Surgical management of cavernous malformations involving the cranial nerves

OBJECTIVE: To analyze the indications and techniques pertinent to the treatment of cranial nerve (CN) cavernous malformations (CMs). METHODS: CN CMs are lesions isolated to the CNs. CMs affecting the optic nerve (CN II), oculomotor nerve (CN III), facial/vestibulocochlear complex (CN VII and CN VIII), and hypoglossal nerve (CN XII) have been described. The records for six patients were reviewed with respect to lesion location, symptoms, surgical approach, and therapeutic considerations. This is the largest series of CMs isolated to CNs reported to date. RESULTS: Three female patients and three male patients (age range, 28-76 yr; mean age, 41 yr) presented with six CN lesions; four lesions involved the optic chiasm and two involved CN VII and CN VIII. The patients with chiasmatic lesions presented with acute visual deterioration. Both patients with CN VII/CN VIII lesions exhibited acute hearing loss. The level of deterioration suggested CM hemorrhage. Orbitozygomatic craniotomies were performed for chiasmatic lesions, and retrosigmoid craniotomies were performed for cerebellopontine angle lesions. All patients experienced symptom improvement after surgery. One chiasmatic lesion recurred after 2 years and required resection. CONCLUSION: CN CMs present with site-specific symptoms and require complex surgical techniques for resection. These lesions are frequently symptomatic, because of the eloquence of the tissue of origin. Therefore, all CN CMs should be resected. Subtotal resection uniformly results in disease and symptom recurrence. CN CMs can be resected safely, with preservation of CN function.