QUANTITATIVE EEG DURING CONTROLLED HYPOGLYCEMIA IN DIABETIC AND NONDIABETIC CHILDREN

We investigated quantitative EEG in 19 diabetic children (mean age 14. 2 (SD 1.4) years, mean HbA(1C) 9.8 (SD 1.2)% and 17 nan-diabetic child ren (14.3 (1.1) years) during and after a gradual reduction in plasma glucose with the glucose clamp technique, The amplitudes of the EEG fr equency bands at each glucose level were compared to the registration prior to hypoglycaemia. At plasma glucose similar to 4 mmol l(-1), a s mall increase in delta (p < 0.05) and theta (p < 0.01) amplitude appea red in the combined diabetic and control group. At similar to 3 mmol l (-1), and at glucose nadir, a further and widespread increase in low-f requency EEG activity was observed. In diabetic and non-diabetic subgr oups with similar glucose nadirs, the diabetic children had more delta (p < 0.01) and theta (p < 0.01) activity, and more epileptiform activ ity (p < 0.05), than the non-diabetic children, In the non-diabetic su bjects, but not in the diabetic subjects, the increase in delta and th eta activity correlated with a hypoglycaemic symptom score (r = 0.75, p = 0.001 and r = 0.77, p < 0.0005, respectively). In conclusion, EEG changes are detectable already at plasma glucose similar to 4 mmol(-1) in children. EEG deterioration during hypoglycaemia is more pronounce d in diabetic than in non-diabetic children. The increase in cerebral disturbances is not accompanied by an increment in hypoglycaemic sympt oms in diabetic children. (C) 1998 John Wiley & Sons, Ltd.