Hypoglycemia may cause acute hemiplegia. The most common diffusion-weighted MR imaging finding in patients with hypoglycemic hemiplegia is the hyperintense lesion involving the internal capsule, mimicking acute ischemic stroke. Thus, in patients with acute onset hemiplegia, it is important to differentiate hypoglycemia on arrival by immediate blood glucose measurement. It has recently been shown that hypoglycemic brain injury start in large white matter tracts such as internal capsule and spread throughout the whole brain, including the gray matter. However, it is still unclear why focal signs such as hemiplegia develope in metabolic disorders affecting the whole brain.