| Abstrakt: |
Introduction. Beacause of its long pathway, the sixth nerve is difficult to identify and evaluate using conventional imaging techniques. For this reason MRI exam, especially T2 weighted spin echo sequences, succeeds to visualise most of the pathway of the cranial nerve. The aim of this study is to evaluate some demographic and clinical features of the sixth cranial nerve palsy. Material and methods. The retrospective study included 48 patients with sixth cranial nerve palsy evaluated with cranial and orbital MRI. None of the patients had a head trauma or a neuromuscular disorder which could cause nerve palsy. Results. The majority of patients were females, under 50 years of age. In 37 cases, the sixth cranial nerve palsy was associated with diabetes, hypertension or hyperlipemia, so the main cause for the palsy was the microvascular lesion. In 7 from the rest of 13 cases, the MRI findings were abnormal (2 tumors and 5 thromboses). From the 6 cases with no pathological aspect on MRI, in 3 cases we observed an arterial compression. In two cases, we couldn't find a cause for the palsy. Conclusions. Sixth cranial nerve palsy is a rare condition, with the most frequent causes being microvascular lesions, tumors, infections, trauma, diabetes and hypertension. Because of the long pathway, the 6th nerve can't be evaluated with classical imaging methods. MRI T2 weighted and CISS sequences are proven to be very useful for an accurate diagnosis. In only 4% of our cases, we couldn't find a cause, even with the aid of MRI examination. [ABSTRACT FROM AUTHOR] |
