 Brain: Again seen are post-operative findings related to a suboccipital craniectomy and resection of the posterior arch of C1 for decompression of Chiari malformation. There is evidence of tonsillar cauterization/resection. There remains some crowding of the remaining cerebellar tonsils at the level of the foramen magnum, which is unchanged. A fluid collection at the surgical bed measures approximately 23 x 33 x 36 mm (AP x TR x CC) compared to 10 x 35 x 36 mm previously and extends inferiorly to the level of the mid C2 vertebral body. Although the collection appears larger in the AP dimension, this may simply represent conformational changes due to patient positioning rather than true increase in size. Even if there has been an increase, it has not increased dramatically. The dura or duraplasty is somewhat irregular in places but we see no obvious defects or gaps. There continues to be no significant edema around the fluid collection. The ventricles and sulci are normal in size. There are no masses, mass effect or midline shift. The pituitary gland is normal in size. There is no evidence for intracranial hemorrhage or acute cerebral, brainstem or cerebellar infarction. No diffusion-weighted abnormalities are identified. The paranasal sinuses and mastoid air cells are clear. There is no abnormal enhancement within the brain. C-spine: Normal cervical lordosis. The vertebral body heights are well-maintained. No focal marrow signal abnormality is appreciated. The spinal cord is of normal caliber. There is a persistent thin syrinx at the right lateral aspect of the cervical cord, which, along with a prominent central canal of the cord, extends inferiorly to the thoracic region but is unchanged. There is no pathological intrathecal enhancement.There is no significant disc bulge, herniation, spinal canal or foraminal stenosis within the cervical spine.
1. Post-operative findings related to Chiari decompression. 2. Mild apparent change in the size of the fluid collection in the surgical bed may simply be related to changes in patient position. Even if there were an increase in size, the collection is not significantly larger. Persistent pseudomeningocele is favored as the diagnosis. Infection is less likely given lack of edema and no change in the enhancement pattern compared to the prior exam.3. Unchanged, mild syringohydromyelia.