Bilateral Acoustic Neurinomas Research Articles

Clinical, paraclinical aspects and complex therapeutical approaches in a patient with incomplete paraplegia, post thoracic menigioma surgically treated, in neurofibromatosis context

Introduction: Neurofibromatosis - type 1 (NF1) and type 2 (NF2) - are genetic disorders of the nervous system that can affect the growth and development of nerve cell tissue and so can determine severe or rather permanent sequels. NF2 implies usually multiple tumors on the cranial and spinal nerves and it is less common than NF1. The most frequent symptom of NF2 is hearing progressive loss, as a consequence of auditory nerves affection and appears at early ages or at twenties. The evolution of a patient with NF2 depends on the number and location of tumors and some of them might develop a life-threatening or disabling condition. With a prompt diagnosis and an appropriate therapy it can be improved the patient prognosis and QOL. Materials and Methods: This paper presents the case of a 43-year-old patient, with personal antecedents of hearing dysfunction, diagnosed in 2013 with neurofibromatosis that was hospitalized at the IV Neurosurgery Clinic of TEHBA in January 2019 and suffered a re-intervention for removal of the spinal cord tumor (psammomatous meningioma) and with spinal cord decompression. In our clinic, the patient was admitted for incomplete AIS/Frankel C paraplegia, he had initially followed a complex nursing program and subsequently a rehabilitation adequate program. The patient was assessed functionally using the following scales: AIS / Frankel, modified Ashworth, Functional Independence Measure (FIM), Life Quality Assessment (QOL), FAC International Scale, Independence Assessment Scale in Daily Activities (ADL / IADL), Walking Scale for Spinal Cord Injury (WISCI). Results: The paraclinical assessments (cerebral and spinal cord MRI) detect multiple cerebral tumors and micro-nodules adjacent to the lumbar spinal roots, which, associated with the bilateral acoustic neurinoma (diagnosed in 2013), contributed to the suspicion of the NF2 diagnosis. The patient had two admissions in our clinic division, benefited from a complex neuro-muscular rehabilitation program, having a favourable evolution, with an increase in the evaluated scales scores, now performing walking with a support from another person in walking frame, as well as sphincter re-education, with the neurogenic bladder remission. Conclusions: Even if there is no cure for neurofibromatosis and no standard treatment, it is important to promptly diagnose such a rare disease and to give an adequate treatment (AINS or other analgesic drugs, surgery, chemotherapy or radiation –when it’s needed, or psychotherapy) for controlling symptoms and also a personalized rehabilitation program (including nursing measures) enhancing including patient's quality of life. Key words: paraplegia, neurofibromatosis, neuro-muscular rehabilitation,

P16.34 * BEVACIZUMAB TREATMENT FOR ACOUSTIC NEURINOMA IN NEUROFIBROMATOSIS TYPE 2: A CASE REPORT

Neurofibromatosis type 2 (NF2) is a dominantly inherited genetic condition. Unlike patients with sporadic tumours, NF2 patients often have multiple meningiomas, acoustic neurinomas and ependymomas. The multiplicity of tumours make surgery and radiation therapy for all tumours impracticable. In effect, bilateral acoustic neurinomas are the hallmark of this disease and these tumours cause progressive hearing loss in most patients. Neovascularization is necessary for tumour growth and is driven by tumour produced angiogenic factors such as vascular endothelial growth factor (VEGF). Bevacizumab is a humanized monoclonal antibody that neutralizes the activity of VEGF. Recent data showed that VEGF is produced by schwannoma tumour cells. Also, bevacizumab treatment, in patients with NF2 who were considered poor candidates for surgery and radiation therapy, was followed by clinically meaningful hearing improvement and tumour-volume reduction. We report the case of a 39 years old woman with sudden rightsided hearing loss. Magnetic resonance imaging (MRI) revealed multiple meningiomas and neurinomas (C2 and L5 lesions) and a right side acoustic neurinoma of 26x24 mm, confirming the diagnosis of NF2. Bevacizumab was given as an infusion every 2 weeks at a dose of 5.0 mg/kg body weight. Before the treatment, the patient has a thorough medical evaluation including blood pressure, urine analysis, liver and kidney function tests, coagulation status and history of thrombosis, hemoglobin, leukocyte count and thrombocyte count. Three months after the start of therapy the patient has reported an hearing response with progressive improvement in audiometry, word recognition and face-to-face conversation. Six months after the start of therapy, the right acoustic neurinoma had regressed and, also, mitigation of brain stem compression was clearly visible on the cranial MRI scans. The patient, after 12 months, continued to be treated with bevacizumab. In our experience no toxic effects drug-related has been seen; anyway, the absence of many common toxic effects of bevacizumab in our patient may have reflected her youth and the lack of other medical conditions. The exact mechanism of the action of bevacizumab on acoustic neurinomas remains to be elucidated. The drug may also suppress growth of tumour Schwann cells directly, a possibility that can be tested in vitro in future studies. The encouraging results with bevacizumab suggest consideration of a prospective clinical trial for progressive NF2-related acoustic neurinomas, especially for patients with imminent total hearing loss.

