Diagnosis Of Cerebellopontine Angle Tumors Research Articles

Frequency of Cerebellopontine Angle Tumors in Patient with Trigeminal Neuralgia


 
 
 
 OBJECTIVES:
 To determine the frequency of cerebellopontine angle tumors in patients presented with trigeminal neuralgia.
 
 METHODOLOGY:
 This descriptive study was conducted in Neurosurgery Department, Hayatabad Medical Complex, Peshawar from 01-01-2016 to 31-12-2019. Patients with either gender and above 18 years of age diagnosed to be having trigeminal neuralgia and being symptomatic from a minimum duration of 03 months were included in the study. All the patients were subjected to a detailed history, thorough physical and neurological examinations and magnetic resonance imaging for the diagnosis of cerebellopontine angle tumors.
 
 RESULTS:
 The mean age group was 43 ± 2.37 years of which 37% were male and 62% were female patients, respectively. Cerebellopontine angle tumors were present in 3% of the patients.
 
 CONCLUSION:
 This study concluded that the frequency of cerebellopontine angle tumors was 3% among patients with trigeminal neuralgia.
 
 
 

The Added Value of MRI in Diagnosis of Cerebello-pontine Angle Tumors

Background; Cerebello pontine angel masses are the most common neoplasm in posterior fossa accounting for 5-10 % of intracranial tumors. Aim; to evaluate the lesions that arise from this angle by using MRI sequences as T1 (with out and with contrast), T2, FLAIR, Diffusion Weighted and spectroscopy. Methods; This study included 25 patients age ranged 25 -55 years, and were subjected to full history talking, Clinical examination, laboratory investigations and MRI for patient with suspected cerebello pontine angle lesions. Results; Females are frequently involved by these lesions (19 patients) while males are less (6 patient). Among our patients , the most common presenting symptoms were hearing loss in 17 patients (68.0%) headache in 10 patients ( 40.0%), tinnitus in 9 patient ( 36.0 %) neuralgia in 5 patients ( 20.0 %), vertigo in 2 patients (8.0%), hemi facial spasm in one patient (4.0%) and wasting of mastication muscles (4.0%). Out of the studied patients , final diagnosis by MRI revealed acoustic schwannoma in 12 patients ( 48.0%) which was the most common pathology ,followed meningioma that were noted in 7 patients (28.0%), epidermoid cyst in one patient (4.0%),prominent AICA in one patient (4.0 %), paraganglioma in one patient (4.0%),cystic neurofibroma in one patient (4.0%), neurofibromatosis type 2 in one patient (4.0%) and arachnoid cyst in one patient (4.0 %). Conclusion: MRI is the gold standard method to differentiate the lesions by anatomical site of origin, shape, signal intensity and behavior after contrast media injection.

Historadiological Correlation of Cerebellopontine Angle Tumors: Series of 122 Cases.

Cerebellopontine angle (CPA) tumours, are diverse pathologically with regard to the site of tumour origin and displacement of the neurovascular structures. In general CPA tumours are divided into acoustic and non-acoustic tumours. The aim of the present study was to see the spectrum of lesions at cerebellopontine angle and their historadiological correlation. A retrospective analysis of 122 cases of CPA tumors diagnosed in the Department of Pathology, IHBAS was done from January 2004 to August 2019. There were 56 males and 66 females in the age group of 8-68years. Clinical history ranged from 10days to 5years. Clinical symptoms included hearing deficit, visual loss, facial nerve dysfunction, nausea, vomiting, headache, seizures, unsteadiness and disequilibrium. Historadiological correlation was found in 112 cases (91%).In our series of CPA tumors, nonacoustic tumors were more frequent than in previous studies. We found that presence of intrameatal fraction is not exclusive only for schwannomas. There can be a rare occurrence of medullobastoma/small round cell tumor in CP angle. The final pathological verification can at times give unexpected results. Immunohistochemistry did not have a significant role in diagnosis of cerebellopontine angle tumors.

