When most people hear the term Parkinson's, they think of the tremors and muscle rigidity that most commonly characterize the disease. But talk to those who've been diagnosed with Parkinson's and they'll tell you that the dementia and mental decline that many Parkinson's patients experience is what they fear most.
"About 40 percent of Parkinson's patients will develop dementia, and it's definitely one of the symptoms people are most fearful about," says Michael Rezak, a neurologist at Central DuPage Hospital in Illinois.
Dementia caused by Parkinson's
Parkinson's causes several types of neurological damage. As the brain cells that produce the neurotransmitter dopamine begin to die off, the loss interferes with nerve pathways, which prevents messages from getting through.
Another type of damage involves the formation of Lewy bodies, which are clusters of abnormal proteins that form in the nerve cells. Based on where in the brain the Lewy bodies are located, they may cause visual hallucinations and dramatic fluctuations in alertness as well as memory loss. Depending on which symptoms develop first, one type of Parkinson's dementia is called Lewy body disease or Lewy body dementia (LBD).
Not all Parkinson's-related dementia is so severe. There are a number of milder mental and psychological problems that many people with Parkinson's experience, and they don't lead to full-blown dementia.
Problems with concentration and focus may begin early on, and in some people, these are among the earliest symptoms. "People say, 'I used to be able to do three things at once, and now I can only do one or I make mistakes,'" says Rezak.
Severe dementia, on the other hand, tends to occur 10 to 15 years into the course of the disease. "Dementia is three to six times more common in elderly patients with Parkinson's than in younger patients, so if you're younger and are having some mild cognitive problems, don't panic and think you're necessarily on your way to dementia," Rezak says.
The most important step you can take to prevent Parkinson's-related dementia is to bring symptoms to the attention of your doctor as soon as you notice them. It's common, Rezak says, for people to let a fear of sounding "crazy" prevent them from telling the doctor they've been experiencing memory lapses, mood problems, or hallucinations. But there are treatments and lifestyle changes that can slow or prevent the progression of dementia, and you need to initiate those treatments in order for them to prevent the situation from getting worse.
Treatments to help prevent Parkinson's from affecting your mind
Medications for memory
In the past few years, there's been new research into drugs that prevent or slow the onset of Parkinson's-related dementia. These medications don't reverse the neurological damage, but they may prevent it from continuing at the same rate. "They buy you some time, and in some patients they do make the memory better and improve concentration," says neurologist Michael Rezak.
The first line of defense is a class of drugs known as cholinesterase inhibitors, which include donepezil (Aricept), rivastigmine (Exelon), and galantamine (Reminyl). Some of these medications, such as Exelon, are FDA-approved for treating Parkinson's dementia; others are approved for Alzheimer's and dementia but are used "off label" for Parkinson's. They work by boosting the level of a chemical messenger in the brain (acetylcholine) that's important for memory. Studies show they can improve alertness and reduce hallucinations.
A number of the drugs commonly used to for the physical symptoms of Parkinson's may also work to prevent or slow Parkinson's-related dementia, but doctors must supervise them carefully to monitor side effects and drug interactions. Levodopa and Sinemet (a combination of levodopa and carbidopa) can be effective, but if side effects develop over time, different dosages may be needed. In some people, another medication, Comtan, helps boost the effectiveness of Sinemet.
Some experts believe the most effective medications are those known as dopamine agonists, which include ropinirole (brand name Requip) and pramipexole (brand name Mirapex), because they stimulate the brain's natural production of dopamine. In most patients these drugs are less likely to cause long-term side effects or lose effectiveness over time in comparison to levodopa, but they can cause dizziness and hallucinations in patients with dementia.
Bottom line: It's important to try these drugs to prevent Parkinson's-related dementia, but there is a risk of worsening dementia symptoms as well, in which case they'll have to be discontinued.
Ibuprofen for inflammation
The power of ibuprofen (brand names include Motrin, Advil) to combat inflammation is well researched. In Parkinson's, inflammation is known to contribute to the death of dopamine neurons. For this reason, many Parkinson's experts have begun to recommend a daily dose of ibuprofen for inflammation prevention, at least in younger patients.
The research on ibuprofen and Parkinson's is recent, but because ibuprofen's side effects are mild, some experts consider it a low-risk gamble. Anyone with Parkinson's should talk to a doctor about whether taking ibuprofen is appropriate, and at what dosage and frequency.
More treatments to help prevent Parkinson's from affecting your mind
"Depression is common among Parkinson's patients," says neurologist Michael Rezak, "and it can appear to be dementia because the symptoms are similar." Those with Parkinson's who suspect that depression might underlie memory and concentration problems should talk to their doctor about being treated with an antidepressant.
Some of these drugs have the additional benefit of helping with fatigue. However, because some antidepressants interact with medications used to treat Parkinson's, a doctor needs to consider everything a patient is taking before deciding which antidepressant to prescribe.
Counseling or a support group may also help relieve depression, and studies have shown that the combination of therapy and antidepressant medication is more effective than either strategy alone.
Parkinson's patients report success with a number of alternative treatments, but there are few definitive studies to prove or disprove their effectiveness. The best approach, says Rezak, is to discuss alternatives with a doctor and check for any risk of medication interactions or side effects before trying one. Treatments include:
Vitamin B-12 and folic acid: An important factor in brain and nerve health, particularly memory, vitamin B-12 is found in meat, fish, eggs, and dairy products. But as people age, many have difficulty absorbing vitamin B12 and may need to take supplements or even shots.
According to the National Parkinson's Foundation, Parkinson's patients may benefit from supplemental vitamin B-12 and folic acid, particularly if -- as is common -- they develop elevated homocysteine levels as a result of taking levodopa. High homocysteine has been linked with memory loss, and taking B12 and folic acid can combat this problem.
Coenzyme Q10 (CoQ10): A compound produced naturally in the body, levels of CoQ10 tend to be low in people with Parkinson's. A few early studies suggested CoQ10 slows disease progression in patients with early-stage Parkinson's and might even improve mental abilities, particularly if mental decline is associated with fatigue. This may be because CoQ10 improves the function of mitochondria, which produce energy in cells.
However, other studies have found little effect from CoQ10, so for someone with Parkinson's, it may require experimenting with dosages and seeing if there's a noticeable difference.
Ginkgo biloba: Some patients swear by Ginkgo biloba, an herbal supplement. Studies show that it boosts memory and concentration. The problem, Rezak says, is that Ginkgo can cause bleeding problems. It's important to tell a doctor when you or a loved one is taking it, to make sure it doesn't interfere with other medications or affect other medical conditions.
Memory-enhancing lifestyle changes
One of the best-proven strategies to prevent Parkinson's-related dementia, experts say, is to boost social interaction. Numerous studies show that social "exercise" of the brain works to stave off all types of dementia, probably because it forces the mind to keep using neural connections.
Parkinson's patients sometimes begin to avoid social situations because of fear and anxiety or embarrassment over their physical symptoms. Parkinson's can also contribute to social problems among patients whose mental response times have slowed or who have difficulty reading social cues.
Experts recommend thinking of social interaction as important mental "exercise" and looking for new opportunities to interact in supportive settings. A Parkinson's support group, an art therapy class, or an adult day program might feel less threatening than a large party or other social gathering.
Exercise is also extremely effective in maintaining brain function. Because many Parkinson's patients have balance issues that restrict or prevent them from exercising, working with a physical therapist or trainer is the recommended way to approach exercise and make sure it stays part of the daily routine.