General description

Hypoglycemic encephalopathy is a brain injury caused by prolonged or severe hypoglycemia, often presenting with symptoms such as altered consciousness, loss of consciousness, and seizures.

It commonly occurs in diabetic patients due to an overdose of insulin or oral hypoglycemic agents, particularly in older adults, for whom it is a significant cause of altered mental states. Other causes include excessive alcohol intake and pancreatic insulinomas. Additionally, non-insulin-related hypoglycemia can arise from hormone deficiencies, such as growth hormone or cortisol insufficiency, which impair blood glucose maintenance. Conditions like Sheehan syndrome can also lead to hypoglycemia due to hormonal deficits.

Radiographic features

In the acute phase, MRI shows T2WI, FLAIR, and DWI hyperintensity in the bilateral hippocampus, cerebral cortex, and basal ganglia. Abnormal signals may also be observed in the periventricular white matter, internal capsule, and the splenium of the corpus callosum. As compensation for hypoglycemia, MRA shows arterial dilation, particularly in the middle cerebral artery region, and SPECT reveals hyperperfusion on the affected side.

In the subacute to chronic phase, T1WI shows hyperintensity along the cerebral cortex, suggesting laminar necrosis.

Typically, the thalamus, brainstem, and cerebellum are spared, as the thalamus is rich in adenosine triphosphate, and the brainstem and cerebellum have a robust blood supply.