Memory loss

• What is memory loss?
• What causes memory loss?
• When do you see your healthcare professional?
• Clinical examination
• Warning signs for dementia
• Management and treatment of memory loss

What is memory loss?

Our memory is where we store, retain and retrieve information. When there is some damage to the part of our brain that performs these functions, memory loss can occur. Memory loss is a symptom in which a person experiences an abnormal level of forgetfulness and inability to recall past events in their life. This is usually a consequence of damage to the brain which may have been caused by disease, injury or excessive emotional stress. Memory loss may be temporary or permanent. Not all memory problems signify dementia or Alzheimer’s. Memory impairment can be caused by many medical conditions, and it is possible that something simple and treatable such as depression or epilepsy or even a medication may be the underlying cause.

Memory loss is a very broad term that can mean any deficit in memory function. There are many different types of memory loss including anterograde (inability to learn new memories), retrograde (forgetting old memories), complete or partial, sudden or long term. Sometimes a person will have only memory loss (sometimes called the ‘amnesic syndrome’) or only mild memory loss (called ‘mild cognitive impairment’). Sometimes a person will have memory loss as part of more general problems, such as in dementia where a person may have difficulty with memory as well as difficulty with speech, fiddly jobs and planning.

Some memory loss is quite common as people get older, and people may be worried that they are developing dementia. For this reason there is included a short paragraph on the warning signs of dementia.

What causes memory loss?

Memory loss is a common health complaint, particularly in the elderly. There is an array of medical conditions that can affect memory and cause memory loss, many of which can be treated easily. Some causes of memory loss include:

• Normal ageing process (age-associated memory impairment);
• Vitamin deficiencies such as B12 and anaemia, electrolyte imbalances;
• Thyroid abnormalities: hypothyroidism or hyperthyroidism;
• Depression, anxiety and stress (pseudo dementia);
• Other psychiatric disorders, especially post traumatic stress disorder;
• Head injuries;
• Dementia: Alzheimer’s disease, vascular dementia, frontotemporal dementia;
• Delirium;
• Temporal lobe surgery;
• Cerebrovascular disease such as stroke, transient ischaemic attack and multi-infarct dementia;
• Sleep apnoea;
• Cerebral tumours;
• Dehydration;
• Cardiovascular disorders: acute myocardial infarction, arrythmias (irregular heartbeat), congestive heart failure;
• Seizures (especially temporal lobe epilepsy);
• Medications (e.g. barbiturates and benzodiazepines);
• Alcohol;
• Drugs: many illicit drugs, including amphetamines, marijuana and cocaine can cause short term memory loss;
• Wernicke-Korsakoff syndrome (thiamine deficiency);
• Encephalitis (especially Herpes simplex infection);
• Infections: meningitis, Creutzfeldt-Jakob disease);
• Multiple sclerosis;
• Electroconvulsive therapy;
• Huntington’s disease, late Parkinson’s disease, Picks’ disease.

Some degree of memory loss is a normal part of ageing and not all people who have memory loss have dementia or any of the above conditions.

When do you see your healthcare professional?

As a result of the ageing process, memory and thinking abilities slow down naturally and it may take longer to remember things. Such mild memory impairment is referred to as age-associated memory impairment and is usually absolutely normal. However, when memory loss has progressed to such an extent that normal every day activities cannot be carried out (such as eating, bathing, shopping, driving and taking medication) then this is an indication that a more severe type of memory dysfunction may be occurring which should be checked by your GP.

It is a good idea to seek help if you are finding that you are:

• Becoming lost in places that are usually familiar to you;
• Repeatedly asking the same questions;
• Confused about time, people and places;
• Frequently losing your belongings (i.e. wallet and keys);
• Forgetting appointments and social commitments.

If you are worried, asking someone close to you if they have noticed any memory problems is a good idea.

Clinical examination

There is a long list of conditions that can cause memory loss, but only some will ever be a possibility for any patient. Because of this, investigation of memory loss always starts with a long history and may then include formal cognitive (memory) testing, blood tests and brain imaging.

History and physical examination

The first thing your medical practitioner will do is take a full detailed medical history in order to identify any treatable underlying medical issues. Inquiries will be made on any family history of memory and/or neurological disorders such as dementia. If you can bring a friend or relative with you, they can often identify when the memory loss began and how long it has been going on.

Questions the doctor may ask include:

• What you actually mean by memory loss:
  • Do you have trouble remembering words, trouble with doing complex things like doing up buttons, trouble identifying common objects like a watch or pen, trouble with skills such as dressing, trouble with orientation or trouble handling money?
  • Do you have neglect (you only see or respond to things on one side)?
  • Is there a general worsening of your health?
  • Is the loss of memory total or partial, long or short term memory?
  • Can you still learn new things?
• Are there any other changes, such as a change in behaviour, mood or energy levels?
• Is it sudden or gradual onset?
• How long has this been happening?
• Has it been getting worse?
• Does it only happen in some situations?
• How does this affect your daily life and ability to perform normal activities such as dressing, washing, feeding, etc?
• Have you noticed it yourself, or has it only come to the attention of friends or family? Alzheimer patients are usually not aware of their impairments;
• Any history of trauma (especially head trauma)?
• Has anything changed recently in your life? Are you sleeping less, or under large amounts of stress or anxiety?
• How much alcohol do you drink?
• Are you taking any medications or drugs?
• Any other symptoms? These includes fever, signs of stoke, etc;
• Any past or ongoing medical problems, including epilepsy and thyroid problems?
• Any past surgery?
• Family history (especially Alzheimer’s disease).

A physical examination may also be performed, looking at temperature, any signs of infection, stroke or other abnormalities.

