We will all have the experience of taking care of a patient in the emergency department who is acting…different than they normally do.  Sometimes, the change can be subtle, maybe a family member will be the first to notice and bring the patient to be evaluated.  Sometimes the patient makes the change abundantly clear.  In either case it is essential to identify the underlying cause and treat any emergent conditions precipitating this dysfunction of the brain.  This month we hear from Dr. Erin McDonough on her approach to the patient with altered mental status (AMS).