Early diagnosis and treatment crucial for dementia

Q: My mother has started showing signs of dementia. Will it be all downhill from here? Or can dementia ever be treated or reversed?

A: There are many different causes of dementia. We can't do much to slow or reverse some of them, but we can reverse and even cure others. Dementia is a catchall term. It covers a variety of illnesses that cause memory loss, confusion, changes in personality and declining ability to perform everyday activities.

The most common type of dementia is Alzheimer's disease. Another common dementia, vascular dementia, is caused by insufficient blood flow to the brain. Once these types of dementia develop, treatment options are limited.

Drugs for Alzheimer's are sometimes used for vascular dementia. However, for both diseases, drugs offer only temporary and modest protection at best.

However, in a small percentage of cases, dementia may be reversed. The following conditions might cause reversible dementia:

• Toxic reactions to drugs. With aging, the liver and kidneys become less efficient at detoxifying medicines and eliminating them from the body. As a result, drugs tend to build up in the body. Older people in poor health and those taking several different medications are especially vulnerable to dementia caused by drugs. Reducing the dose of medicines can sometimes produce dramatic improvement.

• Vitamin B12 deficiency. Nerve cells need vitamin B12 to work. Vitamin B12 deficiency can cause the symptoms of dementia. Vitamin B12 is plentiful in eggs, dairy, meat, fish and poultry. However, with age, people become less efficient at absorbing it from food into the bloodstream. Supplements or injections can help restore healthy levels, and reverse the problems with thinking and memory.

• Normal-pressure hydrocephalus. Hydrocephalus occurs when too much cerebrospinal fluid collects around the brain. This condition affects a small number of older people. In addition to dementia, people with this condition 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 often brings rapid improvement.

• Subdural hematomas. Hematomas are blood clots caused by bruising. Older people sometimes develop them in the brain after even a minor head injury. As blood oozes into a closed space, the hematoma gets bigger and begins to interfere with brain function.

• Thyroid disease. Both an underactive thyroid and an overactive thyroid can cause the symptoms seen in dementia. In the former, the thyroid gland in the body produces too little thyroid hormone. In the latter, it makes too much. Both conditions can be effectively treated.

In all of these cases, the chances of successfully reversing dementia are better the earlier treatment is started. That's why it is important to tell your doctor about any signs of dementia as early as possible.

Don't fall into the trap of thinking "I'd rather get bad news later, rather than sooner." For some people with symptoms of dementia, prompt diagnosis and treatment can convert bad news into good news. Hopefully, that will be true for your mother.

• Dr. Komaroff is a physician and professor at Harvard Medical School. To send questions, go to AskDoctorK.com, or write: Ask Doctor K, 10 Shattuck St., Second Floor, Boston, MA 02115.