This endocrine case report feature a woman with a history of diabetes, hypertension, and marijuana use in her mid 50s brought to the ED for confusion by her friend and neighbor who states that she has been like this for 3 days. Can you determine how best to proceed?
History of Present Illness:
A woman in her mid-50s with diabetes, hypertension, and daily marijuana use is brought to the emergency department for confusion by her friend and neighbor who states that she has been like this for 3 days and her state has not noticeably worsened nor improved during that time.
The patient and friend both deny there has been any vomiting, focal weakness, change in vision or balance, or other complaints. She was seen at another ED the day her symptoms started and had a normal head CT and labs. The physician thought the confusion was probably due to the marijuana and let her go home. The patient had no problem with that, but her friend is concerned that the confusion has not improved and brought her to your hospital for a second opinion.
Vitals and Physical Exam:
Vital signs are normal. The exam is normal except for confusion. She has a particularly hard time following commands.
What testing is the most likely to be useful?