Could changes in thinking skills be reversible dementia?

Sometimes the causes for dementia are linked to medication side effects and underlying conditions.

We use the term "dementia" to describe a number of conditions that cause permanent thinking skills changes, such as memory loss and confusion. The most common kind of dementia is Alzheimer's disease, which is characterized by clumping proteins that get tangled in and around brain cells, eventually causing them to die. The second most common type of dementia is vascular dementia, caused by decreased blood flow to the brain from atherosclerosis—the accumulation of fatty deposits on artery walls.

Once dementia strikes, the damage is permanent, and we don't have many treatment options. So, before a diagnosis is made, it's crucial to rule out whether the causes for dementia are actually reversible conditions.

Reversible dementia

According to the Harvard Special Health Report Living Better, Living Longer: Taking steps now to ensure a happier, healthier future, a small percentage of dementia cases may be reversible dementia if treatment begins before permanent brain damage occurs. That's why it is important to report changes in your thinking skills to a doctor as early as possible.

A doctor would first rule out potential causes for dementia that are due to underlying conditions, such as poor sleep, depression, urinary tract infections, tumors, strokes, dehydration, and malnutrition.

Other underlying conditions that may be causes for dementia symptoms include the following.

• Medication side effects. Some medications can impair cognitive (thinking) skills as a side effect. The prime suspects are a group of drugs called anticholinergics, found in many over-the-counter and prescription medications. These include treatments for incontinence, such as oxybutynin (Ditropan); depression, such as amitriptyline (Elavil); muscle spasms, such as cyclobenzaprine (Flexeril); and allergies, such as diphenhydramine (Benadryl). Taking several of these medications can intensify the side effect.

• Vitamin B₁₂ deficiency. Vitamin B₁₂ is crucial for the functioning of nerve cells, and a deficiency can lead to an apparent case of dementia. This vitamin is plentiful in eggs, dairy, meat, fish, and poultry. However, with age, a person becomes less efficient at absorbing it from food into the bloodstream.

• Normal-pressure hydrocephalus (NPH). This condition is an excess of cerebrospinal fluid around the brain. It occurs in about 700,000 elderly people. Symptoms of NPH are often diagnosed as normal aging, Alzheimer's disease or Parkinson's disease, according to the Hydrocephalus Association . In addition to developing dementia, people with NPH often lose bladder control and walk in a slow, hesitant manner, as if their feet are stuck to the floor. A surgically implanted tube (shunt) that drains this excess fluid from the brain brings rapid improvement.

• Subdural hematomas. Hematomas are blood clots caused by bruising. Elderly people sometimes develop them after a very minor (and, therefore, often forgotten) head injury. As blood oozes into a closed space, the hematoma enlarges and begins to interfere with brain function.

• Thyroid disease. Both overproduction and underproduction of thyroid hormones can cause dementia-like symptoms.

What to expect

Treating underlying conditions may resolve thinking skills problems. However, a more thorough cognitive evaluation may be necessary. That could involve cognitive testing conducted by a neuropsychologist; or an MRI to see if a structural problem, such as a stroke or tumor, is causing memory and thinking problems.

If someone does not have reversible dementia, the doctor may prescribe a medication to help control symptoms of dementia; and also exercise or more social involvement, which are both known to improve thinking skills. Finding answers sooner than later will allow more time to prepare if memory and thinking skills are truly declining.

– By Heidi Godman
Executive Editor, Harvard Health Letter