1/204. choroid plexus papilloma of cerebellopontine angle with extension to foramen magnum.A case of choroid plexus papilloma resembling meningioma of cerebellopontine (CP) angle with its extension to foramen magnum is presented. Occurrence of this tumour in CP angle is very rare. Its extension towards foramen magnum is further rare. It was a real diagnostic enigma preoperatively as the tumour was resembling meningioma upto some extent on radiological study. Retromastoid craniectomy with microsurgical excision of tumour and its extension was achieved in toto. Tumour was attached to few rootlets of lower cranial nerves which were preserved. Attachment of the tumour with lower cranial nerves again caused diagnostic confusion with neurofibroma intraoperatively.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
2/204. Magnetic resonance cisternography using the fast spin echo method for the evaluation of vestibular schwannoma.neuroimaging of vestibular schwannoma was performed with the fat-suppression spoiled gradient recalled acquisition in the steady state (SPGR) method and magnetic resonance (MR) cisternography, which is a fast spin echo method using a long echo train length, for the preoperative evaluation of the lateral extension of the tumor in the internal auditory canal, and the anatomical identification of the posterior semicircular canal and the nerves in the canal distal to the tumor. The SPGR method overestimated the lateral extension in eight cases, probably because of enhancement of the nerves adjacent to the tumor in the canal. The posterior semicircular canal could not be clearly identified, and the cranial nerves in the canal were shown only as a nerve bundle. In contrast, MR cisternography showed clear images of the lateral extension of the tumor and the facial and cochlear nerves adjacent to the tumor in the internal auditory canal. The anatomical location of the posterior semicircular canal was also clearly shown. These preoperative findings are very useful to plan the extent to which the internal auditory canal can be opened, and for intraoperative identification of the nerves in the canal. MR cisternography is less invasive since no contrast material or radiation is required, as with thin-slice high-resolution computed tomography (CT). MR cisternography should replace high-resolution CT for the preoperative neuroradiological evaluation of vestibular schwannoma.- - - - - - - - - - ranking = 3keywords = nerve (Clic here for more details about this article) |
3/204. Midline cerebellar cystic schwannoma : a case report.An extremely unusual case of a cystic schwannoma in the region of the inferior vermis and posterior to the fourth ventricle in a fifteen year old boy is reported. The cystic tumour caused partial obstruction to the outflow of cerebrospinal fluid from fourth ventricle and resulted in development of supratentorial hydrocephalus. On investigations, the schwannoma simulated a Dandy-Walker cyst. The boy presented with symptoms of increased intracranial pressure. On surgery, the lesion was not arising from any cranial nerve, nor was it attached to brain parenchyma, blood vessel or to the dura. The possible histogenesis of the cystic schwannoma in a rare location is discussed.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
4/204. Signet-ring cell ependymoma: case report with implications for pathogenesis and differential diagnosis.We describe light microscopic, immunohistochemical and ultrastructural features of a signet-ring cell ependymoma (WHO grade II) identified in a surgically resected left cerebellar cystic tumor from a 64-year-old man. Part of the tumor showed clear-cell differentiation. Immunohistochemical coexpression of glial fibrillary acidic protein and epithelial membrane antigen, characteristic of ependymoma, was detected in both components. Sinuous intermediate junctions, cytoplasmic lumina, and scant astroglial filaments were demonstrated by electron microscopy. Signet-ring cell change was shown to be induced by disproportionate cavitation of either microvillus-bearing cytoplasmic lumina or microrosettes. The staining qualities of clear cells were mainly due to paucity and degeneration of subcellular organelles. Therefore, signet-ring cell ependymomas represent a unique anomaly of intra- and extracellular compartmentalization to be distinguished from various unrelated forms of cytoplasmic volume increase, resulting in an optically similar "empty" appearance of tumor cells. As a clinically relevant consequence, signet-ring cell ependymoma must be included in the differential diagnosis of primary or metastatic neoplasms of the central nervous system, having in common a phenotype characterized by overdeveloped optically lucent cell bodies.- - - - - - - - - - ranking = 0.015352750862071keywords = organ (Clic here for more details about this article) |
