A patient who is unable to recall events leading up to their head injury is experiencing which type of amnesia?

The patient who is unable to recall events leading up to their head injury is experiencing retrograde amnesia. This type of amnesia specifically affects the ability to remember information or events that occurred before the onset of amnesia, which in this case is the head injury. Following such an injury, individuals often find it challenging to access memories that they had formed prior to the incident.

In contrast, anterograde amnesia involves difficulty forming new memories after the event has occurred, while post-traumatic amnesia refers to a period of confusion or disorientation immediately following the injury, affecting both recall of past and ability to create new memories. Perigrade amnesia is not a standard term used in clinical settings regarding amnesia. Thus, the presentation of being unable to recall events preceding the injury aligns with the definition of retrograde amnesia.