Electroencephalographic findings in essential hypoglycemia.

Abstract Essential hypoglycemia is much more frequent than is generally supposed. Many patients with essential hypoglycemia develop disturbances of their cerebral electroactivity during five hour glucose tolerance tests. Glucose can prevent these disturbances which are for this reason considered to be of metabolic nature. The critical blood sugar level necessary to prevent EEG disturbances varies from person to person. It is possible that the critical blood sugar level varies from time to time in the same individual although further studies are needed to clarify this point. There is evidence in this study and in the existing literature that higher blood sugar concentrations are necessary to prevent cerebral electrical irregularities in younger individuals (10, 11). The five hour tolerance test done in conjunction with the EEG helps determine whether the patient's blood sugar concentration customarily falls below his critical threshold during the course of the day. Patients with functional hypoglycemia who show cerebral dysrhythmia at rest or cerebral electrical instability during overventilation during the course of the five hour tolerance test should be treated with anti-convulsant medication such as Hydantoin Sodium in addition to the standard high protein multiple feeding diet. The concept of individual “critical threshold” for glucose metabolism is advanced and evidence relating to this factor is presented. Further study on this point is necessary but the evidence at this time suggests that the concept has validity.