerve compound action potential. The three techniques with their advantages and disadvantages are discussed. The current trend is to monitor brainstem auditory evoked potentials using digital filtering or to monitor the eighth nerve compound action potential.

Rationale: Patients with cystic vestibular schwannomas (VS) are a radiologically well-defined subgroup of patients who classically have poor outcome after microsurgical resection. Since Pendl's report of a high rate of failures, they are also considered as poor candidates for radiosurgery., Material and Method: Among the 1000 consecutive patients who underwent Gamma Knife surgery in Marseilles, France between July 1992 and January 2002, we have collected and studied 54 patients with cystic VS at the time of treatment., Results: The median follow-up of this group was 26 Months (mean: 33, range: 6-90). Failure (6.4%) led to microsurgical removal in 2 patients and a radiosurgery in 1 patient with a delay of 2 Years for 2 of them and 3 Years for the third. No facial palsy has been reported. Two patients developed transient hypesthesia. Among the 32 patients with functional hearing at the time of treatment, 53% preserved their hearing function at 3 Years., Conclusions: We found an increased risk of failure in this group compared to patients with no cyst at time of radiosurgery (93.6% instead of 98%). But this is also a group were we observe most dramatic shrinkage. Prudent radiosurgical treatment of cystic vestibular schwannomas remains mandatory: strict follow-up is specially important.

Objective: The majority of the patients still lose hearing function in spite of the technical advances in microsurgery. We wanted to evaluate preservation of hearing function potential after Gamma Knife Surgery., Material and Method: In Marseille, we performed 1000 Gamma-Knife procedures for vestibular schwannomas between July 1992 and January 2002. This population included 175 patients undergoing first intention surgery for a unilateral schwannoma with functional preoperative hearing (Gardner and Robertson 1 or 2) who were studied with a follow-up longer than 3 Years. Univariate and multivariate analysis was performed., Results: Numerous parameters significantly influenced the probability of functional hearing preservation at 3 years. The overall rate of preservation was 60%. The main parameters of predictability were limited hearing loss (Gardner and Robertson stage 1 versus 2) before radiosurgery, presence of tinnitus as the initial symptom, young age and the small tumor size. Preservation of functional hearing at 3 years was 77.8% when the patient was initially in stage I, 80% when the patient's first symptom was tinnitus, and 95% when the patient had both. In these patients, the probability of functional preservation at 5 years was 84%., Conclusion: We report a large population of patients treated by radiosurgery with initial functional hearing. These results demonstrate that a large percentage of selected patients can preserve functional hearing after Gamma Knife Surgery, their chances of functional preservation being greater than after microsurgery or simple surveillance.

Rationale: To evaluate the functional results of Gamma Knife surgery of vestibular schwannomas relying on a large and prospective series of consecutive cases., Material and Method: The first 1000 patients with cerebello-pontine angle schwannomas were consecutively treated by Gamma Knife in Marseille Timone University Hospital between July 1992 and March 2001. Patients without NF2 and or clinico-radiological arguments in favor of a facial origin accounted for a population of 927 patients (414 males, for 513 females) including 843 treated in first intention. In this series the Koos classification was: stage I 77 patients, stage II 520 patients, stage III 287 patients and stage IV 42 patients. The average Volume was 12.7mm3. Haring was usefull (Gardner and Robertson) before radiosurgery in 47% of the patients (subnormal in 20.3%)., Results: Tumor control at last follow-up was 97%. Globally, a clinical trigeminal injury was observed in 0.6% of the patients and a facial palsy in 1.3%. There was clearly a decrease of the incidence of neuropathies with time; no facial palsy being reported among the last 258 patients. The rate of functional hearing preservation (Gardner) for patients initially in class I was 77.8% (47.6% for class II) at 3 Years. This rate of functional preservation reached 95% among patients with tinnitus as a first symptom., Conclusion: Today, strong evidence surports the superiority of Gamma Knife surgery in term of functional perservation and equal efficacy compared with microsurgical removal. Consequently, radiosurgery must be preferred as a first intention choice for young patients with few symptoms presenting with a small to middle size vestibular schwannomas (Koos I-III).

