Focal Neurological Seizure due to Hyperglycemic Hyperosmolar Non-Ketotic Syndrome in Undiagnosed Diabetes Mellitus

Hyperglycemic hyperosmolar non-ketotic syndrome (HHNS) is a life-threatening complication of type 2 diabetes mellitus with a wide range of presenting symptoms. Neurological symptoms, such as coma, can also be part of the manifestation of HHNS; however, focal seizures remain a rare but notable association. A 85-year-old male patient with no history of diabetes presented to our emergency department complaining of a two-day history of twitching movements of his left wrist. Laboratory findings suggested HHNS and his hemoglobin A1c were found to be 10.2%. He was aggressively treated in the intensive care unit with fluids and insulin which also resolved his seizure episodes. He was ultimately discharged in stable condition without any seizure-like activity while having good glycemic control. According to the American Diabetes Association, about 25% of all individuals 65 years and older have diabetes mellitus. With an increasing prevalence, the complications of uncontrolled diabetes are also becoming more notable. While the neurological deficits associated with HHNS are focal, the mechanism by which this occurs is still poorly understood and underreported warranting further studies.