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.

[Transcranial magnetic stimulation of the facial nerve in patients with acoustic neuroma].

Magnetic stimulation of the human facial nerve was used in 30 patients with small or medium-sized acoustic neurinomas pre-operatively. Needle-EMG revealed symmetrical aspect in the orbicularis oris muscle on the affected and on the contralateral side. The latencies in the extracranial part of the facial nerve after supramaximal electric stimulation in the area of the stylomastoid foramen and the latencies after temporo-occipital, transcranial magnetic stimulation were measured.

New markers for the neurofibromatosis-2 region generated by microdissection of chromosome 22.

To identify new DNA markers around the neurofibromatosis-2 gene on human chromosome 22, the critical region (22q12-q13.1) was microdissected and microcloned from GTG-banded metaphase chromosomes. Eighteen thousand recombinant clones were obtained.

Extended middle cranial fossa approach for acoustic neuroma surgery.

The enlarged middle cranial fossa approach was used for removal of acoustic neuromas in 209 cases. Complete tumor removal was accomplished in 96% of cases. Hearing was preserved in 51% of cases, with better results in smaller tumors.

Topographical anatomy of the internal auditory canal. Implications for functional surgery in the cerebello-pontine angle.

For exposure of the cerebello-pontine angle by an enlarged middle-fossa approach without destruction of the inner ear, bone removal anterior and posterior to the internal auditory meatus (c.a.i.