A patient fell two weeks ago, striking their head. Today, the patient presented with a persistent headache and nausea and was diagnosed with a small subdural hematoma. The patient has been in the ED for 24 hours awaiting an inpatient bed. The night shift nurse reports the patient has been anxious, restless, shaky, and vomited twice during the night. The patient states they couldn't sleep because a young child kept coming into the room. What is the most likely cause for these signs and symptoms?
a. increase intracranial pressure
b. alcohol withdrawal
c. rhabdomyolysis
d. pulmonary embolus