OHSU Clinical Trial: Home-based Self-delivered Mirror Therapy for Phantom Limb Pain

Beth D. Darnall, PhD, a psychologist at Oregon Health & Science University is conducting a pilot study of self-delivered home-based Mirror Therapy for Phantom Limb Pain.  The clinical trial started January 2009 and will continue through December 2010, and is currently recruiting participants.

In The Oregonian, December 2, 2009 article,  participant Gail Hillyer describes experiencing phantom limb pain soon after surgeons removed most of her right leg, a delayed consequence of damage caused by radiation therapy she underwent for bone cancer as a child.

"It was like someone taking my leg and shoving it on a bed of coals and holding it there," Hillyer says. Pain medications have helped minimize the pain, but she still experiences joint aches, shooting pains, itching and muscle cramps from the leg that is no longer there.

Hillyer decided to volunteer in a clinical trial at Oregon Health & Science University testing a treatment called Mirror Therapy. The technique is simple: She holds a mirror vertically alongside her left leg so that it hides the missing right leg, and what she sees is an image of two intact legs. She spends 25 minutes a day moving the intact limb in the mirror, exposing her brain to views of a functioning, pain-free limb.

The first time she sat down with the mirror, Hillyer experienced startling sensations from her phantom leg.

"When I pointed my toe, I felt a distinct sensation that my other heel was dragging across the bed covers," she says. While rotating her left foot in circles, her big toe accidentally touched the mirror. But instead of feeling cool glass, "it felt as if my two toes were touching," she says. "At some level, I know that didn't happen, but I would vouch for that sensation as being real."

In the OHSU trial, Darnall hopes to show that amputees can use mirror therapy to treat themselves at home without the expense and inconvenience of having to visit a therapist for each session.

How it works remains "a great mystery," says University of Oregon neuroscientist Scott Frey. His group used functional MRI to scan brain activity in people with amputations as they viewed mirror images that appeared to restore the missing limb.

"When you give this visual feedback with the mirror, you tend to see a boost in activity in the brain that would have been used in moving the hand that the person no longer has," Frey says.

Targeted Muscle Reinnervation

Excerpted from The New York Times article, 2/11/09, New Artificial Arm Listens to the Brain.

Man controlled robotic hand with thoughts

AP reported from Rome on December 2, that a group of European scientists say they have successfully connected a robotic hand to a man who had lost an arm, allowing him to feel sensations in the artificial hand and control it with his thoughts.

The experiment lasted a month. Scientists say it was the first time an amputee has been able to make complex movements using his mind to control a biomechanic hand connected to his nervous system.
The Italian-led team said at a news conference Wednesday in Rome that last year they implanted electrodes into the arm of the patient, who had lost his left hand and forearm in a car accident.

The electrodes were removed after a month, during which the man learned to wiggle the robotic fingers and make other movements.

Virtual massage could relieve phantom limb pain for amputees

The Daily Mail of London, England, reported that amputees who experience phantom limb pain could find relief in a surprisingly simple way - by watching someone else rub their hands together.

The treatment seems to fool the brain that it is their missing hand being massaged, according to the American researchers, who worked with combat veterans. Phantom limbs occur when an amputee feels the often painful sensation of touch arising from a limb that is no longer present.

Lead researcher Vilayanur Ramachandran from the Centre for Brain and Cognition at the University of California, used newly discovered properties of mirror neurons to soothe the ache. Mirror neurons fire when a person performs an intentional action - such as waving - and also when they observe someone else performing the same action. They are thought to help us predict the intentions of others by creating a "virtual reality" simulation of the action in our minds.

"You also find cells like this for touch," says Ramachandran. "They fire when you touch yourself and when you watch someone else being touched in the same location."

Ramachandran and his colleague and wife Diane Rogers-Ramachandran used a "mirror box" - a tool that creates the visual illusion of two hands for people who actually only have one. By placing an amputee's arms either side of a mirror - with the missing limb on the non-reflective side, the amputee sees the reflection of their normal hand superimposed on the location of their missing hand.

Two amputees watched their normal hand being prodded, and both felt the remarkable sensation of "being prodded" in their missing hand. In another experiment, when the amputees watched a volunteer's hand being stroked, they too began to experience a stroking sensation arising from their missing limb.
The amputees "felt" the actions of others because their missing limb provided no feedback to partially inhibit their mirror neurons, no longer telling them that they were not "literally" being touched, says Ramachandran.

One woman reported that watching a volunteer rubbing her hand caused the cramping sensation within the phantom limb to cease for 10 to 15 minutes. "If you do it often enough perhaps this pain will go away for good," suggests Ramachandran. "If an amputee experiences pain in their missing limb, they could watch a friend or partner rub their hand to get rid of it."

Massaging the skin helps relieve a painful sensation by restoring blood flow and activating sensory fibres, which inhibit pain messages to the brain. By watching another person rubbing their hand, these amputees are apparently tapping into this latter mechanism, says Ramachandran.

"If performed early enough, this type of therapy may also be used to help stroke patients regain movements by watching others perform their lost actions," he concluded.

