Overview
A type of memory disorder, unable to recall familiar things or experiences mainly manifested as memory loss, can not remember, can not think of the cause is unknown, may be related to brain diseases, brain damage, psychological factors, no specific treatment, mainly for the cause of treatment, with the use of drugs, cognitive training
Definition
Amnesia is not a standardized medical name, but mainly refers to forgetfulness, which is a common symptom of memory disorders.
The patient may not be able to recall past information, or may not remember newly created memories, or both may exist simultaneously, far exceeding the degree of occasional forgetfulness of normal people, causing obvious impact on normal life, learning, and work.
Unlike cognitive disorders, dementia, or mental illness, amnesia does not affect a person’s intelligence, common sense, awareness, concentration, judgment, personality, or perception of self.
In other words, patients do not appear to forget who they are and recognize that they have memory loss.
Staging or Classification
Classification by etiology
Psychogenic amnesia: often occurs suddenly after severe trauma and is characterized by an inability to recall experiences related to the trauma.
Organic amnesia: caused by brain diseases, commonly after traumatic brain injury or cerebrovascular disease. Usually, it is easy to forget the recent events, while the early memory is maintained better.
Classification according to the performance of amnesia
Retrograde amnesia: refers to the patient can not recall the experience of a period of time before the onset of the disease. Most commonly seen in traumatic brain injury, concussion, acute disorders of consciousness. Usually, the more serious the brain injury, the longer the amnesia lasts.
Paradoxical amnesia: refers to the patient can not remember what happened in a period of time after the onset of the disease. Commonly seen in high fever delirium, epilepsy, intoxication, traumatic brain injury, encephalitis, subarachnoid hemorrhage.
Others: progressive amnesia, systemic component amnesia, selective amnesia and transient amnesia.
Morbidity
There is no authoritative data on the incidence of the disease. It is common in middle-aged and elderly people, and the incidence of the disease has tended to be younger in recent years.
Etiology
Pathogenesis
Memory is the brain’s ability to retain and recall information from the past, and is divided into three stages: encoding, storage and retrieval. Problems in any of these stages can cause memory disorders, including amnesia.
Encoding: The brain takes in new information and creates a series of “codes” to represent it, which can be linked to other previously stored information.
Storage: These “codes” remain in the brain whether they are used or not.
Retrieval: When needed, the brain searches for and extracts these “codes” by creating new or finding related links to information, i.e., recalling or recognizing information from the past.
Pathogenic factors
Normal memory function involves many brain regions, and forgetfulness can be caused by damage to the limbic system of the brain (thalamus, medial temporal lobe, hippocampus, etc.), an area that also controls emotions and psychology.
Damage to either brain structure or brain function may interfere with the memory process and cause memory impairment.
Common causes of organic amnesia include:
Stroke: e.g., cerebral hemorrhage, cerebral infarction, transient ischemic attack (TIA).
Traumatic brain injury: e.g., concussion, cerebral contusion, diffuse axonal injury, intracranial hematoma.
Intracranial inflammation and infection: such as herpes simplex virus encephalitis, autoimmune encephalitis, brain parasites, neurosyphilis, paraneoplastic limbic encephalitis.
Ischemic-hypoxic encephalopathy: such as heart attack, sudden cardiac death, asphyxia, respiratory distress, carbon monoxide poisoning.
Nutritional metabolic encephalopathy: chronic alcoholism leads to Wernicke-Korsakoff syndrome.
Brain tumors, occupations: such as cerebral glioma, brain metastases, brain cysts.
Neurodegenerative diseases: such as Alzheimer’s disease, Lewy body dementia, Parkinson’s disease, etc.
Other: e.g. seizures, use of benzodiazepines or other tranquilizing drugs such as diazepam, zolpidem tartrate, etc.
Psychogenic amnesia: Also known as psychological or dissociative amnesia, it is less common and is mainly caused by emotional trauma, such as survivors of car accidents and victims of violent crimes.
Risk factors or predisposing factors
People with the following conditions are more likely to develop brain damage and symptoms of amnesia.
Chronic mental and psychological stress.
Chronic drinking, smoking, late nights, chronic insomnia, being overweight.
Malnutrition, B vitamin deficiency.
Suffering from diabetes, hypothyroidism and other diseases.
