Fourth Nerve Schwannoma

This is a case of IVth cranial nerve schwannoma, showing an enhancement in the subarachnoid space consistent with the clinical presentation. Figure 1a : T1-weighted axial brain MRI Figure 1b : T1-weighted axial brain MRI : magnification of the brainstem Figure 1c : T1-weighted axial brain MRI : cranial nerve four course Figure 2 : T1-weighted axial brain MRI (without contrast) : The brain MRI without contrast is unremarkable. Because of its small diameter. CN IV is not routinely visualized. Figure 3: T1-weighted axial brain MRI with contrast: There is focal enhancement along the course of the right CN IV, suggesting a small mass on the right CN IV Figure 4: 4a: The brain MRI without contrast is unremarkable (the arrow shows the lesion seen on the MRI with contrast) ; 4b: There is focal enhancement of CN IV (yellow arrow)