The principal objectives of acoustic neuroma surgery in the order of priority are absence of mortality and neurological morbidity, total removal of the lesion, preservation of facial function, and preservation of hearing. The aim of this work was to evaluate the selection criteria and the therapeutic strategy for hearing preservation in acoustic neuroma management. This retrospective study included 436 consecutive patients referred to our department for an acoustic neuroma. The population comprised 365 patients (84%) treated surgically, 66 patients (15%) managed conservatively, and 5 irradiated patients (1%). The mean age was 54 years (range: 13-87). The mean follow-up period was 24 months (range: 1-120). The surgical approaches were translabyrinthine in 294 (81%), retrosigmoid in 37 (10%), and through the middle fossa in 34 cases (9%). Approaches preserving the labyrinth were employed in patients aged less than 60 years with lesions measuring or=50%). A serviceable hearing was preserved in 53% of the cases with a serviceable hearing in 44% of the cases. Postoperative normal or subnormal facial function was obtained in 72 to 98% of cases depending on tumor size. Two cases (0.5%) of recurrence were reported. In conclusion, our surgical strategy based on age, tumor size and pre-operative hearing function permitted hearing preservation in 50% of selected cases, a high rate of facial function preservation and a low risk of recurrence.

Introduction: Preservation of functional hearing can be now attempted during the surgical treatment of a vestibular schwannomas. The probability of functional hearing preservation for each of the neurosurgical approaches is currently under evaluation. We report here a preliminary evaluation of our radiosurgical experience., Material and Method: In Marseilles, we performed 800 gamma-knife procedures for cochleovestibular schwannomas by between July 1992 and December 2000. These patients were evaluated systematically according to a prospective methodology. We report here the study of the population of 211 patients with unilateral schwannoma and a functional preoperative hearing (Gardner and Robertson 1 or 2) treated as first intention, with a follow-up longer than two years., Results: Hearing was improved with the radiosurgery in 3% of cases with a average gain of 10 decibels. Average loss in decibel on the four main frequencies (500, 1,000, 2,000, 4,000 Hz) was 17 dB. The probability of functional hearing preservation with radio surgery was high: 73%. However, this probability depended on numerous factors related to the patient and to the "operative technique". The main parameters of predictability were limited preoperative tonal loss, Gardner and Robertson stage 1 (versus 2), multiisocentric planning, peripheral dose lower than 13 Gy. So a Gardner and Robertson stage 1 intracanalicular tumor treated in accordance with "the state of the art" with a gamma-knife and a marginal dose inferior to 13 Gy has a probability of functional conservation at 2 years greater than 95%., Conclusion: Our results are preliminary and they require the confirmation of a more extensive and more prolonged follow-up. However, the large size of this population and the systematic methodology should help us in determining more precisely the place of radiosurgery and especially to better inform the patients of their chances of hearing preservation according to their individual risk profile.

We propose a point by point response to the questions raised at this round table concerning the spontaneous and postoperative course of grade I and II vestibular schwannomas, focusing on hearing function. The questions concerning non-operated schwannomas are: For operated schwannomas, the questions are: Spontaneously, 75-80% of these schwannomas progress significantly with a degradation of hearing function in more than half of the cases. We monitor clinical disorders and order routine audiometry and MRI. For us, Gardner and Roberson class A or 1 is truly useful hearing function. Preservation of truly useful hearing function after microsurgery is no better than 10%; satisfactory facial motor function is preserved in 70-80% of the cases with grade I, II, or III schwannomas and in more than 50% for grade IV schwannomas. Incomplete excision to preserve hearing function is compromised by recurrence. We preferably treat the smaller grade I schwannomas by radiosurgery to halt tumor progression and attempt to preserve hearing function.

A perfect knowledge of the anatomy of the vestibuloacusticofacial pedicle is required to preserve hearing and facial functions during cerebellopontine angle surgery for vestibular schwannoma. A clarification of the anatomy of this pedicle, in particular of its blood supply, is presented here, based on a review of the available literature, as well as on the author's data issued from anatomical dissections on latex-injected fresh specimens, and from radiological images of the cerebellopontine angle. The blood supply to the vestibuloacusticofacial bundle arises from the meatal loop of the anterior inferior cerebellar artery most often exhibited at the porus of the internal acoustical meatus. The labyrinthine artery is particularly exposed to injury between the cochlear and facial nerves. In addition, dissection in between these two nerves is likely to sever vessels directed to these nerves even though the labyrinthine artery is not interrupted. Thus, aside from a direct injury to the labyrinth, auditory function can be impaired through two distinct ischemic lesion types. Although the facial nerve is supplied through three main arterial systems (from the labyrinthine, the middle meningeal, and the stylomastoid arteries), its labyrinthine portion is more likely to suffer from ischemic damage as it is only supplied by meatal arteries. A refinement of our anatomical knowledge of the vestibuloacusticofacial pedicle, from a functional point of view, could arise from laser Doppler measurements of labyrinthine and facial blood flow during surgery, in an attempt to improve our functional preservation rate during therapeutic procedures for vestibular schwannoma.

