Arachnoid cysts in children: a European co-operative study.

The data on arachnoid cysts in children (0-15 years) operated upon between 1980 and 1988 were analysed in a retrospective, co-operative study. The results from 285 patients indicate a predominance of these lesions in boys (64%) more than girls (36%) and a mean age of 6 years at onset of symptoms. Focal EEG patterns corresponding to the cyst's location were encountered in 32%. About 40% of all cysts were located along the midline, the sylvian fissure representing the predominant location. Open surgery, i.e. total excision or marsurpialization (together 43.3%), emerged as the first-choice surgical procedure. The type of surgery switched somewhat to shunting procedures in cases of lesions in deeper locations (22.8%). Morphological results on follow-up revealed a reduction of the size of the cyst in a significant majority (61%); in 18% the cyst had disappeared completely on CT scans. There was an obvious correlation between postoperative morphological findings and clinical outcome.