Have risk factors for cerebrovascular disease such as hypertension, hyperlipidemia, hyperhomocysteinemia.
Symptoms
Main symptoms
Paradoxical amnesia: the most common, manifested as the inability to form new memory information after the onset of the disease, and the inability to remember new occurrences. For example, it is difficult to remember whether salt has been put in the stir-fry just now or where the cell phone has been put.
Retrograde amnesia: It is difficult to remember what happened in a period of time before the onset of the disease. For example, patients with traumatic brain injury cannot remember what they were doing before the injury, but they can recall earlier events and information, such as the name of an old friend or a phone number that has been used for several years.
Temporary amnesia: manifested as short-term forgetfulness, which can return to normal after a period of time.
Progressive amnesia: This is characterized by increasingly severe amnesia.
Selective amnesia: Amnesia only for a particular event or detail, usually related to mental stimulation.
Other symptoms
Patients usually have other types of memory impairment, such as misrecognition and fictionalization.
Misconstruction: Mismatch of time, place, and circumstances of past events, “putting words in their mouths”.
Fiction: filling in missing parts of the memory by fictionalizing things that did not happen, often vivid, varied, and absurd, but not subjective to the patient.
Complications.
When the symptoms persist and seriously affect the patient’s normal life and work can cause psychological problems, such as depression and anxiety.
Often manifested as low mood, pessimism, loss of interest, slow thinking, nervousness, fear, fatigue, overthinking and other symptoms.
It can also cause sleep disorders, which are characterized by insomnia, excessive dreaming and waking up easily.
Consultation
Department of Medicine
Neurology
When the patient has obvious memory loss, can’t think, can’t remember, affecting normal life and work, it is recommended to seek medical treatment in time.
Psychiatry
If obvious memory loss occurs after psychological or mental trauma, timely consultation is recommended.
Rehabilitation
After the cause of the disease is clearly defined, clinical treatment should be accompanied by cognitive training, and systematic treatment in the Department of Rehabilitation is recommended.
Preparation
Consultation: registration, preparation of information, common questions
Tips for medical treatment
Patients need to be accompanied by family members, preferably those who know the patient’s medical history, in order to provide detailed diagnostic evidence.
Forgetting symptoms is not easy to express, you can tell the doctor some specific examples during the consultation.
Preparation List
Symptom list
Especially focus on the time of onset of symptoms, special manifestations, etc.
Do you often forget what you have said or done?
Do you often lose things, forget things you have promised or phone numbers?
Are there any changes in personality or mood?
Are there any symptoms of stress, late nights, dreams, etc.?
How long have the symptoms lasted? Has there been any treatment and how effective is it?
List of medical history
Do you have hypertension, diabetes mellitus, hyperlipidemia, high homocysteine, etc.?
Any stroke, coronary heart disease, atrial fibrillation, atherosclerosis, traumatic brain injury, brain tumor?
Are you a chronic smoker, alcoholic, overweight, or stay up late?
Has anyone in the family suffered from similar diseases?
Checklist
Examination results in the past six months, which can be brought to the doctor’s office
Imaging tests: Cranial CT, Cranial Magnetic Resonance Imaging (MRI), Positron Emission Tomography (PET), etc.
Laboratory tests: blood glucose, blood lipids, homocysteine, etc.
Medication list
Medication used in the last 3 months, if available in a box or package, bring it with you to the doctor’s office
Cognitive improvement medications: donepezil, memantine, sodium mannitol, etc.
Diagnosis
Diagnosis based on
Medical history
History of brain injury or trauma, such as stroke, traumatic brain injury, encephalitis, carbon monoxide poisoning, etc.
Have long-term psychological stress, insomnia, psycho-emotional trauma, etc.
Middle-aged or elderly people, with long-term smoking, drinking, staying up late, being overweight, using sedative-hypnotic drugs, etc.
Clinical manifestations
Often forgetting what has been said and done, losing things, emotional anxiety, depression, insomnia.
Laboratory Tests
Common items: blood routine, C-reactive protein, biochemistry full, vitamin B12, hemoglobin measurement, etc.
Purpose of examination: To assess the overall body condition and assist in determining the cause of the disease, whether inflammation, nutrition, metabolism, intoxication, hypoglycemia, etc. is present.
