What Causes Memory Loss?

There Are Many Reasons for Poor Memory

Oct 14, 2008 John Richard Roberts

The causes of memory impairment range from the trivial but often worrying to the serious and permanent. The more serious causes are often associated with other features.

It’s probably because of all the publicity concerning Alzheimer’s disease that many people become concerned when they experience bouts of forgetfulness. But poor memory on its own is very unlikely to be a sign of dementia which comes with other features as do most of the more serious causes.

Memory seems to exist in two different forms (at least) within the brain. Initially when you absorb information it is stored as short term memory. This probably exists as a circuit of nerve impulses. After around 20 minutes this information is laid down in more permanent fashion as long term memory, probably in protein structures. It is for this reason that short term memory is very vulnerable to insult to the brain.

Dementia patients often retain memories of events long ago but can’t remember if they had eaten lunch an hour ago. Two types of memory loss can occur with head injury: retrograde amnesia and post traumatic memory loss. In the former, memory of events immediately prior to the trauma is lost and in the latter, events after the injury are not recalled.

Causes of Memory Loss

• Aging: to a small degree memory becomes less efficient in older years. This is most likely a problem of recall rather than loss of memory – as if the filing system isn’t as efficient as it used to be. This is nothing to be concerned about and can be countered by leaving memos around or making lists. Exercise and a healthy diet can help brain function including memory.
• Dementia: all the dementias can lead to memory loss. It often comes packaged with other changes such as altered personality and intellectual decline. Quite a bit of long term memory is usually preserved.
• Epilepsy: seizures of all types can give rise to bouts of temporary memory loss often associated with some disorientation.
• Drugs: some drugs, benzodiazepines for example, can cause temporary memory disturbance as can anaesthetics.
• Alcohol: there are two ways in which alcohol can affect memory. In acute form – getting very drunk – the loss is temporary and often relates to what happened during the period of intoxication. In alcoholism vitamin B12 can become deficient. This vitamin is vital to proper functioning of the nervous system. The memory loss normally affects short term memory and can be permanent.
• Neurodegenerative disease: multiple sclerosis and Parkinson’s disease may involve memory loss in addition to other features.
• Head injury: the loss is often temporary and retrograde, however more serious injury can produce permanent memory impairment.
• Stroke: again the degree of impairment varies according to the amount of damage caused. Nearly always occurs in conjunction with other types of neurological deficit such as paralysis or speech problems.
• Tumours: if a tumour occurs in a part of the brain involved in memory then impairment may occur. As with stroke there are often other signs or symptoms as well.
• Infections: will normally bring about inflammation of brain tissue and this involves swelling and consequent reduction of blood flow and possible damage to memory areas.
• Psychological causes: probably the most common reasons for memory impairment. Both anxiety and depression can do this. Worry about the memory loss can of course exacerbate the anxiety and lead to more memory problems.
• Therapeutic causes: in addition to drugs brain surgery and electroconvulsive therapy can result in memory loss.

This article is for information only. If you have any health concerns you should consult your doctor.

Resource

Neurology: A Concise Clinical Text. Swash and Schwartz. Pub. Bailleire Tindall 1989

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