Male, 27 years old, with hand numbness, history of basilar invagination, Chiari malformation. Evaluate for worsening stenosis or cord edema. Suboccipital craniectomy and resection of the C1 posterior arch are redemonstrated. The thecal sac becomes tight at the C1 level with effacement of the CSF and some cord deformation, but this is similar to the prior postoperative exam. Above and below this level, the thecal sac is more capacious. The cerebellar tonsils are not crowded.The clivus is dysmorphic and the odontoid process projects through the foramen magnum. The odontoid process impresses upon the brainstem which has assumed a kinked morphology. T2 signal abnormality and slight volume loss affect the left lateral cord at C1. Faint signal abnormality is also detected in the left lateral cord throughout the cervical region. Findings are unchanged.Spinal alignment is otherwise anatomic. Vertebral body heights are preserved. Marrow signal characteristics are within normal limits. No disc herniations are seen. The spinal canal and neural foramina are otherwise patent.
1.Findings are redemonstrated compatible with Chiari decompressive surgery. At the C1 level, the thecal sac is tight with effacement of the CSF and cord deformation, but this appearance is unchanged. Above and below this level, the thecal sac is of adequate caliber. 2.Basilar impression is redemonstrated. The odontoid process impinges upon the brainstem which is kinked. Findings are unchanged. 3.Cord signal abnormality suggestive of myelomalacia is seen in the left lateral cord at C1, and faintly through the remainder of the left lateral cord. These findings are also unchaged.4.No definite new findings or significant interval changes are seen to account for the patient's symptoms.