Cerebellar Hemangioblastoma Manifesting as Hearing Disturbance -Case Report-

A 49-year-old man presented with a rare case of cerebellar hemangioblastoma manifesting as only hearing disturbance. He had suffered from hearing difficulty in the right ear for a few months. Magnetic resonance imaging revealed a cystic mass lesion with an internal fluid level and surrounding flow voids in the right cerebellopontine (CP) angle. Cerebral angiography disclosed a vascular-rich tumor fed by both the superior cerebellar and anterior inferior cerebellar arteries. En bloc resection of the tumor was planned under a preoperative diagnosis of cerebellar hemangioblastoma. The tumor protruded into the CP cistern and compressed cranial nerve VIII. The feeding arteries were meticulously coagulated and the tumor was successfully removed. The histological diagnosis was hemangioblastoma. After the operation, the patient’s hearing acuity improved dramatically. Cerebellar hemangioblastoma should be considered in the differential diagnosis of CP angle tumors associated with hearing disturbance.

Cerebellopontine angle lymphoma: a case report and review of the literature

Background Although malignant lymphomas of the central nervous system have been reported to be increasing in frequency, cerebellopontine (CP) angle lymphoma is rare and only 13 cases have been reported previously in the literature. Case Presentation A 63-year-old woman had progressive dizziness and nausea for 2 months. Computed tomography scanning and magnetic resonance imaging (MRI) revealed a mass lesion in the left CP angle, that was compressing the lateral-dorsal aspect of the pons and the fourth ventricle. This tumor was avascular on angiography. The tumor was surgically removed through a left lateral suboccipital approach. It was considered to arise from the subarachnoid space of the CP angle cistern. For some reason, the histologic diagnosis was not definitively made, and therefore radiation therapy was not planned. The tumor recurred within 50 days after the tumor excision. Surgical excision of the recurrent tumor was performed again. The histologic diagnosis was B-cell type malignant lymphoma. Radiation therapy was performed. In the 27 months since irradiation, a recurrent tumor has not been detected on MRI. Conclusions Although erosion and expansion of the internal auditory canal suggest an acoustic neurinoma, CP angle lymphoma can, in rare circumstances, erode the internal auditory canal. There are three distinct patterns in which malignant lymphomas occupy the CP angle: (1) an extra-axial CP angle lymphoma, (2) an intra-axial lymphoma extending to the CP angle, and (3) a leptomeningeal lymphoma presenting as a CP angle lesion. Although malignant lymphomas rarely occupy the CP angle, it should be considered in the differential diagnosis of CP angle tumors. It is desirable to obtain a frozen section in all CP angle tumors during surgery to identify the tumor, because aggressive removal is not necessary, but radiation therapy should additionally be performed for malignant lymphomas.

Proposed algorithm to aid the diagnosis of cerebellopontine angle tumors.

Hearing and/or balance disorders are symptoms that may be associated with tumors of the cerebellopontine angle (CPA). Between March 1988 and May 1995, 22 patients had diagnosis or evaluation of CPA tumors at Cleveland Clinic Florida. The most common presenting signs or symptoms included unilateral low-frequency tinnitus, unsteadiness, and/or asymmetric hearing loss. On the basis of our experience, we have constructed an algorithm to help identify and manage acoustic nerve dysfunction. We compare our findings with national epidemiologic data and current medical reports.

The burden of screening for acoustic neuroma: asymmetric otological symptoms in the ENT clinic.

The rising numbers of legal cases relating to delay in the diagnosis of acoustic neuroma, combined with the increasing availability of magnetic resonance, is increasing pressure on otologists to make an early definitive diagnosis of cerebellopontine angle tumours. Unilateral or asymmetrical otologic symptoms not explained by external or middle ear disease are elicited in 16.6% of 500 consecutive attenders to an otolaryngology clinic. An agreed policy of risk stratification of patients with unexplained asymmetric otological symptoms is required if expense is to be limited and litigation minimized.

