Amnesia: Difference between revisions

From WikiMD's Wellness Encyclopedia

← Older edit
CSV import
CSV import
 
(3 intermediate revisions by the same user not shown)
Line 1: Line 1:
''Amnesia''' is a complex neurological condition marked by impaired [[memory]] functions, often as a result of brain injury, disease, psychological trauma, or the use of certain medications. The primary manifestation of amnesia is the disturbance of memory, where patients may struggle to recall past events or find difficulty forming new memories. The specific form and severity of amnesia can vary greatly, depending on the underlying cause and the specific areas of the brain affected<ref>{{Cite web|url=http://www.emedicine.com/neuro/topic380.htm|title=Transient global amnesia|publisher=eMedicine}}</ref>.


== Classification of Amnesia ==
{{Infobox medical condition
| name            = Amnesia
| synonyms        = [[Memory loss]]
| specialty      = [[Neurology]], [[Psychiatry]]
| symptoms        = [[Memory loss]], difficulty recalling past events, inability to form new memories
| onset          = Sudden or gradual
| duration        = Can be temporary or permanent
| causes          = [[Brain injury]], [[traumatic events]], [[stroke]], [[alcohol abuse]], [[encephalitis]], [[Alzheimer's disease]]
| risks          = [[Head injury]], [[substance abuse]], [[psychological trauma]]
| diagnosis      = [[Neuropsychological tests]], [[brain imaging]] ([[MRI]], [[CT scan]])
| differential    = [[Dementia]], [[delirium]], [[depression]], [[conversion disorder]]
| treatment      = [[Cognitive therapy]], [[occupational therapy]], [[medication]]
| prognosis      = Varies depending on cause; some cases may improve over time, others may be permanent
| frequency      = Common in cases of [[traumatic brain injury]] and [[neurodegenerative diseases]]
}}
{{SI}}
{{Infobox medical condition
| name = Amnesia
| synonyms = Amnesic syndrome
| image =
[[File:Noun Forget 1816.svg|Noun_Forget_1816]]
| image_size =
| caption = Depiction of memory impairment in amnesia
| field = [[Neurology]], [[Psychiatry]]
| symptoms = Memory loss, confusion, inability to retain new information
| complications = [[Cognitive impairment]], loss of autonomy, emotional distress
| onset = Sudden or gradual, depending on cause
| duration = Temporary or permanent
| types = [[Anterograde amnesia]], [[Retrograde amnesia]], [[Dissociative amnesia]], etc.
| causes = [[Brain injury]], [[stroke]], [[neurodegenerative disorders]], psychological trauma, [[alcohol abuse]]
| risks = Head trauma, [[epilepsy]], [[encephalitis]], substance use
| diagnosis = [[Neuropsychological testing]], [[MRI]], [[CT scan]], [[EEG]]
| differential = [[Dementia]], [[Delirium]], [[Depression]]
| prevention = Preventing head injuries, managing substance use, early intervention in infections
| treatment = Supportive care, cognitive rehabilitation, psychotherapy
| medication = [[Vitamin B1]] in cases like [[Korsakoff's syndrome]]
| prognosis = Varies by type and cause
| frequency = Uncommon overall; varies with underlying condition
| deaths = Rarely fatal directly
}}
'''Amnesia''' is a [[neurocognitive disorder]] characterized by partial or complete loss of [[memory]], either short-term, long-term, or both. It can result from a variety of causes including [[neurological]] damage, [[psychological trauma]], or [[toxic]] exposures. Individuals with amnesia may be unable to recall past experiences, form new memories, or both, depending on the type and extent of brain involvement.
== Classification ==
Amnesia is broadly categorized based on the type of memory affected and the underlying cause.
=== Anterograde Amnesia ===
=== Anterograde Amnesia ===
[[Anterograde amnesia]] is a form of memory loss where the ability to create new memories post-amnesia onset is impaired, while past memories remain intact. People with anterograde amnesia often forget events shortly after they occur and struggle to retain new information for longer periods.
[[Anterograde amnesia]] is the inability to form new memories following the onset of the condition, often caused by damage to the [[hippocampus]] or related structures.
 
