A simplified suboccipital technique for trigeminal, acoustic, or glossopharyngeal rhizotomy.

A new technique for the suboccipital approach to the cerebello-pontine angle was presented to this society* in November, 1941, but because of the advent of war, publication was postponed. This technique was developed principally for section of the trigeminal root . for tic douloureux, but is useful for certain other procedures in the angle. The present report is based on our experience with this method in about 175 cases. This approach has prowed in my experience to be easier to carry out than the temporal approach. Furthermore, the clinical result has been superior in that subjective numbness is considerably less and the corneal reflex can almost always be preserved. Although the technique is simple, observance of several essential points is required; otherwise, the procedure may prove to be difficult or even hazardous. The patient is placed on his side and the head of the table is elevated well above the lumbar region. The patient's head is flexed well forward to facilitate access to the sub-occipital region. A lumbar spinal puncture is performed, but no fluid is released. An incision is made 4 to 5 cm. in length and is placed vertically with its mid-point about 5 cm. posterior to the external auditory canal. This is carried to the bone and an adequate area of bone is exposed with a periosteal elevator. A small, self-retaining retractor will usually control the bleeding, although electro-coagulation may be necessary. Occasionally the mastoid emissary vein may be torn, but can be controlled easily by electrocoagulation and bone wax. Although I perform the procedure through a burr hole one inch in diameter, a larger opening is recommended until the surgeon becomes accustomed to the procedure. If a small opening is used, a headlight which provides light between or near the operator's eyes is essential. The burr hole is placed so that its r includes the bloi suture and the lateral margin inc_Tudes the occipito-