Last year a close friend of mine lost his elderly father to complications from Parkinson's Disease. This was a once-vibrant, keenly intelligent, accomplished man who'd been ravaged by a steady decline in neural and motor function, plus the unpleasant side effects that accompanied some of the medications to treat his condition. The decline occurred over the course of 15 long years, and while losing his father was devastating for my friend -- as losing a loved one always is -- I suspect that his father's passing was also something of a relief, since it was tough to watch that slow inevitable decline, knowing the man his father had once been. [UPDATE: We join our Spousal Unit and countless others in the physics community who mourn the passing of Harvard physicist Sidney Coleman, who suffered from Parkinson's for several years, and was a truly incomparable human and scientist.]
It's safe to say that most people have heard of Parkinson's Disease, at least in passing, if only because actor Michael J. Fox (Family Ties, Spin City, the Back to the Future film franchise) suffers from it, and established an eponymous Foundation for Parkinson's Research to promote R&D to treat and hopefully one day cure the disease. To his credit, Fox hasn't shirked from going public with his condition, or from occasionally displaying the terrible impact it has had on his motor functions. Sure, for a guest TV stint, while he was still in the early stages, he kept his hands in his pockets to hide their shaking, but his controversial TV ad espousing stem cell research last year was a poignant reminder of just how debilitating the disease can be.
Sadly, people lost no time politicizing the personal, using as an excuse the fact that the ad was, technically, associated with a Missouri Democratic effort to pass a bill on stem cell funding. That belligerent blowhard, Rush Limbaugh, predictably wasted no time denouncing Fox's on-camera behavior as "exaggerated," concluding that either he hadn't been taking his medications, or he was "acting" to gain the sympathy vote. To which one can only respond (and many people did): oh, please. Wherever you stand on the issue of stem cell research (we are heartily in favor, for the record, and pleased that the state of California supports it, too), accusing someone who has such a debilitating disease of "faking it" to further your own political agenda is ethically beyond the pale. Because Parkinson's Disease is first and foremost a personal tragedy, not just for the sufferer, but for his/her loved ones as well. It's a bit like Alzheimer's in that respect -- another degenerative disease that could benefit from increased stem cell research.
Parkinson's is officially defined as a progressive, degenerative neurological disorder of the central nervous system that afflicts somewhere between .5 and 1.5 million people in the US alone, and as many as 6 million people worldwide. The name derives from the British physician, James Parkinson, who was the first to formally characterize the disease (then known as paralysis agitans) and its symptoms in 1817 in his treatise, An Essay on the Shaking Palsy.
There's a region of the brain called the substantia nigra, whose cells produce the chemical neurotransmitter, dopamine, which is responsible for transmitting signals within the brain that allow for coordination of movement. Without enough dopamine, neurons fire without the usual level of control, so sufferers are less able over time to direct or control their movements. Nobody knows what causes the loss of dopamine and, hence, the disease, exactly, but studies point to a combination of genetic and environmental factors. Early signs include the onset of tremor: a telltale slight shaking in the hand, sometimes even in the legs. There may also be some cognitive or speech impairment: mild memory loss, perhaps, or soft, mumbling speech.
One of the most common symptoms of advancing Parkinson's is that as the disease progresses, the sufferer experiences greater difficulty walking. Specifically, they tend to take small little stutter steps, exhibiting a shuffling walk, an unsteady gait, and a stooped posture. There's a medical term for it: akinesia (or bradykinesia, if you're referring to the whole range of slowed motion that accompanies the progression of the disease).
Usually this is treated with a drug called Levadopa, or L-dopa, a chemical precursor of dopamine that can be found naturally in plants and animals. The brain's nerve cells convert L-Dopa into dopamine, often reversing many of the more disabling symptoms of Parkinson's. (One cannot, alas, just administer dopamine directly, because it can't cross the protective blood-brain barrier -- that meshwork of tightly packed cells in the walls of the brain's capillaries that serve to screen out certain substances. L-dopa can penetrate that barrier, although it diffuses so much that only a small amount actually gets to the brain. Combining L-dopa with another drug, carbidopa, makes it a bit more effective, and also reduces some of the unpleasant side effects, which include involuntary movements, hallucinations, a drop in blood pressure when standing, and nausea.)
