Further observations on the "bobble-headed doll syndrome".

Two patients are presented with a head-bobblng "tic" classically associated with a suprasellar cyst. The first of these showed hypothalamic, neuroendocrinological and limbic abnormalities not previously described, although with a classic arachnoidal suprasellar cyst. The second of these patients showed head-bobbling behaviour during the first years of life as a manifestation of one out of many episodes of ventricular shunt obstruction. This case is therefore the first reported whose head bobbling was observed with an acute lesion.