Cognitive testing

After a detailed history, formal cognitive testing may be performed. For people with a cause of memory loss (such as head trauma or infection) this is usually unnecessary.

The most commonly used test is the Mini-Mental State Examination (MMSE). This test only takes 5-10 minutes to perform and provides information about orientation, memory and attention. There are, however, many tests that can be used.  Some of these tests will include following instructions, copying pictures, remembering numbers and even interpreting proverbs. While some of these tests may seem strange, they provide an important tool for checking how the brain is working.

Blood tests

Blood tests to identify some treatable causes such as vitamin deficiencies (B12), thyroid abnormalities and any infections.

The blood tests performed may include:

• Full blood count and ESR;
• Electrolytes, calcium, renal function tests;
• Blood sugar level;
• Thiamine levels;
• Liver function tests;
• Thyroid function tests;
• Tests for infection.

Imaging

Brain imaging such as a CT or SPECT imaging can determine if any parts of the brain are not functioning well, it also measures blood flow to the brain and can detect lesions such as tumours.

An MRI of the brain can detect brain atrophy or evidence of cerebrovascular disease. Imaging can be important for some people, especially in sudden memory loss or if there is a history of head injury.

In rare cases other tests such as an EEG (electroencephalogram), lumbar puncture or brain biopsy may be required.

If further testing is required for a diagnosis, you may be referred to a memory clinic, or other specialist such as a geriatrician, neurologist, psychiatrist or neuropsychologist.

Warning signs for dementia

Many people may be very worried that they might have dementia or Alzheimer’s disease. Dementia is more than just memory loss; it is a general impairment. However, early stages of dementia can be very similar to normal forgetfulness. The doctor must take a careful history to distinguish between what is normal and what is not.

There are some pointers to determine whether it is dementia or just the normal ageing process. Some of the warning signs of dementia include:

• The person is unaware of their impairment, it is a friend or relative that brings it to the doctor’s attention;
• There is a substantial change in overall thinking and ability to do normal tasks. For example, you may have difficulty following instructions like a simple recipe, or doing complex tasks such as a crossword;
• You have problems with everyday tasks, such as using a telephone, organising medications or controlling money;
• You have considerable trouble learning any new information.

Simply forgetting certain words or names or where you put certain objects is normal and not a sign of dementia.

Mini-cog The Mini-Cog is a 3 minute test which can be used to discriminate between demented and non-demented persons.

Dementia Benchmark Checklist Once this checklist is completed the scores will establish a benchmark for all subsequent checklists. Ideally, these should be completed every 6 months.

Management and treatment of memory loss

If the cause of memory loss is identified to be attributable to underlying depression, nutritional deficiencies or a side effect of medication, these can be treated easily. SSRIs (selective serotonin reuptake inhibitors) can be used for depression, anxiety and other personality disorders.

However, for many people there will be no easily reversible cause of memory loss and these people need ongoing therapy for the memory loss. There are some treatments available for Alzheimer’s, but these treat the symptoms rather than the disease and, if stopped, the symptoms will return. These include the cholinesterase inhibitors such as donepezil (Aricept), rivastigmine (Exelon) and gantamine (Reminyl) which act to improve cognitive function. Another drug used for dementia is memantine. These drugs are very good at helping to improve memory and reduce other problems for a short period of time, but they do not slow the progress of Alzheimer’s. These drugs have only been shown to work for people with quite severe Alzheimer’s disease and so are only available for patients who meet certain criteria.

Dementia can also be accompanied by changes in behaviour such as agitation, depression, anxiety and sleeplessness. These all decrease the quality of life of both the patient and their caregivers. To help reduce these problems and improve the quality of life of the patient several different drugs can be considered. These include antipsychotics such as risperidone (Risperdal), antidepressants and sleeping pills. These drugs need to be closely monitored to achieve the best results.

What can relatives/carers/friends do to help reduce the effects of memory loss?

If you are diagnosed with a form of dementia, your care, safety and security is very important and should be discussed with family and carers.  It is important for you to maintain a daily routine with constant supervision to make sure you eat, bathe and take medication properly. If the condition is severe and progressive then hospitalisation or extended care facilities may have to be considered.

Organise legal and financial affairs as soon as possible in case your condition deteriorates quickly. Wills and power of attorney should be discussed with family and any one else involved. You should also discuss if you would prefer to have a carer or live in an aged care home, and your funeral details.

There are other things you can do to manage memory loss, improve memory and prevent it from deteriorating further. For example:

• Keep a diary or notebook with appointments, to-do lists, important phone numbers, names you need to remember, and details of medication you need to take;
• Put important every-day items in the same place (e.g. purse, keys, glasses);
• Spend time with friends and family to help keep your memory sharp;
• Keep photos of friends and families with details of their names and what they do.

There are also programs in your local community that can help you or your relatives/carers deal with your memory loss. These can give you the opportunity to learn more about memory loss, ask questions and meet people with similar problems.

Tips for improving memory and slowing down memory loss

• Get enough physical exercise;
• Eat well and avoid alcohol and smoking;
• Get involved in activities to keep the mind active. E.g. learn a new skill or volunteer in your community.

We have all heard the expression “use it or lose it”. Non-pharmacological treatment tries to stimulate the brain and train it to work faster and more effectively.  This can include memory skills training, motor memory training, number training and even speech therapy. This sort of rehabilitation has been shown to be very useful for people who have suffered a head injury or stroke. This sort of therapy is also useful for people with dementia, and may allow people with early dementia to remain independent for longer.

More information

For more information on different types of dementia, memory loss and Alzheimer’s disease, see Dementia.

 

References

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