Atypical Ischemic Cranial Nerve Palsy in a Diabetic Patient

Purpose: We report an atypical case of ischemic oculomotor palsy occurring sequentially in both eyes and then improving, fol-lowed by a new abducens palsy in a diabetic patient with poor blood sugar control.Case summary: A 51-year-old woman presented with diplopia, dizziness, and pain in the right eye and was diagnosed with ocu-lomotor palsy in the right eye. Magnetic resonance imaging of her brain was normal but glycated hemoglobin concentration was 13.4%. After 2 months, the third nerve palsy in the right eye had recovered completely but a new third nerve palsy occurred in the left eye. 1 month later, the symptoms had improved, and the patient did not return to our clinic until 18 months later, when she re-turned with new diplopia. This time, she was diagnosed with a sixth nerve palsy in the left eye and was observed while controlling her blood sugar. She recovered after 4 months.Conclusions: Generally, cranial nerve palsies occur unilaterally in situations that can cause ischemia, such as diabetes, high blood pressure, and hyperlipidemia. Rarely, they occur bilaterally, or two or more cranial nerve palsies occur simultaneously. However, it is very rare that cranial nerve palsy occurs sequentially in both eyes under the same systemic blood sugar control. Diabetic patients with poor blood sugar control require long-term monitoring, considering the possibility of symptoms developing in both eyes with a time lag or other forms of ischemic cranial nerve palsy.J Korean Ophthalmol Soc 2023;64(3):266-271