Neurofibromatosis type 2 (NF2)

Other names: central neurofibromatosis; bilateral acoustic neurofibromatosis; bilateral acoustic neurinoma; bilateral acoustic schwannomas. Inheritance: autosomal dominant with almost complete penetrance; frequency is 3/10 newborns; neomutation represent 50% of cases; variable expressivity from mild disease through life (Gardner type) to severe condition at young age (Wishart type: with more than 3 tumours).

The superiority of 3D-CISS sequence in displaying the cisternal segment of facial, vestibulocochlear nerves and their abnormal changes

Objective To select the best imaging method for clinical otologic patients through evaluating 3D constructive interference of steady state (CISS) image quality in visualizing the facial, vestibulocochlear nerves (CN:VII–VIII) and their abnormal changes. Methods The CN:VII–VIII as well as inner ear structures in 48 volunteers were examined using 3D-CISS and 3D turbo spin echo (TSE) sequences respectively, and displayed to the full at the reformatted and maximum intensity projection (MIP) images. The nerve identification and image quality were graded for the CN:VII–VIII as well as inner ear structures. Statistical analysis was performed using the Wilcoxin test, p < 0.05 was considered significant. In addition, 8 patients with abnormality in facial or vestibulocochlear nerves were also examined using 3D-CISS sequence. Results The identification rates for the cisternal segment of facial, vestibulocochlear nerves and corresponding membranous labyrinth were 100%. Abnormal changes of the facial or vestibulocochlear nerves were clearly shown in 8 patients, among them 1 was caused by bilateral acoustic neurinoma, 1 by cholesteatoma at cerebellopontine angle, 1 by arachnoid cyst, 1 by neurovascular adhesion, 4 by neurovascular compression. Conclusion With 3D-CISS sequence the fine structure of the CN:VII–VIII and corresponding membranous labyrinth can be clearly demonstrated; lesions at the site of cerebellopontine angle can also be found easily.

Bilateral acoustic neurinomas presenting as subarachnoid hemorrhage: case report

听神经瘤通常导致面部神经和听觉的缺陷，并且很少导致潜水艇 arachnoid 出血(SAH ) 。在 2002，我们对待一个病人，双边的声学的 neurinomas 作为 SAH 介绍。

Bilateral acoustic neurinomas

A 20-year-old girl with family history of neurofibromatosis presented with complaints of decreased hearing in both ears, change in voice, headaches and progressive ataxia for the past 1 year. On admission, she was alert, active but dysarthric. There was bilateral horizontal gaze evoked nystagmus. Fundus examination revealed bilateral papilledema. The right corneal reflex was depressed and the sensations over the right side of face were marginally decreased. There was right facial paresis, bilateral sensorineural deafness and severe truncal ataxia. There were marked bilateral cerebellar signs. MR imaging showed large bilateral acoustic neurinomas severely compressing the brainstem [Figures 1 and 2]. It was difficult even to identify the brainstem in certain sequential images. A radical resection of both acoustic neurinomas was performed through bilateral retromastoid craniectomies in two stages at an interval of 3 months. On both sides, a thin sheath of tumor was left behind adjacent to the facial nerves in an attempt to save their function. The patient developed right facial palsy following the first surgery and needed tarsorrhaphy. However, her ataxia improved remarkably. Post-operative MR imaging showed considerable reformation of the brainstem [Figure 3].

Gamma knife radiosurgery of acoustic neurinomas.

