A 42-year-old man is brought to the emergency department by police officers after he was found wandering aimlessly at an airport. The man is alert and answers questions appropriately; however, he appears to be confused about his identity and does not recognize the name on his Nevada driver's license in his wallet. Extensive inquiry fails to reveal any helpful information as the patient is perplexed and does not remember where he lives, how he got to the airport, his family members, or his profession. His cognitive function is otherwise intact. A search of his personal belongings reveals an airline ticket from Las Vegas to Arlington, Virginia. An emergency contact on the patient's phone leads to his wife in Nevada, who reports that her husband "just disappeared" after he found out that his father had passed away that morning. Physical examination, routine laboratory values, and brain CT scan are unremarkable, and a urine toxicology screen is negative. Which of the following is the most likely diagnosis?

Question

A 42-year-old man is brought to the emergency department by police officers after he was found wandering aimlessly at an airport.  The man is alert and answers questions appropriately; however, he appears to be confused about his identity and does not recognize the name on his Nevada driver's license in his wallet.  Extensive inquiry fails to reveal any helpful information as the patient is perplexed and does not remember where he lives, how he got to the airport, his family members, or his profession.  His cognitive function is otherwise intact.  A search of his personal belongings reveals an airline ticket from Las Vegas to Arlington, Virginia.  An emergency contact on the patient's phone leads to his wife in Nevada, who reports that her husband "just disappeared" after he found out that his father had passed away that morning.  Physical examination, routine laboratory values, and brain CT scan are unremarkable, and a urine toxicology screen is negative.  Which of the following is the most likely diagnosis?

Quizplus · Accepted Answer

11ec25c8_d7c6_322f_bc81_0b055a414a69_MD0003_00 This patient's inability to recall important autobiographical information is suggestive of dissociative amnesia. It can consist of localized or selective amnesia for a particular event or, as in this patient, more generalized amnesia for personal identity and history. Onset is typically sudden and preceded by overwhelming or intolerable events. If the amnesia is associated with traveling or wandering, the term "dissociative fugue" (previously a separate diagnosis in DSM-IV) is used as a specifier for dissociative amnesia in DSM-5. Definitive diagnosis requires ruling out effects of a substance (alcohol "blackouts," drugs, medications) or a neurological condition. Dissociative amnesia is not diagnosed if the disturbance is better explained as a symptom of acute or post-traumatic stress disorder (PTSD) or dissociative identity disorder. (Choices A and F) Symptoms of acute stress disorder and PTSD can include dissociative amnesia. However, symptoms of hyperarousal (eg, hypervigilance, startle response, sleep disturbance), intrusive memories, and avoidance behaviors would be expected. (Choice B) Patients with brief psychotic disorder present with delusions, hallucinations, disorganized behavior, or confused speech, none of which this patient displays. This disorder is often precipitated by a stressor and resolves within a month. (Choice C) In depersonalization/derealization disorder, the patient generally has intact autobiographical memory but experiences repeated or chronic feelings of unreality or detachment. (Choice E) Although gaps in memory can be experienced in dissociative identity disorder, the diagnosis requires evidence of 2 or more distinct identities that alternate in assuming control of the patient's behavior. This patient is acutely confused about his identity and shows no evidence of having developed 2 or more distinct personalities. (Choice G) Transient global amnesia presents as anterograde amnesia for time and place. There is no associated loss of personal identity, as in this patient. The memory loss typically resolves within 24 hours. Educational objective: Dissociative amnesia involves isolated impairment in autobiographical memory. If the amnesia is accompanied by travel or wandering, the specifier of "with dissociative fugue" is given. References: Dissociative disorders in DSM-5. (http://www.ncbi.nlm.nih.gov/pubmed/23394228)

A 42-Year-Old Man Is Brought to the Emergency Department by Police