Chiari malformation with progression of optic neuropathy. Again noted are changes compatible with prior suboccipital craniectomy and posterior fossa decompression, with creation of a neo foramen magnum. Low-lying cerebellar tonsils extend to the inferior margin of the anterior arch of C1, not significantly changed since the prior study. Biphasic CSF flow is robust anteriorly. At the level of the neo foramen magnum, there is a paucity of CSF flow posteriorly along the cerebellar tonsils and no definite CSF flow is appreciated directly posterior to the tonsils. The ventricles and sulci are normal in size for age. There is prominent volume loss involving the superior cerebellar vermis similar to prior. There is no mass, mass effect, or midline shift. Few scattered foci of T2/FLAIR hyperintensity are seen in the bilateral subcortical and periventricular white matter, which are nonspecific, but compatible with mild chronic small vessel ischemic changes. Brain parenchyma is otherwise unremarkable for age. The pituitary gland is normal in size. There are no foci of increased susceptibility. No diffusion-weighted abnormalities are identified. There are no extraaxial fluid collections or subdural hematomas. Flow voids are present within the major vessels indicating patency. The paranasal sinuses and mastoid air cells are clear. Postcontrast images are motion degraded but demonstrate no abnormal parenchymal or meningeal enhancement. Subcentimeter focus of enhancement in the left frontal calvarium is nonspecific and unchanged since 4/27/2009.No masses are seen within the orbits or abnormal enhancement. The right optic nerve is tortuous making evaluation of signal abnormality suboptimal on the coronal sequences however no abnormal optic nerve T2 signal is definitively appreciated. No mass, compression, or abnormal signal involving the optic chiasm.Small cervical syrinx and myelomalacia are partially visualized and better assessed previously.
1.Again seen are postsurgical changes following posterior fossa decompression for Chiari decompression, without significant interval change in position of low lying cerebellar tonsils. No definite CSF flow is appreciated posterior to the cerebellar tonsils at the level of the neo foramen magnum similar to prior.2.No intracranial mass or mass effect. No evidence of infarct. No masses within the orbits or signal abnormality involving the optic nerves is appreciated. 3.Partially visualized cervical syrinx and myelomalacia, better assessed on prior dedicated cervical spine studies.