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Query: UNIPROT:P50583 (asymmetrical)
 12,197 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

The diagnostic possibilities concerning the early diagnosis of an acoustic neurinoma are discussed. As it is very important to detect these tumors in the otological stage, we scrutinize the different symptoms and signs which can arise this suspicion and try to delineate the criteria for further investigation, which signifies the indications for the radiological investigation: tomography and cisternography. The survey of the results obtained during 1976 confirms the value of the rules we adopted. Every patient complaining of hearing loss or tinnitus has to be examined by audiometry. Every unilateral or asymmetrical perceptive deafness calls for an examination of the functional state of the vestibular system. A perceptive hearing loss with unilateral vestibular functional loss, is an indication for a radiological investigation of the MAI and here a tomography has to be preferred. If the tomography indicates an asymmetry corresponding with the functional loss, a cisternography is to be done. In the cases in which the functional loss goes together with normal radiography, we advise a close follow-up, repeating the functional evaluations at fixed intervals. In case of further deterioration, a control tomography and a cisternography is to be taken into consideration. The case with borderline data, or in which some opposition in the findings is recorded, the cases with negative cisternography and certainly the cases with a dubious cisternography are to be followed too. As on the one side a negative tomography can hide a tumor, and on the other hand a cisternography is a heavy decision for a dubious anomaly, we are inclined to insist more and more on a close functional follow-up rather than extend the indications for cisternography.
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PMID:The early detection of the acoustic neurinomas. Otoneurological indications of the radiological investigation. 35 13

Eighty patients with a main complaint of tinnitus were assessed. In only 32 was help possible. In 16 of these symptomatic relief utilized the masking technique which is briefly described. These results though not outstanding are encouraging and represent a definite step forward in helping patients with this unpleasant condition. Apart from symptomatic treatment of tinnitus, the clinic allowed early diagnosis of noise-induced hearing loss in some patients. Several patients had asymmetrical hearing loss, but despite extensive investigation no cerebellopontine angle tumors were identified. These patients are being followed. For these reasons, the tinnitus clinic is regarded as a success and will continue to function as a specialty clinic in otolaryngology at Vancouver General Hospital.
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PMID:A tinnitus clinic. 50 73

With increasing use of imaging in the investigation of cerebello-pontine angle (CPA) tumours, the role of audio-vestibular and electrophysiological testing has changed. Field performance data on the efficiencies of these tests to screen for CPA tumours are lacking, but must be known to choose an appropriate testing strategy. A prospective observational study of 237 patients attending a neuro-otology clinic for audio-vestibular investigation was carried out. The aim was to provide field performance data on which to base an effective protocol to screen for CPA tumours. All patients presenting at the ENT department and meeting any of the following criteria were referred to the neuro-otology clinic and included in the study: (1) asymmetrical sensorineural hearing loss, (2) unexplained asymmetrical tinnitus with normal bearing thresholds, (3) unilateral bearing difficulties with normal hearing thresholds and (4) other neurological indications. In addition to audio-vestibular and auditory brainstem response (ABR) investigation, every patient underwent computed tomography (CT), with magnetic resonance imaging (MRI) in cases having marginal results on CT, to exclude or confirm the presence of a tumour. Pass or fail on each test was based on a priori criteria from other studies. Eighteen patients were found to have CPA tumours. ABR testing was the only effective procedure for screening, but had some limitations. A contingent protocol using ABR in all cases except those with asymmetrical tinnitus and normal bearing thresholds, those with severe hearing loss, and those with neurological signs, was retrospectively defined: the exceptions would go straight to CT. This protocol would have missed two of the 18 tumour patients. CT scanning alone would have missed one small intra-canalicular tumour, which was picked up on MRI triggered by abnormal ABR. Based on the results from the present study we conclude there is no effective screening protocol for detecting CPA tumours, as MRI scanning with gadolinium enhancement will identify virtually all tumours. Where MRI is available but waiting lists are long, the described strategy using ABR to select priority referrals for MRI scanning is recommended.
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PMID:Efficiency of tests used to screen for cerebello-pontine angle tumours: a prospective study. 881 45

