Brains and Mysteries

Whitehouse, N.J.: My dad died of Parkinson's and Alzheimer's. What is the chance that I would be diagnosed with one or both of these diseases? Is there anything I can do in middle age to cut my risk?
Dr. Martin A. Samuels: Both Parkinson's disease and Alzheimer's disease may be rarely familial, but more often we believe that there is a genetic predisposition acted upon by as yet unknown factors, some of which a person may be able to control. At the moment, we have no scientific proof that you can do anything to reduce your risk of these illnesses, but it makes good sense to keep your blood pressure and cholesterol under good control. And minimize excessive drinking of alcohol, and smoking. Let me add that when I refer to "unknown factors," I mean an incalculable and unavoidable array of stimuli, such as innocent viral infections, which might give one person a common cold but another person, with the correct genetic predisposition of the immune system, an immune-mediated disease such as MS or lupus.

Calgary, Alberta, Canada: I am a partial paraplegic. I fell in 1979 and partially severed my spinal cord. I have been walking with braces and crutches. About two years ago (26 years after the accident) I suddenly developed new feelings, muscles and strength in my legs. What's going on? Why did it take so long? Will it continue?
Recovery from spinal-cord injury depends on the extent of the injury and the amount of retained function. In most cases, the spinal cord is not completely severed but rather traumatized by crush or vascular injury. There are two phases of recovery; the first is rapid, within days or weeks. The second is very prolonged, measured in years. It is believed that partially damaged fibers in the spinal cord may reconnect after long delays. It is also possible that some nerves and muscles that were not completely damaged have taken over the functions of those that suffered irrevocable damage, thus allowing for a very delayed recovery of some functions.

Jacksonville, Fla.: I have several medical problems involving my immune and nervous systems. My family has a history of Alzheimer's. I worked in pest control for several years and dealt with multiple chemicals. Could these have caused my medical symptoms?
It is very unlikely that chemicals encountered in the workplace would cause disorders that are as diverse as immune disorders and Alzheimer's disease. In general, stimuli from the environment, including some toxins, trigger just certain diseases, and do so mainly when there is a genetic predisposition. Many toxins are known to damage the nervous system in specific ways. For example, lead can cause cognitive delay in children exposed to high levels, as in lead paint. Mercury, often found in fish, can also cause nerve damage at high levels. Stimulant drugs, such as cocaine and methamphetamine, may cause strokes and seizures. Some patent medicines may contain potentially toxic levels of minerals that can damage the nervous system. Usually, when a toxin has damaged the nervous system it is possible to demonstrate very high levels of the offending drug or toxin in tissues, such as blood, hair or nails. Most concerns about microscopic levels of minerals (iron, lead, mercury) or minor trauma (head injury, occupational injuries) as the sole cause of diseases are grossly exaggerated and lead to an enormous amount of hypochondriasis, obsessional dietary habits and other behaviors, which serve only to reduce the richness of life.

Madison, W.Va.: My husband is 57. He was diagnosed with Alzheimer's in 2003. He has been to the University of Pittsburgh Alzheimer Disease Research Center. Is there any place in the United States where stem-cell therapy is being used as a treatment?
Stem-cell therapy is not yet an approved treatment for any human neurological disease. It is one of many avenues being explored in the effort to develop effective therapies. The ADRC at Pittsburgh is one of the best places in the country for the care of dementia. I recommend following its instructions and possibly enrolling in approved clinical studies that are underway.

Dresden, Ohio: I had two siblings with MS. My brother passed away 14 years ago, at 34, from complications of the disease. My sister, who is now 36, is struggling with it. I also have a first cousin who was diagnosed with MS 30 years ago. He has a brother who has been hit with the disease. We have been told time and again that MS is not genetic. If that is so, how could so many members of the same family be victims? We were born and raised in a Minnesota farming community. My cousins lived on a dairy farm their entire lives. It makes me wonder if there might be some kind of environmental link.
MS can be genetically determined, in that there is clearly a genetic predisposition to the disease. Having a close relative with MS definitely increases the risk of acquiring the disease, but it doesn't mean you are going to get it. Recent research has shown that most of the geographic variation seen in MS is due to genetic rather than environmental factors, so it is unlikely that growing up in a rural environment has much to do with it.

About four years ago I began having strong tremors in my right hand, leg cramps, balance problems, disorganization and other neurological symptoms. The worst was bumping into my wife of 30 years at work and not being able to remember her name or who she was. A neurologist diagnosed Parkinson's disease. I also had recurring sinus problems. An MRI revealed only a massive sinus infection, which was treated with surgery. The day after the operation, all of my neurological symptoms vanished and have not returned. Is there a possible connection?
There is no evidence that sinus infections could cause a disease that looks clinically like Parkinson disease. Chronic infection, could, however, bring out the symptoms of a neurological disorder. Conversely, treating the sinus disease would not directly treat the neurological disease, but could ease the symptoms in an indirect fashion. I would recommend another neurological opinion about the possibility of Parkinson disease. A good general internist should be able to further evaluate the sinus problem. Also, there are some rheumatic conditions that can cause sinus inflammation and neurological problems. These should be easily diagnosed with the proper blood studies ordered by an internist or rheumatologist.