As we age, we frequently spend more time worrying about the causes of memory loss primarily because of fearing the onset of Alzheimer’s disease. However, short-term memory loss, forgetfulness, and periodic mental confusion may indicate the presence of a condition that is entirely treatable and reversible.
What is Memory?
The ability to remember facts, events from the past (episodic memory), dates and names fundamentally rely on the hippocampus, its neural connections to the cortex and various nuclei surrounding the hippocampus. Interestingly, a type of memory called procedural memory, which allows us to always remember how to ride a bike or drive a car, does not seem to be associated with causes of memory loss related to a dysfunctional hippocampus. Rather, procedural memory is associated with areas in the basal ganglia, the motor cortex and the cerebellum.
This explains why many Alzheimer’s patients can remember how to drive a car, although they may not be able to remember where they are going. Neurodegenerative diseases that damage the basal ganglia and cerebellum such as Huntington’s will impair the ability to recall procedural memories.
Although it seems that AD patients cannot “remember” anything, it is actually their capacity to retrieve memories that is debilitated. Scientists believe that all past information that has been encoded in the brain is ultimately retrievable, a hypothesis supported by several deep-brain electrical stimulation experiments resulting in subjects “remembering” events and scenes from their past they had long forgotten.
When we remember something, the brain is actually “replaying” a specific neural activity pattern originally created when we initially encoded the memory. However, this “review” is not 100 percent identical to the original pattern, which explains why people can have different memories of the same event.
Dementia and Alzheimer’s
The primary causes of memory loss, such as Alzheimer’s and vascular dementia, affect a person’s ability to recall and recognize due to disruptions in neural connections and incapacitated brains cells that have suffered damage from lack of blood, oxygen or AD-specific plaques and tangles. Dementia can occur without evidence of Alzheimer’s disease due to:
- Strokes and/or cardiovascular disease
- Heavy drug use
- Brain infections such as syphilis, encephalitis or Lyme disease
- Thyroid disorders
- Head trauma
- Severe depression, schizophrenia and bi-polar disorder
Fortunately, some of these dementias are reversible, such as vitamin deficiencies (specifically B1 and B12), thyroid problems, mental illness, operable tumors and head injuries. When caught in time, memory problems caused by mental disorders, alcoholism or drug use may be reduced or eliminated if damage to the brain’s gray matter is minimal and medication prescribed to correct the condition is taken as prescribed.
Among the hundreds of frequently prescribed medications that are known to exacerbate forgetfulness and short-term memory loss, some of these more well-known medications include:
- Ambien (sleep aid)
- Effexor (antidepressant)
- Imitrex (nasal spray)
- Maxalt (for migraines)
- Prinzide (hypertension)
- Xanax (anxiolytic)
Symptoms of Vascular Dementia and Alzheimer’s
Similar in content and intensity, symptoms of memory problems caused by Alzheimer’s and vascular dementia usually begin as mild cognitive anomalies that worsen over time. Signs that decreased blood flow or plaques and tangles may be affecting the brain’s ability to function are an inability to communicate rationally and mental confusion, involving place, time and date. Other signs include sudden spells of agitation and anxiety, inappropriate social behavior (laughing aloud at a funeral, for example) and failing to properly follow through with necessary everyday tasks (hygiene, preparing meals and paying bills).
Additional Causes of Memory Loss
While the majority of most conditions producing memory loss are related to Alzheimer’s, strokes, Parkinson’s, substance abuse or mental illness, some are less common but still entirely viable as a diagnosis. These conditions include:
- Creutzfeldt-Jakob disease
- Lead poisoning
- Morgellon’s disease
- Pick’s disease
- Wilson’s disease
- Multiple sclerosis
- Electro-convulsive therapy (for severe depression)
Only two of these conditions are reversible–lead poisoning and ECT. Generally, removing the individuals from the source of their memory problems usually allows the brain to return to normal functioning as long as no underlying serious issues occurred as a result of chronic exposure to the aggravation.
How Memory Loss is Diagnosed
Physicians will use blood tests to rule out nutritional deficiencies, thyroid disease and infections as causes of memory loss. Brain imaging scans such as MRIs and CTs can detect abnormal brain shrinkage or ventrical enlargement that is associated with Alzheimer’s and vascular dementia.
EEGs determine whether a deviancy exists in brain wave patterns generated by the electrical system of communication among neurons. Cerebral angiographies are conducted when a physician suspect arteriosclerosis, brain tumors, or damaged blood vessels in the brain are causing memory deficits.
Preventing cognitive decline may be applicable in cases where Alzheimer’s, stroke and substance abuse is involved by engaging in regular exercise, eating a healthy, low-fat diet, getting enough sleep and enjoying a variety of tasks that create new neuronal connections like learning a new language or volunteering to help nonprofit organizations. Senior citizens also need to have complete health examinations every six months to catch the causes of memory loss in the early stages so that treatment can be expedited.