| Namespace | MPheno.ontology | Obsolete | false |
| description | the luminal space of one or more of the four communicating cavities within the brain that are continuous with the central canal of the spinal cord are severely reduced in volume or area, possibly due to reduced or absent cerebrospinal fluid production; collapsed ventricles can be a sign of increased intracranial pressure and accumulation of water in the brain parenchyma |
