Classic Case

Intracranial hypotension may occur spontaneously or be secondary to known CSF leakages. The most frequent symptom is orthostatic headache. The classic MRI findings are bilateral subdural collections (A, yellow arrows) and pachymeningeal enhancement (B and C, yellow arrows). Distended dural venous sinuses (venous distension sign) (C, white arrow) and enlargement of the pituitary gland (C, red arrow) can be seen in postcontrast sagittal T1-weighted imaging. The presence of in situ VP shunt (A, red arrow) suggests intracranial hypotension secondary to CSF overshunting.