Bobble-head doll syndrome associated with subduroperitoneal shunt malfunction.

Bobble-head doll syndrome is known to be associated with aqueductal stenosis or cystic lesions of the III ventricle. The direction of movement is usually vertical. In the literature, only five cases of purely horizontal movement have been reported. Bobble-head doll syndrome manifested as a sign of shunt malfunction has been described in one case with a ventriculoperitoneal shunt. The authors report on a 10-year-old boy who showed subduroperitoneal shunt malfunction associated with horizontal bobble-head doll syndrome. The head bobbing disappeared immediately after shunt revision. Unlike the previously reported cases, in the present case the lesion was asymmetric, though the significance of this for the lateral movement is not clear. This case also showed more marked ventricular dilatation on subduroperitoneal shunt malfunction than in the pre-shunt state. The underlying mechanism of the ventricular dilatation is unknown.