=== Retrograde Amnesia ===
=== Retrograde Amnesia ===
Contrasting with anterograde amnesia, [[retrograde amnesia]] presents as an inability to recall events that happened before the onset of amnesia. Despite this, the ability to form new memories remains unaltered.
[[Retrograde amnesia]] involves the loss of pre-existing memories prior to the onset of amnesia. It often spares older memories while more recent ones are affected.
 
=== Transient Global Amnesia ===
[[Transient global amnesia]] (TGA) is a sudden, temporary episode of memory loss not attributable to more common neurological conditions like [[epilepsy]] or [[stroke]].
=== Dissociative Amnesia ===
[[Dissociative amnesia]] is typically psychological in origin, where individuals block out memories related to stressful or traumatic events. It is associated with [[post-traumatic stress disorder]] (PTSD) and [[dissociative disorders]].
=== Traumatic Amnesia ===
=== Traumatic Amnesia ===
[[Traumatic amnesia]] is a temporary or permanent memory loss induced by a physical injury to the brain, such as a concussion. The severity and duration of amnesia correlate with the extent of the injury.
Often seen after head injuries, [[traumatic amnesia]] may involve both retrograde and anterograde memory loss, depending on the severity of the [[traumatic brain injury]].
 
=== Dissociative Amnesia ===
In [[dissociative amnesia]], long-term memories, typically associated with traumatic or stressful events, are repressed. This condition, deeply intertwined with mental health, is often seen in patients with post-traumatic stress disorder (PTSD).
 
=== Korsakoff's Syndrome ===
=== Korsakoff's Syndrome ===
Chronic alcohol abuse can lead to a specific type of memory loss known as [[Korsakoff's syndrome]]. This condition stems from vitamin B1 deficiency leading to brain damage. Korsakoff's syndrome generally manifests as progressive memory loss and cognitive decline if alcohol consumption continues and nutritional deficiencies persist.
[[Korsakoff's syndrome]] is a chronic memory disorder caused by severe deficiency of [[vitamin B1]] (thiamine), most often due to chronic [[alcoholism]].
 
=== Lacunar Amnesia ===
=== Lacunar Amnesia ===
[[Lacunar amnesia]] describes memory loss specific to a singular event or small span of time. Individuals with this form of amnesia typically maintain a normal memory function outside of this specific 'gap' in their memory.
[[Lacunar amnesia]] refers to memory loss of a specific event, leaving the rest of memory intact. It may occur in cases of [[stroke]] or localized brain trauma.
 
=== Fugue State ===
=== Fugue State ===
Also known as [[dissociative fugue]], this type of amnesia is characterized by temporary, often sudden, memory loss related to one's identity or history. This form of amnesia is usually associated with severe psychological trauma.
Also known as [[dissociative fugue]], this condition involves sudden, unplanned travel away from home combined with memory loss regarding personal identity.
 
=== Infantile Amnesia ===
=== Childhood or Infantile Amnesia ===
Also referred to as [[childhood amnesia]], it is the normal inability of adults to recall memories from the early years of life, typically before age three.
[[Childhood amnesia]], also known as infantile amnesia, describes the general inability of adults to recall events from early childhood. The exact cause is debated, with theories ranging from language development processes to the immaturity of certain brain regions during early life.
 
=== Global Amnesia ===
[[Global amnesia]] is a severe form of memory loss, resulting in complete or near-complete inability to recall past events or form new memories. This form of amnesia is often associated with significant trauma.
 
=== Posthypnotic Amnesia ===
[[Posthypnotic amnesia]] involves the inability to recall events or information encountered while under hypnosis. This form of amnesia is usually temporary and reversible.
 