Purpose: Sudden idiopathic deafness is a sensorineural hearing loss with no recognized causes at the time of onset. The impairment site is usually localized in the cochlea, but some cases of retrocochlear lesions (e.g., cerebellopontine angle tumors, degenerative neural diseases, neuraxial ischemic lesions) can induce sensorineural deafness. The medical management of patients presenting with sudden deafness aims at detecting a causal mechanism, and at administering emergency therapeutic drugs. The diagnosis of idiopathic sudden deafness can be definitely made when no causes are found. Usually, the impairing mechanism involves the cochlea. The pathophysiology of this sensorineural alteration is still unknown. It is most likely that several mechanisms are associated together, their common point being an impairment to the feedback loop of the organ of Corti., Current Knowledge and Key Points: It is very likely that reactivation of neurotropic viruses and/or cochlear ischemia are frequent etiologies. Whatever the cause, the treatment is to be administered urgently, and consists of a high-dose corticotherapy at the least. Other treatments have never really proven to be effective. It is secondarily checked that no retrocochlear pathological processes, such as a cerebellopontine angle tumor, is present, in particular in young people., Future Prospects and Projects: One of the current objectives is to determine when cochlear ischemia is involved, in a mini-invasive manner, such as with laser Doppler flowmetry, so that the treatment can be optimized. From a therapeutic point of view, early acoustic protection has been proven to be effective in cases of cochlear ischemia in small laboratory animals. Its efficacy in case of sudden deafness, non-exclusive of other causes than ischemia, is being assessed in a multicentric project.

Unlabelled: The purpose of this research was to evaluate long-term results of fractionated radiation therapy (RT) in the treatment of cerebello-pontine angle schwannomas., Methods: from January 1986 to October 1995, 29 patients with stage III and IV scwhannomas were treated with external fractionated RT. One patient was irradiated on both sides and indication for RT was as follows: a) poor general condition or old age contraindicating surgery, 16 cases; b) hearing preservation in bilateral tumors after contralateral tumor removal, 6 cases; c) partial resection or high risk of recurrence after subsequent surgery for relapse, 5 cases; d) non surgical relapse, 3 cases. Most patients were irradiated with 6 to 10 MV photons. A three- to four-field technique with coplanar static beams and conformal blocks was used. Doses were calculated on a 95 % isodose and were given 5 days a week for a mean total dose of 51 Gy (1.8 Gy/fraction)., Results: Median follow-up from RT was 66 months (7 to 120); seven patients died, two with progressive disease, five from non tumoral cause. Two patients underwent total removal after RT (1 stable and 1 growing tumor). On the whole, tumor shrinkage was observed in 13 patients (43.3 %), stable disease in 14 (46.6 %), and tumor progression in three. Hearing was preserved in 4 out of 6 hearing patients (1 class A hearing, 2 class B and 1 class C). No patient experienced CN5 or CN7 neuropathy., Conclusion: long-term efficacy or fractionated RT is well documented in this series. Acute and delayed tolerance was excellent. Hearing can be preserved for a long time.

In this report, we present five cases of acoustic neuroma in children; one of them concern a case of neurofibromatosis 2. The most common symptom is a deafness, but it can also be revealed by a tinnitus, a vertigo, a facial nerve paralysis or headache. Diagnosis is confirmed by T1 and T2-weighted MRI with intravenous infusion of gadolinium. The deals of the treatment are tumor's control and preservation of the hearing and facial nerve functions. The means used are either microsurgery with a preference for posteriors approaches to translabyrinthic one, or radiosurgery with gamma knife which seems to be a promising technique for stades II and III tumors. Only children with small acoustic neuroma and good hearing can be simply watched. In neurofibromatosis 2, acoustic neuromas are bilateral and can be associated with other neuromas and cutaneous or ophtalmologic symptoms. Surgery is indicated in first on the side of the biggest tumor or the worst hearing function. Only a few patients well selected may benefit from an auditory brainstem implant.

We performed a retrospective review of the audiologic, radiologic and clinical data on 239 patients operated on for acoustic neuroma from 1987 to 1995 at Beaujon Hospital. In 16 patients or 6.6% of the total group, we identified as having experienced sudden hearing loss by history. The 16 tumors involved were 1 stade I; 8 stade II, 5 stade III and 2 stade IV. In 14 cases, the tumor was removed by translabyrinthine approach, 1 case by masto-retrosigmoid approach and 1 case by middle fossa approach. The hearing was preserved in the two latter cases. The purpose of this study is to illustrate and reaffirm the importance of a thorough neurotologic evaluation and to discuss the diagnostic methods in this select patient population.

The value of Head-Shaking maneuver has brought scientific controversies regarding its role as a clinical tool. In the following publication, we explain the discrepancies between the different studies and find out the role of such a maneuver for clinical evaluation during the pre and post operative period. We showed the influence of the diagnosis and the importance of time interval in the post Head-Shaking responses.

