Michael J. Fox’s ad in support of stem cell research, for Missouri Democrat candidate Claire McCaskill‘s Senate campaign, has been viewed nearly 2 million times since it was uploaded to YouTube on 20th October:
In an appalling tirade, radio talk show host Rush Limbaugh, who supports the Republican party, accused Fox of exaggerating his symptoms. Limbaugh infamously remarked that “he was either off his medication or he was acting” (and, apparently, mocked the actor by waving his arms and shaking in his chair):
Fox has early-onset Parkinson’s Disease (PD); he was diagnosed with the condition 15 years ago, when he was just 30 years old. PD is a progressive neurodegenerative disorder which affects movement, and most commonly affects elderly people. The main symptoms of the disease are tremors, muscle rigidity and hypokinesia (less frequent voluntary movements); these are often accompanied by dementia. The symptoms are the result of the death of neurons in a part of the midbrain. Specifically, the cells that die are dopaminergic neurons in the substantia nigra. Therefore, the first-line treatment for PD is Levodopa (L-Dopa), a dopamine receptor agonist. The effectiveness of L-Dopa declines as treatment progresses. Uwanted side effects include acute nausea and low blood pressure, which are experienced at the beginning of L-Dopa treatment but disappear after a few weeks. Involuntary choreiform (or dance-like) movements and ‘on-off’ hypokineasia and muscle rigidity normally develop within 2 years of beginning treatment.
In this interview with Katie Couric for CBS News, Fox says that he was actually over-medicated in the ad, so he may have been displaying the side effects of L-Dopa rather than the symptoms of the disease.