Then there's physical and/or occupational therapies, to retard the degradation of motor function. Along with akinesia, there's also an intriguing counter-phenomenon called kinesia paradoxa, in which Parkinson's patients begin to walk normally when triggered by the placement of physical obstacles at their feet. Walking up regularly spaced stairs, for example, can "unfreeze" someone who otherwise has difficulty walking with a normal gait. The same effect can be achieved with black and white tiles spaced evenly on a floor. The black tiles appear as objects to avoid, or as guides, thereby triggering a reflexive landing of the feet between the black spaces.
In general, though, most "normal" or "natural" environments are sadly lacking in these critical visual cues. This is where a California podiatrist named Tom Reiss comes in. He was diagnosed with Parkinson's at the age of 33 -- like Fox, struck down in his prime -- and wasn't content to merely accept the associated reduced motor functions. Instead, he spent 16 years working in his garage, using himself as the main test subject, trying to figure out adaptive methods for countering his impaired walking abilities. He noticed the kinesia paradoxia effect while shopping at Safeway, because the floors were lined with evenly-spaced black and white tiles, and also noticed the same thing happened when walking up the stairs. Reiss compares the visual cues to an array of ordinary playing cards, displayed like the rungs of a ladder, with the subject landing his feet between the rungs.
He built several prototype cueing devices over the years, some of them owing more than a little to quirky inventor Rube Goldberg's influence. He used coat hangers to attach playing cards to the tips of his tennis shoes, for example, because the cards appeared to be evenly spaced objects as he walked -- an approach he describes as "not too socially acceptable, but it worked!" Then he heard about an off-the-shelf Virtual Vision Sport Personal Viewing system, essentially a pair of "augmented reality" goggles that superimpose a virtual TV screen image onto the real world a few feet ahead of the wearer, in such a way that both were visible at the same time. So the wearer could watch TV while mowing the lawn, for example.
For Reiss, the system offered the perfect solution for his impaired walking abilities, and he ended up working with the University of Washington's Human Interface Technology lab to demonstrate the effectiveness of his glasses concept. The first time he donned the prototype goggles, he saw the real world augmented by a series of small, colored moving squares, projected into space at regular intervals in front of him. Wearing them, he could walk normally. So he founded his own tiny start-up company, HMD Therapeutics, to further develop his invention, which he called Central Field Cueing Device Glasses.
The glasses have an array of light-emitting diodes (LEDs) working in conjunction with a computer chip embedded in the sidebar of what would otherwise be a fairly typical pair of wraparound sunglasses. The LEDs produce a pattern of thin, horizontal virtual lines projected onto a transparent screen across the wearer's entire field of view. The lines appear to scroll towards the wearer in an even flow when s/he is stationary, but appears stationary when s/he is walking. Should the user look up, the lines disappear entirely. There are also built-in mercury switches to track head movements so the glasses can "choreograph" the appropriate visual cues.
The glasses are light, portable, relatively inexpensive, easily scaled up for commercial manufacture and offer hands-free control to the user. Most importantly, they're pretty stylin'. These are not the visual equivalent of orthopedic shoes, or some bizarre cyber-punk apparatus (although I suspect there might be a market for that, too); Reiss recognizes the need to make his product attractive. Parkinson's sufferers don't need to feel any more like outsiders than they already are.
Reiss's invention may soon be available to the public at large, thanks to a company called Enhanced Vision, which has licensed his patented technology to refine and perfect the prototypes into a viable commercial product. And he's continued making improvements to the original design, thanks to a Small Business Innovative Research (SBIR) grant. A more recent version, called Virtual Vection Glasses, uses LEDs to generate peripheral cues to not only promote a "normal" walking gait, but also to help suppress another complication of Parkinson's, dyskinesia -- the jerky, uncontrolled movements so painfully evident in Fox's televised plea on behalf of stem cell research, resulting from the body's attempts to process "apparently irrational peripheral movements," and from the excessive build-up of L-dopa in the body.
It's an inspiring story, and Reiss has deservedly received his proverbial 15 minutes of media exposure because of it. But ultimately, it's about reclaiming the life that Parkinson's Disease gradually takes away from sufferers. We fully expect one day soon to see Reiss, Fox and any other sufferers happily strolling along city streets and parks with fully normal gaits, outfitted with stylish sunglasses that only they know serve more purpose than merely blocking out the sun's blinding rays.