=== Psychogenic Amnesia ===
=== Psychogenic Amnesia ===
[[Psychogenic amnesia]], unlike organic amnesia, is not due to direct physical damage to the brain. Instead, it is caused by psychological factors, often related to stress or trauma.
[[Psychogenic amnesia]] is caused by emotional trauma or psychological conflict, without any detectable brain injury.
 
=== Source Amnesia ===
=== Source Amnesia ===
[[Source amnesia]] is a specific type of memory disorder where an individual can remember certain information, but cannot recall how or where they learned it.
[[Source amnesia]] refers to the inability to remember the origin or source of learned information while retaining the factual content.
 
=== Alcohol-Induced Amnesia ===
=== Memory Distrust Syndrome ===
Also called [[blackout (alcohol-related amnesia)|alcohol-induced blackouts]], these are temporary memory lapses caused by excessive alcohol consumption.
[[Memory distrust syndrome]] is a term coined by psychologist [[Gisli Gudjonsson]] to characterize a condition where a person is unable to trust their own memory. This syndrome often presents in individuals who question the authenticity of their recollections and can be seen in various psychological and neurological disorders.
== Causes ==
 
Amnesia can arise from:
=== Alcohol-induced Amnesia ===
* [[Brain injury]] (trauma, surgery)
Also known as "blackouts," short-term excessive alcohol consumption can induce symptoms akin to amnesia. This condition often results in an inability to recall events that occurred while under the influence of alcohol.
* [[Stroke]]
 
* [[Infection]]s such as [[encephalitis]]
== Causes and Mechanisms ==
* [[Neurodegenerative disease]]s like [[Alzheimer's disease]]
 
* [[Psychological trauma]]
Amnesia can have both organic and functional causes. Organic causes involve direct damage to the brain from physical trauma, disease, or certain medications, particularly those with sedative effects. Functional causes are usually psychological, such as defense mechanisms employed following traumatic experiences.
* [[Anesthesia]] or sedation
 
* Substance abuse, particularly [[alcohol]]
The neuroanatomical basis of amnesia often centers around damage to brain structures critical for memory processing and storage, particularly the medial [[temporal lobe|temporal lobes]] and the [[hippocampus]]. The pattern of memory loss—whether it affects old memories or the formation of new ones—can help localize the brain damage and identify the type of amnesia.
Damage to brain regions involved in memory processing — especially the [[hippocampus]], [[thalamus]], [[prefrontal cortex]], and [[amygdala]] — is typically implicated in organic amnesia.
 
== Diagnosis ==
== Treatment and Management ==
Diagnosis involves a combination of:
 
* Detailed [[clinical history]]
The treatment for amnesia is contingent on its underlying cause. Addressing the root cause may lead to an improvement in memory function. For instance, if the amnesia is drug-induced, discontinuing the drug usually leads to improvement. In the case of vitamin deficiency, like in Korsakoff's syndrome, vitamin supplementation and improving diet can help.
* [[Neurological examination]]
 
* [[Neuropsychological tests]]
In other cases, treatment involves supportive care and rehabilitation to help the person cope with the condition. Memory training and occupational therapy can often be of substantial benefit. In the case of psychological forms of amnesia like dissociative amnesia, therapy or counseling may be necessary.
* [[Magnetic resonance imaging|MRI]] or [[computed tomography|CT scan]]
 
* [[Electroencephalogram|EEG]] (to rule out seizures)
== Treatment ==
Treatment depends on the cause:
* '''Reversible causes''' (e.g., vitamin deficiency or medication side effects) are treated by correcting the underlying condition.
* '''Cognitive therapy''': Occupational therapy and memory training strategies can help patients adapt.
* '''Psychotherapy''': Used in dissociative or psychogenic amnesia to uncover and address underlying trauma.
* '''Pharmacotherapy''': In some cases, medications to treat underlying conditions (e.g., antidepressants for PTSD-related amnesia) may be used.
== Prognosis ==
== Prognosis ==
 
The outcome of amnesia depends on its cause and severity:
The prognosis for amnesia varies widely and depends on the cause and the severity of the memory impairment. Some forms of amnesia, such as those caused by minor head injuries or transient global amnesia, are temporary and self-limiting. Others, such as amnesia from severe brain injury or progressive neurological disease, may be permanent.
* Temporary amnesia (e.g., from minor head trauma or stress) often resolves completely.
 
