Prepared encephalocele. Rhinorrhea. Question CSF leak. There is a large defect at midline involving the floor of the anterior cranial fossa through which a combination of CSF and dysplastic brain parenchyma extend to completely fill the nasal cavity. The herniated, dysplastic brain parenchyma also shows cystic change, which likely represents cystic encephalomalacia. Linear T2 hypointense structure (probably graft material from previous repair) is oriented higher anteriorly than posteriorly. There is an apparent, 9-mm in transverse diameter defect posterior to this presumed graft and anterior to the body of sphenoid. Through this defect, there is apparent direct communication between the nasal cavity and the anterior cranium. Multiple foci of susceptibility effect are related to previous repair or calcifications.T2 hyperintensity and volume loss involving the inferior aspect of the frontal lobes is probably gliosis and encephalomalacia, possibly relating to previous repair. The large nasoethmoidal cephalocele and the encephalomalacia/gliosis in the frontal lobes are associated with expected ex vacuo enlargement of the frontal horns of the lateral ventricles, left more than right. The frontal horn of the left lateral ventricle is pulled inferiorly towards the encephalocele opening as well. These parenchymal changes are associated with expected anterior thinning of the corpus callosum. The olfactory bulbs are not well delineated. The remainder of the brain shows no significant abnormality. The pituitary gland and infundibulum are normal. There is mild hypertelorism and orbital deformity which are better appreciated on the comparison CT scan. The optic nerves, chiasm and tracts are normal. The left internal carotid artery is small and shows attenuated flow-related signal/loss of signal up to the supraclinoid segment where it is joined by a large left posterior communicating artery which provides the flow to the left middle and anterior cerebral arteries. The flow void in the left M1 segment is partially attenuated compared to the normal right one, which may reflect slower flow. The sylvian branches are fairly symmetric and normal. These left internal carotid artery findings are probably related to prenatal thrombosis/injury given the that left petrous carotid canal is very small. The right anterior cerebral artery and its branches are smaller than on the right but show no focal stenosis. The vertebral arteries included are symmetric and normal. There is a small fenestration along the proximal basilar artery which is otherwise normal. In addition to the large left posterior communicating artery, there is a smaller right posterior communicating artery as well. The included downstream segments of the posterior cerebral arteries included are symmetric.The nose is markedly deformed without normal anatomic landmarks or features. As discussed above, the nasal cavity is entirely occupied by the cephalocele. While the hard palate is present, there is no soft palate. There is asymmetric, right more than left, enlargement of the palatine and pharyngeal tonsils. The nasopharynx is partly filled with secretions but the patient is intubated. There is T2 hyperintensity in the mastoid cells and middle ear cavities. The inner ears are unremarkable. Mucosal thickening in the maxillary sinuses may part relate to obstruction of outflow by the large nasoethmoidal cephalocele.Please refer to the companion CT scan for better assessment of the osseous structures involved.
1.While there are changes suggesting previous repair, there is still a large anterior encephalocele containing CSF and dysplastic likely partially encephalomalacia brain parenchyma occupying the nasal cavity. 2.The presumed graft along the floor of the anterior cranial fossa is deficient posteriorly with a 9 mm left paramedian defect as described above.3.Apart from expected changes in the frontal lobes related to the large nasoethmoidal cephalocele and its repair, the brain shows no significant abnormality. 4.Markedly attenuated flow in the left internal carotid artery is probably related to antenatal insult as described above. A left posterior communicating artery provides flow to the left anterior and middle cerebral arteries. Please see above for more details.