方向感検査による小脳橋角部腫ようの早期診断

The authors report 22 patients with cerebello-pontine angle lesions: 15 with acoustic tumors and 7 with menigiomas, epidermoids or trigeminal neurinomas. Nearly all showed close to normal or only slightly impaired hearing threshold levels on their audiograms.All patients received the full battery of directional hearing tests, speech audiometry, acoustic reflex threshold, and decay test, ENG and caloric test, and ABR test. Finally, they received CT scanning or MRI tests, and cerebello-pontine angle lesions were confirmed.Twenty patients (91%) had very positive findings, especially increased thresholds of interaural time discrimination in the directional hearing tests. This test has good sensitivity for retrocochlear lesions; it is very simple and needs only a few minutes to perform. The authors conclude that this test provides the most useful information in the early diagnosis of cerebello-pontine angle tumors, as a screening test.We present a flow-chart of the battery of tests in which the directional hearing test is performed in the early stage of test procedures.

ABR Latency-Intensity Function Abnormality in the Early Detection of a Cerebellopontine Angle Tumour: a Case Study

A case is presented of a 27-year-old male subject with a cerebellopontine angle tumour which was provisionally diagnosed on the basis of the ABR latency-intensity function findings and later confirmed by MRI. The patient initially presented with decreased hearing sensitivity, tinnitus and dizziness. The findings of neuroaudiological assessments and radiological examinations are described. The importance of the neuroaudiological test battery, in particular the ABR latency-intensity function, in this case is discussed; and the need for its inclusion for earlier detection and diagnosis of cerebellopontine angle tumours emphasized.

Diagnosis of cerebellopontine angle tumors.

Between 1980 and 1990, 9,176 patients suffering from otoneurological disorders were investigated in our clinic. Sixty-six (0.72%) internal auditory canal or other cerebellopontine angle tumors (CPAT) were diagnosed. Brainstem auditory evoked potentials (BAEP), interaural time discrimination, and magnetic resonance imaging (MRI) revealed to be the most sensitive and efficient tests for the detection of CPAT. However, the investigation of otoneurological symptoms cannot be limited to BAEP and MRI on the a priori of a hypothetical CPAT. Electrophysiologic tests such as impedancemetry, and electronystagmographic testing are also needed to elucidate the many causes of otoneurological symptoms.

Otologic and neurosurgical co-operation in diagnosis of cerebello-pontine angle tumours

The literature abounds with articles which review large series of cases of acoustic neuroma and attempt through retrospective analysis, to find a reliable protocol of investigation to screen for this. Such studies, from recognised centres of neuro-otology, seek a logical approach to diagnosis which is cost effective, reliable ad avoids invasive investigations, such as contrast meatography, unless there are strong indications.

The behaviour of wave V latency in cochlear hearing loss.

The audiological approach to the early diagnosis of cerebellopontine angle tumours (APC) is based mainly on ABR. In present work, wave V latency has been studied in two groups of patients: 308 cochlear cases and 74 retrocochlear cases (APC surgically confirmed tumours), in order to increase the sensitivity and specificity of the diagnostic indexes I-V, IT5 and Delta V. Wave V latencies have been evaluated in relation to hearing loss at 2-4 kHz and audiometric profile. Both these factors show a highly significant positive correlation with the latency, which consequently increases proportionally to hearing loss and high-frequency audiometric loss. A multiple regression analysis was therefore used to analyse the effects from the two variables, and a correction factor was calculated to compensate the latency values for hearing loss and threshold configuration. The effects of such a correction on the clinical results consist mainly of a reduction in the rate of cochlear false-negative results, which corresponds to improving the ABR specificity.

Audiovestibular tests in the diagnosis of cerebellopontine angle tumours.

Symptoms and signs were recorded in a series of 78 patients with a cerebello-pontine-angle (CPA) tumour and in 92 patients with symptoms and signs suggestive of such a lesion but with a negative CT scan. Variable symptomatology was found in the tumour cases. A substantial proportion of the patients had experienced sudden phenomena such as rotatory vertigo and/or sudden hearing loss. A CPA tumour must therefore be considered in almost every case of unilateral auditory or vestibular disturbances. Unfortunately, conventional audiovestibular tests have a low sensitivity of around 50%, with the exception of stapedial reflex threshold elevation (89%). The specificity on the other hand is quite low for this test, whereas other test results, like a genuinely pathological stapedial reflex decay, carry a high specificity of 60%. However, brainstem response audiometry (BRA) exhibited a very high sensitivity (100%) coupled with a reasonable specificity (54%), making it a suitable single test for screening patients suspected of having a CPA tumour. A program for the diagnostic work-up is suggested.