5/204. cerebellopontine angle lipoma: case report and review of the literature.Intracranial lipomas located in the cerebellopontine angle are extremely rare. These tumours are mal-developmental lesions which can cause slowly progressive neurological symptoms. The clinical management of these tumours differs significantly from other lesions in this region. A 27 year old woman presented with a 2-month history of vertigo and a slowly progressive deterioration of hearing in the left ear. Computed tomography (CT) revealed a large low-density mass in the left cerebellopontine angle without any contrast-enhancement. In T1-weighted magnetic resonance imaging (MRI) the lesion was hyper-intense and did not enhance after application of gadolinium. Areas of lower signal intensity inside of the lesion were suggested as incorporated cranial nerves. A left retro-sigmoidal approach in a semi-sitting position was chosen to expose the tumour. After reducing the tumour mass, the tumour was dissected from the cranial nerves which were incorporated into the tumour. The residual tumour was adherent to the brain stem and the encased lower cranial nerves, allowing only a near subtotal resection of the highly vascularized tumour in order to avoid neurological deficits. The histological examination revealed a lipoma. Attempts at complete removal of cerebellopontine angle lipomas usually result in severe neurological deficits. Conservative treatment should therefore be preferred. Limited surgery is indicated if the patients suffer from disabling neurological symptoms and signs e.g., vertigo, nausea, trigeminal neuralgia, facial weakness or facial spasm.- - - - - - - - - - ranking = 1.5keywords = nerve (Clic here for more details about this article) |
6/204. A case of endolymphatic sac tumor with long-term survival.A 72-year-old man developed left facial palsy at age 14 and left-sided hearing loss at age 20. At the age of 59, he presented with gait disturbance, and a large left cerebellopontine angle tumor was detected, which had markedly destroyed the pyramidal bone. The tumor was subtotally resected, but he required two more operations at the ages of 64 and 69 because of tumor regrowth. At the present time, recurrent tumor has destroyed the occipital bone and is invading the scalp. However, even though he has several cranial nerve palsies and cerebellar ataxia, he remains in stable condition and demonstrates long-term survival. The patient's surgical specimens revealed a papillary adenoma, which was recently thought to be of endolymphatic sac origin, although the origin of this kind of tumor, whether arising from the middle ear or from the endolymphatic sac, has not been established with certainty so far. In this paper, we provide further evidence that this tumor originates from the endolymphatic sac, based on anatomical, histopathological, and embryological evidence.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
7/204. radiosurgery for bilateral neurinomas associated with neurofibromatosis type 2.OBJECTIVE: The clinical course of bilateral acoustic tumors associated with neurofibromatosis (NF2) is generally troublesome, and no definite treatment strategy has been established. Follow-up results of bilateral acoustic tumors after radiosurgery are reported herein. methods: The current indications for radiosurgery are 1) a growing tumor less than 30 mm in mean diameter, 2) the ipsilateral ear has no serviceable hearing, and 3) there is risk of brain stem compression or brain stem dysfunction. Twenty cases of bilateral acoustic tumors were treated with the gamma knife, including 7 males and 13 females. The mean age was 38.2 years and the mean tumor size 24.4 mm. The tumors were treated with mean maximum and marginal doses of 26.8 Gy and 13.0 Gy, respectively. Among them, 12 patients had profound hearing loss in the ipsilateral (treated) ear, but the other 8 had serviceable hearing.RESULTS: Tumors treated with radiosurgery showed central necrosis in 60% of the cases at 6 months and in 70% at 9 months after radiosurgery. Thereafter, the tumors often demonstrated slow regression. The rate of tumor shrinkage was 20% at 12 months, 35% at 24 months, and almost 60% at 36 months. At the last follow-up (mean 33.6 months), the tumors demonstrated shrinkage in 50% and tumor control in 100%. The contralateral tumors were stable in 12 (60%) and enlarged in 8 (40%). Preservation of serviceable hearing ipsilaterally was obtained in 33.3%. Deterioration of ipsilateral facial nerve function, either in the natural course or as a complication, occurred in 10%. CONCLUSIONS: Because of good tumor control and tumor shrinkage as well as an acceptable complication rate, radiosurgery should be incorporated in the treatment strategy for bilateral acoustic tumors associated with NF2.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
