Intracranial hypotension

There are numerous findings of intracranial hypotension, namely:

• biconvex margins of the dural venous sinuses with altered flow-voids
• enlarged pituitary gland (1 cm craniocaudal)
• decreased mamillopontine distance (2 mm)
• decreased pontomesencephalic angle (roughly 25 degrees)
• effacement of the supra-sellar cistern with descent of the optic chiasm which is draped over the pituitary gland
• descent of the midbrain with an elongated appearance on axial slices
• pons flattened on clivus
• cerebellar tonsillar ectopia
• slit-like third ventricle with descent and convex aspect of the infundibular and supra-optic recesses

Also noted are many very T2-hyperintense trans-spatial lesions visible in the intrinsic tongue muscles, behind the right mandibular ramus and in the right head extensor muscles, most likely representing venous or venolymphatic malformations.

Unrelated right cerebellar developmental venous anomaly.

Annotated images show selected findings of intra-cranial hypotension:

• biconvex margins of the dural venous sinuses with altered flow-voids (blue)
• enlarged pituitary gland (green)
• decreased mamillopontine distance (red)
• decreased pontomesencephalic angle (orange)
• descent of the optic chiasm (teal) which is draped over the pituitary gland
• effacement of the supra-sellar cistern (purple) which should be visible on at least one thick axial T2 slice as mainly cerebrospinal fluid (CSF) signal, which is not the case here
• elongated appearance of midbrain on axial slices (white)
• pons flattened on clivus, with barely any CSF visible between these structures (yellow)
• cerebellar tonsillar ectopia (grey)
• descent and convex aspect of the infundibular and supra-optic recesses of the third ventricle (pink)