Postural Instability and Gait Disturbances in Parkinson's Disease

PIGD not helped by current PD medications but there is hope for treatments

Steve had several PD precursor symptoms for years. Some motor symptoms appeared early but did not interfere with lifestyle. Postural Instability appeared about a year prior to his diagnosis.  The appearance was subtle. He would climb a ladder to perform some honeydo chore and come back down saying that he felt uncomfortable, unsteady, not right about being on a ladder. And this was inside the house. He felt that the sensation was real - as his wife I had some doubts. He was right; I wish he'd been wrong. He was exhibiting one of the Big 4 Parkinson's symptoms.

What is Postural Instability? To my eyes it is the failure to be able to identify the vertical but really it is much more. It occurs when reflexes are unable to adjust or compensate for sway, vertical, horizontal and diagonal and environmental changes. Gait Disturbances such as freezing or the loss of the natural rhythms which initiate and maintain gait, the rhythm aids in turning and in stride length are interrupted or short circuited.

An easy way to identify how a PwP might sense the problem is to visualize a set of steps which do not  conform to the normal rise and/or tread depth. Imagine (feel) walking up or down the stairs where the next step you take is not the same height difference as the previous step so that the spacing rhythm is disrupted. Perhaps one riser is the code max of 7.75" while another is 8" or 8.5". You automatically reach for the next step and it isn't where it is supposed to be. I've seen it when an amateur cuts a step stringer and it can kill you. Your body has a natural rhythm when descending or ascending a flight of stairs. You can simulate this by placing a magazine on one step, two on the next, none after that. You'll feel very disconcerted and off balance. You grab for the handrail. What should come naturally doesn't. That's just a part of Postural Instability and Gait Disturbance.  

We recently received an email asking for information about a procedure known as ExAblate®. The writer wanted to know if there was hope for Parkinson's patients with Postural Instability after she had seen the Diane Sawyer segment on ABC World News in which a ET patient of  Dr William Jeff Elias discussed her Essential Tremor life before and after this unique targeted laser procedure. Although there may be a genetic link between some cases of ET and some cases of PD, the targeting will be different.

ExAblate® is a procedure done using Magnetic Resonance guided Focused Ultrasound *MRgFUS) technology developed by a Swiss company, InSightec. Although there is a study underway for Parkinson's patients, it will only take place at the Center of Ultrasound Functional Neurosurgery in Solothurn, Switzerland.  The studies being conducted by Dr William Jeff Elias in the US are directed to Essential Tremor as the specific brain targets have been identified. 

The Parkinson's study by Insightec is geared towards long-term chronic, therapy-resistant movement disorders. Perhaps there will be some surprise results as Postural Instability (PI) or Postural Instability and Gait Disturbances (PIGD) are inadvertently addressed as well. We can only hope.

There is some research in progress. In 2009 the Michael J Fox Foundation awarded five research grants totaling $2 million for research addressing Postural Instability and Gait Disorders. 

Over the last few years there has been research into a part of the brain stem known as the pedunculoponitine nucleus (PPN) which is a bi-lateral target for stimulation to address gait freezing. We plan to write more about it. The PPN processes sensory and behavioral data, is related to arousal, attention. learning, locomotion rewards and voluntary limb movement. While the PPN gets input from several areas of the brain, it sends but does not receive information from the substantia nigra pars compacta. Autposies of PD brains show degeneration of the pedunculopontine nucleus. Researchers identifed the PPN as a target for Deep Brain Stimulation and the first PPN DBS surgeries have shown promise. The point is that the PPN seems to be very significant in Parkinson's disease. 

 While there don't seem to be medications which work effectively to address Postural Instability, there are some exercises which might help if done on a regular basis. We covered marching in place as a chair exercise a few years ago. Shoulder exercises are important for posture and range of motion. This week we'll post two more excellent exercises.

Additional reading - just click the links while holding the shift key:

Michael J Fox Foundation grant awards 

Pedunculopontine nucleous stimulation for gait freezing in Parkinson's disease

Cerebral blood flow changes induced by pedunculopontine nucleus stimulation in patients with advanced PD

PPN as a target for DBS 

Topical organization of the pedunculopontine nucleus by Christina Martiniz-Gonzalez, J Paul Bolan and Juan Mena-Segovia from the Medical Research Council Anatomical Neuropharmacology Unit, Dept of Pharmaacology, University of Oxford, Oxford, UK 

Anxiety and Parkinson's Disease

We Don't Know Why but Anxiety Is a PD symptom

Frankly, at this time, I'm not so concerned with the why but rather the effect of anxiety on Steve's Parkinson's disease progression.  While anxiety is not unexpected when one receives a diagnosis, from what I've read, it is a more common symptom in PD than in say Diabetes, Rheumatoid Arthritis and Multiple Sclerosis. As a matter of fact it is a PD precursor symptom, often accompanied by pessimism. I always thought that Steve was over-thinking things and expressing them in a negative way; now I realize that this was a PD potential rearing its head when he was still a young man.

