Etiologic distribution of isolated abducens nerve palsy: Analysis of 807 patients and literature review

Abstract

Background and Purpose The etiologies of abducens nerve palsy have shown a large variability among studies. This study aimed to establish the clinical features and underlying etiologies of isolated abducens nerve palsy by recruiting patients from all departments in a referral‐based university hospital. Methods We reviewed the medical records of 807 patients with a confirmed diagnosis of isolated abducens nerve palsy at all departments of Seoul National University Bundang Hospital, Seongnam, Republic of Korea, from 2003 to 2020. We also compared the proportion of etiology with that of the patients pooled from the previous studies. Results The most common etiology was microvascular (n = 296, 36.7%), followed by idiopathic (n = 143, 17.7%), neoplastic (n = 115, 14.3%), vascular anomalies (n = 82, 10.2%), inflammatory (n = 76, 9.4%), and traumatic (n = 35, 4.3%). Patients were mostly managed by ophthalmologists (n = 576, 71.4%), followed by neurologists (n = 479, 59.4%), emergency physicians (n = 278, 34.4%), neurosurgeons (n = 191, 23.7%), and others (n = 72, 8.9%). The proportion of etiology significantly differed according to the age and sex of the patients and the specialties involved in the management (p < 0.001). Compared to the pooled data from the previous reports, the current study showed a higher prevalence of microvascular cause but a lower occurrence of traumatic and neoplastic causes. Conclusions The results of previous studies on etiologic distribution of isolated abducens nerve palsy should be interpreted with consideration of the demographic features of patients recruited and the specialties involved.

Etiological distribution of isolated oculomotor nerve palsy: analysis of 633 patients and literature review

“…This finding is similar to that observed in our previous studies on isolated trochlear and abducens palsies [18,19]. However, the proportion of involved specialists differed markedly amongst the isolated ocular motor nerve palsies (Figure 6c).…”

“…The etiological distribution of isolated oculomotor nerve palsy observed in this study was significantly different from that of the data pooled from the previous reports with a higher prevalence of neoplastic etiology and lower prevalence of microvascular, idiopathic and traumatic etiologies. Our previous study also showed etiologies of isolated abducens nerve palsy that were different from those of the previous studies [19]. These findings seem to be related to a referral bias since our hospital is less frequently involved in the management of traumatic patients.…”

“…Even though our hospital has neuroophthalmological clinics run by ophthalmologists and neurologists independently but in close cooperation and consultation, it was previously found that only 37.9% of the patients with binocular diplopia as the primary symptom were managed by both neurologists and ophthalmologists in our institution [17]. Furthermore, the etiological proportion of diplopia, trochlear palsy and abducens nerve palsy significantly differed between the clinics [17][18][19].…”

“…The etiological distribution differed amongst the groups of isolated ocular motor nerve palsy recruited from our institution over the same period [18,19]. These differences may be due to the anatomical and physiological characteristics of each ocular motor nerve.…”

“…The results of this study were compared with those of our previous reports on isolated trochlear palsy and isolated abducens nerve palsy performed in the same institution with the same methods during the same period [18,19].…”