What is the most likely diagnosis in this patient with a right frontoparietal subdural hematoma?
Spontaneous intracranial hypotension. There is diffuse pachymeningeal thickening and enhancement with vascular distension.
What is the Monro-Kellie hypothesis?
This doctrine underlines a constant sum of the major intracranial components (brain, CSF, blood). A decrease in any of these will result in compensatory increase of the others to achieve intracranial dynamic equilibrium.
A follow-up contrast-enhanced MRI revealed increase in thickness of the previous right frontoparietal subdural hematoma, with mild mass effect manifested by effacement of the adjacent sulci, particularly in the right parietal lobe.
Uniform diffuse pachymeningeal thickening and enhancement, associated with distension of the dural venous sinuses and minimal downward displacement of the splenium of the corpus callosum "droopy penis sign".
The brainstem is unremarkable. No tonsillar ectopia.