* Chronic or progressive causes (e.g., Korsakoff’s syndrome, Alzheimer's) may lead to permanent memory loss.
The impact of amnesia on a person’s life depends on its severity and the person’s individual circumstances. Some people can lead relatively normal lives, while others require full-time care.
* Psychological forms may improve with therapy.
 
== See also ==
== Summary ==
* [[Memory]]
Amnesia is a complex and diverse condition, encompassing a range of memory disturbances. Further understanding of the mechanisms and causes underlying these various types of amnesia can aid in the development of more effective treatments and interventions, thereby improving the quality of life for those affected.
* [[Hippocampus]]
 
* [[Neuropsychology]]
== See also ==  
* [[Dementia]]
* [[Betrayal#Political Betrayal Trauma|Betrayal Trauma]]
* [[Cognitive rehabilitation]]
* [[Clive Wearing]]
* [[Wernicke–Korsakoff syndrome]]
* [[Emotion and memory]]
* [[Brain plasticity]]
* [[HM (patient)]]
== External links ==
* [[Phip Staufen|Mr. Nobody]]
* [https://www.ninds.nih.gov/health-information/disorders/amnesia National Institute of Neurological Disorders and Stroke – Amnesia]
* [http://www.psychnet-uk.com/dsm_iv/dissociative_amnesia.htm Psychnet UK, Treatment]
* [https://medlineplus.gov/amnesia.html MedlinePlus – Amnesia Overview]
{{stub}}
== References ==
<references/>
[[Category:Neurological disorders]]
[[Category:Neurological disorders]]
[[Category:Memory]]
[[Category:Neuropsychology]]
[[Category:Neuropsychology]]
[[Category:Memory disorders]]
[[Category:Psychiatry]]
[[Category:Psychiatry]]
{{No image}}

Latest revision as of 01:02, 4 April 2025


Amnesia
Synonyms Memory loss
Pronounce N/A
Specialty Neurology, Psychiatry
Symptoms Memory loss, difficulty recalling past events, inability to form new memories
Complications N/A
Onset Sudden or gradual
Duration Can be temporary or permanent
Types N/A
Causes Brain injury, traumatic events, stroke, alcohol abuse, encephalitis, Alzheimer's disease
Risks Head injury, substance abuse, psychological trauma
Diagnosis Neuropsychological tests, brain imaging (MRI, CT scan)
Differential diagnosis Dementia, delirium, depression, conversion disorder
Prevention N/A
Treatment Cognitive therapy, occupational therapy, medication
Medication N/A
Prognosis Varies depending on cause; some cases may improve over time, others may be permanent
Frequency Common in cases of traumatic brain injury and neurodegenerative diseases
Deaths N/A


Editor-In-Chief: Prab R Tumpati, MD
Obesity, Sleep & Internal medicine
Founder, WikiMD Wellnesspedia &
W8MD medical weight loss NYC and sleep center NYC

Amnesia
Noun_Forget_1816
Synonyms Amnesic syndrome
Pronounce N/A
Specialty N/A
Symptoms Memory loss, confusion, inability to retain new information
Complications Cognitive impairment, loss of autonomy, emotional distress
Onset Sudden or gradual, depending on cause
Duration Temporary or permanent
Types Anterograde amnesia, Retrograde amnesia, Dissociative amnesia, etc.
Causes Brain injury, stroke, neurodegenerative disorders, psychological trauma, alcohol abuse
Risks Head trauma, epilepsy, encephalitis, substance use
Diagnosis Neuropsychological testing, MRI, CT scan, EEG
Differential diagnosis Dementia, Delirium, Depression
Prevention Preventing head injuries, managing substance use, early intervention in infections
Treatment Supportive care, cognitive rehabilitation, psychotherapy
Medication Vitamin B1 in cases like Korsakoff's syndrome
Prognosis Varies by type and cause
Frequency Uncommon overall; varies with underlying condition
Deaths Rarely fatal directly


