Neurorehabilitation - gaming systems

In a marriage of medicine and gaming culture, virtual reality games have been investigated in the rehabilitation of stroke patients.¹

Researchers in Barcelona have investigated novel technology-based neurorehabilitation techniques in the treatment of strokes. A special aspect of this technique was the fact that the game could be adjusted and personalized for each patient.

While a stroke causes massive damage, brain cells can reorganize themselves. Therefore the aim of rehabilitation is to maximize the effect of this plasticity. The Spanish research team developed the Rehabilitation Gaming System (RGS), a virtual reality-based neurorehabilitation program .

The RGS tracks arm and finger movements and maps them onto a virtual environment. The user controls the movement of two virtual limbs that are viewed on a screen. The RGS "game" that the researchers used was called Spheroids (see figure below). In this game the user has to catch and place spheres that move towards them. The idea behind this is that, when the patients use their limbs and observe the virtual limbs move in a way that is controlled by them, conditions are created that stimulate the reorganization of neurons involved in motor functions.


The researchers also tried to make the tasks just challenging enough to remain engaging for the patients. The RGS automatically adjusts the difficulty of the task with respect to the measured performance of a subject in order to keep them encouraged and to maximize effect.

The researchers concluded that the RGS is a promising neurorehabilitation tool that can be used to alleviate the deficits brought on by lesions to the central nervous system as the ones caused by stroke.

¹ Cameirão MS, Bermúdez i Badia S, Oller ED, Verschure1 PFMJ. Neurorehabilitation using the virtual reality based Rehabilitation Gaming System: methodology, design, psychometrics, usability and validation. Journal of NeuroEngineering and Rehabilitation 7:48 (2010).
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Bone Marrow Mononuclear Cell Therapy

"Bone Marrow Mononuclear Cell Therapy" is a form of stem cell therapy. There has been a lot of research on the use of stem cell therapy to treat heart attacks, emphysema, as well as stroke. This entry focuses on stroke treatment.

A novel approach to treating stroke has been invstigated by a research group in Germany.¹ The investigators took bone marrow cells from human volunteers, isolated mononuclear cells from it, and used these to treat stroke in rats.

The bone marrow cells were transplanted directly into the carotid artery three days after stroke was induced in the rats. Rat behaviour was tested before stroke, as well as 2, 5, 14, 23 and 30 days after stroke.

Unfortunately, treatment didn't improve recovery compared to non-treated rats. This study was based on previous research focusing on the treatment of heart attack with mononuclear bone marrow cells, and suggests that one therapy can't directly be translated to another disease. However, the fact that researchers waited three days before treating the stroke might also be significant. It is essential that stroke patients are treated as soon as possible after stroking - for strokes caused by blood clots the treatment window is 3 hours after stroke.²

Previous research into treating stroke with bone marrow cells focused on the use of stromal bone marrow cells³ and not mononuclear cells. Mononuclear cells come mostly from red bone marrow, which gives rise to cells associated with the immune system such as monocytes and lymphocytes. In contrast, stromal stem cells come from the stroma which contains a number of cells that create the correct environment for the production of mononuclear cells in the red bone marrow. The bone marrow stroma contains cells like fibroblasts and macrophages, as well as other factors like colony stimulating factor, which all support the differentiation of blood-related cells in the red bone marrow. Therefore the type of cell used to treat stroke might also be of significance.

Even though mononuclear cells did not effectively treat stroke in this study, mononuclear cells have been used with success in the treatment of heart attack ^{4, 5} and emphysema. ⁶

¹ Minnerup et al. Intracarotid administration of human bone marrow mononuclear cells in rat photothrombotic ischemia. Exp Transl Stroke Med. 2: 3. (2010) (doi:10.1186/2040-7378-2-3)

² http://www.ninds.nih.gov/news_and_events/news_articles/stroke_pooled_analysis_030404.htm

³ Andrews et al. Human adult bone marrow-derived somatic cell therapy results in functional recovery and axonal plasticity following stroke in the rat. Experimental Neurology 211: 588-592 (2008).
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⁴ Lunde K et al. Intracoronary Injection of Mononuclear Bone Marrow Cells in Acute Myocardial Infarction. New England Journal of Medicine 355: 1199-1209 (2006).
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⁵Leblond, A-L et al. Bone marrow mononuclear stem cells: potential in the treatment of myocardial infarction. Stem Cells and Cloning: Advances and Applications 2: 11–19 (2009).
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⁶ Cruz F et al. Bone Marrow-derived Mononuclear Cell Therapy Improved Lung Mechanics And Histology In A Murine Model Of Emphysema. Am. J. Respir. Crit. Care Med. 181: A1013 (2010).
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Stroke treatment

Granulocyte colony stimulating factor (G-CSF) is a molecule that carries a signal to the bone marrow, causing it to produce granulocytes and neutrophils (types of white blood cell), as well as stem cells.

Researchers have recently found that G-CSF can cause the growth of neurons (nerve cells - such as those in the brain) in young animals. A lot of scientists disagree whether neurons can grow in adult animals (or humans), and believe that damaged brain cells or other neurons cannot be replaced. However, a study¹ has shown that treatment with G-CSF after a stroke improved recovery in aged rats. Treated rats survived better and showed greater improvement in mobility and memory. The scientists observed an increase in a number of neurons, which shows that neurons can be "born" even in adult animals.

This research points the way towards more effective treatment of stroke victims, and could mean an improved prognosis for many stroke patients in the future.

¹ Popa-Wagner A et al. Effects of Granulocyte-Colony Stimulating Factor After Stroke in Aged Rats. Stroke 41:1027 (2010).
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