Medically Unexpained Symptoms: Amnesia
Michael Kopelman
Psychological forms of Memory Disorders
1.
Global:
Entire earlier life + personal identity (‘self’)
e.g.
‘Fugue state’ - transient
Psychogenic focal retrograde amnesia - persisting
2.
Situation-specific:
‘Gaps’ in memory for specific events:
e.g.
P.T.S.D. (Post-Traumatic Stress Disorder).
Victims of crime e.g child sexual abuse, rape
Perpetrators of crime e.g homicide
PSYCHOGENIC FUGUE STATE
Syndrome consisting of:
1.
Sudden loss of memory
2.
Involving loss of autobiographical memories and the sense of
personal identity.
3.
Usually associated with a period of wandering.
4.
Normally lasts a few hours or days only (up to about 3-4 weeks).
5.
Subsequent amnesic gap on recovery for the period of ‘fugue’.
6
If the amnesia persists
Psychogenic Focal Retrograde Amnesia.
PREDISPOSITIONS TO FUGUES
1.
Severe precipitating stress
-
marital
financial
bereavement
offence
war
2.
Depressed mood + suicidal ideas
3.
Past history of a transient ‘neurological’ amnesia
-
head of injury
-
alcohol ‘blackout’
-
epilepsy
(Kopelman, 1987: see also Brain, 2002)
‘Focal Retrograde Amnesia’
• Term coined by Narinder Kapur (1993).
• Strictly, R.A. in the absence of any anterograde memory loss.
• Sometimes, initially accompanied by a transient loss of personal identity
• Unlike ‘fugue state’, the memory disorder persists
• Often (but not always) follows mild concussion or other cerebral event.
• Usually has been assumed to reflect underlying brain pathology.
• Brain imaging usually normal.
• Some reported cases in the literature are not in fact ‘focal’
• Others may well be psychogenic (Kopelman,2000).
PSYCHOGENIC FOCAL RETROGRADE AMNESIA
COMPARISON and DIFFERENTIATION OF FUGUE /
PSYCHOGENIC AMNESIA versus T.G.A. / T.E.A.
• In both:
- Can be preceded by precipitating stress / significant life-event.
- Standard investigations (routine EEG, CT, MRI) can be normal.
• Differentiation:
- Loss of personal identity in fugue
(never in 114 cases of TGA: Hodges and Ward, 1989).
- Repetitive questioning in TGA / TEA
(seldom in fugue/psychogenic, where may get ‘la belle indifference’)
- Other signs eg. sensorimotor in TEA, wandering in fugue.
- ‘Temporal gradients’ of retrograde amnesia.
MANAGEMENT OF SUCH CASES:
• Make the diagnosis!
Treat any underlying depression.
• Engage the patient sympathetically: no use confronting.
• Don’t rush in with interview under sedation: may be more useful later.
• But get as much information as possible: subtle detective work.
• Emphasise disadvantages of amnesia and advantages of confronting
underlying problems and offer help with these. Engage family members
• If amnesia well entrenched / long-standing and family enmeshed in
system - very hard to shift.
SOCIAL FACTORS & BRAIN SYSTEMS INFLUENCING MEMORY RETRIEVAL & PERSONAL IDENTITY:
Kopelman , Brain (2002)
SOCIAL FACTORS & BRAIN SYSTEMS INFLUENCING MEMORY RETRIEVAL & PERSONAL IDENTITY:
Kopelman , Brain (2002)
NEUROIMAGING CORRELATES OF MEMORY SUPPRESSION
Anderson
et al., 2004
At least TWO ROUTES TO
PSYCHOGENIC FOCAL RETROGRADE AMNESIA
Head injury
/cerebral ‘event’
(may be mild)
Predisposing
psychological factors
Predisposing
psychosocial
factors
Fugue episode:
not treated appropriately
/ behaviour reinforced
(Persisting) Focal Retrograde Amnesia
53 cases of Psychogenic Amnesia:
preliminary findings
Federica Corno, Kim Friedner, Sarah Casey, Neil Harrison, Kate Johnston,
Eli Jaldow, Michael Kopelman
53 cases of Psychogenic Amnesia:
• Psychogenic Fugue
• Fugue-like
N=16
Focal retrograde amnesia
N=16
• Psychogenic focal retrograde amnesia
eg after minor head injury
N=16
• Gaps in memory
N=5
Total N=53
Review of case records and neuropsychological test scores
Summary
• In fugue, the memories return – normal: personal semantic facts
-- near-normal: episodic incidents
• Lesser (and variable) improvement in F.R.A.
-- reversed temporal gradient still
• Consistent with memory inhibition.
Levels of awareness
in psychogenic memory loss:
- Deliberate or unconscious mechanism?
Psychogenic fugue /Focal retrograde amnesia cases:
• Very difficult / impossible to know the extent to which people
are deliberately avoiding painful / difficult memories or
the extent to which that this is a ‘truly’ unconscious
process.
• “It’s like a box locked away and I don’t really want to open it.”
• “I put things in boxes. I choose to put them in the back of my mind.
I’ve always done that. I know the memories are there…but (I)
cannot get access to them.”
Conclusions:
• Psychogenic amnesias can be interpreted at different levels
- cognitive, neurophysiological, or psychodynamic.
• They involve the avoidance of painful / unpleasant memories
- may involve varying degrees of conscious awareness.
• Frontal inhibitory control mechanisms may well be implicated
- some functional imaging support for this.