Functional amnesia and memory consolidation: A case of severe and persistent anterograde amnesia with rapid forgetting following whiplash injury

Abstract

Extensive neuropsychological testing is reported on a 30-year-old patient (TA) with amnesia persisting 3 ½ years after a major whiplash injury. TAs brain was investigated repeatedly with static and dynamic imaging techniques (computed tomography, magnetic resonance imaging, positron emission tomography) without detecting signs indicative for her amnesia. This amnesia started immediately after the whiplash injury and made the former university student totally dependent on her mother's care and guidance. TA is disoriented with respect to time. She demonstrates a sharp border between superior knowledge of facts and episodes from the time prior to whiplash injury and no memories at all for the period after it. The amnesia is global and persistent in spite of superior intelligence. It is concluded that traumatic, stressful events can induce persistent memory blocks even in the absence of measurable brain injury. Furthermore, it is proposed that there are several stages of memory formation, and that both environmental and internal processes may block or interfere with a smooth information transfer. The consequence may be measurable as delayed amnesia.

Key Words:

• whiplash injury
• episodic memory
• retrograde amnesia
• positron emission tomography