New Study Shows Amputees Can Mentally Move Missing Limbs In Impossible Ways

Excerpted from the Science News article: An experiment explores the connections between brain and body By Stephen Ornes, Web edition : Thursday, November 19th, 2009

“Phantom” pain is like a ghost in the body — but it’s anything but imaginary. People who have had an arm or leg amputated can often still feel sensations of the missing limb, even though it’s no longer there. These sensations can be painful, and scientists are always looking for new ways to help relieve this phantom pain for amputees. Treatment often involves using mirrors to visually trick the person’s brain. The thinking is that, if a person can “see” his own body in a new way, his brain may stop sending pain messages.
In a new study, a team of neuroscientists have made another surprising discovery about amputees: They can be taught to mentally move their missing limbs in ways that are impossible in the real, physical world. It’s impossible for a person to bend his wrist down and then twist his hand around in a full circle.
Seven people who had had their arms amputated above the elbow participated in the experiment. After extensive mental training, four of the seven were able to feel the sensation of this impossible act, and describe it in detail.
“It is very surprising that anybody — amputees or not — can learn impossible movements just by thinking about it,” Henrik Ehrsson of the Karolinska Institutet in Stockholm, told Science News. Ehrsson is a neuroscientist, which is a scientist who studies the brain and nervous system.

Preventing Phantom Limb Pain with Immediate Post-Operative Prostheses (IPOP) Procedure

Though the Immediate Post-Operative Prostheses (IPOP) Procedure offers the highest rate of healing of any of the post operative modality treatments for lower limb amputation, it is not widely in use.

The primary reasons for its modest use include the fact that the process itself is slightly more time consuming in the O.R.(approx. 20 min); requires more monitoring of the wound itself; possible payment issues for the prosthetist for the procedure, including the frequency of subsequent visits and lack of familiarity with the treatment itself.   Many surgeons performing the amputation are not trained in IPOP principles nor have knowledge of the benefits in the rehabilitation aspect.  Many do not have a working relationship with a prosthetist who will be performing this procedure in the O.R. immediately after they are finished.  And, the prosthetist needs to be available for this critical time period to apply the rigid dressing & the associated components.

These, and any other objections, are greatly offset by the benefits to the patient/client, when used immediately after lower limb amputation:

Accelerates recovery – Early use of a prosthesis often results in shorter hospital stays and a faster transition to a temporary prosthesis as patients begin to develop a tolerance to weight bearing.

Controls swelling – In applying gentle pressure to the patient’s residual limb, an IPOP will minimize swelling. This helps the healing process, shaping the limb, making the final custom-made prosthesis easier to fit and in a more timely manner.

Reduces pain – In controlling the swelling, pain is often reduced. This reduces the use of drugs, decreasing costs and may even eliminate drug dependency.  Research also indicates that early prosthetic use made possible with the IPOP Procedure, may reduce (or eliminate) the occurrence and severity of phantom limb pain and sensations.

Protection and Safety – Especially in patients who are in a weakened condition, elderly or have other medical considerations, IPOP practice shows a dramatic reduction in the number of falls and can help prevent additional injury to the wound.

Prevents knee flexion contractures and loss of muscle strength – By allowing amputees to stand almost in very short order and to gradually begin using their legs, an IPOP can significantly improve rehabilitation – again, reducing hospital stays & costs.

Greater stability - An IPOP, which is a rigid locked knee above a "weightless" prosthesis, gives the patient more stability than prior to the surgery, when they undoubtedly had a painful or weak leg.  It is usual practice to mobilize patients within 24 hours post-surgically.  At a minimum to have the patient stand and transfer to the toilet or wheelchair using a limb. The importance of minimal ambulation in therapy from the second day onwards cannot be emphasized enough. The minor risk of harm involved with minimal weight bearing and the brief stance phase on the amputated leg is outweighed by all the general advantages to the patient for ultimate survival.

Psychological benefits – Patients learn immediately what it feels like to wear a prosthesis and thereby can focus more on their rehabilitation than on their missing limb. This is usually very positive as long as it does not delay the process of accepting the loss of their limb. Having an IPOP can help them return to their homes, or workplaces, sooner especially if wheelchair accessibility is a problem.  The new amputee generally has a more positive outlook on their future.

The risks and side effects of an IPOP also need to be considered. Not every patient is an ideal candidate for an IPOP. It should be a decision reached by the patient, the physician(s) and any others in the rehab team to determine if the benefits outweigh the risks.

Side effects can be avoided or minimized with attentive care by a well-trained rehab team. Damage to the wound can occur from excessive weight bearing too soon after amputation. To use an IPOP correctly, the patient must be able to limit the amount of weight he or she applies to it.

Pre-existing disease issues can complicate matters – diabetes and other circulatory problems should be taken into consideration along with general health, age and strength factors.  Although rare, in some cases a patient may develop an infection or non-healing surgical wounds. In this situation, the use of the IPOP is discontinued while the problem is being addressed.  It can be reinstituted at the soonest appropriate time after the ‘problem’ has been eliminated or determined.  Sometimes a slight elevation in temperature has worried hospital staff to the point that the IPOP is removed - only to find out that the wound was perfectly fine.  The IPOP/rigid dressing then has to be re-done.

Other issues would include cognitive dysfunction and delirium, poor nutrition and the presence of a stroke.  They sould be strongly taken in to consideration in the determination to use or not use an IPOP.  .

Open-Source Colaborative Approach To Better Prosthetics

A recent NPR article and webcast features Jonathan Kuniholm, who, after a tour of duty in Iraq, was missing part of his right arm — which he lost when his Marine patrol was ambushed near Haditha.

When Kuniholm returned to his design shop, Tackle Design, he brought along three prosthetic arms given to him at Walter Reed Medical Center — the same body-operated hook many veterans have used since World War I, a shorter utility prosthetic, and a new, state-of-the-art myoelectric arm. Each one had its drawbacks — and when Kuniholm and his Tackle Design colleagues disassembled them, they quickly concluded that they could improve on the designs.

They founded the Open Prosthetics Project, an open-source collaboration that makes its innovations available to anyone. And Kuniholm signed on with Revolutionizing Prosthetics, an initiative of the Defense Advanced Research Projects Agency, or DARPA.