Brainstem auditory evoked responses of 355 patients with uni- or bilateral tinnitus were recorded in order to evaluate the effect of tinnitus on the central auditory system. The amplitudes of waves I, III and V and the latencies of each wave and interpeak latencies were compared to those of a group of 129 controls with normal hearing. The study of the control group initially identified a certain number of concurrent parameters. The brainstem evoked responses of men and women evolved differently from the age of 30 years, latencies of I-III and I-V in men lengthening with age and those of women tending to shorten. The patient groups were therefore compared to a control group of the same sex ratio or of the same sex, half being between 30 and 56 years of age. The tinnitus patients were divided into three groups according to the side affected by tinnitus. Latencies and amplitudes in these groups differed significantly from those of the control group. In order to eliminate hearing loss, the most difficult concurrent factor and almost always associated with tinnitus, the results of individuals with symmetrical hearing loss were compared to those of the control group. Tinnitus was always associated with significant lengthening of 0-I and I-V latencies on the tinnitus-affected side, with a significant reduction in amplitudes of waves I and III, and sometimes of wave V, particularly in the group with left-sided tinnitus. Comparison of tinnitus patients with symmetrical and asymmetrical hearing by sex showed that tinnitus patients of all groups had lengthening of right and left 0-I latencies, apart from the women in the group with right-sided tinnitus, and significant reduction in amplitudes of waves I and III in women and of left III only in men. When hearing loss was asymmetrical and on the tinnitus-affected side, there was also lengthening of 0-I latencies on the tinnitus-affected side in both sexes and of ipsi- and contralateral I-V latencies in women. Right- and left-sided tinnitus was associated with additional differences between the three groups. Correlation coefficient study confirmed that 0-I, I- III and I-V latencies were independent of the mean degree of deafness, deafness at high frequencies and at frequencies around the tinnitus, up to a threshold of hearing loss of 40 dB, above which 0-I and 0-V lengthened in addition to tinnitus. On the other hand, whatever the frequency, tinnitus involved significant lengthening of wave I latencies and modification of the previously recorded amplitudes. Two groups of tinnitus patients could be distinguished: the first, with symmetrical hearing loss, with symmetrical normal latencies, apart from 0-I latencies and the amplitude of the wave on the tinnitus side, and the second with hearing loss predominant on the tinnitus-affected side, with different latencies on each side, 0-I being shorter on the unaffected side, I-III and I-V being lengthened on the unaffected side and 0-I being lengthened on the tinnitus-affected side. Moreover, as disturbances of brainstem evoked responses caused by tinnitus particularly affected waves I and III, the hypothesis of possible involvement of the efferent systems could be proposed.
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PMID:Brainstem auditory evoked responses in patients with tinnitus. 883 9

Improvements in MR imaging techniques allow visualisation of the anatomy of the cerebellopontine angle (CPA) in increasingly accurate detail, revealing the complex interrelationship of the neurovascular structures in this region. We wished to assess whether vessels and vascular loops intimately associated with cranial nerves VII and VIII, corresponded to any abnormality or symptom pattern, and thus had any clinical significance. The MR scans of 108 patients were retrospectively reviewed and the imaging status of VII, VIII, the vessels, presence of vascular loops and their relationship to the nerves, coded and recorded. The patients' records were independently reviewed and the presence and "sidedness' of asymmetrical hearing loss, tinnitus, vertigo, and the results of caloric and brain stem evoked responses recorded. The vessels were closely associated with VII and VIII in over 30% of this sample with vascular loops imaged in 21% of patients, and clearly imaged entering the IAM in 7% of both right and left CPAs studied. There was no statistically significant relationship demonstrated between the proximity of the vessels, or vascular loops, to the nerves and a symptom, or symptom pattern. These findings should be considered a normal variant on MR scanning.
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PMID:MR imaged neurovascular relationships at the cerebellopontine angle. 888 96