The authors report on their series of 40 patients with 41 acoustic neurinomas (ACNs), including one patient with bilateral acoustic neurinomas suffering from neurofibromatosis type 2 (NF II) who were treated with the gamma knife unit at their institution between August 1992 and October 1995. Of these 41 tumours, 21 ACNs had been operated on before (1 to 4 times), 20 ACNs were exclusively treated by gamma knife radiosurgery (GKRS). The maximal axial tumour diameter ranged from 6 to 33 mm (median: 25 mm), the maximal transverse tumour diameter ranged from 7 mm to 36 mm (median: 16 mm). The dose distributed to the tumour margin was 10 to 17 Gy (median: 12 Gy) by enclosing the tumour with the 40% to 95% isodose line (median: 50% isodose line) and using 1 to 12 isocenters (median: 5 isocenters). Central loss of contrast enhancement was observed in 78% of the patients within six to 12 months after radiosurgery. Thirty-two patients were observed over a minimum follow up period of at least 36 months, 9 patients were lost to follow up as they died of unrelated causes or refused further check-ups. Within the follow up period of up to seven years, magnetic resonance imaging (MRI) control scans revealed the tumour diameter stable or decreased in 29 cases and increased in three tumours. Of 14 patients with useful hearing before treatment, 9 patients were examined in addition to pure tone audiogramm by measurement of brainstem auditory evoked potentials (BAEPs) one to four years after radiosurgery. None of these patients showed a postoperative loss of the cochlea function. According to slight alterations of the cochlea function (cochlea summating action potential), pure tone audiometry of those patients revealed only slight changes of the hearing level (HL) within a maximum range of +/-15 Decibel (dB). The hearing threshold improved in two, was stable in four and deteriorated in three patients, respectively. We observed postradiosurgical aggravation of a pre-existing facial weakness in two out of 13 patients, a new occurrence of facial palsy was seen in two cases (four years after treatment), one of them was previously operated on and both suffered from cystic degeneration with mass effect. Tinnitus improved in six out of 13 patients, deteriorated in two and never appeared as a new permanent sequela. Trigeminal hypaesthesia did also not appear as a new permanent symptom, improved in three out of 9, and deteriorated in one out of 9 patients. Vertigo increased in six out of 23, was stable in 8 and decreased in nine out of 23 patients each. GKRS proves to be a safe and highly satisfactory therapeutical option or addition to open surgery, especially for radiologically verified regrowing residual ACNs, but also as primary treatment in selected patients. A high rate of tumour control can be achieved with an acceptable rate of neurological deficits.

First Croatian auditory brainstem implantation

A deaf female patient was diagnosed with bilateral acoustic neurinomas. Diagnosis incorporated the standard audiological battery for sensorineural hearing loss, computed tomography and magnetic resonance imaging. The left side had been operated on four years previously in another clinic using the suboccipital approach. The auditory brainstem implant surgery was performed on the 'second side' using the same approach. It was an uneventful operation with good anatomy and no serious post-operative complications. Post-operatively, the patient performed exceptionally well, with up to 50 per cent of words recognized in the opened set and 85 per cent in the closed set, both without lip-reading.

Schwann cell proliferation as the cause of peripheral neuropathy in neurofibromatosis-2

We report a 18-year-old man who developed slowly progressing right drop foot. Bilateral acoustic neurinoma was found and he was diagnosed as neurofibromatosis-2. Right sural nerve biopsy showed multiple small onion-bulb-like structures in the nerve fascicle. Electronmicroscopic and immunohistochemical studies on this structure confirmed cytological characteristics of Schwann cells, while previous reports suggest that this structure originates from perineural cells. The present report is the first to show both ultrastructurally and immunohistochemically that the onion-bulb-like structure is derived from Schwann cell.

Neuro-ophthalmological findings in neurofibromatosis: Clinical and neuroradiological study of 125 patients

As a part of a continued clinical and genetic study of neurofibromatosis (NF) in Northern Finland (population about 650,000), a neuro-ophthalmological examination was performed on 106 out of 125 patients with a definite diagnosis (according to the NIH criteria) of NF 1 (116), NF 2 (4), and NF 5 (5). Thirteen additional patients had an ophthalmological examination. On examination with a slit lamp, Lisch nodules were found in 59 (96.7%) of the 61 adults and in 32 (71.1%) of the 45 children with NF 1, in one (20%) of the five patients with NF 5, and in none of the four patients with NF 2. Computed tomography (CT) and/or magnetic resonance imaging (MRI) were performed on 102 patients. CT was normal in 41 out of 97 cases. All 27 MRI scans showed some abnormalities. Glioma of the optic nerve and/or chiasm were diagnosed or suspected in 23 of the 96 cases with NF 1 (24%) and caused reduced visual acuity and visual field defects unilaterally in three cases and bilaterally in eight. Operative and/or radiation therapy was given to three children. Follow-up without therapy in the case of 17 patients did not reveal progression. Epiretinal membrane was found in two and presenile cataract in one of the four patients with NF 2, and three had neuro-ophthalmological findings caused by bilateral acoustic neurinomas or their operations.

