Post-cranioplasty cerebrospinal fluid hydrodynamic changes: Magnetic resonance imaging quantitative analysis

The syndrome of the trephined has been described in many patients with cranial defects as an indication for cranioplasty. Cerebral blood Now changes, the effect of the atmospheric pressure on the brain, as well as cerebrospinal fluid hydrodynamic changes have been postulated as the possible reasons for this syndrome. Using dynamic phase-contrast magnetic resonance imaging we measured arterial, venous, and cerebrospinal fluid Now into and out of the skull, before and after cranioplasty in one patient whose bone nap was removed because of osteomyelitis. We report significant changes in the oscillatory CSF Now after cranioplasty. A moderate increase in venous outflow as well as a two-fold increase in craniocaudal cerebrospinal fluid systolic Now velocity was measured after the skull closure. The changes in the cerebrospinal fluid oscillatory Now at the level of the craniovertebral junction could reflect changes in the compliance of the craniospinal system produced by closure of the cranial defect.