Non-Ketotic Hyperglycemia Causing a Transient Unilateral Homonymous Hemianopia: A Manifestation of Occipital Lobe Seizure

Focal seizures related to non-ketotic hyperglycemia (NKH) are rare in clinical practice. Plasma glucose levels are usually above 16.6 mmol/L and with normal or slightly elevated serum osmolality. The occurrence of focal seizures may be augmented by the absence of ketoacidosis. Electroencephalogram (EEG) during seizures usually confirms the diagnosis, however, the absence of epileptiform discharges does not rule out seizures. A non-ketotic hyperglycemia-associated occipital lobe seizure can manifest itself as color flashes, blurry vision with periodic confusion, and usually resolves with insulin treatment and rehydration. We are reporting a 65-year-old male patient who presented with intermittent confusion and left-sided visual disturbances, found to have a blood glucose of 33.7 mmol/L with a normal anion gap of 10 and calculated serum osmolality of 303 mOsm/L. The patient's visual disturbances responded very well to rehydration and insulin treatment.

Keywords: nonketotic hyperglycemia; normal brain imaging; normal eeg; occipital lobe seizure; type 2 diabetes; unilateral homonymous hemianopia.