8/204. The transmastoid partial labyrinthectomy approach to medial skull base lesions.INTRODUCTION: It has long been thought that surgical disruption of the membranous labyrinth invariably results in sensorineural hearing loss and balance dysfunction. Recent evidence suggests that the inner ear can withstand such manipulation without loss of function. The technique of transmastoid partial labyrinthectomy has recently been described as a means of providing access to lesions of the medial skull base by removing part of the labyrinth and at the same time attempting to preserve hearing and vestibular function of the lateral semicircular canal (LSCC) and otolithic organs. PROCEDURE: An extended cortical mastoidectomy is performed and the posterior and middle cranial fossa dura are exposed widely. The posterior and superior semicircular canals are occluded at their ampullated ends and at the crus commune, and then resected. The LSCC and vestibule are left undisturbed. The petrous apex is removed and the medial end of the internal auditory canal is exposed. Posterior cranial fossa dural flaps are raised allowing access to the brainstem, petro-clival area and cerebellopontine angle. Temporal and suboccipital craniotomies can be performed, as required. RESULTS: Four patients underwent this procedure by a joint Otolaryngological-Neurosurgical team for access to the following lesions: three intra-axial pontine cavernomas and a basilar artery aneurysm. The preliminary hearing and balance results are discussed. CONCLUSIONS: The partial labyrinthectomy approach provides improved access to certain lesions of the medial skull base and requires less brain retraction compared with the retrolabyrinthine approach. It also has the potential to preserve serviceable hearing.- - - - - - - - - - ranking = 0.015352750862071keywords = organ (Clic here for more details about this article) |
9/204. meningioma manifested as temporomandibular joint disorder: a case report.Pain in the temporomandibular joint (TMJ) and the surrounding region constitutes a symptom of TMJ disorders. Various dental causes usually stimulate the trigeminal nerve, developing facial pain which triggers trigeminal neuralgia. However, trigeminal neuralgia may also arise from irritation of the endocranial root of the nerve, due to occult damage which has not yet manifested other symptoms, for example a meningioma. In this manner, the actual cause of pain in the ipsilateral half of the face may be interpreted incorrectly and may possibly be attributed to a TMJ dysfunction syndrome. This results in long-term frustration and burdening of the patient. The case of a 47-year-old woman is presented who complained of symptoms of a painful TMJ disorder. She was initially treated with the appropriate dental procedures and, upon continuation of the pain, was examined with CT scanning, which proved to be negative despite the existence of a cerebral lesion. Further investigation with MRI, however, revealed a meningioma of 5 mm size, in the region of the cerebellopontine angle.- - - - - - - - - - ranking = 1keywords = nerve (Clic here for more details about this article) |
10/204. Subarachnoid fat dissemination after resection of a cerebellopontine angle dysontogenic cyst: case report and review of the literature.OBJECTIVE AND IMPORTANCE: This case report illustrates the clinical and radiological relevance of extensive intracranial subarachnoid and ventricular dissemination in dysontogenic (dermoid) tumors. CLINICAL PRESENTATION: We describe a patient with a cerebellopontine angle dysontogenic tumor. Postoperatively, the cyst disseminated fat particles extensively into the subarachnoid space. magnetic resonance imaging (MRI) studies revealed continuous dispersion of the fat particles into the cerebral cisterns, subarachnoid space, and ventricles. INTERVENTION: Eight years of clinical and MRI follow-up demonstrated neither neurological deterioration in the patient nor growth of the multiple lesions. CONCLUSION: Intracranial subarachnoid dissemination of fat material may occur during the preoperative or postoperative course of dermoid and epidermoid cysts. Aseptic meningitis or other complications such as hydrocephalus, seizures, or cranial nerve deficits also may occur owing to spillage of intracranial cyst contents into the subarachnoid space. MRI can detect the presence of fat drops that may adhere to the surrounding structures or migrate with the cerebrospinal fluid flow. Intracranial disseminated fat particles can remain silent without radiological or neurological change, justifying a wait-and-see approach. During long-term postoperative follow-up, however, regular MRI studies and clinical examinations are necessary to avoid potential complications.- - - - - - - - - - ranking = 0.5keywords = nerve (Clic here for more details about this article) |
| | Next -> |