Communicating hydrocephalus in dogs with congenital ciliary dysfunction.

Magnetic resonance imaging (MRI) and radionuclide ventriculography were performed in 5 dogs with congenital ciliary dysfunction (CDD) and 3 normal dogs. Ventricular and brain dimensions and volumes, and CSF flow rates were measured or calculated from the MR images and radionuclide clearance. All CCD dogs had hydrocephalus based on previously published criteria of a percent vertical brain dimension (PVBD) greater than 14%. The PVBD was significantly larger (p = 0.001) in the dogs with CCD (mean +/- SD) 33.00 +/- 5.42% than in normal dogs (11.07 +/- 0.61%. The ventricular volume was significantly larger (p = 0.021) in CCD dogs 10,841 +/- 4,127 mm3 compared to the volume measured in normal dogs 3,069 +/- 1,167 mm3. The CSF flow rate was not significantly different p = 0.876) between CCD dogs (253.00 +/- 147.25 mm3/h) and normal dogs (267.667 +/- 47.61 mm3/h). This suggests that the ventricular dilation in CCD dogs is not due to impedance of CSF flow from the ventricular system by dysfunctional ependymal cilia.