Precautions: During the course of treatment, some tests need to be performed on an empty stomach, and some items may need to be rechecked periodically.
Head CT/Magnetic Resonance Imaging (MRI)
Purpose of examination: It can clarify whether there is organic brain lesion.
Common results: It can detect brain hemorrhage, ischemic foci, tumors, etc. MRI can also measure whether the hippocampus is atrophied and the degree of atrophy.
Precautions
CT has a certain amount of radiation and should not be used frequently.
You should not bring any metal objects into the MRI examination room. Those who have dentures or metal implants in their bodies, such as heart stents, etc., need to inform the radiologist, who will determine whether the MRI examination can be performed.
Positron Emission Magnetic Resonance Imaging (PET/MRI)
Purpose of the examination: The purpose of the examination is roughly the same as that of MRI, and the metabolic status of the lesion or hippocampal area can also be observed.
Precautions
Fasting is generally required for 6 hours before the examination, avoiding high sugar foods, and drinking as much water as possible after the examination to promote the elimination of contrast agent metabolism.
Other precautions are the same as head MRI.
Neuropsychological scales
Memory, comprehensive cognitive related scales: Auditory Word Learning Test-Huashan version, Wechsler Memory Scale (WMS), Clinical Memory Scale, Memory Executive Rating Scale, Rivermead Behavioral Memory Function, Rating, MMSE, etc.
Psychological assessment scales: Hamilton Anxiety Scale, Depression Self-Rating Scale, etc.
Significance of results: The score of memory scale helps to determine the severity of symptoms and identify organic and functional memory disorders; psychological assessment scale helps to determine whether the patient has symptoms of anxiety and depression.
Note: The above scales need to be used and interpreted by clinicians in conjunction with clinical manifestations, and self-assessment is not recommended.
Other Tests
Electroencephalography (EEG) is performed on patients with a history of convulsive seizures, and lumbar puncture is performed on patients with fever and headache symptoms.
Clarify the presence of epilepsy, intracranial infection, and inflammatory response.
Differential diagnosis
Patients presenting with amnestic symptoms mainly need to identify different etiologies.
Table 1. Common causes of amnesic symptoms
Disease History Symptoms Auxiliary tests
Alzheimer’s disease has no history of cerebrovascular disease, brain tumor, etc., with insidious onset and slow progression of the disease with memory loss as the main early manifestation, followed by labyrinthine, computational, language decline, personality changes and other manifestations, and cranial MRI may show atrophy of the hippocampus and the medial temporal lobe without local manifestations of cerebral ischemic foci, hemorrhagic foci, etc.
Alzheimer’s disease
No history of cerebrovascular disease, brain tumor, etc., with insidious onset and slow progression.
Memory loss is the main early manifestation, followed by labyrinthine, computational, language decline, personality changes and other manifestations.
Hippocampal and medial temporal lobe atrophy can be seen on cranial MRI, with no localized manifestations such as ischemic foci or hemorrhagic foci.
Transient ischemic attack with hypertension, diabetes mellitus and other cerebrovascular risk factors, impaired executive function, often accompanied by hemiparesis, sensory deficits and other neurological impairments, paroxysmal, usually less than 1 day cranial MRA or CTA may show cerebral vascular sclerosis or stenosis manifestations
Transient ischemic attack
Cerebrovascular risk factors such as hypertension and diabetes mellitus.
Impairment of executive function, often accompanied by hemiparesis, sensory deficits and other neurological damage, paroxysmal, usually less than 1 day
Cerebral vascular sclerosis or stenosis may be seen on cranial MRA or CTA.
Transient generalized amnesia without aura symptoms, sudden onset of short-term memory loss, inability to recognize time and place, but normal conversation, writing and arithmetic ability, lasting for a few hours, usually completely resolved within 24 hours may not have any abnormal manifestations.
Transient amnesia
No aura, sudden onset
Short-term memory loss, inability to recognize time and place, but normal conversation, writing and arithmetic skills, lasting several hours, usually resolving completely within 24 hours.
May have no abnormal manifestations
Treatment
Aim of treatment: to control the underlying disease and improve the symptoms.
Treatment principle: no specific treatment, focusing on controlling the underlying disease and cooperating with rehabilitation training.
Etiologic treatment
Patients with a clear cause need to emphasize the treatment of the original disease.
