Posttraumatic stress disorder in patients with neurogenic amnesia for the traumatic event

The development of symptoms of posttraumatic stress disorder (PTSD) in pati ents with neurogenic amnesia for the traumatic event is recorded in 2 own p atients and in 19 cases from the clinical literature. With a single excepti on, all patients were accident victims with closed head injuries. Only abou t three quarters of the patients completely fulfilled DSM-III-R criteria of PTSD. Nineteen patients displayed involuntary conscious memories of aspect s of the traumatic event (presenting as recurrent intrusive thoughts, image s or dreams) co-existent with a complete or partial lack of voluntary consc ious memories of the trauma, suggesting that different memory systems and d istinct brain mechanisms subserve these phenomena. The said clinical observ ations are discussed against the background of current neuropsychological m odels of multiple memory systems. The recorded cases demonstrate that decla rative episodic memory is not necessary for symptoms of PTSD to emerge, whe reas preserved functions of non-declarative memory systems represent a suff icient condition for the development of PTSD symptoms.