A 63 year old female is noted to have left pupil irresponsive to light and is dilated. What is the most probably diagnosis?

The key is B. Subdural hemorrhage. [In elderly extradural hemorrhage is unlikely and subdural

hemorrhage is more common.Traumatic expanding subdural hematomas may present with third nerve

involvement and are usually accompanied by additional neurological dysfunction. Dilated, sluggish, or

fixed pupil (s), bilateral or ipsilateral to the injury occur due to increased intracranial pressure (ICP) or

transtentorial herniation].