Bill Clinton and Parkinson's Disease

This story has been bouncing around for a while. I'm not sure when it started but it was given a boost by a visible tremor during his appearance on The Daily Show with Jon Stewart in September 2008.

Bill, 63 years old, may have Parkinson's Disease (PD). The mean age of onset for PD is around 58 or 59, around the time Bill began having his tremor, hardly proof, however. If anything, this episode in the life of Bill offers an opportunity to clear up a few things.

Here's what he had to said on Larry King about the rumors.

He's a politician and not a physician, so understandably some of what he says needs to be clarified.
1. There is no test for PD. It is a clinical diagnosis with tremor as only one component. The tremor is present mainly at rest, but may be present with action. The two other cardinal signs are rigidity or passive resistance to movement; and bradykinesia, small and slow movement. There may be postural instability characterized as imbalance, shuffling, and an increased tendency to fall. If the disease is suspected, there should be an evaluation by a movement disorders specialist or a neurologist. It is not clear if he was evaluated by a movement disorder specialist whose opinion would be more trustworthy since they spend the majority of their time treating Parkinson's.
2. Benign essential tremors rarely begin later in life. By definition they are chronic and slowly progressive without other neurologic dysfunction.
3. Fatigue and stress worsen all movement disorders, essential tremor and Parkinson's Disease included. Whether a tremor is affected by being tired does not play a role in the diagnosis.

A few more points: There are good symptomatic treatments for PD. There isn't a cure. Some genes have been identified, but they still account for the minority of patients. Motor symptoms in Parkinson's often present asymmetrically. Masked facies or decreased facial expression is a symptom frequently encountered. It has been suggested that Bill's facial expression is decreased. Tremor-predominant Parkinson's Disease (which would characterize Bill's symptoms) has the mildest, more benign course.

Another blog post about this topic (with some misleading comments hopefully addressed above). Without an exam it is difficult to be sure whether our former President has Parkinsons's or not, but there are elements of his history that suggest he may.