Diagnosis: Arnold-Chiari syndrome without spina bifida or hydrocephalusClinical question: Re evaluate right cerebellar signal abnormality and Chiari malformationSigns and Symptoms: headache MRI brain:The CSF spaces are appropriate for the patient's stated age with no midline shift. The cerebellar tonsils extend approximately 7 mm below the level of foramen magnum. There is no evidence for ventriculomegaly.No CSF flow abnormalities are appreciated at the level of the foramen magnum.There is redemonstration of a 12 mm x 8 mm axial dimension signal hyperintense lesion located in the deep gray nuclei of the cerebellum on the right side previously measured the same dimensions. This is also unchanged since the exam of 3/28/13 and 1/12/2013The central canal is dilated to approximately 1.5 mm at the C6 vertebral body level for a length of approximately 1 cm. This has not changed since the prior exam.No abnormal enhancing mass lesions are appreciated intracranially. No intracranial hemorrhage is identified. No edema is identified within the brain parenchyma.Normal vascular flow voids are present in the distal carotid and vertebral arteries, the basilar artery and the proximal anterior, middle and posterior cerebral arteries as well as the internal cerebral veins and superior sagittal sinus.The visualized portions of the paranasal sinuses demonstrate mucosal thickening. The visualized portions of the mastoid air cells are clear. The visualized portions of the orbits are intact.MRI cervical spine:The cervical vertebral bodies are appropriate in overall alignment and height. No abnormal enhancing lesions are identified in the cervical spine. There is redemonstration of aAt C2-3 there is no significant compromise to the spinal canal or neural foramina.At C3-4 there is no significant compromise to the spinal canal or neural foramina.At C4-5 there is no significant compromise to the spinal canal or neural foramina.At C5-6 there is no significant compromise to the spinal canal or neural foramina.At C6-7 there is no significant compromise to the spinal canal or neural foramina.At C7-T1 there is no significant compromise to the spinal canal or neural foramina.The vertebral artery flow voids appear to be intact.
1.Findings are compatible with Chiari I malformation. There is no convincing evidence for CSF flow abnormality at this time. There is no evidence for ventriculomegaly.2.Small syrinx in the cervical spinal cord at the C6 vertebral level is stable3.A lesion centered in the right dentate nucleus is stable and compared to the prior exam.