What we do know is that embarrassment is a risk factor for anxiety and social fears. We know that there might be an association with levodopa although probably not the other PD meds.  We know that there may be an association with norepinephrine (dopamine is the norepinephrine precursor so you can't have one without the other) and we know that there are several other neural pathways which might contribute. We've got our eye on Serotonin and GABA.  

Here's the thing, we know that anxiety was behind Steve's first bout of dehydration even though the underlying issue was actually Benign Prostatic Hyperplasia (BPH) or enlarged prostate. This in turn exacerbated feelings of urinary incontinence which in its own turn triggered extreme  anxiety - enough to stop all fluid intake except for a morning cup of coffee and enough water to swallow pills and supplements. We focused on the dehydration, how to rehydrate and how to get him back on his feet to think and to function on his own again.  We treated the cause and he started taking a common (and risky) prostate medication which he had turned down a several years earlier when he and his doctor discussed his prostate issue and actually checked for and ruled out prostate cancer.  But we never looked at the other issue - the anxiety which overrode all else.

The treatments for PD anxiety at this time are problematic.  Antidepressants of various classes: Tricyclics, SSRIs, Anti-psychotics, Benzodiazepines, and non-selective MAOIs.  In early 2010 we just weren't ready to risk the motor symptom treatment for the anxiety/non-motor symptom.



So what happened in the late summer and early fall with the second round of dehydration?  The second time around was easier to spot and know what to do. I was prepared already with electrolyte beverages - mostly fruit flavored. We kept the drinks flowing. He prefers ice water from the pitcher.  We had the adult incontinence briefs on hand to relieve the issue of weakened ability to get to the bathroom on time and to get through the night. Although there was no question of doing the right things for recovery, each time there seems to be a larger cognitive deficit.

We recently made some other nutritional supplement changes and I adjusted up and down to determine if they constituted any part of the problem. All the time, the vivid dreams, the hallucinations and illusions increased making Steve's reality very confusing; contributing to the a high anxiety level.

We finally resorted to using an herbal to help with the anxiety after I realized that he was self-medicating with aspirin and found an empty bottle - which had been almost full a week before. I read everything I could find about the herbal components because it does help relieve the anxiety on a short term basis. The best I can say is that it seems to have the fewest contraindicated ingredients.  Certainly a better option now than prescription medications. 

In addition to retreating to the safety of his bedroom for frequent naps - mostly because he feels anxious, one significant new issue was freezing. We are still working through this problem. Steve now has his key words to help him through the tight spots but it took 3 months and he intermittently lets panic rule so that he mixes up the words in the commands:  Look Up and Walk Forward. Mostly they had a calming effect and then anxiety takes over and the words become other words - the wrong commands.  

I can now see that fear in his shuffle step. It makes me wonder how many shufflers out there are just plain scared.  I hadn't seen it in those movements for many months but now I recognize the enemy. It isn't just postural instability - a precursor or early symptom of his - it is his terror that something bad will happen on the next step.

I know he has recovered just enough arm swing with the new form of buffered creatine monohydrate that he can walk at a slow pace but with a normal balanced stride, shifting his weight from side to side, using his shoulders to propel himself forward (that's Walk Forward)  He has to be reminded in the early morning, when he wakes from a nap and in the evening but sometimes he can let himself relax enough to walk without anxiety. That makes my heart sing.

Watch those stairs

Our next project will be stairs.  He's gone downstairs only a few times since the dehydration but he had few problems going down and none on the way back up.  But he is afraid. He sees a black hole and not the steps leading to the 1st floor. He is anxious every time he walks past the stairway. His sister, a nurse, mentioned that perhaps it is eyesight issues which help trigger the fear and we'll check that possibility. 

We're looking for solutions to the anxiety, the cognition losses, and the PD psychosis which play a large part in making his world a more frightening place. One possible solution may lie in a clinical trial taking place in our neck of the woods.  We provided a link to the Fox Trial Finder in the right column under Clinical Trials but how serendipitous to have a reminder email from PAN (Parkinson's Action Network) this morning. I used that link, and looked at trials in our area again and found some new ones.  So we sent an email to the Pimavanserin Trial, heard back promptly with a phone number and are waiting to hear back from the Cleveland Clinic Study Coordinator. We are hoping that if the psychosis can be treated, we can work more effectively to lessen the anxiety.

