A 32 year-old male presents after slipping and falling off the roof of his home and striking his head. He suffered a brief loss of consciousness. Since that time, he has noted increasing urination and thirst. His serum chemistries reveal an elevated sodium level. His urine specific gravity is 1.003. Which of the following is the most likely diagnosis?
1) cerebral contusion
2) subarachnoid hemorrhage
3) epidural hematoma
4) diabetes insipidus
5) renal contusion