Low grade astrocytomas in the West of Scotland 1987-96: treatment, outcome, and cognitive functioning

Background-Low grade astrocytomas are among the most common central nervous system tumours in children. Aims-To identify risk factors for the development of persistent intellectua l handicap. Methods-The notes of 30 children with histologically proven low grade astro cytoma who presented during the period 1987-96 were reviewed. Thirteen of t hese children who were diagnosed with intracranial tumours between 1992 and 1996 underwent cognitive assessment one year after the completion of treat ment. Results-Low grade astrocytomas were found in the cerebellum (59%), thalamus (17%), cerebral hemispheres (10%), and the cervical spinal cord (9%). Wher e possible all patients were treated with gross total resection of the tumo ur. Symptomatic children with tumours judged to be inoperable underwent bio psy followed by radiotherapy (13%). Three patients developed progressive di sease following surgery and underwent repeat surgery and radiotherapy. Surv ival at a median follow up of 75 months (range 30-131) is 97%. At one year after the completion of treatment persisting cognitive impairment was commo n. The strongest predictor of IQ scores was the duration of symptoms of inc reased intracranial pressure preoperatively. Conclusions-Although the overall survival rate of children with low grade a strocytoma is excellent, significant long term disability occurs. Early dia gnosis is essential to reduce postoperative cognitive morbidity.