Hearing preservation in bilateral acoustic neurinomas

Bilateral acoustic neurinomas are found in almost all patients with neurofibromatosis 2 (NF2). With better knowledge of the disease and development of diagnostic procedures, an increasing number of patients have been detected at an early stage of the disease. Preservation of hearing in these cases has become more feasible. Between 1979 and 1992, 110 acoustic neurinomas in 74 NF2 patients have been resected in this department. All tumours but 11 were completely removed. In 11 cases deliberate subtotal tumour removal was performed: bilaterally in one deaf patient for brainstem decompression, and unilaterally in nine patients with the aim of hearing preservation. In seven of these nine cases hearing was preserved. The total rate of hearing preservation was 36%. Considering only those patients with good preoperative hearing and small tumours, the rate of hearing preservation was 58%. Facial nerve preservation was 92%. Nerve reconstructions were performed in cases of facial nerve damage, with good results in most of the cases. The importance of early detection of the disease and early removal of tumours is stressed. Surgical decision making based on the author's personal experience in dealing with these cases is discussed, and some cases are illustrated.

Full recovery from deafness after removal of a large acoustic neurinoma associated with neurofibromatosis 2: Case report

The first case of full recovery from deafness after radical intracapsular removal of a large acoustic neurinoma, more than 4 cm in diameter, is reported. The patient, a 17-year-old woman, had multiple intracranial and intraspinal tumors in addition to bilateral acoustic neurinomas. Radical intracapsular removal is a useful technique to preserve nerves in patients with large acoustic neurinoma. When identifiable evoked potentials are preserved in brain stem auditory evoked potential, hearing preservation should be tried despite preoperative hearing level.

Facial nerve reconstruction in neurofibromatosis 2.

Between 1979 and 1989, 13 patients with neurofibromatosis 2 underwent reconstructions of the facial nerve after removal of bilateral acoustic or facial neurinomas. Seven patients received hypoglossal-facial nerve anastomosis, and five received sural nerve grafting in the cerebellopontine angle. End-to-end anastomosis and intracranial-intratemporal sural grafting were performed for one patient each, respectively. Re-innervation was seen in all cases. The results were good in 11 cases. Two patients presented with poor results due to development of neurinomas close to the site of the nerve reconstruction. The importance of reconstructive surgery in patients with neurofibromatosis is stressed. The problems regarding failure of re-innervation in some cases and difficulties in their management are discussed.

Mapping the breakpoint of a constitutional translocation on chromosome 22 in a patient with NF2.

Neurofibromatosis type 2 (NF2) is an autosomal dominant disorder characterized by development of bilateral acoustic neurinomas and increased incidence of meningiomas. Frequent losses of I allele of chromosome 22 in neurinomas and meningiomas has indicated that the gene responsible for NF2 functions as a tumor suppressor. Although the NF2 gene has been mapped within a 13 cM region between D22S1 and D22S28 by linkage analysis, its location with respect to D22S15 is uncertain. We previously reported an NF2 patient with a constitutional balanced translocation t(4;22)(q12;q12.2); the NF2 gene is probably disrupted at the breakpoint. To define the location of this breakpoint on chromosome 22, we performed fluorescence in situ hybridization (FISH) with DNA markers in the NF2 region and determined the physical order of 5 loci: D22S1-NF2-LIF-D22S15-D22S32.

Preservation of hearing in bilateral acoustic neurinomas by deliberate partial resection.

With the aim of preserving hearing, 20 acoustic neurinomas in 17 patients with neurofibromatosis 2 were intentionally submitted to an incomplete (80%) tumour removal. In 12 cases this was an operation on the last hearing ear with total deafness of the contralateral ear. If an auditus existed in both ears the better hearing ear was selected for the primary intervention. Early audiological controls evidenced residual hearing in 19 of the 20 cases operated on by the enlarged middle fossa approach, which was utilized inspite of the tumour diameters being between 1 and 6 cm in the cerebello-pontine angle. The oncologic and functional follow-up over 1 to 7 years showed different patterns of slow progression of hearing loss and of persistent auditory function over 2 to 7 years. Facial nerve function was excellent in 16 of the 18 controlled cases. Continued CT or MRT imaging revealed no signaling in 2 cases, constant tumour sizes in 10 cases and slow progression in 3 cases. With regard to the importance of an auditory communication in the younger adult, the described treatment modality appears to be the first choice method.

