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At least 19 recordsLinked to original sources
PubMed2000

Relationship between cystic change and rotatory vertigo in patients with acoustic neuroma.

Acoustic neuromas are benign neoplasms that most often arise from the vestibular nerve. Many patients with this tumor experience some degree of vestibular symptoms. However, patients rarely complain of rotatory vertigo. Acoustic neuromas are known to exhibit a cystic appearance in some patients. It was hypothesized that cystic change might be a causative factor for rotatory vertigo. A retrospective study of 178 patients with unilateral acoustic neuroma who underwent surgery in the Department of Otolaryngology at Tokyo Medical and Dental University was carried out. The cystic appearance of the tumors was detected preoperatively by magnetic resonance imaging and confirmed at surgery. The relationship between cystic change of the tumor and presentation with rotatory vertigo was examined. Of the 178 patients studied, only 10 had both cystic change of the tumor and rotatory vertigo, and 120 had neither cystic tumor nor rotatory vertigo. Of the remaining 48 patients, 24 experienced rotatory vertigo with negative findings for cystic tumor and the other 24 had evidence of cystic tumor but no rotatory vertigo. Tumor with cystic change was observed in 34 patients, accounting for 19.1% of all patients studied. Rotatory vertigo was also experienced in 34 patients (19.1%). Of the 34 patients with cystic lesions, 29.4% (10) had rotatory vertigo. The difference in percentage of the two groups did not reach statistical significance. It is suggested that there may be other factors causing rotatory vertigo in patients with acoustic neuromas than cystic change of the tumor.

Acute Disease↗
PubMed1990

Estrogen and progesterone receptors in acoustic neuromas.

Acoustic neuromas are more frequent, larger, and more vascular in women, and their growth rate increases during pregnancy. Estrogen receptors were claimed to be demonstrated in these neoplasms for the first time in 1981. Since then, numerous diverging studies, using various biochemical and histochemical methods, have been published on the contents of estrogen and progesterone receptors in acoustic neuromas. We determined the content of estrogen and progesterone receptors by means of an immunohistochemical method, using monoclonal antibodies, which has proved to be reliable, reasonably sensitive, and clinically relevant in other tissues, especially in breast carcinomas. No estrogen or progesterone receptors could be found in 18 consecutive acoustic neuromas from 7 men and 11 women, ranging in age from 26 to 73 years. The results do not support preoperative hormone treatment of acoustic neuromas.

Adult↗
PubMedDate not supplied

The radiographic detection and evaluation of acoustic neuromas.

Acoustic neuromas are rare benign tumors that appear in the inner ear. Radiology plays a major role in the diagnosis and assessment of this entity. This article explains radiologic methods used for the detection and evaluation of acoustic neuromas.

Humans↗
PubMed2006

[Size and proliferative index correlation in acoustic neuromas].

Acoustic neuromas are the most common tumors in the cerebellopontine angle. The molecular mechanisms involved in generation and growth of these tumors are not completely elucidated. Many radiological, clinic and immunohistochemistry data were correlated to tumor growth. We studied 11 acoustic neuromas surgically treated at Hospital São Paulo/Unifesp and correlated clinical and radiological data with proliferative index (Ki-67). The size of the tumors were positively correlationated with proliferative index. No other correlation had statistic significativity.

Adult↗
PubMed1995

When to suspect an acoustic neuroma.

Acoustic neuroma is a rare but important cause of sensorineural hearing loss. Patients with asymmetric hearing loss or unilateral tinnitus should be evaluated expeditiously to prevent further neurologic damage. Gadolinium-enhanced magnetic resonance imaging is the best tool for making the diagnosis of acoustic neuroma. Surgical removal using a translabyrinthine approach, is the favored treatment, although radiation therapy and expectant management may be chosen for patients at high surgical risk.

Cerebellar Neoplasms↗
PubMed1990

Acoustic neuroma.

