Introduction: Isolated craniosynostosis is often thought to be a benign condition with mainly aesthetic repercussions but psychomotor delay has been reported. A few studies have assessed the impact of this condition on cerebral perfusion using SPECT. We hypothesized that craniosynostosis can influence the cerebral blood flow by constricting or deforming the brain. Arterial spin labelling MRI is a validated technique to assess the cerebral perfusion. The aim of this study was to measure the perfusion of various areas of the brain using ASL MRI in patients with craniosynostosis.
Methods: Seven groups of 10 patients each had pre-operative MRI with ASL-sequence: (1) scaphocephaly less than 6 month of age, (2) scaphocephaly between 6 and 12 months of age, (3) scaphocephaly between 12 and 24 months of age, (4) right plagiocephaly, (5) left plagiocephaly and age-matched control groups. None of the patients had other brain conditions or known mutations. ASL measurements were performed on pre-operative MRI by the same operator for all the patients using 100 mm2 ROI for each of the following areas on both sides: frontal, parietal, temporal, occipital, insula, brainstem, and cerebellum.
Results: In patients with sagittal craniosynostosis aged less than 6 months, a right significant occipital hypoperfusion was observed compared to the age-matched control group (p<0,05). A lower perfusion was observed in the occipital area compared to the frontal area in this group on both sides (p<0.01) contrary to the age-matched control group. In the 20 patients older than 6 months, an occipital decreased perfusion compared to the frontal area was only observed on the right side (p<0.05). In the group of 30 patients with sagittal craniosynostosis, lower cerebral perfusion was observed in the occipital area compared to the frontal area in both sides (p<0.01).
In patients with plagiocephaly, no difference of cerebral perfusion was shown between the side of the coronal fusion and the other side. In patients with left plagiocephaly, a lower cerebral perfusion was observed in left parietal, temporal and occipital areas compared to left frontal area (p<0.05). In patients with right plagiocephaly, the only difference was observed between right frontal and parietal areas (p<0.01).
Conclusion: Premature fusion of skull sutures influences brain perfusion. Sagittal synostosis seems to lower the posterior perfusion of the brain. The impact of unilateral coronal synostosis needs further investigations because of the physiological difference of ASL between the right and the left hemisphere. A pre/post-operative study is furthermore needed to assess the benefits of surgery.