Amnesia is a neurocognitive disorder characterized by partial or complete loss of memory, either short-term, long-term, or both. It can result from a variety of causes including neurological damage, psychological trauma, or toxic exposures. Individuals with amnesia may be unable to recall past experiences, form new memories, or both, depending on the type and extent of brain involvement.

Classification[edit]

Amnesia is broadly categorized based on the type of memory affected and the underlying cause.

Anterograde Amnesia[edit]

Anterograde amnesia is the inability to form new memories following the onset of the condition, often caused by damage to the hippocampus or related structures.

Retrograde Amnesia[edit]

Retrograde amnesia involves the loss of pre-existing memories prior to the onset of amnesia. It often spares older memories while more recent ones are affected.

Transient Global Amnesia[edit]

Transient global amnesia (TGA) is a sudden, temporary episode of memory loss not attributable to more common neurological conditions like epilepsy or stroke.

Dissociative Amnesia[edit]

Dissociative amnesia is typically psychological in origin, where individuals block out memories related to stressful or traumatic events. It is associated with post-traumatic stress disorder (PTSD) and dissociative disorders.

Traumatic Amnesia[edit]

Often seen after head injuries, traumatic amnesia may involve both retrograde and anterograde memory loss, depending on the severity of the traumatic brain injury.

Korsakoff's Syndrome[edit]

Korsakoff's syndrome is a chronic memory disorder caused by severe deficiency of vitamin B1 (thiamine), most often due to chronic alcoholism.

Lacunar Amnesia[edit]

Lacunar amnesia refers to memory loss of a specific event, leaving the rest of memory intact. It may occur in cases of stroke or localized brain trauma.

Fugue State[edit]

Also known as dissociative fugue, this condition involves sudden, unplanned travel away from home combined with memory loss regarding personal identity.

Infantile Amnesia[edit]

Also referred to as childhood amnesia, it is the normal inability of adults to recall memories from the early years of life, typically before age three.

Psychogenic Amnesia[edit]

Psychogenic amnesia is caused by emotional trauma or psychological conflict, without any detectable brain injury.

Source Amnesia[edit]

Source amnesia refers to the inability to remember the origin or source of learned information while retaining the factual content.

Alcohol-Induced Amnesia[edit]

Also called alcohol-induced blackouts, these are temporary memory lapses caused by excessive alcohol consumption.

Causes[edit]

Amnesia can arise from:

Damage to brain regions involved in memory processing — especially the hippocampus, thalamus, prefrontal cortex, and amygdala — is typically implicated in organic amnesia.

Diagnosis[edit]

Diagnosis involves a combination of:

Treatment[edit]

Treatment depends on the cause:

  • Reversible causes (e.g., vitamin deficiency or medication side effects) are treated by correcting the underlying condition.
  • Cognitive therapy: Occupational therapy and memory training strategies can help patients adapt.
  • Psychotherapy: Used in dissociative or psychogenic amnesia to uncover and address underlying trauma.
  • Pharmacotherapy: In some cases, medications to treat underlying conditions (e.g., antidepressants for PTSD-related amnesia) may be used.

Prognosis[edit]

The outcome of amnesia depends on its cause and severity:

  • Temporary amnesia (e.g., from minor head trauma or stress) often resolves completely.
  • Chronic or progressive causes (e.g., Korsakoff‚Äôs syndrome, Alzheimer's) may lead to permanent memory loss.
  • Psychological forms may improve with therapy.

See also[edit]

External links[edit]

Retrieved from "https://wikimd.com/index.php?title=Amnesia&oldid=6542493"