Answer for CoW 23 July 2017
Diagnosis :
Intracranial hypertensionwith sinovenous thrombosis
Findings
Empty sella Posterior globe flattening Transverse sinus narrowing Optic Nerve Sheath enlargement Optic nerve tortuosity
Discussion
Intracranial hypertension: Empty sella sign :Is associated with the longstanding effects of increased ICP and is thought to result from a downward herniation of an arachnocele through the diaphragma sella. Transverse sinus narrowing : A small or absent bony groove in the occiput in conjunction with the compressible nature of the transverse sinus makes this structure vulnerable to tapering with increased ICP. This particular imaging finding is more frequently noticed on MR venography studies. Posterior globe flattening : Sine qua non neuroimaging sign of PTC and can be seen on both CT and MR imaging . Globe flattening may be explained by the direct correlation between elevated ICP and IOP via the transmission of elevated CSF pressure through the subarachnoid space, extending through the ONS to the posterior globe. Intraocular protrusion : Manner similar to posterior globe flattening and is another sign associated with PTC.The optic nerve head is considered by some to be the most vulnerable site; thus, this finding on MR imaging may well correspond to the presence of visual symptoms, in light of its absence in patients with PTC lacking visual symptoms. ONS enlargement: Widened ring of CSF around an optic nerve, which may appear compressed on coronal images, and as widened CSF signal intensity on either side of the optic nerve on axial images. Optic nerve tortuosity : The distal and proximal points of fixation of the optic nerve enable it to kink freely in its course to the globe on protrusion of the intracranial contents under pressure. The sensitivity of observing optic nerve tortuosity in either the vertical or horizontal planes is dependent on section thickness. Horizontal tortuosity is thought to be less frequently visualized but more specific to intracranial hypertension. MR Venography: Many authors propose that any patient with suspected elevated intracranial hypertension undergo MR venography in addition to traditional MR orbital imaging to evaluate venous thrombosis or stenosis as the etiology of PTC symptoms. Newer imaging methods have enhanced detection of intracranial sinovenous stenoses previously undetected due to artifactual flow voids in the transverse sinuses on traditional time-of-flight MR venography. Bilateral sinus flow gaps can be seen.
Intracranial hypertensionwith sinovenous thrombosis
Findings
Empty sella Posterior globe flattening Transverse sinus narrowing Optic Nerve Sheath enlargement Optic nerve tortuosity
Discussion
Intracranial hypertension: Empty sella sign :Is associated with the longstanding effects of increased ICP and is thought to result from a downward herniation of an arachnocele through the diaphragma sella. Transverse sinus narrowing : A small or absent bony groove in the occiput in conjunction with the compressible nature of the transverse sinus makes this structure vulnerable to tapering with increased ICP. This particular imaging finding is more frequently noticed on MR venography studies. Posterior globe flattening : Sine qua non neuroimaging sign of PTC and can be seen on both CT and MR imaging . Globe flattening may be explained by the direct correlation between elevated ICP and IOP via the transmission of elevated CSF pressure through the subarachnoid space, extending through the ONS to the posterior globe. Intraocular protrusion : Manner similar to posterior globe flattening and is another sign associated with PTC.The optic nerve head is considered by some to be the most vulnerable site; thus, this finding on MR imaging may well correspond to the presence of visual symptoms, in light of its absence in patients with PTC lacking visual symptoms. ONS enlargement: Widened ring of CSF around an optic nerve, which may appear compressed on coronal images, and as widened CSF signal intensity on either side of the optic nerve on axial images. Optic nerve tortuosity : The distal and proximal points of fixation of the optic nerve enable it to kink freely in its course to the globe on protrusion of the intracranial contents under pressure. The sensitivity of observing optic nerve tortuosity in either the vertical or horizontal planes is dependent on section thickness. Horizontal tortuosity is thought to be less frequently visualized but more specific to intracranial hypertension. MR Venography: Many authors propose that any patient with suspected elevated intracranial hypertension undergo MR venography in addition to traditional MR orbital imaging to evaluate venous thrombosis or stenosis as the etiology of PTC symptoms. Newer imaging methods have enhanced detection of intracranial sinovenous stenoses previously undetected due to artifactual flow voids in the transverse sinuses on traditional time-of-flight MR venography. Bilateral sinus flow gaps can be seen.
Note:
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!
We do not discourage differential diagnosis. But all the differentials must satisfy the findings noted in the case.
If you feel you have answered rightly but cannot find your name in the above list, please call 09551942599.
Did you Know?
The order in which the names appear in this winner's list is based on the time of submission. The first person to send the correct answer gets his/her name on top of the list!