Tinnitus is a sensation of sound generated by the auditory system due to pathology, without any external acoustic or electrical stimulation. Clinical reports have indicated that tinnitus affects the left ear more frequently than the right one. Previous data suggest that the asymmetrical distribution of tinnitus is linked to handedness or other lateral signs, but no studies have heretofore examined lateral preferences in addressing this relationship. The literature concerning the laterality (localisation) of tinnitus is reviewed. The data confirm an asymmetrical distribution of tinnitus. Results of 7 studies (altogether 4634 patients) demonstrate that tinnitus occurs more often bilaterally (48.8%) than on the left side (28.0%) or the right (23.2%). There is no general predominance of the left ear. Handedness, eyedness, footedness, earedness and dichotic listening are examined in our own sample of 58 patients (23 men and 35 women) with acute, subacute or chronic tinnitus. A right sided preference was found for hand, foot, eye, ear preference and dichotic listening among 91%, 86%, 78%, 69% and 85% of the sample, respectively. Sixty per cent of the sample heard tinnitus only in the left ear, 21% only in the right ear and 19% in both ears. There is a higher correlation between localisation of tinnitus and dichotic listening than between other lateralities. Our investigation shows a significant relationship between localisation of tinnitus and laterality of dichotic listening, suggesting a possible link between tinnitus and hemisphere dominance. The result suggests a "functional" asymmetry of tinnitus.
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PMID:[Laterality of tinnitus: relationship to functional assymetries]. 1123 68

Pulsating tinnitus is uncommon in the general population. This clinical manifestation can be associated with severe intracranial pathologies and is particularly characterized by a rhythm and synchronism reflecting the heart beat. This work presents a clinical case of pulsating, subjective tinnitus associated with a high homolateral jugular bulb and marked hypoplasia of the contralateral transverse and sigmoid sinuses and the clinical-radiological examinations that made diagnosis possible (particular reference going to CT, MRI and angio-MRI). The intracranial venous drainage pattern varies and is nearly always asymmetrical. The jugular bulb is defined as "high" when its upper edge extends nearly to the level of the tympanic anulus, a condition found in 6-20% of the general population. In many cases it is found by chance as often this condition is asymptomatic. However, the pathological picture associated with pulsating tinnitus is highly complex and requires a detailed diagnostic process which some Authors have arranged in specific "flow charts". Imaging methods are essential and must be identified according to the clinical-audiological findings. The radiologist can avail himself of CT, MRI (in association with angio-MRI), Doppler ultrasound of the supraortic and transcranial branches, and digital imaging subtraction angiography. The therapeutic approach to the patient manifesting a "high" jugular bulb is surgical and makes use of such procedures as: ligature of the internal jugular vein, extracranial transposition of the bulb and, in cases of dehiscence of the limiting bone, hypotympanum repair using an autologous or homologous graft of cartilage or bone. Whichever the case, an accurate cost-benefit evaluation must be made, particularly in regard to the risks of endocranial hypertension from the reduced venous drainage, a condition which is significantly increased when concomitant abnormalities of the dural sinuses are present. In the present case, this risk was quite high because of the particular venous morphology described and the patient refused surgery. Currently the patient is under clinical-radiological observation.
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PMID:[Pulsating tinnitus associated with high homolateral jugular bulb and aplasia of the contralateral transverse and sigmoid sinuses]. 1177 47