Addendum 3/12:
On 3/06/12 The Parkinson's Disease Foundation presented an Expert Briefing, A Closer Look at Anxiety and Depression in Parkinson's Disease led by Dr Laura Marsh. The archived webinar/podcast is now available at PDF.  Listen rapidly as Dr Marsh covered a lot of material in a short period of time. I plan to listen again.

Additional Reading:
Anxiety disorders in Parkinson's disease: prevalence and risk factors

Anxiety Affliction in patients with Parkinson's disease 
Parkinson's disease: depression, personality and anxiety 
Pessimism and Anxiety Linked to Parkinson's

Step out with Parkinson's Disease

Walking Aids for PD
If you're a regular reader you know that Steve walks with a cane for maintaining balance and especially to support his arthritic knee(s). The cane is used in public and around the house. The cats are careful but sleeping dogs are often in the way. While the dogs don't jump up to throw him off balance, they usually remain stationary unless instructed to move. Their decision to lie still seems to be made either because they know they mustn't move suddenly or because they don't realize that they are spread across a hallway or blocking a narrow passage in our office.

Steve has no problem with gait freezing so he can use a regular cane, purchased not for beauty but for adjustability and economy. Early on when his cane use was arbitrary, he used to misplace them. He'd walk into a room with a cane but leave without it. Later the cane would be "lost." So we bought several including a folding cane for airplane use.

For those who need more balance support, there are four-footed style "quad" canes which provide that extra stability. There is a "couch/recliner" cane with a skid proof base and extra long grips to help one rise from a sitting position. A cane will support about 25% of your weight.

For those with gait freeze, there are laser canes which assist the PWP (person with Parkinson's) by shining a red laser light across the path to break the freeze and direct the next step. The canes are adjustable and battery operated. They cost between $225.00 and $275.00.

There are adjustable walkers with padded backs and seats, baskets and brakes. These have weight capacities between 250 to 400 pounds and sell for between $150.00 and $200.00 plus shipping. Walkers can support up to 50% of your weight.

The U-Step walker is exactly what you would expect, a solid walker complete with a seat for about $550.00 and up plus the add-on laser for $200.00. It has dead-man brakes which will also lock the wheels so that you can sit when necessary. The padded seat lifts to provide access to the basket. It is the laser light add-on which makes this walker unique. More expensive than a verbal cue, turning a cane upside down or a wadded piece of paper dropped as a marker, it is also practical for those with more advanced walking issues.

Currently there is an open label clinical trial NCT00320242 in Phase III sponsored by Beth Israel Deaconess Medical Center in Boston to assess the efficacy of visual cues of the laser cane or the U-Step Walker with laser accessory for PWP with gait freeze. The trials are located in Boston and at The Neurological Institute of New York at Columbia University.

There is also a Virtual Reality device available at a significantly higher price from two companies. Medigait LLC has two models for assistance. The less expensive model, the GaitAid Auditory Walker, provides a signal through the headphones depending upon foot placement. The goal is to create a ryhthmic and longer stride. The GaitAid Virtual Walker includes the auditory tones while the user wears see-thru goggles which superimpose a grid pattern on the floor. It is reported that there is a serious improvement after just two practice sessions of 30 minutes each. The figures vary but are a testament to the plasticity of the brain and the ingenuity of scientists and researchers. These goggles are meant for (re)training purposes only and are not worn on the street.

Apparently still in pre-production is the brainchild of Tom Riess, a podiatrist with PD who developed spectacles - augmented reality - which are now known as a visual cueing system. He sold the concept to HMD Therapeutics who in turn licensed it to Enhanced Visual Systems. Unlike the GaitAid Virtual Walker, these glasses appear to fit over even very large eyeglasses.

Loss of mobility is a serious problem for PWP but having aids can be a quality of life-saver.

Clinical trial:
NCT00320242 is a can't lose clinical trial since it is open label and is a comparison of efficacy of these gait freeze aids.
http://clinicaltrials.gov/ct2/show/NCT00320242
Interesting reading:
http://portal.acm.org/citation.cfm?id=1498190
How to use walkers and canes:
http://orthoinfo.aaos.org/topic.cfm?topic=A00181
Kinesia Paradoxa or gait freeze
http://www.hitl.washington.edu/publications/prothero/node13.html
Detailed information on virtual reality glasses
http://cordis.europa.eu/ictresults/index.cfm?section=news&tpl=article&BrowsingType=Features&ID=57062
Specifics on the visual cueing system and Kinesia Paradoxa in Parkinson's disease
http://www.rehab.research.va.gov/jour/07/44/3/pdf/kaminsky.pdf
You'll find a video here:
http://www.sciencedaily.com/videos/2007/1201-glasses_help_parkinsons_patients.htm