Understanding Amnesia

Types and Symptoms of Amnesia

Amnesia refers to the partial or total inability to recall past experiences or store new memories, involving significant memory loss.

There are many types of amnesia, and an individual can have more than one type of amnesia. Amnesia can be temporary or long-lasting.

The symptoms of amnesia depend on the type of amnesia. Common symptoms include impaired ability to remember past events or learn new information, impaired short-term memory, partial or total memory loss, experiencing real memories misplaced in time or completely invented memories (confabulation), and confusion.

The common types of amnesia include:

• Retrograde amnesia occurs when an individual is unable to recall events from the past. This type of amnesia usually affects recently formed memories first.
• Anterograde amnesia usually results from brain trauma. Affected individuals tend to have their full memory from the time before the trauma and cannot remember new information.
• Transient global amnesia is a short-lived amnesia that involves both retrograde and anterograde amnesia. One may experience memory loss in the hours leading up to the amnesia and tend to have no recollection of the experience. Transient global amnesia usually resolves within 24 hours.
• Post-traumatic amnesia usually results from a head injury whereby the affected individual may experience temporary loss of consciousness or even go into a coma. Post-traumatic amnesia is usually temporary but how long it lasts depends on the severity of the injury.
• Dissociative amnesia or fugue state usually occurs due to a traumatic event. The affected individual may forget both their past and their identities.

Causes of Amnesia

Neurological causes

Neurological causes of amnesia involve damage to the brain or disruptions in brain activity, such as Alzheimer’s disease, brain aneurysms, brain tumours, cerebral hypoxia (insufficient oxygen to the brain), epilepsy and seizures, brain infections, stroke, degenerative brain diseases (e.g., Parkinson’s disease, multiple sclerosis), and toxins poisoning.

Psychological causes

Psychological causes include dissociative disorders (especially dissociative amnesia) and post-traumatic stress disorder (complex PTSD). Psychological causes of amnesia tend to involve a traumatic event or severe emotional distress. While experts do not fully comprehend why this occurs, they suspect that it is the brain’s way of protecting an individual from psychological harm.

Diagnosis of Amnesia

Your physician will take a detailed medical history (including from family members or caregivers) and conduct a series of neurological examinations before ordering diagnostic laboratory tests and imaging scans to help confirm the diagnosis.

The tests recommended varies depending on your symptoms and the suspected underlying cause of the amnesia. These include neuropsychological assessment, computed tomography (CT) scan, magnetic resonance imaging (MRI) scan, electroencephalogram (EEG) to look for seizure activity, blood tests (to look for infection, nutritional deficiency, electrolyte levels and blood sugar levels), and spinal tap (lumbar puncture) to examine cerebrospinal fluids for possible causative factors.

Treatment Options for Amnesia

In many cases, amnesia may resolve spontaneously. However, amnesia due to an underlying physical or mental disorder may require treatment.

Individuals with amnesia may not understand what is happening to them, preventing them from making informed decisions regarding their medical care. These individuals will require a family member or caregiver to help make these decisions for them.

Cognitive behavioural therapy and occupational therapy can help with recovering from memory loss. These therapies will enable individuals with amnesia to acquire skills to compensate for memory loss and related abilities. Family support is also vital. Spending time together and revisiting old memories can help bring back memories from the past.

Preventing Amnesia

Amnesia is usually unpredictable and happens suddenly, causing acute memory loss. Gradual loss of memory, on the other hand, could be a symptom of degenerative brain disease. Some preventive measures that can be taken to reduce the risk of having amnesia include wearing safety equipment, when necessary (for example, helmet), eating a balanced diet, having enough rest and managing stress properly, stay physically and mentally active, quit smoking, avoid excess consumption of alcohol.

Make an Appointment at Gleneagles Hospitals

If you have questions about amnesia, get in touch with us to book an appointment today for a consultation, or visit our Neurology Department at your nearest Gleneagles Hospital.