Acoustic neuromas are benign schwannomas that arise from the vestibular portion of the eighth cranial nerve. Small tumors confined to the internal auditory canal may be removed via an extradural subtemporal approach. Tumors that involve the cerebellopontine angle require posterior fossa craniotomy utilizing either the suboccipital or translabyrinthine technique. The choice of surgical approach depends primarily on the size of the tumor, its location, and the status of hearing in the involved ear. Operative mortality is very low. The most common sources of morbidity are hearing loss and facial nerve dysfunction.

Craniotomy↗
PubMed1993

Does the distribution of Schwann cells correlate with the observed occurrence of acoustic neuromas? .

Acoustic neuromas account for 75 to 80 percent of cerebellopontine angle tumors and 8 to 10 percent of all intracranial neoplasms. These tumors arise from the Schwann cell sheath that surrounds the peripheral portion of the facial, cochlear, superior, and inferior vestibular nerves. Theoretically, a schwannoma may arise from Schwann cells anywhere along these nerves from the glial-Schwann cell junction to the end organ. Clinically, however, they most frequently originate from the vestibular nerves, occasionally from the facial, and only rarely from the cochlear nerve. This investigation utilized light microscopy, immunochemistry, and digital optical morphologic analysis to determine the distribution of Schwann cells along the facial and vestibulocochlear nerves in an attempt to explain the observed distribution of tumors, and to evaluate currently accepted theories. No direct correlation between the distribution of Schwann cells and the observed distribution of schwannomas was found. Thus, this study did not confirm the currently held theories regarding schwannoma distribution in these nerves.

Cell Count↗
PubMed1977

Internal auditory canal enlargement in neurofibromatosis without acoustic neuroma.

Acoustic neuroma has always been reported to accompany neurofibromatosis in patients with enlargement of the internal auditory canal. The authors describe a case in which the internal auditory canal was enlarged but there was no tumor. This may represent a normal variant or a manifestation of the bony dysplasia of neurofibromatosis.

Adult↗
PubMed1986

[Origin of acoustic neuroma].

Acoustic neurinomas are vestibular schwannomas. Ultramicroscopic examination of the root of these tumors, removed using a petrosal approach (translabyrinthic, suprapetrosal) in 20 cases, investigated the site of origin of the schwannoma. Tumoral capsule was absent between Scarpa's ganglion cells and tumoral cells, these two types of cells being intermingled. The fact that the very small tumors, 3 to 5 mm in diameter, were all derived from Scarpa's ganglion and were separated by a capsule from the other structures of internal auditory canal prove that acoustic neurinoma arises from Scarpa's vestibular ganglion. Other studies have shown the absence of myelin surrounding bodies of Scarpa's ganglion cells in humans, inversely to findings in other vertebrates. Since on the one hand the appearance in humans is similar to that observed during development of Scarpa's ganglion in the rat, and on the other hand acoustic neurinoma has never been demonstrated in the animal, it can be suggested that acoustic neurinoma development in humans corresponds to cellular immaturity of Scarpa's ganglion.

Cranial Nerve Neoplasms↗
PubMed1988

Diagnostic strategies in search for acoustic neuromas. Findings in 300 acoustic neuroma patients.

The diagnostic findings in 300 patients with acoustic neuromas are reported. Because of a centralized treatment of acoustic neuromas, we have a uniform work-up of all the patients, which enables us to make a non-selected comparison of the diagnostic efficiency of the various tests. Diagnostic dilemmas in patients with normal hearing, anakusis, normal auditory brainstem recordings, normal vestibular function and normal tomography of the internal acoustic meatus are discussed. In patients with hearing better than 80 dB, a normal ABR, the presence of recruitment and a normal caloric reaction can exclude the presence of a tumour, making tomography superfluous. In patients with poor hearing, the need for tomography is imperative. We perform CT if two procedures among the following produce tumour-positive results: ABR, recruitment tests, caloric test, and tomography. Those who have only one tumour-positive finding at the screening are re-examined after one year. If, even with contrast enhancement, CT proves negative, we continue to perform air CT. Only then do we know for sure whether the patient has a tumour or not. An advantage with using many tests for the same physiological function is that they complement each other, though, on the other hand this often adds to the confusion. With fewer tests, the confusion is reduced, but the requirements regarding technical quality must be very stringent. ABR, the Metz recruitment test and tomography are purely objective, while the caloric test is subjective on the part of the investigator. The Hallpike procedure, however, has stood the test of time in separating pathologic from normal.

