Cerebellopontine Angle Region Research Articles

Intramedullary epidermoid cyst in the brain stem: Case report

The incidence of intracranial epidermoid cysts is between 0.2% to 1.8% of all brain tumors. They usually occur in the cerebellopontine angle or parasellar region. Intramedullary epidermoid cyst is rare and only nine cases have been previously reported. A 69-year-old woman had progressive left hemiparesis for 2 years. Computed tomography scanning and magnetic resonance imaging (MRI) revealed that there was a cystic tumor in the pons that was compressing the brain stem. A part of the tumor cyst wall and the content of the cyst were surgically removed by right subtemporal transtentorial approach. The histologic diagnosis was epidermoid cyst. After the surgery, the left hemiparesis was improved and there was no sign of the tumor growth by MRI. The outcome of the previous cases with radical tumor resection was poor compared with the present case in which only a part of the cyst wall and the content were removed. Therefore, radical removal of the whole tumor may not be necessary for intramedullary epidermoid cyst of the brain stem.

Gross (mesoscopic) and applied anatomy of the anterior inferior cerebellar artery in man with special reference to its course through the cerebellopontine angle region.

In the present paper, we describe anatomical variants of the anterior inferior cerebellar artery in man for applicative purposes. Our goal was to provide the surgeon with a detailed anatomical view of the region. This is similar to what he may observe through the surgical microscope using modern microsurgical techniques. We have focused our attention on the segments of the artery comprising its origin, its course until it reaches the cerebellum and its main collateral branches. Our results confirm the great variability of the elements under study, but enable the establishment of a few basic variational patterns. These patterns together with their relative frequency may be helpful in microsurgery.

Intracranial metastasis of a choroid plexus papilloma originating in the cerebellopontine angle region: A case report

The authors present a rare case in which a choroid plexus papilloma originating in the left cerebellopontine angle region metastasized and formed a space-occupying lesion in the right temporal region. A 46-year-old woman with choked disks presented with two separate mass lesions in the right temporal and the left cerebellopontine angle regions. Magnetic resonance imaging exhibited the relationship between the tumors and the surrounding structures. To our knowledge, no case has been reported in which a choroid plexus papilloma originating in the cerebellopontine angle region formed a space-occupying lesion in the right temporal region.

Linear versus zirkulär polarisierte Kopfspule - Vergleich am Phantom und in der Klinik

Two different head coils--one with linear polarization and the other with circular polarization--were compared under the same measurement conditions. Comparison was done on a phantom with water-filled and gadolinium-filled pin-holes, as well as on anatomical MR images of 23 volunteers. In three volunteers the whole brain was examined while, in the remaining 20 volunteers the sella region or cerebellopontine angle region was examined. Criteria for comparison were signal-to-noise ratio, background noise, and detail resolution (phantom), as well as subjective criteria--image sharpness, anatomical, contrast, and recognition of anatomical details--, evaluated on anatomical MR images by four radiologists independently of each other. The results show a significant improvement of signal-to-noise ratio, lower background noise and therefore marked improvement of images sharpness, and moderate improvement in the recognition of anatomical details using the circular polarized head coil; as for as detail resolution and anatomical contrast were concerned, however, no significant difference was seen between the two coils. Major advantages of the circular, polarized head coil in clinical application are shorter measurement times (reduced number of acquisitions), as well as thinner slices without loss of signal-to-noise ratio.

Infratentorial neoplasms, including the internal auditory canal and cerebellopontine angle regions

Infratentorial neoplasms, including the internal auditory canal and cerebellopontine angle regions

三叉神経鞘腫の2例

Symptomatologic and neurological features of two cases of trigeminal neurinoma are reported.Case 1. A 22-year-old male, complained of left facial disturbance and hypogeusia. Neurological examination revealed damage of the Vth cranical nerve. Cerebellar symptoms were noted. His functional examination of equilibrium showed Bruns nystagmus, direction changing positional nystagmus, saccadic pattern on ETT, hyporesponse on OKP and OKAN, and positive visual supression test. Enhanced CT scan disclosed a mass in the left cerebellopontine angle region. The cystic mass was removed by the subtemporal approach, and diagnosed as trigeminal neurinoma.Case 2. A 36-year-old female had difficulty in walking. Neurolog i cal examination reveraled damage of the Vth cranical nerve. Cerebellar symptoms were noted. Her functional examination of equilibrium showed right spontaneous nystagmus, Bruns nystagmus, direction changing positional nystagmus, saccadic pattern on ETT, hyporesponse on OKP and OKAN, and positive left visual supression test. Enhanced CT scan disclosed a ring enhanced mass in the left cerebellopontine angle region. The cystic mass located at the posterior fossa was removed by the left retromastoid suboccipital approach, and diagnosed as trigeminal neurinoma.

Gefäßschlinge - Ein Beitrag zum vaskulären Kleinhirnbrückenwinkel-Syndrom

Modern diagnostic methods such as brainstem-evoked response audiometry and CT scanning with positive and negative contrast enhancement represent a major advance in the diagnostic evaluation even of small acoustic neuromas. However difficulties arise in differentiation between tumours and other cerebellopontine angle lesions, as shown by means of a case report. An arterial loop of the anterior inferior cerebellar artery (AICA) between the facial and the eighth cranial nerve was the cause of progredient neural hearing loss, peripheral vestibular dysfunction and hemifacial spasm. Vascular decompression was performed with total relief of spasm and partial restitution of hearing. In differential diagnosis of the pathology of the cerebellopontine angle region and the internal auditory canal the clinical symptoms are important.

A Case of AVM of the Cerebellopontine Angle Region Distinctly Diminished by Radiation Therapy

A Case of AVM of the Cerebellopontine Angle Region Distinctly Diminished by Radiation Therapy