Virtual Reality (VR) Mirror Therapy and Stroke: A Diary

WARNING: I am not a medical professional, nor am I an expert on virtual reality or stroke. However, I think it might be helpful for some people to read about my dad’s experience as a paralyzed stroke victim trying VR mirror therapy.

My dad tried virtual reality (VR) mirror therapy to help relieve pain in limbs paralyzed by a massive stroke. He was 79 years old during the therapy and the stroke had occurred about eight years earlier. Mirror therapy is usually used for phantom pain caused by amputated limbs, but I hoped that my dad’s paralysis was similar enough to benefit. This article is for anyone wondering if mirror therapy can help pain from paralysis, particularly after a stroke. It is also for people curious about using virtual reality to soothe pain, a technique also known as virtual reality analgesia (VRA).

Mirror therapy tries to trick part of a patient’s brain into thinking that his missing limbs are functional. Special mirrors make the patient’s reflection look as if the patient is moving his non-functional limbs. By seeing his missing limbs moving normally in the mirror, part of the patient’s brain hopefully decides to reduce pain signals.

With virtual reality (VR), mirror therapy can be done without the burden of physical mirrors. It can sometimes be hard to maintain the illusion of mirror therapy with physical mirrors, because the mirrors are difficult to ignore. In addition, physical mirrors only allow a very limited range of motion, because moving too much can also break the illusion of the reflection.

In VR mirror therapy, the patient usually wears eye goggles and headphones, so everything he sees and hears is filled with a virtual world. (See the photo at the top of this article.) It’s kind of like the movie The Matrix. Other people (outside the VR world) can watch what the patient is seeing on a computer screen connected to the VR system.

When a patient puts on VR goggles and headphones, he can see his “reflection” (which is an artificial virtual reflection) in a computer-generated mirror. When he raises his actual functional arm in the physical world, BOTH arms in the virtual reflection are raised. Because the patient is absorbed in the sights and sounds of the VR world, seeing both arms (or legs) functioning normally in the VR world will hopefully seem more realistic than a jerry-rigged physical mirror in the physical world.

Doing VR mirror therapy requires access to VR equipment, which is now sold by many companies for home use. I used an Oculus Rift VR system with my dad. The software that I found was specifically designed for mirror therapy, as opposed to simply being a virtual mirror in a non-therapeutic VR experience.

Although some studies have shown the potential for VR to relieve pain, my dad’s emotional and cognitive impairment were too great to benefit from the therapy. Unlike pharmaceuticals, mirror therapy requires the active participation of patients, and my dad was mostly unwilling to perform the therapy. If patients have brain damage that has left them psychologically unwilling to participate, then the therapy seems likely to have little benefit.

It’s possible that my dad might have benefited from mirror therapy in physical reality rather than virtual reality. The presence of a physical therapist and physical mirror might have spurred him to participate more willingly. In addition, the virtual reality might have been too unusual for his brain to handle in a mature manner. (He sometimes claimed to not understand the VR environment, but he might have been lying, since he was able to understand it at other times.)

In addition, my dad’s inability might have been due to my own lack of experience with physical therapy. As you will see in the diary below, I sometimes had to decide what I would do if I were a trained physical therapist, and I was often unsure of the correct decision.

My dad tried VR mirror therapy at the age of 79, about eight years after his stroke. The stroke had affected the right side of his brain, causing extensive vascular dementia (brain damage) and hemiparesis (paralysis) on the left side of his body. He had become wheelchair-bound, mostly unable to care for himself, and required 24-hour monitoring. He had also lost much of his ability to perform basic mental reasoning or converse in an adult manner.

In addition, my dad had developed the following health issues after his stroke:

1. Extreme chronic pain on his paralyzed left side

2. Obsessive-compulsive behavior

3. Anger and physical agitation lasting hours, days, or even weeks

4. Severe depression

5. Significant memory loss, both long-term and short-term

6. Severe anxiety

The VR software company that was kind enough to let my dad use its product also asked me to not give its name. When I contacted the company’s public liaison, she told me that the heads of the company would have to discuss whether to let me use their software. After several rounds of email and phone calls they agreed to give me permission. The company provided training to use the software. The training was probably unnecessary for anyone who already knows how mirror therapy or VR are supposed to work.

I tried VR mirror therapy for the first time by myself. In the software that I used, the patient watched his reflection in a virtual mirror and imitated the motions of a computer-generated therapist standing in front of him. The patient and therapist did several exercises, such as lifting arms above the head or rotating forearms. Each exercise was repeated 10–15 times. The therapist also verbally instructed the patient about what to do. Other people (outside the VR world) could watch what the patient was seeing on a computer screen.

I made the mistake of giving the software my dad’s weight instead of my own, so my virtual arms were not positioned for my body type. This occasionally made the VR movements clunky. The software sometimes had a hard time locating the VR controllers in my hands, but that might have been because I had a small area for moving my actual physical body.

My dad tried VR mirror therapy for the first time. It went badly. I kept having to tell him to look at the virtual mirror, which he would only do for a few seconds at a time. Then he would drop his head to the right, so almost all he could see in the VR world were his legs. I’m not sure why he did this. He had always been resistant to physical therapy with my mom or therapists in the past, so this could have been his normal stubbornness. It might also have been due to his left-sided neglect, the weight of the goggles, or other unknown factors.

Because my dad could not (or would not) look at the virtual mirror, I eventually had to hold his head in the correct position. He then followed along with the VR therapist’s motions for about a minute, but only sporadically after that. At first I tried just reminding him every time he didn’t follow the virtual therapist, but I also tried moving his arm myself.

My dad then asked me to take the therapist’s clothes off. When I told him that I couldn’t do that, he got upset and stopped following along with the therapy altogether. Eventually he began saying that he “couldn’t see,” even though he’d already been following along with the therapist. To test if he was lying, I asked: “Is everything just black?” and he seemed to lie, saying: “Yes, everything is just black.”

My original plan had been to run through all the exercises twice on this first day, but that wasn’t possible. I wondered if I would have to get “tough” like my mom and physical therapists had done in the past. But I also wondered if he would be able to focus on the mirror if I were tough with him. Watching the mirror was the point of the therapy, not the physical exercise. Then again, physical therapists do have a reputation for being tough. One of my dad’s therapists had once joked: “What’s the difference between a therapist and a terrorist? You can negotiate with a terrorist.”

Second VR mirror therapy session with my dad. This session went even worse than the first one. At least in the first session my dad had followed along with the VR therapist for about a minute. This time he almost immediately began complaining that the lens was touching his left eye. I checked and adjusted the goggles a couple times, and the lens was definitely not touching his eye, but he continued to complain that it was. I don’t know if he was just repeating these words obsessively (he had developed OCD since the stroke), if he was openly lying, if his damaged brain actually thought the lens was touching his eye, or if there were some other reason.

I had to hold my dad’s head in position again, as with the first session. He again demanded that I take off the VR therapist’s clothes. He only managed to focus enough for a few arm lifts in the first exercise. I decided to not get “tough” with him, because I didn’t think he would be able to focus on the mirror. So I stopped the therapy.

I provided my feedback and results to the software company and thanked them. I let them know that my dad had been unable to do the therapy, but this was mostly because of him (and possibly me) rather than the therapy itself. I still feel that VR mirror therapy has tremendous potential. I hope that researchers continue to explore and improve it for future patients.