Adolescent↗
PubMed2004

Patient perception of comorbid conditions after acoustic neuroma management: survey results from the acoustic neuroma association.

OBJECTIVES/HYPOTHESIS: Based on survey results of the Acoustic Neuroma Association, the patient ratings of the most difficult aspects of acoustic neuroma management were reported and a review of the literature was made regarding comorbid conditions associated with acoustic neuroma treatment and their impact on patient quality of life. STUDY DESIGN: Cohort study of 1940 patients who were members of the Acoustic Neuroma Association. METHODS: A detailed questionnaire was mailed to 2372 members of the Acoustic Neuroma Association to identify preoperative and postoperative symptoms, complications, and long-term effects on physical and psychosocial function. For 1940 respondents (81.8%) who reported the "most difficult aspect of the AN [acoustic neuroma] experience," the responses were analyzed by tumor size, surgical approach, and patient age and sex. Statistical analysis was performed using SPSS software. RESULTS: Respondents reported that the most difficult aspect of the acoustic neuroma experience was hearing loss (25.8%), followed by facial weakness (17.9%), eye problems (10.8%), and headache (10.5%). In order of frequency, men reported hearing loss, balance problems, perioperative surgical experience, and eye and facial weakness, and women reported hearing loss, facial weakness, eye problems, and headache. Facial weakness was a morbidity more often reported for men and women who had large tumors, who were young, or who had undergone the retrosigmoid approach. Balance dysfunction was significant in patients older than 75 years of age. In patients with small tumors, headaches and balance problems were frequently reported. CONCLUSION: In the large cohort study of patients with acoustic neuroma, perceptions regarding the impact of treatment illustrated why it is incumbent on physicians to understand the sentiments of patients with acoustic neuroma when counseling them and recommending optimal management strategies.

Aged↗
PubMed2005

Headache: a quality of life analysis in a cohort of 1,657 patients undergoing acoustic neuroma surgery, results from the acoustic neuroma association.

OBJECTIVES: On the basis of survey results of the Acoustic Neuroma Association (ANA), we report patient ratings of postoperative headache (POH) symptoms, determine its effect on quality of life (QOL), and review the literature regarding POH after acoustic neuroma (AN) treatment. STUDY DESIGN: In this cohort study, 1,657 patients who underwent surgical treatment of AN reported their experiences of POH. METHODS: A detailed questionnaire was mailed to members of the ANA to identify preoperative and postoperative headache symptoms, complications, and long-term effects on physical and psychosocial function. Questions were answered by 1657 (85.4%) respondents that were intended to qualify and quantify the effects of POH, including QOL issues. Responses were analyzed by tumor size, surgical approach, and patient age and sex. Statistical analysis was performed with the SPSS software. RESULTS: Preoperative headache was reported in approximately one third of respondents. Typical POHs occurred more than once daily (46%), lasted 1 to 4 hours in duration (43.1%), and were of moderate intensity (62.6%). The worst headaches were rated as "severe" by 77% of respondents. Treatment most often reported for typical headaches were nonprescription medications including nonsteroidal anti-inflammatory drugs in 61.3% (P < .01) and regular use of narcotics in 15%. Patients who underwent the retrosigmoid approach were significantly more likely to report their worst POH as "severe" (82.3%) compared with the translabyrinthine (75.2%) and middle fossa approaches (63.3%). Women and younger patients tended to have poorer outcomes with regard to POHs. CONCLUSIONS: In this large cohort study of AN patients, POH was a significant morbidity among AN patients with persistent headaches. Treating physicians should be aware of the risk factors identified and the effect POH has on the QOL when counseling patients regarding optimal treatment management.

