Electroencephalographic changes in diabetic ketosis in children with newly and previously diagnosed insulin-dependent diabetes mellitus

Abnormal electroencephalograms in patients with long-standing diabetes mellitus have been attributed to hypoglycemia. EEG changes in newly diagnosed patients or in patients during episodes of diabetic ketoacidosis have not previously been reported. We performed serial EEGs at one, 12, 24 hours and five days after initiation of treatment for DKA on 39 patients aged 11 months to 16 years with newly or previously diagnosed insulin-dependent diabetes mellitus. Twenty-seven patients were in ketoacidosis and 12 patients ketotic only. Abnormal EEGs were found in 30 patients on admission. The EEG changes at one hour, classified in order of increasing severity, correlated with the serum glucose, osmolality, bicarbonate, beta-hydroxybutyrate, and acetoacetate values, but not with pH or glycosylated hemoglobin. The rate of improvement of the EEGs was unaffected by the addition of phosphate to the intravenous fluids during therapy. EEG changes persisted in five of the seven children who had follow-up studies at two to five months, and in two of the six children one year after admission. We conclude that EEG changes are common in children with DKA or ketosis, the severity of the abnormalities being most closely associated with the degree of hyperosmolality rather than acidosis. These changes may persist in some cases, possibly accounting for the increased frequency of EEG abnormalities in diabetic children.