Surgical perspectives of endoscopy of the cerebellopontine angle.

Owing to distal light and panoramic view, the endoscope expands the view inside the cerebellopontine angle without touching the cerebellum or the brain stem and allows clear identification of the vascular and nervous components crossing the cerebellopontine angle. Using a retrosigmoid approach with a combined surgical and endoscopic procedure, the surgeon gets more accurate information to visualize the adjacent structures to a small acoustic neuroma, to check the lateral part of the internal auditory canal, and to locate a vasculonervous cross-conflict. In the future, an endoscopic vestibular neurotomy or an endoscopic microvascular decompression seems to be a possible approach.

[Contribution of endoscopy of the cerebellopontine angle by retrosigmoid approach. Neuroma and vasculo-nervous compression]. / Apport de l'endoscopie de l'angle ponto-cérébelleux par voie rétro-sigmoïde. Neurinomes et conflits vasculo-nerveux.

An endoscopic approach to the cerebellopontine angle has been suggested by several authors over the last 20 years but it is only recently that the technical and operative conditions for successful endoscopy could be met. The retrosigmoid approach provides simple and direct access to the cerebellopontine zone. The endoscope, with its distal light source, provides excellent illumination of a wide visual field within an anatomical site particularly rich in neurovascular structures. Endoscopic and microsurgical techniques may be combined for the surgical management of acoustic neuroma with the advantage of assuring better exposure of structures adjacent to the tumor and better control of the quality of dissection of the fundus of the internal auditory canal. The addition of endoscopic techniques, during surgery for trigeminal neuralgia or unilateral facial spasm, makes it possible to accurately locate the site of neurovascular compression without either retraction of the cerebellum or unnecessary dissection.

[Otologic manifestations of the pain dysfunction syndrome of the stomatognathic system]. / Manifestations otologiques du syndrome algodysfonctionnel de l'appareil manducateur (S.A.D.A.M.).

Phylogenesis, ontogenesis and anatomy explain the close relationship between temporo-mandibular joint and the middle ear and can therefore help understanding otologic symptoms such as: otalgia which often correspond to articular and muscular pain irradiation (coming from sterno-cleido-mastoid, lateral and medial pterygoid, deep layer of the masseter and temporal muscles); acouphens and ear block sensation that could be caused by a spasm extension of the manducatory (i.e. medial pterygoid) to levator and tympani tensors. These three muscles, which originate from the first branchial arch, have a proprioceptive sensitivity and share the same innervation. What is more tensor and levator veli exchange certain muscular fibers. Tensor tympani spasm can be held responsible both for a decrease or abolition of the Klockhoff's reflex, together with a decrease of the stapedian reflex, the latter due to tympani rigidity induced by a spasm of the tensor tympani.