The present work provides clinical-functional findings, results and surgical complications observed in a consecutive series of 100 subjects with acoustic neuroma (AN). Analysis of the data has made it possible to draw some important conclusions. Compromised hearing is found in 90% of the ears affected by AN. Indeed the percentage of normal hearing in such cases does not exceed 5%. There is, however, no clear correlation between degree of hearing and tumor size. The symptoms of AN do not always present unilateral or asymmetrical hearing loss, unilateral tinnitus and/or dizziness. At times AN presents atypical symptoms and can even be asymptomatic. Sudden onset of unilateral hearing loss, acute vertigo, persistent monolateral tinnitus and even isolated symptoms of the V or VI cranial nerve should lead one to suspect AN. Only by applying the diagnosis of suspected AN in a large number of cases is it possible to lower the time gap between the onset of symptoms and the definitive diagnosis of AN, increasing the number of cases diagnosed while the AN is still small. Auditory brainstem responses (ABR) are still the means of choice for screening and following up subjects where AN is suspected. Reduced ABR sensitivity reported in the literature for intracanal ANs must induce further testing with magnetic resonance imaging with gadolinium in all subjects where an AN is suspected, even when the ABR is normal. Recording of transient evoked otoacoustic emissions in the presence and in the absence of contralateral white noise has proved to be a simple, inexpensive, non-invasive test for the diagnosis of suspected retrocochlear pathologies. A deficit in vestibular function is most frequently encountered when the AN is already quite large and an alteration in the smooth pursuit test is only found when the AN involves the brainstem. These data have led us to conclude that vestibular reflex studies do not play any role in early diagnosis of AN. Surgical exeresis is the treatment of choice in those cases where "watch and scan" (only hearing ear in the absence of neurological complications; AN < 0.5 cm in the ponto-cerebellar angle, particularly in elderly patients) is not indicated. The enlarged translabyrinthine approach is indicated in all cases of AN, no matter what the tumor size and extent of pre-operative hearing. Promptly and correctly treating intra and postoperative complications, most frequently encountered in patients with AN > 2 cm, reduces the mortality and morbidity to a minimum. Modern otological microsurgery and monitoring techniques make it possible to preserve the VIIth facial nerve in more than 90% of the ears, consequently preserving or nearly preserving normal VIIth nerve function 1 year after surgery in at least three out of four patients. No matter what approach is used, hearing can be preserved measurably in approximately 50% of the ears undergoing surgery and to a socially useful or nearly useful level in a significantly lower proportion of patients. In this regard the most satisfactory results are obtained when preoperative hearing is normal and the AN is < 2 cm.
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PMID:[Acoustic neuroma: clinical-functional finding, results and surgical complication]. 1186 92

Pure tone audiometry, PTA, has been regarded as an initial step when starting acoustic neuroma, AN, diagnostic service. If observing unilateral/asymmetrical sensorineural hearing loss, electronystagmography, ENG, and registration of auditory brainstem responses, ABRs, are instructed to perform. The measures of the methods are listed appearing particularly effective for AN detecting. Efficacy of ENG and ABR approaches in verification of ANs of even initial stages has been stated to reach the absolute identification score, 100%. In tinnitus and/or vertigo complaints, ENG and ABR examinations are recommended to utilize under normal PTA even. The positive evidence of ANs via ENG and ABR has to validate by contrasting magnetic resonance imaging, MRI, while MRI data are advised to utilize for assessment of concrete strategy of surgical intervention. Under negative ENG and ABR outcomes, on the other hand, MRI is considered as a hardly urgent procedure.
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PMID:Acoustic neuroma diagnosis. 2152 35

A 23-year-old man complained of progressive left ear hearing loss and tinnitus and was unsuccessfully treated with steroids and mannitol. Four months later he presented with sudden, severe, asymmetrical, bilateral sensorineural hearing loss. The results of the laboratory workup were normal except for antinuclear autoantibodies. Auditory brain stem responses showed absent peak and interpeak latencies on both sides. The combination of plasma exchange with high doses of steroids resulted in a definite improvement. Plasmapheresis combined with steroid administration can be used as second-line therapy in idiopathic, sudden sensorineural hearing loss.
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PMID:Apheresis as rescue therapy in a severe case of sudden hearing loss. 2178 50


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