Hyperosmolar hyperglycemic state (HHS), also known as nonketotic hyperglycemia (NKH) occurs in a poorly controlled diabetic. HHS is characterised by high blood sugars (usually more than 600 mg%), increased serum osmolarity and profound dehydration.
80-year old lady presented with acute onset altered sensorium and involuntary choreiform movements affecting the left upper and lower limbs. There was mild weakness of the left upper and lower limbs. Blood glucose at admission was 850 mg%.
MRI brain was done, which showed hyperintense lesions on T1W images, affecting right caudate and lentiform nucleus.
Asymmetric hyperintensity affecting caudate nucleus and lentiform nucleus is almost exclusively seen in nonketotic hyperglycemia/hyperosmolar hyperglycemic state.
Conditions that can cause symmetrical hyperintesities in caudate nucleus & lentiform nucleus on FLAIR/T2W MRI images include liver disease, manganese toxicity (in patients on long term total parenteral nutrition), hypoxic-ischemic injury, etc.