In the cerebral palsy patients, it is often difficult, on the basis of clinical examination and conventional investigations, to assess the functional impairment of brain. This study was planned to evaluate the impairment of brain as a quantitative method using ^99mTc-HMPAO brain SPECT by the regional index(RI). The ^99mTc-HMPAO brain SPECT was studied in the 25 children with cerebral palsy aged from 6 months to 52 months(mean 17.1 months).

The results were as follows:

1) Abnormal findings of brain SPECT were 96%.

2) There was significant difference in the RI in each lobe(p<0.05). The number of the abnormal distribution was 23 in frontal lobe, 14 in parietal lobe, 12 in basal ganglia, 6 in temporal, and 3 in cerebellum and the number of the hemispheric lesion was 8 patients in left, 5 patients in right, and 11 patients in both.

3) The RI of each lobe had no significant difference between the cerebral palsy type(p>0.05) except for spastic hemiplegia(p<0.05).

4) There was no significant correlation between the severity of motor developmental impairment and the RI.

5) The RI of the cerebral palsy with and without suspicious retarded mentality had no significant difference in each lobe(p>0.05).

In conclusion, the ^99mTc-HMPAO brain SPECT seemed to be a useful tool as a index for the functional impairment in brain.