If I Don't Have Alzheimer's, Could I Have Something Else?

In my household we blame our cognitive shortcomings on the fact that we all have a lot on our minds, and one of us just got off the cholesterol-lowering drug Crestor.

But there are many other conditions that also can cause or mimic senile dementia.

• Depression and Alzheimer's disease cause many of the same symptoms, but there are subtle differences. When people who are cognitively intact become depressed, they typically suffer mood disorders. They feel sad. They may become suicidal. They become anxious. They may eat too much or too little or sleep too much or too little. When people who have Alzheimer's disease become depressed, they usually have motivational problems. They may simply stop caring. They physically slow down. They become extremely fatigued. There are no black and white distinctions between the two kinds of depression, although the (US) National Institute of Mental Health has developed diagnostic criteria for depression in Alzheimer's disease.

• Traumatic brain injury causes some of the same symptoms as Alzheimer's disease, but there is usually very different "picture" of the brain as shown by MRI and CAT scans. Both traumatic brain injury (getting hit in the head) and Alzheimer's cause formation of tangled plaques in the brain, but the tangles accumulate in different places. Alzheimer's disease typically causes plaques in two regions of the brain known as the entorhinal cortex and the hippocampus first. Traumatic brain injury typically causes plaques in the neocortex rather than other parts of the brain. People who suffer dementia caused by blows to the head are often aggressive. They may develop shaking on one side of the body, then both sides of the body. They are more likely to suffer headaches, dizziness, and problems with impulse control than people who have Alzheimer's disease.

And there are some causes of Alzheimer's-like symptoms that are relatively easy to treat if they are properly diagnosed:

• Vascular disease, especially atherosclerosis of the carotid artery, often causes symptoms that mimic Alzheimer's. Major depression with passive wishes to die (but no active plans for suicide) are not uncommon with this condition.

• Vitamin B12 deficiency, which can result from pernicious anemia, the absence of carrier proteins in the stomach to help the body absorb vitamin B12 from food, can cause severe but easily treatable memory loss. An injection of vitamin B12 is all that is needed.

• Hypoglycemia, low blood sugar levels, often makes people "loopy." A friend of the author started driving erratically and was pulled over by a policeman, whereupon she started hitting the policeman with her purse. Charges were not filed when it was discovered that she had a blood glucose level of 12 mg/dl (less than 1 mmol/L). Fluctuations in blood sugar levels caused by imprecise treatment of diabetes can cause Alzheimer's-like symptoms that "come and go" as blood sugar levels rise and fall.

• Thyroid problems cause changes in behavior. During Hashimoto's thyroiditis or autoimmune hyperthyroidism, excess production of thyroid hormone can cause "hyper" behavior. When the thyroid later "burns out," insufficient thyroid hormone can cause memory loss similar to that in Alzheimer's disease.

• Hyponatremia, or low sodium levels, often caused by extreme low-sodium diets or excessive diuretic medications, causes memory loss, muscle cramps, and headaches, along with other symptoms.

• Uncorrected hearing and vision problems can give the impression of Alzheimer's disease.

And sometimes we just have age-related cognitive impairment. Our brains don't work the same way they used to, but we aren't on our way to becoming demented, thank you.

If you really are on your way to Alzheimer's, there may not be anything you can do to stop it, but there are lots of things you can do to slow it down. Stay active. Train your brain by learning new things. Exercise your independence, but develop relationships with people you trust. 

And make sure your doctor knows all the medications you take. More than any other controllable factor for most people over 60, avoiding medications that cause symptoms of memory loss or inattention can help you stay mentally fit and active for many more years.