Neuro_MR_Brain: 29 F, remote cerebellar AVM s/p resection and XRT, recent AMS and decline.
MRI BRAIN WITH AND WITHOUT CONTRAST:
CLINICAL HISTORY: 29 years of age, Female, history of prior cerebral AV malformation status post radiosurgery and resection. Complains of sleepiness and headaches.
Parenchyma: Postsurgical changes related to prior occipital craniectomy with resection of AVM in the right cerebellum, with interval development of marked cerebellar atrophy and collapse of the posterior fossa. The diencephalon and mesencephalon are markedly deformed and downwardly displaced. Presence of left occipital approach shunt with tip in the right cerebellar fossa. Multiple foci of GRE susceptibility in the posterior fossa, likely related to prior embolization material. Slight prominence of vessels at cerebellar vermis and adjacent to the right vertebral artery (8/6) without associated hyperperfusion on ASL, may represent prominent and tortuous veins. Additional diffuse prominence of the leptomeningeal vessels. Postoperative changes related to prior left frontal approach ventriculostomy catheter.
Ventricles and extra-axial spaces: Absence of suprasellar and prepontine cisterns related to downward displacement of the diencephalon and mesencephalon. Right frontal approach ventriculostomy catheter with tip crossing midline and ending at the body of the left lateral ventricle. Markedly decompressed ventricular system with slit-like ventricles.
Visualized paranasal sinuses: Clear.
Mastoid air cells: Clear.
Bones: Occipital craniectomy as described.
Additional comment: None.
1. Posttreatment changes related to prior embolization and resection of right cerebellar AVM. Compared to 2008, interval progression of post surgical changes and development of marked cerebellar atrophy as well as severe downward displacement of the diencephalon and mesencephalon, concerning for severe intracranial hypotension of indeterminate etiology. CSF leak cannot be excluded. Comparison with any interval studies since 2008 would be very helpful.
2. Markedly decompressed ventricles with right frontal approach ventriculostomy shunt in place, atypical for intracranial hypotension. Overshunting should be considered as an etiology. There also appears to be a shunt in the posterior fossa.
3. Some residual tortuous vessels, likely veins. No convincing evidence of AV shunting.