The interaural time discrimination (ITD) is one of the azimuthal sound location cues. In multiple sclerosis subjects, deficits in binaural timing discrimination are closely related to abnormalities in brainstem auditory evoked potentials (BAEPs). To determine if psychophysical performances could be related to the BAEPs in other otoneurological deficits, thresholds of ITD were measured in 168 patients and the results correlated to the electrophysiological responses to clicks. Both tests were normal in 29.8% and abnormal in 42.2% of cases. A discrepancy existed in 28.0%: ITD abnormal--BAEPs normal in 23.2%, ITD normal--BAEPs abnormal in 4.8%. In conclusion, in cases with normal ITD thresholds, the probability of a retrocochlear lesion is low. The test of ITD is helpful when the interpretation of the BAEPs is difficult because of desynchronized waves.

The results of brainstem evoked response audiometry (BERA) in a series of 113 patients with neurosensory hearing loss from both tumoral and non tumoral origin are reported. In 37 cases of non tumoral pathology, confirmed by CT-scan or NMR (14 cases) a retrocochlear type of evoked response was observed. The tumoral cases were mainly neurinomas (70 cases). There was a kophosis in 14 cases, typical retrocochlear responses in 52 cases, doubtful responses in 2 cases and in another 2 cases no electrophysiological disturbances could be observed. The systematic stimulation at 4 KHz seems to sensitize the BERA method. According to the authors it remains the first choice investigation technique of unilateral hearing loss. The results of this study are compared with those of the literature.

The authors carry out a retrospective study of the diagnostic procedures used in a series of 50 acoustic neuromas. AEP were performed for thirty-four neuromas at some stage of their history. The findings were perfectly normal for eight of them, which represents a sensitivity level of 76%. Various elements likely to account for this are put forward, then the role of AEP and MRI in the diagnostic strategy for neuroma is discussed in the light of this study. Finally, the authors emphasize the necessity to regularly evaluate the diagnostic methods in order to guarantee their quality and reliability.

There are two types of neurofibromatosis, i.e. peripheral neurofibromatosis (type 1) and central neurofibromatosis (type 2). Neurinomas of the acoustic nerve are basically seen in central neurofibromatosis, in which case they are generally bilateral. Surgical indications for neurinoma are rare and 5 patients will be discussed: 2 of these underwent an operation on the neurinoma by the posterior route on several occasions, while 1 patient was operated by the trans-labyrinth route. Nuclear magnetic resonance remains the best means of monitoring.

Computerized gas meatography ( CGM ) represents the must reliable method for detection of stages I and II of acoustic neurinomas. A critical study of its indications was conducted based of results in a series of 14 tumors of less than 2 cm diameter and of 43 CGM . Although early auditory evoked potentials are currently the most significant selection criteria, procedures for detecting retrocochlear lesions remain unchanged, particularly for the ENT specialist.

27 patients with an acoustic neurinoma were submitted to a complete cardiological survey oriented towards the detection of mitral valve prolapse (2D echo) and ECG signs of a particular risk of arrhythmia (standard ECG and continuous Holter monitoring). 9 of these 27 patients presented MVP, but none of them presented any serious ventricular arrhythmias. The corrected QT interval was significantly longer in patients without MVP. The frequency of the association of MVP and acoustic neurinoma can not be explained simply by the female predominance of the series and its should be interpreted with reservation in the absence of a control series. The absence of pre-operative arrhythmia does not exclude the potentiating role of MVP in the development of certain cases of unexplained post-operative death.

After relating two cases of retro-cochlear affection, where the relation between the first clinical impression and the final diagnosis is not evident, the author emphasizes on the importance of using objective diagnostic methods. Particularly, the discovery of retro-cochlear tumors owing to the study of evoked potentials and the blink reflex.

Forty patients with suspected tumoral syndrome of ponto-cerebellar angle were investigated by NMR imaging. The method proved to be reliable, less invasive (lack of irritation and absence of iodized contrast) and as rapid as CT scan imaging for the diagnosis of presence and extension of an VIIIth nerve neurinoma. It also allowed avoidance of computerized gas meatography during screening for intracanal neurinomas.

A group of 146 patients with surgically proved C-P angle tumors were studied in respect of the incidence of the trigemino-facial and cochleo-vestibular signs. The particular purpose of this study was to determine the pertinent signs in the early diagnosis of the C-P angle tumor, its stage and histo-pathologic feature's determination. The principal indices of C-P angle tumor are: Wrisberg nerve dysfunction; neural hearing loss as designed by stapedius reflex study and BERA; unilateral vestibular deficit without true and persistent vertigo, first at all when associated with central vestibular signs. The central vestibular syndrome grade, the trigeminal hyposensitivity and the cophose can perform a correction of the stage estimation in 39% when false estimation has been done. Endly, 7 criteria are proposed which help the histopathologic feature differentiation.