Rationale: Electroencephalographic (EEG) changes are frequently observed not only by epileptic seizures but also by metabolic encephalopathies. The EEG changes during hypoglycemia are known as mixed frequency theta to delta activity with higher amplitude than the initial background rhythm. Although there are many reports about hypoglycemia induced EEG changes, few studies of hypoglycemic EEG patterns have been evaluated between arousal and sleep stage.
Patient concerns: A 45-year-old man who had been diagnosed as type 1 diabetes mellitus for 15 years admitted to the emergency room due to seizure attack. The EEG findings of the patient showed increased amplitude of theta slowing on both hemispheres. The abnormal EEG finding had recovered and the background frequency remarkably increased as the patient fell asleep, but reappeared when he woke up.
Diagnosis: The patient was diagnosed as hypoglycemia with altered mentality.
Interventions: Fifty percent dextrose fluid 50 mL was loaded and maintained with 10% dextrose water afterwards.
Outcomes: The patient improved after medical treatment.
Lessons: The EEG presentation of hypoglycemia involves low frequency and increased amplitude of delta-theta activity. As the previous studies, we observed medium amplitude semi-rhythmic theta slowing EEG findings on both hemispheres during arousal, indicating hypoglycemia. However, it was stabilized during sleep as background frequency increased and medium amplitude of slowing disappeared. Although there are many reports about hypoglycemia induced EEG changes, few studies of hypoglycemic EEG patterns have been evaluated between arousal and sleep stage. We report a case of different EEG patterns between arousal and sleep stage during hypoglycemia.