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Causes and symptoms
- Anterograde. This form of amnesia follows brain trauma and is characterized by the inability to remember new information. Recent experiences and short-term memory disappear, but victims can recall events prior to the trauma with clarity.
- Retrograde. In some ways, this form of amnesia is the opposite of anterograde amnesia: the victim can recall events that occurred after a trauma, but cannot remember previously familiar information or the events preceding the trauma.
- Transient global amnesia. This type of amnesia has no consistently identifiable cause, but researchers have suggested that migraines or transient ischemic attacks may be the trigger. (A transient ischemic attack, sometimes called "a small stroke," occurs when a blockage in an artery temporarily blocks off blood supply to part of the brain.) A victim experiences sudden confusion and forgetfulness. Attacks can be as brief as 30-60 minutes or can last up to 24 hours. In severe attacks, a person is completely disoriented and may experience retrograde amnesia that extends back several years. While very frightening for the patient, transient global amnesia generally has an excellent prognosis for recovery.
Rarely is the memory completely obliterated. When amnesia results from a single physical or psychologic incident, such as a concussion suffered in an accident or a severe emotional shock, the victim may forget only the incident itself; the victim may be unable to recall events occurring before or after the incident or the order of events may be confused, with recent events imputed to the past and past events to recent times. In another form, only certain isolated events are lost to memory.
Amnesia victims usually have a good chance of recovery if there is no irreparable brain damage. The recovery is often gradual, the memory slowly reclaiming isolated events while others are still missing. Psychotherapy may be necessary when the amnesia is due to a psychologic reaction.
Persons with a dissociative disorder may at times forget what they are doing or where they are; when they regain self-awareness, they cannot recall what has taken place. A less severe form than amnesia is sleepwalking. Dissociative disorders are very likely an attempt by the mind to shield itself from the anxiety caused by an unresolved conflict. The patient, upon encountering a situation that may be symbolic of this inner conflict, goes into a form of trance to avoid experiencing the conflict.
amnesia/am·ne·sia/ (am-ne´zhah) pathologic impairment of memory.
amnesiaA pathological impairment or lack of memory, which is often temporally linked to a traumatic event.
No memory for that occurring after a triggering event.
A dramatised version of memory loss for any event occurring after a triggering event, which occurs at dramatically convenient times (the return of which is also discretionary).
No memory for that occurring before a triggering event; amnesia may be organic, emotional or mixed origin, and/or time-limited.
amnesiaNeurology A pathologic impairment or lack of memory, which is often temporally linked to a traumatic event Types Anterograde–no memory for that occurring after the event; retrograde–no memory for that occurring before the event; amnesia may be organic, emotional, mixed origin, or time-limited. See Anterograde amnesia, Hysterical amnesia, Retrograde amnesia, Selective amnesia, Sensorimotor amnesia, Source amnesia.
amnesiaLoss of memory as a result of physical or mental disease or injury, especially head injury. Amnesia for events occurring before the head injury is called retrograde amnesia. Anterograde amnesia is loss of memory for events occurring after the injury.
Patient discussion about amnesia
Q. bipolar amnesia? I am 39 yrs old and suffer from Bipolar Disorder. Last March I suffered from a severe depressive episode and was hospitalized. Since I was 19yrs old, I have been hospitalized 3 times. Each time I suffered from a weird kind of amnesia. I don't recall long periods of time while I was falling into this depressive state. It is pretty unnerving. Anyone ever experience this type of amnesia and how do you cope? It is scarey to not remember some pretty significant times-- my husband will bring up things that I have no recollection of. Any help or support will be greatly appreciated.
Q. How do I break it to my mother that I have infantile amnesia