Cranial mononeuropathies in diabetes mellitus: A comparative clinical study of oculomotor (CN III) and abducens (CN VI) nerve palsies

Diabetic cranial mono-neuropathiesis a distinct, acute focal manifestations of microvascular angiopathy that affect multiple cranial nerves. The extraocular motor nerves are vulnerable to ischemic events within the vasa nervorum. Objective: this study aimed to evaluate and compare the clinical presentation, metabolic profiles, and prospective recovery timelinesbetween diabetic patients presenting with isolated, microvascular oculomotor nerve (CN III) palsies versus abducens nerve (CN VI) palsies. Material and methods. A prospective cohort study was conducted on 94 patients aged ≥40 years presenting with acute, isolated diabetic CN III palsy (n=50) or CN VI palsy (n=44) for the period from 1st of January 2024 to the 1st of January 2026. Baseline clinical characteristics, duration of diabetes mellitus (DM), and glycated hemoglobin (HbA1c) profiles were evaluated at presentation. Patients were actively followed up to document the exact timelines required to achieve initial clinical improvement and complete functional resolution of ptosis and binocular diplopia. Results. The study cohort demonstrated an overall mean age of 61.3±8.4 years, characterized by a prominent male predominance (61.7% male vs. 38.3% female). The prodromalperiorbital or brow pain was significantly more prevalent and severe in the CN III compared to the CN VI cohort (84.0% vs. 45.5%). The systemic metabolic profile revealed poorly optimized glycemic control (overall mean HbA1c: 7.85%±1.12%), withoutsignificant variation between the two nerve groups. Spontaneous, complete functional neural recovery was successfully achieved in all cases within a 24-week observational window. Notably, the CN VI palsy initiated clinical recovery significantly faster (4.2±1.1 weeks vs. 5.1±1.3 weeks) and reached complete functional resolution significantly earlier (8.4±1.9 weeks vs. 10.2±2.4 weeks) than the CN III. Conclusions. Isolated diabetic CN III and CN VI mononeuropathies share an identical metabolic microvascular background and carry a uniform prognosis for spontaneous recovery. However, CN VI palsies exhibit significantly faster resolution.