Clinical neurological findings of children with acute lymphoblastic leukaemia at diagnosis and during treatment.

Serial neurological evaluation was performed on 40 consecutive children with acute lymphoblastic leukaemia (ALL) at the time of diagnosis and during treatment. Abnormal neurological signs were found in 23% of the patients, including some without neurological symptoms on admission. Six patients (15%) had abnormal funduscopy findings, papilloedema or preretinal haemorrhages, and 3 of them had increased intracranial pressure measured in connection with a diagnostic lumbar puncture but without blasts in their CSF. The reason for the increased intracranial pressure remained unclear. The development of neurological symptoms caused by peripheral neuropathy during induction therapy was related to the total dose and duration of vincristine therapy. The most severe walking difficulties, patients moving about on all fours for as long as 6 weeks-5 months, occurred in a group who were significantly younger than the other children (P < 0.03). Fine and gross motor disturbances occurred in 18% and 30% of the whole patient group, respectively, after 2-3 years of therapy. Impaired short-term memory was observed in 21% of the patients after 2-3 years of therapy, indicating impaired CNS function. The results indicate that chemotherapy also seems to influence CNS abilities, since there was no significant difference between the patients treated with or without cranial irradiation. Neurological evaluation of children with ALL at diagnosis and during treatment is of value with respect to abnormal findings which persist and are not caused by leukaemia, in order to determine the types of difficulties involved and to consider intervention.