Neal Hermanowicz (Director of the Movement Disorders Program) gives expert video advice on: What are some of the other names for Parkinson's?; Who is at most risk for getting Parkinson's? and more...
What is Parkinson's?
Parkinson's is a brain disease that affects certain types of brain cells. It doesn't affect the entire brain. It's somehow, for reasons we don't understand, it's causing an impact on certain types of brain cells that are largely involved with mobility. But it may have an impact on other parts of the brain as well.
What is the history of Parkinson's?
It was first identified as a separate entity, distinct from, say Multiple Sclerosis or Lou Gerhig's disease by James Parkinson when he wrote that initial monograph published in 1817. And actually it wasn't until the mid 1800s that credit was given to Dr. Parkinson by a French neurologist by the name of Charcot, who was one of the giants of modern neurology, one of the people who created modern neurology and did give credit due back to James Parkinson. It didn't really get a lot of attention when it was published in 1817. But Parkinson's contribution was again sort of teasing us away from these other neurological disorders because prior to that time people sort of thought of MS or ALS and Parkinson's as all being kind of the same thing and not a discreet entity. Over the years, the pathology has been identified, meaning the brain changes that are associated with Parkinson's disease. These have been identified almost 100 years ago. The brain chemical abnormality, at least one of the central chemical abnormalities, a dopamine deficiency was identified in 1959, which really launched the modern area of treatment of Parkinson's disease by using medications.
What are some of the other names for Parkinson's?
It's generally called Parkinsons Disease and nothing else these days, but in the past, it was sometimes referred to as a palsy, or a shaking palsy. In one area where the name Parkinsons Disease remains sort of archaic is for medicare billing purposes; it's still listed as Paralysis agitans, and I'm not sure why that persists.
How many people have Parkinson's?
It's not an uncommon disease. It's not exactly known, oddly enough, but the estimates are somewhere in the ballpark of a million people being affected in the United States with Parkinson's Disease. It may be somewhat less, it may be somewhat more, but that's roughly a correct number in the United States. We don't have any kind of formal registry as we do with some other diseases. There has been an effort, particularly here in California, to create such a registry to enable us to know how many cases there are in certain parts of the country. For example, are there some parts where it's more common than others? This would also enable doing what's called epidemiological research, looking at issues of how populations are affected by Parkinson's Disease and with that, what may be other risk factors associated with Parkinson's Disease. But right now, we don't really have that database formally established.
Who is at most risk for getting Parkinson's?
There are some other things that have come up along the way, but the only risk factor identified has been age. It does affect men more than women at a ratio of about three men for every two women. There may be some racial differences as well. But again, it's mostly age and not anything else clearly that places people at risk for Parkinsons disease.
Who is qualified to diagnose Parkinson's?
To diagnose Parkinson's, any physician who is familiar with the clinical presentation or even other clinicians such as nurse practioners who are familiar with the symptoms that people who have Parkinson's Disease develop initially as well as the findings and the examination would be qualified. Most neurologists through their training during their residency in neurology will have some exposure to this. It can be tough to diagnose. I do this day in, day out and I still see cases almost everyday that I am not quite if sure they have Parkinson's Disease or not. The reason it is tough is there isn't any test yet that confirms or rules out the diagnosis of Parkinson's Disease. Brain scans, MRIs and so forth are not reliable Even some of the functional imaging like PET scans or SPECT scans are not entirely reliable in terms of establishing a diagnosis. So the diagnosis remains on a clinical basis meaning the symptoms that we elicit talking to the patient and the things that we see on the examination.
What are some other diseases that are mistaken for Parkinson's?
Probably most commonly would be essential tremor. We think of these as being distinctly different, but their clinical overlap can be substantial in some cases. It can be a head-scratcher to try to distinguish these two things. There are other so called degenerative diseases, or neuro-degenerative diseases. Things where parts of the brain are beginning to malfunction, usually in association with age, that can sometimes mimic findings in Parkinsons disease. These are usually far less common than Parkinsons disease but they still do show up.
What's the difference between essential tremor and Parkinson's?
Essential tremor is not regarded as a neurodegenerative disease, meaning that when we look at the brains of people with essential tremor there's not structural change that has been identified. Even when you look carefully, if you take sections from the brain of somebody with essential tremor who has passed away and look at it under a microscope, we don't see any kind of structural change. So there's some sort of chemical or circuit anomaly that is contributing to essential tremor, but it is not causing a structural change; no loss of certain brain cells or neurons that we do see in Parkinsons disease. The clinical presentation is often different. The tremor of Parkinsons disease is most often on one side of the body, right or left side, initially, then later, perhaps after a couple of years it may show up on the opposite side. The tremor of Parkinsons disease is classically thought of as being at rest when people are not using their hands. In contrast, essential tremor usually begins on both sides, both hands, and is more evident to people when they are actually using their hands, when they go to put a key in a lock or lift a cup of coffee to their lips for example, or eat soup with a spoon, then the tremor becomes apparent, but at rest the tremor is much less or even absent.