Cerebrovascular disease
Commonly used drugs: aspirin, atorvastatin, nifedipine, metformin, etc.
Control the symptoms of hypertension, diabetes mellitus, cardiovascular and cerebrovascular diseases and other underlying diseases, reduce the risk of recurrence, and delay disease progression.
Chronic Alcoholic Encephalopathy
Vitamin B1 supplementation is available for patients with chronic alcoholic encephalopathy.
Helps prevent further brain damage, but difficult to improve amnestic symptoms.
Epilepsy
Patients with epilepsy can avoid further brain damage by controlling seizures with medications.
Commonly used drugs: diazepam, carbamazepine, sodium valproate, oxcarbazepine, etc.
Medication
Improvement of cognitive function
Commonly used drugs: memantine, donepezil, carboplatin, galantamine, sodium glycinate.
Precautions: should be used with caution in epileptic patients, those with a history of convulsions, and should not be combined with amantadine, dextromethorphan and other drugs.
Improvement of anxiety and insomnia
Commonly used drugs: alprazolam, eszopiclone, lorazepam and so on.
Precautions: Fatigue, drowsiness, dizziness, unsteady gait or aggravation of forgetfulness may occur after using the drug.
Improvement of depressive symptoms
Commonly used drugs: fluoxetine, paroxetine, citalopram, sertraline
Precautions: Adverse effects such as nausea, sweating, arthralgia, fatigue, appetite changes, insomnia may occur while monitoring platelets.
Rehabilitation
Cognitive training should be carried out early and throughout the course of the disease, commonly used methods are as follows:
External information storage: applying external memory tools such as calendar, diary, memo, timetable, schedule, map, photo, landmark, etc., replacing “memory” with “external storage”.
Environmental modification: This is to reduce the difficulty of memorization by arranging the patient’s living and working environments, placing frequently used items in an orderly manner, reducing unnecessary changes, and adding conspicuous and necessary hints.
Verbal mnemonics: It improves memory by organizing the information to be memorized through the connection between languages. For example, first word mnemonics, association, temporal order, cause and effect, importance ranking, story making method, etc.
Visual Image Techniques: Aids in the memorization of information through visual images, images, diagrams, and other elements. Including placement of place method, connection or link method, categorization method, etc.
Prognosis
Cure.
The prognosis of patients with amnesia is closely related to the cause of the disease and varies widely.
For example, patients with psychogenic amnesia can be cured after removing the influence of psychogenic factors, while patients with Alzheimer’s disease and vascular dementia will continue to progress to dementia.
Prognostic factors
The prognosis is mainly related to the following factors:
Etiology: Organic amnesia usually has a poorer prognosis than psychogenic amnesia.
Age of onset: the older the patient, the worse the prognosis.
Underlying disease: If the underlying disease such as diabetes mellitus or hypertension is well controlled, the risk of progression of vascular dementia or recurrence of stroke is low and the prognosis is relatively good.
Complications: If severe anxiety, depression, insomnia, etc. are present, they can further aggravate the symptoms of amnesia.
Harmful effects
Memory impairment, anxiety and depression can affect the patient’s normal life, work, socialization ability and reduce the quality of life.
Patients with severe memory impairment are unable to take care of themselves and need to be supervised or admitted to a long-term care facility.
Daily
Daily Management
Dietary management
A Mediterranean diet based on vegetables and fruits, fish, grains and cereals, legumes and olive oil is recommended.
For patients who have difficulty eating orally for various reasons, food can be ground and fed nasally to supplement nutrition.
Stroke patients should follow a low-salt, low-fat and low-sugar diet.
Lifestyle management
Regular work and rest, ensure sufficient sleep time, do not smoke, do not drink alcohol.
Create a quiet and comfortable living environment and avoid exposing patients to excessive stimuli, such as noise, crowds and noises.
Overweight or obese patients should keep their weight within the standard range.
Management for memory impairment
Help memory through diaries, calendars, photos, and setting reminders on smartphones.
Secure everyday items such as keys, wallet, and cell phone in the same place in the house.
Keep medications in a prominent place and use a daily checklist to record dosages.
Psychological support
Avoid excessive mental stress. Family members should encourage and comfort the patient, build up confidence in treating the disease, and reduce the impact of adverse emotions.
Seek help from professional psychological practitioners if necessary.