Cranio-cerebral Disproportion as a Late Complication

Abstract

Cranio-cerebral disproportion (CCD) is a late complication of chronic CSF shunting with a poorly understood pathogenesis. Although the CSF shunt plays undoubtedly the leading role, the pathogenetic mechanism is probably more complex than hypothesized so far. Indeed, also the brain and the skull play an active role, thus configuring a “three actors drama”. The diagnosis of CCD is based on the clinical picture, that is characterized by intermittent symptoms and signs of raised intracranial pressure in subjects shunted before the age of 2-3 years. However, the integration with instrumental data is crucial for the differential diagnosis with other late complications of chronic CSF shunting, such as the slit ventricles syndrome (SVS), which may have similar clinical presentations. CT scan and MRI may actually show the peculiar modifications of the calvarium (decreased intracranial volume, thickened calvarial bones) associated with the condition together with the evidence of effaced subarachnoid spaces unable to accomodate for sudden volumetric increases of the intracranial content. Though theoretically the only effective way to prevent CCD is avoiding to place a CSF shunting device, various surgical measures can be utilized to decrease the risk of its occurrence or can be adopted once the complication is established.