+1-888-360-0001 8:00AM to 6:00PM EST
For Physicians
SignUp    

Amnesia

Overview

Amnesia is a condition in which you are unable to recall facts and information from your memories. In simple words, it refers to the loss of memories. Your brain stores a vast array of information you utilize in your daily routine. If amnesia occurs, you will be unable to remember many important things or unable to form new memories. Amnesia should be differentiated from usual forgetfulness. It appears as a consequence of an injury, illness, or severe psychological trauma. 

Causes

Any medical disease, physical injury, or psychological trauma that affects your brain can disrupt your memories. The part of the brain that controls your memories is known as the limbic system. Damage to this region can cause neurological amnesia. It can occur due to stroke, encephalitis, insufficient oxygen to the brain, brain tumor, chronic alcohol abuse, degenerative brain diseases, and seizures. Certain medications such as benzodiazepines that sedate your nervous system may also cause amnesia.  Severe head injuries from a road traffic accident or athletic injury can cause damage to parts of the brain that involve the storage and formation of memories. Amnesia can also occur from an emotional or psychogenic shock. It can occur due to a severe traumatic event such as being the victim of a crime. 

Types

There are many different types of amnesia, but it can be broadly classified into two main categories.

Anterograde amnesia is the type in which a person is unable to form new memories after an incident. This can result after a traumatic head injury or brain damage. The affected person will have full memories before the incident occurred but will have difficulty forming new ones.

 

Retrograde amnesia is almost the opposite of anterograde amnesia, in which the person is unable to recall memories prior to the incident, but they do remember what happened after it. It can also occur after a direct blow to the head or brain injury. 

Risk Factors And Epidemiology

Amnesia can occur in any age group, but the risk increases with age. A direct blow to the head or traumatic brain injury after an accident can increase the risk of amnesia. Besides physical damage, psychological trauma from the past can also trigger temporary loss of memories known as dissociative amnesia. Positive family history of stroke, genetic brain diseases, and other medical conditions can also increase your risk of developing amnesia. Other risk factors include depression, sleep deprivation, chronic alcohol abuse, severe malnutrition, dialysis, chemotherapy, and chronic stress.

 

The incidence of amnesia varies based on its certain types. For example, dissociative amnesia is present in 1.0 to 2.6% of the population. Gender and racial prevalence also vary for different types of amnesia. The risk is greater for older age people above the age of 60. 

Signs And Symptoms

The primary sign of amnesia is loss of memories without any other major cognitive disability. You may be unable to form new memories (anterograde amnesia) or have difficulty recalling old memories before the onset of amnesia (retrograde amnesia). You may have confusion and difficulty recalling your experiences. People with amnesia with isolated memory loss can perform all other cognitive tasks such as reading, writing, typing, etc. This differs from dementia, in which memory loss occurs along with cognitive impairment. You may be able to recall memories after a temporary loss (transient global amnesia) or progress to a more severe stage with permanent memory loss. 

Diagnosis

A detailed history and examination are required to figure out if the memory loss is due to amnesia or other possible causes. These factors will also help in determining the type of amnesia present. Your doctor can ask about the onset, duration, and events before or after memory loss. A physical examination is also done to check coordination, balance, reflexes, sensory and motor function. Cognitive tests can be performed to evaluate thinking, judgment, and memory. Diagnostic tests include imaging scans such as CT and MRI, blood tests to check for infections and other abnormalities, and electroencephalogram for electrical activity. 

Differential Diagnosis

Since there are many different types of amnesia, such as transient global amnesia, dissociative amnesia, post-traumatic amnesia, drug-induced amnesia, etc., they should be differentiated on the basis of history, symptoms, and diagnostic tests. Memory loss due to amnesia should also be distinguished from other causes such as dementia, Alzheimer’s disease, or brain tumor. 

Treatment

Many cases of amnesia recover well without any treatment. However, while the duration of amnesia lasts, your doctor may refer you to a therapist to guide you through this phase. An occupational therapist can help in learning new information to replace lost memories. Psychotherapy or cognitive behavioral therapy (CBT) can also be used to deal with this condition. Some people are able to recall old memories through the technique of hypnosis.

 

Smartphones and watches can be used to set reminders for day-to-day tasks. Improved technology has made it easier for people with amnesia to track and remember their routine activities. It is also important to address the cause of amnesia to recover from it. For example, amnesia in Wernicke-Korsakoff syndrome (WKS) is caused due to vitamin B1 deficiency. Targeted nutrition to fulfill this vitamin deficiency can help recover from amnesia. There are no specific medications or drugs that are known to reverse the effects of amnesia. 

Prognosis

Majority of the cases of amnesia recover well. In patients with a traumatic head injury, the prognosis is determined by the severity of injury and duration of loss of consciousness. Early diagnosis and treatment can prevent further neurological complications. 

Prevention

Amnesia can be prevented to a certain extent by wearing protective headgear during diving or sports to avoid traumatic head injury. It is also recommended to drive while wearing a seatbelt and avoid driving if drunk. People over the age of 60 or 65 years should get regular checkups to prevent the risk of sudden falls. Maintain a balanced diet with all necessary nutrients and exercise regularly to improve blood circulation to your brain.