‘Watch and learn’ – how mirror neuron therapy can help improve neglect

July 13, 2018

Have you ever been told to ‘watch and learn’? There is actually some science to support that saying. We learn from each other by watching and imitating. This process has to do with something known as mirror neurons. As we observe someone performing an action, neurons in our brain behave as if we are doing the same thing. This phenomenon has great potential for patients recovering from a stoke.

The understanding of mirror neurons in recent years is possibly one of the most important discoveries in neuropsychology to date. 

Check out this video for an introduction to mirror neurons (skipping to 1:23 minutes will take you straight to the explanation).

Basically, the same neurons that “fire” in your brain when you complete a task will also “fire” when you watch someone else do the same task. Since the late 90s, substantial evidence has emerged supporting the use of Mirror Neuron Therapy (MNT). It uses our understanding of mirror neurons to help stroke patients in their physical recovery. MNT is relatively easy to do. It can potentially deliver fast results, and there is a strong theoretical basis to support it. Sounds pretty good, right? So far, MNT has been used to treat stroke-induced movement disorders. But until now the potential effects on patients with hemispatial neglect had not been researched.

Understanding hemispatial neglect

Hemispatial neglect is a common condition after a stroke. It means that the patient’s visual awareness of objects on one side of their body is reduced or altered. The patient will “neglect” the side opposite to that of their stroke. For example, someone who has had a stroke in the right hemisphere of their brain may experience left-sided hemispatial neglect and would miss objects placed on the left side of their visual field. There is a range of the severity of hemispatial neglect. And in more severe cases it can be a completely debilitating condition.  

Using mirror neuron therapy to treat hemispatial neglect

Researchers in China trialed the use of MNT with two patients experiencing hemispatial neglect to test whether the therapy could be helpful for treating this condition.  Due to the complex technology used in this study, the sample size was admittedly small. Only two subjects participated in the study, a 64-year-old male and a 45-year-old female. Both patients had experienced right-sided strokes resulting in left hemispatial neglect.

Each of the patients underwent an “ABA” sequence of therapy. This means that there were two protocols of therapy. The “A” protocol was a video series showing 105 daily life movements, such as turning on a tap, with equal video of right and left sided movements. The researchers designed the protocol to activate the motor neuron system by showing the patients functional tasks which could activate mirror neurons.

The “B” protocol acted as a control and included videos of non-human or animal scenes (i.e., mountains, rivers, and forests). The patients sat with a computer screen in their midline and watched the above videos for 30 minutes per day, 6 days per week over 3 weeks as part of their rehabilitation. During the first and third weeks of the study, they watched protocol “A”. During the second week, they watched protocol “B”, creating the “ABA” pattern.

In addition to these case studies, the researchers used functional magnetic resonance imaging (fMRI) scanners to examine the differences in brain activation for two healthy male subjects when watching protocol A compared to protocol B.

Mirror neuron therapy is effective for treating hemispatial neglect

The study found that the protocol A resulted in better scores on hemispatial neglect tests compared to protocol B, even after just the first week. They also saw that in fMRI testing, watching protocol A activated brain regions commonly associated with hemispatial neglect (i.e., the right inferior parietal lobe) while watching protocol B did not. Because of these findings, the researchers believe that MNT can activate brain areas affected by hemineglect. They also think that MNT has the potential to improve visual-spatial perception for stroke patients. This is a small study with only two cases. But these results pave the way for more extensive studies with the potential for further insight into this exciting rehab technique.

After hearing these results, you might be interested in using mirror neuron therapy to treat hemispatial neglect. Speak with your therapy team about how best to go about this. A very simple way to implement these principles is by showing the stroke survivor videos of tasks they would usually perform or by demonstrating these tasks for them in person. Is the stroke survivor a passionate foodie? Have them watch short clips of a favorite cooking show. Are they an avid card-player? Watching someone shuffle cards or deal a hand may be a great place to start.

The lead author of this study was Wai Wang, Department of Rehabilitation Medicine, First Affiliated Hospital of Nanjing Medical University, China.

Editorial note:

Mirror Neuron Therapy (MNT) offers new hope when it comes to treating hemispatial neglect.

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