The Treatment of Neurofibromatosis Involving Trigeminal Ganglion

ABSTRACT

Neurofibromatosis is a syndrome of multiple neurofibromas, abnormal skin pigmentation and certain bony abnormalities. Sometimes the growth of plexiform neurofibromatosis on the face or trunk is centripetal and usually involves the mediastinum and skull base. However, it is very rare that neurofibromatosis involves the trigeminal ganglion. Its encroachment around the foramina of the skull base may induce facial palsy or conductive hearing loss. The guiding principle in the treatment of generalized neurofibromatosis is a radical excision with preservation of vital structures and an immediate reconstruction of the bony skeleton and soft tissue defect. The authors experienced 4 cases of neurofibromatosis involving the trigeminal ganglion. All had trigeminal symptoms for 3 to 4 years. These were severe headache and intractable trigeminal neuralgia. Tumors in all 4 cases were spread in the centripetal type from extracranial neurofibromatosis. The facial nerve was affected in 4 cases. Malignat Schwannoma occurred in 1 case. Accurate diagnosis and assessments were necessary with CT, MRI art oomputer-aided simulation design. Intraoperative bleeding was minimal with hypotensive anesthesia. Surgical approach to the middle cranial fossa involved temporary removal of the zygomatic arch and TMJ disarticulation with downward traction of the mandible. Satisfactory results have been obtained far 3 to 7 years(mean 5 years) follow-up.