Acquired isolated abducens nerve palsies: a retrospective study on etiology in an Iranian population

Abstract

Objective: We investigated causes of abducens nerve paralysis, the side of the involvements, age, and sex distribution of causes. Background: Abducens nerve paralysis is the most common nerve palsy among ocular motor nerves, which have not been investigated in Iran yet. Material and Methods: This is a retrospective case-series study performed from April 1995 to April 2000. We investigated 50 patients who attended to the Neuro-ophthalmology Clinic in Farabi Eye Hospital and were diagnosed as acquired isolated unilateral or bilateral abducens nerve paralysis. Results: The most common causes were ischemia (44%), tumors (18%), idiopathic intracranial hypertension (14%), and multiple sclerosis (8%). The less common causes were trauma, undetermined, arteriovenous fistula, aneurysm, syphilis, and temporal arteritis. The paralysis was seen in 28 women (56%) and 22 men (44%). Seventy percent of patients were older than 40 years of age, and also peak incidence of abducens nerve paralysis was at the sixth decade of life. Conclusion: In contrast to earlier studies, in our study the most common cause of abducens nerve paralysis was ischemic cause and the undetermined cause was not a prominent cause of paralysis. Moreover, the age peak of abducens nerve paralysis was a decade earlier than a similar earlier study, which is probably due to high prevalence of diabetes mellitus as ischemic cause in our country.

• Abducens Nerve Palsy
• Etiology
• Ischemia