Divided 3, 284 patients of the head injuries into three age groups, the children, the adults, and the aged, and investigated the relationship of their clinical pictures, X-ray evidences, and EEG abnormality.
1) EEG abnormality of the head injuries most frequently appeared in the children (49%), less frequently in the aged (35%), and least frequently in the adults (24%).
2) As to the relationship between the consciousness disturbance and EEG abnormality, 10 mins interval of the unconsciousness became a borderline; the abnormal EEG more frequently appeared, when the unconsciousness was more than 10 mins.
3) The diffuse abnormality frequently appeared in the children, and the frequent focal abnormality was found in the aged.
4) About half of the patients of skull fracture showed the abnormal EEG.
5) As to burst, theta waves frequently appeared in the children; alpha range wave in the adults; and delta waves in the aged.
6) Spike, spike and wave complex, and sharp wave were mainly found in the children.
7) The slowing trend like diffuse slow wave, posterior half slowing, and such was found in the aged.
8) Slow wave of high amplitude like posterior half random δ, θ waves were found many in the children.
9) Abnormal wave activated by the hyperventilation and photic stimulation was observed frequently in the children and rarely in the aged.