Male, 26 years old, with new right-sided weakness. Agenesis of the corpus callosum is again seen. Also redemonstrated is marked parenchymal deformity and encephalomalacia affecting the left parietal and occipital lobes. Scattered additional smaller foci of signal abnormality are unchanged in the periventricular regions. No definite evidence of any new parenchymal lesion is seen. No restricted diffusion is demonstrated.Artifact is seen related to a left parietal approach ventricular shunt catheter. Generalized ventricular dysmorphism is unchanged. The ventricles are not enlarged and are stable in caliber. Dural thickening is noted along the encephalomalacic left parietal and occipital lobes with prominent posterior falcine calcification. No pathologic intracranial enhancement is seen.The posterior fossa is small with herniation of the cerebellar tonsils through the foramen magnum similar to prior. The CSF space at the level of the foramen magnum is crowded and there is little detectable CSF flow through the foramen magnum.
1.Stable chronic and/or congenital brain dysmorphism including agenesis of the corpus callosum and encephalomalacia of the left parietal and occipital lobes.2.Stable shunted ventricular system with no evidence of ventriculomegaly.3.Redemonstration of findings related to Chiari I malformation.4.No new or acute intracranial abnormalities are detected to account for the patient's new right-sided weakness.