The value of CT in the diagnosis of tumours of the cerebello-pontine angle. Comparison of various radiological, clinical and otological examination

An attempt has been made to define the role of CT in the diagnosis of cerebello-pontine angle tumours; 190 patients with this suspected diagnosis were examined by CT (including intravenous contrast enhancement and CT air cisternography) as well as other radiological, otological, neurological and audiometric investigations. Amongst these methods, CT is of most value. A knowledge of the variations of the internal auditory meatus and measurements of the porus acousticus are essential for evaluating the computer tomographic appearances.

ABR audiometry in the diagnosis of cerebellopontine angle tumors.

Auditory brain-stem responses (ABR) examination with simultaneous lobe-vertex (L-V) and membrane-vertex cm-v) recording was performed in 34 ears with cerebellopontine angle tumors. The detectability of wave I was better in M-V recording than in L-V recording, whereas L-V recording exhibited better detectability of wave V. ABR waveforms were classified into three groups, and the relations between the waveforms and the size of tumor or the degree of hearing loss were analyzed. Positive finding in ABR were obtained in 25 out of 34 ears in the present study. It was stressed that this dual recording in ABR was extremely useful in the diagnosis of cerebellopontine angle tumors.

Evaluation of Auditory Brainstem Response in the Diagnosis of Cerebello-pontine Angle Tumor

Evaluation of Auditory Brainstem Response in the Diagnosis of Cerebello-pontine Angle Tumor

Differential diagnosis of cerebellopontine angle tumours with special reference to the galvanic test

In the present paper an attempt to evaluate the diagnostic importance and reliability of the various vestibular tests was made. Special attention was paid to the galvanic test and its typical patterns of retrolabyrinthine lesions. The galvanic test is an important diagnostic method allowing a differentiation between a lesion of the vestibular endorgan and its peripheral neuron at an early stage. 40 surgically confirmed cases (24 acoustic neuromas and 16 cerebellopontine angle tumours) were analysed. In 36 cases the neurootologic diagnosis was correct while 4 cases of acoustic neuroma were not recognized as such. The diagnostic failure and some common pitfalls in the neuro-otological diagnosis of CPAT are discussed.

Computer Tomography of Cerebellopontine Angle Lesions

Computer tomography (CT) was used in 53 consecutive patients with a working diagnosis of cerebellopontine angle tumor. The CT was performed with the 160 X 160 matrix scanner, height of sections was 13 mm. Metrizoate sodium (1.5 ml/kg of body weight) was used for tumor enhancement. Seventeen CT scans revealed tumors; one patient proved at operation to be false-positive. Thirty-six CT scans revealed no tumors; two examinations may prove to be false-negative, but surgical verification has so far not been obtained. The smallest tumor demonstrated by CT extended 7 mm into the angle, while one of the possible false-negative CT scans after iophendylate injection cisternography showed a tumor extending 5 mm into the angle. It is concluded that CT is a harmless, noninvasive neuroradiological procedure, and should precede invasive procedures. It can be used safely in patients with increased intracranial pressure.

Auditory Brain Stem Responses in the Diagnosis of Cerebellopontine Angle Tumours

There is a constant search for more reliable methods of diagnosing cerebellopontine angle tumours at an early stage. The auditory brain stem responses promise to be of use as such a method. In two patients with extracanalicular neurinomas we found a definitely abnormal brain stem response even though conventional tests produced a cochlear type of test pattern. In a third patient with a meningeoma we obtained a similar type of response. Here the conventional tests clearly pointed to the presence of retrocochlear disease. Characteristic findings are a broadening of the whole nerve action potential and a delay in the appearance of the Jewettv-FFP7 complex.

Auditory Brain Stem Responses in the Diagnosis of Cerebellopontine Angle Tumours

Auditory Brain Stem Responses in the Diagnosis of Cerebellopontine Angle Tumours