Male, 2 years old, with recent abnormal movements, status post tethered cord release three months ago, evaluate for tethered cord, syrinx. Also with left eye droop. Brain:The right parietal approach ventricular shunt catheter remains in stable position. Also unchanged is the right-sided subdural catheter. The lateral ventricles remain dilated but the caliber is decreased by several millimeters when compared to the prior MRI. The third ventricle remains mildly dilated and the fourth ventricle is small, similar to prior.Multiple developmental anomalies of the cerebrum and cerebellum are redemonstrated. Briefly, these include absence of the septum pellucidum, dysmorphic contour of the ventricles, a thinned and stretched corpus callosum, and white matter volume loss. T2 hyperintense rimming of the ventricular system appears mildly more conspicuous.Anomalies of the posterior fossa are also redemonstrated including nonvisualization of the cerebral aqueduct and rhomboencephalosynapsis. The posterior fossa is crowded which causes the cerebellum to herniate superiorly through the tentorial incisure, and the left cerebellar tonsil to herniate down through the foramen magnum. The fourth ventricle is partially effaced. Findings have not significantly changed.No evidence for restricted diffusion or parenchymal edema is seen. Scattered foci of parenchymal susceptibility are unchanged. No evidence of acute intracranial hemorrhage is seen.Orbits:The left optic nerve appears to be slightly smaller than the right. However, no abnormal signal abnormality is seen within the nerve or nerve sheath. The globes are slightly flattened bilaterally at the optic nerve heads but otherwise unremarkable. The extraocular muscles are within normal limits. No intraorbital mass or fluid collection is seen.Spine:Postoperative findings are demonstrated centered at L4 compatible with tethered cord release. The cut ends of the fatty filum terminale are visualized on sagittal T1 imaging with a 3 cm gap in between. The superior end appears to have retracted to the L3 level while the inferior end is at L5. However, it should be noted that axial T1-weighted images were inadvertently not acquired through the lumbar region which prevents more detailed assessment. On prone imaging, there is mild anterior shifting of the conus and some of the cauda equina nerve roots relative to supine imaging.Minimal prominence of the central canal of the spinal cord is seen in the lower thoracic region, similar to prior. Otherwise, the spinal cord demonstrates normal signal characteristics. No significant compromise of the spinal canal or neural foramina is detected. Spinal alignment is anatomic. Vertebral body height and morphology are within normal limits. No pathologic marrow replacement or edema is seen. No epidural lesions are detected.
1.The shunted lateral ventricles have decreased in caliber. Mild T2 hyperintense rimming of the ventricles appears slightly more conspicuous, but this is a finding of uncertain clinical significance.2.Extensive dysmorphism of the brain and cerebellum is again seen. This includes absence of the septum pellucidum, nonvisualization of the cerebral aqueduct, rhomboencephalosynapsis, and a small posterior fossa which causes superior and inferior cerebellar herniation. All findings are similar to prior.3.No definite orbital lesions are seen. The left optic nerve may be slightly smaller than the right, but this could also be a technical artifact. Slight flattening of the globes at the optic nerve heads is of uncertain significance, but this finding can occasionally be seen in the context of increased intracranial pressure.4.Findings are demonstrated compatible with tethered cord release. The cut ends of the fatty filum terminale are visualized with a gap of several centimeters in between. Furthermore, there does appear to be at least a small amount of conus and cauda equina mobility when prone and supine images are compared.