[Skull base metastases with cranial nerve deficits : Clinical profile of a severe disease]. / Schädelbasismetastasen mit Hirnnervenaffektionen : Klinischer Steckbrief einer schwerwiegenden Erkrankung.

BACKGROUND AND PURPOSE: 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. METHODS: 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. RESULTS: 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). CONCLUSION: 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.

Focal hand dystonia: lack of evidence for abnormality of motor representation at rest.

OBJECTIVE: To examine whether the corticospinal system emanating from the primary motor cortex may be organized to facilitate generation of dystonic movements. METHODS: In this cross-sectional observational study, finger movement (FM) representations were assessed in 10 patients with focal hand dystonia (FHD) and 10 matched healthy controls by transcranial magnetic stimulation during rest. Evoked finger movements of the right hand were recorded using an instrumented data glove. Patterns of finger joint movements were analyzed using cluster analysis. Principal component analysis and centers of gravity for finger movement representations and motor evoked potentials recorded from the abductor pollicis brevis and abductor digiti minimi muscles were computed. For comparison, high-resolution somatosensory evoked potentials (SSEP) were recorded after electrical stimulation of the thumb (D1) or little finger (D5) in the same patients. Source reconstruction for the N20 SSEP component was performed using a dual-dipole model. RESULTS: Stimulation of the resting motor cortex did not reveal overt abnormalities in FHD, neither with respect to finger joint movement patterns nor with respect to the topologic organization of finger movements or intrinsic hand muscle representations. However, in line with previous reports, the distance between the dipole sources of D1 and D5 in the somatosensory cortex (S1) was smaller in patients with FHD, suggesting disruption of homuncular finger representations in S1. CONCLUSIONS: Our findings may imply that abnormality of motor organization in focal hand dystonia arises principally only during activation, when abnormal somatosensory representations are functionally integrated.