Global psychogenic amnesia

Global psychogenic amnesia

1. Psychogenic focal retrograde amnesia

   • Subject loses memories for entirety of previous life
   • Memory loss usually prolonged
   • New learning is preserved
   • Does not necessarily involve loss of personal identity
   • Period of wandering is unusual
   • Case reports suggest condition commonly follows minor head injury (so may not be truly psychogenic)

2. Patient NN lost his personal identity eight months prior to reported investigation  All neurological exams, including structural MRI, were normal.  Above-average intelligence & anterograde memory abilities. No retrograde amnesia for facts was detected

   • Measured brain activation with PET while patient presented with sentences about his personal experiences  Increases in brain activity in memory related fronto-temporal areas in left hemisphere only  In control subjects activation was seen in similar network in right hemisphere  Patient’s brain treats personal information in a neutral, ‘semantic’ ‘left-hemisphere’ way?

3. right vs left hemisphere

   • right hemisphere involved in retrieving personal, episodic memory
   • left hemisphere more involved in retrieving semantic material

4. a.m.n - 23yr old man put out fire and went bed the next morning he woke up 17. PET scans show abnormally low glucose metabolism. After psycho-pharmaceutical treatment his memory eventually recovered & glucose metabolism returned to normal

5. distinction between organic and psychogenic amnesia - Clinically  because it guides our understanding of the patient and his/her care and management  Neuropsychologically  because it influences the interpretation we place upon small anomalies on EEG, SPECT, o