Amnesia

Amnesia
Amnesia is a disorder of memory operation, during which the individual is unable to retain or retrieve previously stored information. The causes of amnesia are organic or functional. Organic causes include damage to the brain caused by disease or trauma, or use of certain drugs. Functional causes are psychological factors, such as defense mechanisms. The post-traumatic amnesiahysterical is an example of this factor. Amnesia may also be spontaneous, in the case of transient global amnesia has the highest rate of cases in people in middle age and the elderly, particularly males, and usually lasts less than 20 hours.
Amnesia is a very used in fiction. Anterograde amnesia is shown in the movie Memento, dissociative amnesia shown in the anime series Elfen Lied and lacunar amnesiais represented in the film Eternal Sunshine of the Spotless Mind. In the TV series House MD, appears a case of retrograde amnesia in chapter 15 of the fourth season, in which Gregory House after suffering a concussion in a bus accident loses four hours of memory. In the third season of Smallville, Lex Luthor accuses his father of having sabotaged the plane he was traveling in his honey moon, whichcrashed on an island and that as a result, Lex lost all memory of a week of his life (the time it sank in that island). According Lex to be "rescued" by his father, he took him to a mental rehabilitation center where he was made to completely lose the memory of what happened on the island, I do believe that had a psychogenic amnesia or, rather, dissociative . Filmmaker David Lynch also makes anexcellent representation on Mulholland Drive, where a woman suffers from amnesia after a traumatic car accident.

In summary, we can define the amnesia as a brain disease that makes people forget data previously stored in the brain. The types of amnesia can be classified according to the rigor or patterns that loss of memory, depending on character antegrade, retrograde or dissociative.

Inmovies is usually represented as a second blow to the head cures amnesia. Really a second concussion can have catastrophic consequences: syndrome known as dual impact and have serious consequences
Anterograde amnesia. New events are
transferred to long-term memory, so the sufferer will not be able to remember anything that happened after the onset of this type of amnesia for more than a shorttime. The complement to this is the retrograde amnesia

    
Retrograde Amnesia. No recall events that occurred before the onset of disease.

These terms are used to categorize symptoms, not to indicate a particular cause or etiology. Both categories of amnesia can occur together in the patient, and are a result of damage to brain regions closely associated with episodic memory / declarative:the medial temporal lobes and especially the hippocampus.
According Aetiological classification

    Posttraumatic amnesia. Generally caused by a head injury (fall, blow to the head) that does not penetrate the skull. It is often transitory duration of amnesia is related to the degree of injury and may give an indication of prognosis for recovery of other functions. A slight trauma, like acar accident that results in no more than a slight whiplash, can cause the occupant does not remember the events just before the accident due to a brief interruption in the transfer mechanism of memory from short to long term. This mechanism is called and memory consolidation has the same molecular changes based on forming protein synthesis in the brain fixed representations. The person sufferingpost-traumatic amnesia may also file a coma that can last from seconds to weeks, depending on the severity of the trauma. After coma presents a period of confusion. The person will have anterograde amnesia of the events of the period of confusion.

    Dissociative Amnesia. usually refers to a long-term repressed memory as a result of trauma either psychological or emotional.

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