Adolescent↗
PubMed1993

Molecular genetic analysis of the mechanism of tumorigenesis in acoustic neuroma.

OBJECTIVE: Acoustic neuroma, both familial and sporadic, is clinically and biologically a heterogeneous condition with a wide variation in age of presentation, length of history, and tumor growth rate. In an attempt to correlate this clinical diversity with the underlying molecular pathology, we have analyzed 43 paired blood-tumor DNA samples from patients with acoustic neuromas. DESIGN: Molecular genetic analysis. SETTING: Molecular genetic research laboratory. PATIENTS: Paired blood-tumor DNA samples were obtained from 43 patients (41 sporadic and two patients with neurofibromatosis type 2). MAIN OUTCOME MEASURES: Loss of constitutional heterozygosity was looked for in the region of tumor suppressor genes on chromosomes 3p, 5q, 11p, 17p, 17q, and 22. RESULTS: We found loss of heterozygosity exclusively for markers on chromosome 22. Thirty-nine percent of tumors showed allele loss, and in each case the loss of heterozygosity included the region of the neurofibromatosis type 2 (NF2) gene. No loss of heterozygosity was detected in the region of known or putative suppressor genes in chromosomes 3p, 5q, 11p, 17p, and 17q. CONCLUSIONS: This study has demonstrated that (1) chromosome 22 allele loss is a frequent event in sporadic acoustic neuroma; (2) the minimal region of loss of heterozygosity in acoustic neuroma includes the NF2 gene; (3) the known tumor suppressor genes investigated (VHL, adenomatous polyposis coli, WT2, p53, and NF1) do not appear to be important in the pathogenesis of acoustic neuroma; and (4) patients with extensive chromosome 22 loss tended to be younger and with a slightly shorter clinical history than those with no detectable allele loss.

Adult↗
PubMed2004

The immunohistochemical localisation of somatostatin receptors 1, 2, 3, and 5 in acoustic neuromas.

AIMS: Acoustic neuroma is a benign tumour, which develops through an overproliferation of Schwann cells along the vestibular nerve. Somatostatin is a naturally occurring peptide, which exerts antiproliferative and antiangiogenic effects via five membrane bound receptor subtypes. The aim of this study was to determine whether somatostatin receptor subtypes (SSTRs) 1, 2, 3, and 5 are present in acoustic neuromas. METHODS: The expression of SSTRs 1, 2, 3, and 5 was studied in both the Schwann cells and blood vessels of eight acoustic neuroma specimens, by means of immunohistochemistry using novel rabbit polyclonal antibodies raised against human SSTR 1, 2, and 5 subtype specific peptides, and a commercial anti-SSTR3 antibody. RESULTS: SSTR2 was the most prevalent subtype in Schwann cells (seven of eight), with intermediate expression of SSTR3 (six of eight), and lower expression of SSTRs 1 and 5 (four of eight and five of eight, respectively). There was ubiquitous vascular expression of SSTR2, with no evidence of SSTR 1, 3, or 5 expression in blood vessels. CONCLUSION: SSTRs 1, 2, 3, and 5 are differentially expressed in acoustic neuromas. Somatostatin analogues may have a therapeutic role in the management of this rare and challenging condition.

Adult↗
PubMedDate not supplied

The origin of acoustic neuromas.

Small acoustic neuromas, operated on through transpetrosal approaches were studied by light and transmission electron microscopy. All schwannomas were found to interpenetrate the vestibular ganglion without a space or a capsule. In the abnormal ganglion areas, free tumour Schwann cells were observed. These results suggest that acoustic neuromas originate from the vestibular ganglion. The fact that the sheath of vestibular ganglion bipolar cells in man are devoid of myelin may account for the elective origin of acoustic neuromas in the Scarpa ganglion in the human.

Humans↗