Hypoglycemic Encephalopathy:A Case Report And Literature Review

[Backgroud and Objective]Hypoglycemic encephalopathy (HE) refers to a series of nervous and mental symptoms when the blood glucose is below2.8mmol/L. At a level of0.56mmol/L, there is profound coma that may result in irreversible injury to the brain if not corrected immediately by the administration of glucose. Here we report a case of hypoglycemic coma that happened to a woman with a history of malignant pancreatic tumor and hepatic metastasis. DWI revealed diffuse hemispheric white matter lesions. The patient was in persistent coma even after the blood glucose restored to normal level and died of complications at last. We give a brief analysis of the possible causes of hypoglycemia for this patient. Through the review of relevant literatures, we generalize the etiology, clinical manifestation, diagnosis and treatment of HE. We focus on the pathogenesis of HE, DWI characteristics in acute phase and the relationship of DWI result with prognosis.[Methods]We conduct a literature search using the search terms "hypoglycemia","hypoglycemic","encephalopathy","brain damage","mechanism","magnetic resonance imaging","diffuse weighted imaging" in various combinations via the Pubmed and CNKI. We subsequently review the retrieved publications by reading the abstracts or the full papers according to the relevancy. [Conclusion]Hypoglycemia is seen in the context of numerous metabolic and medical diseases, but most common among patients with diabetes. Profound hypoglycemia, accompanied by EEG isoelectricity and neuronal death, occurs mainly when insulin or oral hypoglycemic agents are administered. Various factors contribute to the high incidence of hypoglycemia with diabetic patients. The neuronal death induced by hypoglycemia is a set of active pathological processes rather than a direct result of energy failure. There is no definite correlation between the initial blood glucose level and poor prognosis for hypoglycemic coma patients. The lesions revealed by DWI in acute phase are not limited to the hemispheric gray matter, basal ganglia, and hippocampus. The white matter is more frequently involved than we have thought and diffuse hemispheric white matter lesions may indicate a poor short-term outcome.