Temporal Bone Pathology of Acoustic Neurinoma (Unilateral and Bilateral) in Relation to the Internal Auditory Canal Surgery

Temporal bone pathology of 3 cases with large unilateral acoustic neurinoma (AN) and 2 cases with large bilateral AN (neurofibromatosis 2; NF2) were studied. One case with unilateral AN was diagnosed as neurofibromatosis 1 (NF1). Unilateral AN had distinct borderlines at the fundus in 5 of 12 examination points between tumor tissues and nerve fibers, but only 1 of 12 was distinct around the porus acousticus. Bilateral AN showed no distinct borderlines at the fundus and around the porus acousticus. These findings suggest that clear separation of the VIIth or VIIIth nerve from large tumors is very difficult, especially in cases of bilateral AN. Geniculate ganglion cells of tumor origin on ears were fairly well preserved in 2 cases with unilateral AN and 1 case with bilateral AN. Well preserved geniculate ganglion cells could be dependent on blood supply not from the internal auditory artery.

Radiosurgery for Acoustic Neurinomas: Early Experience

Abstract We reviewed our early experience with the first 26 patients with acoustic neurinomas (21 unilateral, 5 bilateral) treated by stereotactic radiosurgery using the first North American 201-source cobalt-60 gamma knife. Follow-up ranged from 6 to 19 months (median, 13 months). Serial postoperative imaging showed either a decrease in tumor size (11 patients) or growth arrest (15 patients). Loss of central contrast enhancement was a characteristic change (18 patients). Seven patients had good or serviceable hearing preoperatively. In all 7 the preoperative hearing status was retained immediately after radiosurgery. At follow-up, 3 had preserved hearing, I had reduced hearing, and 3 had lost all hearing in the treated ear. Hearing in 1 patient that was nonserviceable preoperatively later improved to a serviceable hearing level. Delayed facial paresis developed in 6 patients, and delayed trigeminal sensory loss developed in 7 patients, none of whom had significant deficits before radiosurgery. Both facial and trigeminal deficits tended to improve within 3 to 6 months of onset with excellent recovery anticipated. Lower cranial nerve dysfunction was not observed. All 26 patients remain at their preoperative employment or functional status. At present, stereotactic radiosurgery is an alternative treatment for acoustic neurinomas in patients who are elderly, have significant concomitant medical problems, have a tumor in their only hearing ear, have bilateral acoustic neurinomas, refuse microsurgical excision, or have recurrent tumor despite surgical resection. Although longer and more extensive follow-up is required, the control of tumor growth and the acceptable rate of complications in this early experience testifies to the future expanding role of this technique in the management of selected acoustic neurinomas.

Radiosurgery for acoustic neurinomas

We reviewed our early experience with the first 26 patients with acoustic neurinomas (21 unilateral, 5 bilateral) treated by stereotactic radiosurgery using the first North American 201-source cobalt-60 gamma knife. Follow-up ranged from 6 to 19 months (median, 13 months). Serial postoperative imaging showed either a decrease in tumor size (11 patients) or growth arrest (15 patients). Loss of central contrast enhancement was a characteristic change (18 patients). Seven patients had good or serviceable hearing preoperatively. In all 7 the preoperative hearing status was retained immediately after radiosurgery. At follow-up, 3 had preserved hearing, 1 had reduced hearing, and 3 had lost all hearing in the treated ear. Hearing in 1 patient that was nonserviceable preoperatively later improved to a serviceable hearing level. Delayed facial paresis developed in 6 patients, and delayed trigeminal sensory loss developed in 7 patients, none of whom had significant deficits before radiosurgery. Both facial and trigeminal deficits tended to improve within 3 to 6 months of onset with excellent recovery anticipated. Lower cranial nerve dysfunction was not observed. All 26 patients remain at their preoperative employment or functional status. At present, stereotactic radiosurgery is an alternative treatment for acoustic neurinomas in patients who are elderly, have significant concomitant medical problems, have a tumor in their only hearing ear, have bilateral acoustic neurinomas, refuse microsurgical excision, or have recurrent tumor despite surgical resection. Although longer and more extensive follow-up is required, the control of tumor growth and the acceptable rate of complications in this early experience testifies to the future expanding role of this technique in the management of selected acoustic neurinomas.

Total Removal of an Intramedullary Meningioma of the Medulla Oblongata

A 12-year-old boy had central von Recklinghausen's neurofibromatosis with multiple intracranial meningiomas and bilateral acoustic neurinomas. One of the meningiomas was found in the parenchyma of the medulla oblongata and was successfully removed. To our knowledge, this is the first reported case of surgical removal of an intramedullary meningioma of the medulla oblongata. Details of the clinical, neuroradiological, and operative findings are described.

Operated Bilateral Acoustic Neurinoma with Preservation of Hearing and Facial Nerve Function

After a brief survey of the microsurgical methods for acoustic neurinomas, a case is described in which a successful bilateral operation has been performed. Facial nerve function could be preserved on both sides and on the side of the still functioning ear hearing could also be saved. At 12 months following the operation pure tone and speech hearing were found to be the same as before the operation.