[Skull base metastases with cranial nerve deficits : Clinical profile of a severe disease]

Skull base metastases are a severe complication of various malignant tumors. If cranial nerves are involved even small lesions can cause significant symptoms. Specific clinical characteristics like neurological symptoms, associated primary tumors, prognosis and optimal treatment are poorly defined and are systematically described in this article.

In a monocentric retrospective study patients with skull base metastases and cranial nerve deficits who received treatment between 2006 and 2018 were analyzed concerning clinical characteristics at initial diagnosis, treatment and course of the disease.

In this study 45 patients with skull base metastases and cranial nerve deficits were included. The most frequent primary tumors were prostate cancer (27%), breast cancer (22%) and multiple myeloma (16%). The most involved cranial nerves were trigeminal nerve (42%), oculomomotor nerve (33%) and facial nerve (27%). Of the patients 84% had additional bone metastases outside the skull base. Dural infiltration or meningeal carcinomatosis were each observed in 13% of the patients. After radiotherapy cranial nerve deficits remained stable in 61% of all cases and in 22% symptoms improved. Median overall survival from treatment was 8 months (range 0.4-51 months). Patients with dose-escalated radiotherapy appeared to live longer (16.4 months vs. 4.7 months). This effect persisted in a multivariate analysis including the Karnofsky index, number of metastases, primary tumor and radiation dose (HR 0.37, p = 0.02).

Skull base metastases with cranial nerve deficits are complex diseases with poor prognosis. Precise diagnosis and treatment are required. Further research is needed to improve treatment.