Neuropsychological abnormalities following CNS prophylaxis in children with acute lymphatic leukemia.

The pattern and prevalence of neuropsychological abnormalities in children receiving combination CNS prophylaxis (2000 rads cranial irradiation and intrathecal methotrexate) during therapy for acute lymphoblastic leukemia (ALL) were studied. Thirty five children (25 boys) in the age group 5-15 years (mean 9.3) with no evidence of CNS leukemia were included and 20 age matched normal siblings served as controls. Neuropsychological parameters of general intelligence (Malin's modification of WISC test); attention and concentration (colour cancellation test); memory (modified PGI memory test) and visuomotor perception (Bender Gestalt test) were evaluated at least 6 months after CNS prophylaxis. Six (17.1%) patients had mean intelligence quotients (IQ) less than 85, while all controls had IQ > 85 (p < 0.05). The mean IQ of the patient population (93.4 +/- 11.9) was significantly lower than the control group (107 +/- 8.4) (p < 0.001). Scores on the colour cancellation test were lower in the patients as compared to controls (148.7 +/- 27.7 versus 184.9 +/- 23.9; p < 0.01). The mean memory quotient in the patient population was also lower than in controls (74.5 +/- 12 versus 93.6 +/- 9.2; p < 0.001). Scores on the Bender-Gestalt test did not show a significant difference. The presence of significant neuropsychological abnormalities in patients of ALL indicates the need for modification of the schedule of CNS prophylaxis. A comprehensive psychometric evaluation at regular intervals is essential for longterm rehabilitation.