retrograde amnesia


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Related to retrograde amnesia: anterograde amnesia

amnesia

 [am-ne´zhah]
pathologic impairment of memory. Amnesia is usually the result of physical damage to areas of the brain from injury, disease, or alcoholism. Psychologic factors may also cause amnesia; a shocking or unacceptable situation may be too painful to remember, and the situation is then retained only in the subconscious mind. The technical term for this is repression. (See also dissociative disorders.)

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.
anterograde amnesia impairment of memory for events occurring after the onset of amnesia. Unlike retrograde amnesia, it is the inability to form new memories.
circumscribed amnesia loss of memory for all events during a discrete, specific period of time. Called also localized amnesia.
continuous amnesia loss of memory for all events after a certain time, continuing up to and including the present.
dissociative amnesia the most common of the dissociative disorders; it is usually a response to some stress, such as a threat of injury, an unacceptable impulse, or an intolerable situation. The patient suddenly cannot recall important personal information and may wander about without purpose and in a confused state.

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.
generalized amnesia loss of memory encompassing the individual's entire life.
lacunar amnesia partial loss of memory; amnesia for certain isolated experiences.
post-traumatic amnesia amnesia resulting from concussion or other head trauma. Called also traumatic amnesia. See also amnestic syndrome.
psychogenic amnesia dissociative amnesia.
retrograde amnesia inability to recall events that occurred prior to the episode precipitating the disorder. Unlike anterograde amnesia, it is the loss of memories of past events.
selective amnesia loss of memory for a group of related events but not for other events occurring during the same period of time.
transient global amnesia a temporary episode of short-term memory loss without other neurological impairment.
traumatic amnesia post-traumatic amnesia.

ret·ro·grade am·ne·si·a

amnesia in reference to events that occurred before the trauma or disease that caused the condition.

retrograde amnesia

Neurology Amnesia that extends to before the trauma or events that caused the loss of memory. See Amnesia. Cf Anterograde amnesia.

ret·ro·grade am·ne·si·a

(ret'rō-grād am-nē'zē-ă)
Lack of memory about events that occurred before the trauma or disease (e.g., cerebral concussion) that caused the condition.

retrograde amnesia

Loss of memory for a period before the time of a head injury. In general, the more severe the injury and the longer the period of loss of memory after the injury, the longer will be the retrograde amnesia.
References in periodicals archive ?
Susumu Tonegawa, the director of the RIKEN Brain Science Institute in Saitama in Japan and lead author of the study said, "Our conclusion is that in retrograde amnesia, past memories may not be erased, but could simply be lost and inaccessible for recall.
Differently stated, the pattern of extended retrograde amnesia and the absence of a reminiscence bump effect in the AD group are compatible with the ungraded AbM retrieval deficit found in previous studies involving AD patients when considering strictly episodic memories solely [12, 13, 27, 37].
Benzodiazepines also may cause dizziness, confusion, tolerance and cognitive impairment, especially retrograde amnesia. Most authorities recommend that these drugs be used for no more than two to three weeks when treating insomnia.
This search revealed reports listed as transient amnesia, transient global amnesia, wandering amnesia, anterograde amnesia, dissociative amnesia, and retrograde amnesia. No reports were uncovered using the terms memory loss, memory disturbance, or memory disruption; yet memory impairment revealed multiple reports.
He regained consciousness in the morning, but had a dense left-sided hemiplegia, expressive dysphasia and retrograde amnesia. Two months later he presented with additional symptoms of right-sided neck pain, worse on turning his head to the right, occasional left chest pain, and grand mal epilepsy controlled with phenytoin.
Following a Confusional Arousal, the person usually falls back to sleep with no recollection of the event (retrograde amnesia) upon awakening the next morning.
All patients with moderate to severe injuries, and most with mild injuries, experience amnesia with regard to the events immediately preceding (retrograde amnesia) and following the injury (posttraumatic amnesia or PTA).
Retrograde amnesia occurs when the athlete does not remember events that occurred before the injury.
Memory protective effect of indomethacin against electro convulsive shock induced retrograde amnesia in rats.
Amnesia is characterized by a disturbance in memory that is manifested either by an inability to recall previously learned information or past events (retrograde amnesia) or, less relevant here, an inability to learn and retain new information (anterograde amnesia).