Perimesencephalic hemorrhage

Thought to be due to rupture of perimesencephalic vein
Symptoms: headache
Most do not rebleed; epicenter of hemorrhage is just anterior to the midbrain with extension into either the ambient cistern or Sylvian fissure although the entire subarachnoid space will not be filled
After ruling out a berry aneurysm with an angiogram, no further treatment is warranted