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Amnesia - Memory Loss


Overview, Causes, & Risk Factors

Memory loss is the inability to recall people, objects, places, or events that took place in the recent or distant past.

What is going on in the body?

The brain stores different types of information in different places. Short-term memory involves recalling details that have been catalogued seconds or minutes before. Examples include reciting a phone number, recognizing a new face, or repeating a list of 3 objects seen 2 or 3 minutes earlier. For this to happen, distinct areas deep in the brain need to function properly.

Long-term memory involves the ability to recall events that took place in the distant past. For short-term memory to convert to long-term memory, other permanent changes to brain cells have to take place. This is similar to creating a permanent file or recording. Other parts of the brain perform this filing function.

Occasional memory lapses or forgetfulness are common. These may be associated with depression, stress, lack of sleep, and normal aging. Memory loss only becomes a problem when it is severe and interferes with daily living.

Amnesia is a severe form of memory loss. It may be a partial or complete lack of recall. Depending on the cause of amnesia, the memory loss may arise suddenly or slowly. It also can be temporary or permanent.

What are the causes and risks of the symptom?

Common medical causes of memory loss include:

  • normal aging
  • Alzheimer's disease, a progressive brain disorder causing deterioration in memory and thought processes
  • depression
  • head injury
  • seizures
  • chronic alcohol abuse
  • barbiturates, hallucinogens, and medications such as those used for anesthesia
  • electroconvulsive therapy, or ECT, which is used to treat some mental disorders
  • surgery in the temporal lobe of the brain, such as a craniotomy for a brain tumor
  • lack of oxygen to the brain, such as a near drowning
  • stroke
  • Huntington's disease
  • atherosclerosis, or hardening of the arteries
  • multiple sclerosis, a degenerative disorder caused by destruction of the lining of nerves throughout the body
  • HIV, the immunodeficiency disorder associated with AIDS
  • Parkinson's disease, a degenerative disorder of part of the nervous system
  • Creutzfeldt-Jakob disease, a rapidly progressing degenerative disorder of the nervous system causing problems with walking, talking, and the senses
  • Pick's disease, a disorder of the brain that causes slowly progressing dementia
  • viral or bacterial encephalitis, an inflammation of the brain
  • Lewy body disease, a degenerative disease of the nervous system
  • normal pressure hydrocephalus, or increased cerebrospinal fluid in the brain
  • chronic subdural hematoma, or bleeding between the brain lining and brain tissue
  • brain tumor
  • Wilson disease, a rare disease causing an accumulation of copper in the liver, brain, kidneys, and corneas
  • neurosyphilis, an infection of the nervous system by the Treponema pallidum\ bacteria. Less often, syphilis is transmitted from a pregnant woman to her baby. This form of syphilis is known as \congenital syphilis.\ ',CAPTION,'Syphilis');" onmouseout="return nd();">syphilis bacteria which causes weakness and mental deterioration
  • Certain abnormalities of a person's metabolism or hormones may also be responsible for memory loss. These include:

  • hypothyroidism, which is an underactive thyroid gland
  • hyperthyroidism, which is an overactive thyroid gland
  • high-dose steroid abuse
  • deficiency, or low body levels, of B1\ \B2\ \B6\ \pantothenic acid\ \folic acid\ \niacin\ \biotin\ Cobalamin is the general name for vitamin B12. ',CAPTION,'Vitamin B12');" onmouseout="return nd();">Vitamin B12
  • vitamin B2\ \niacin\ \vitamin B6\ \vitamin B12\ \folate\ \biotin\ \pantothenic acid\',CAPTION,'Vitamin B1');" onmouseout="return nd();">thiamine deficiency
  • deficiency of niacin, which is vitamin B3
  • chronic alcohol abuse
  • chronic exposure to metals, such as lead or mercury, and to dyes, such as aniline
  • medication side effects or drug interactions