[Isolated abducens paralysis--a retrospective study of 165 patients]

In this retrospective study the case reports of 165 patients suffering from an abducens nerve palsy as the main presenting symptom were evaluated. The sixth nerve palsy was more frequent on the left (52%) than on the right hand side (38%), in 10% there was bilateral involvement. In 49 cases a vascular origin was suspected (29.7%), with diabetes mellitus as the most important risk factor (n = 35). Abducens palsies in inflammatory diseases (n = 32, 19.4%) were seen most often in multiple sclerosis (n = 11), viral meningoencephalitis (n = 5) and accompanying systemic viral infections (n = 5). Postvaccinal paresis was seldom (n = 1). Tumours (n = 18, 10.9%) causing sixth nerve paresis were metastases to the brain (n = 7), meningiomas (n = 3) and glioblastomas (n = 2). Nasopharyngeal carcinomas lead in 4 cases to an involvement of the abducens. Aneurysms causing sixth nerve palsy (n = 7, 4.2%) most frequent being located at the intracavernous region of the internal carotid artery (n = 4). In traumatic abducens paresis (n = 5, 3.1%) pathological findings of neuroradiological examinations are rare. In 48 patients (29.1%) diagnosis remained unclear, especially in young adults between the 20th and 40th year of age. Prognosis of abducens paresis is good in lesions of vascular and unknown origin; in these cases non-steroidal antiphlogistics are of benefit.