Isolated oculomotor nerve palsy after lumbar epidural steroid injection in a diabetic patient

BACKGROUND: In patients with diabetes mellitus, epidural steroid injections (ESI) have been noted to cause significant elevation of blood glucose levels, typically lasting 1–3 days. Here, we describe a previously unreported complication of a diabetic third nerve palsy associated with an ESI. CASE DESCRIPTION: A 66-year-old man with a history of coronary artery disease, hypertension, and insulin-dependent diabetes mellitus presented with low back pain and left lower extremity radiculopathy. The lumbar magnetic resonance imaging (MRI) revealed mild spondylosis, most severe at the L4-5 level, accompanied by a broad based disc protrusion resulting in mild central and moderate biforaminal stenosis. The patient underwent a left-sided L4-L5 transforaminal ESI resulting in transient elevation of his blood glucose levels. On post-procedure day 2, he developed a frontal headache and a complete right third nerve palsy with partial pupillary involvement. The MRI and MR angiography (MRA) of the brain revealed no compressive lesions or oculomotor abnormalities. Ophthalmoplegia and pupillary dysfunction resolved spontaneously over 4 months. CONCLUSIONS: Although rare, a history of a recent ESI should be considered as the etiology of an isolated oculomotor palsy in diabetic patients.