How could stroke rehab be improved?

Meet Thaiana Marcelino, a Brazilian scientist, who studied in her Master’s thesis how to improve rehabilitation after stroke. Besides her dedication to promoting better health care, she is into vegetarianism and making animations.

Since high school, Thaiana Marcelino Lima already saw herself as a health worker. In a chat about professions of this area held by her school, physical therapy emerged as a great option. Since then, she has been concerned with promoting the best possible treatment for patients. Her Bachelor’s in Physiotherapy made her see the patients beyond the disease, taking into account the human side and their context. In college, it was the first time she had contact with scientific investigation, what she continued doing during her Master’s. Research, then, won her over: she found herself having the chance to “take on the role of someone who sees a problem and tests solutions,” she says. Her problem-solving side could, thus, be useful to research how to improve clinical care and treatment.

During her undergraduate studies, the physical therapist worked on two projects, that later came to define her Master’s thesis research focus. It started with a project with children with cerebral palsy. Next came a project with neurologically affected adults. These experiences made her interested in the area of physical therapy that focuses on the recovery from neurological diseases that affect movement, the neurological physical therapy. And so, in her Master’s, when her supervisor suggested her to work on a project with stroke patients, it was easy to decide to accept the proposal. In her Master’s thesis in Health and Biological Sciences at the Federal University of Vale do São Francisco (UNIVASF) in Brazil, she, then, studied how to improve the treatment of stroke patients.

Stroke is the deterioration or death of brain cells due to the blockage or rupture of an artery in the brain. For brain cells to function well, they need oxygen and glucose. These reach the brain through the cerebral arteries. If the blood flow in one of these arteries is somehow interrupted, the brain area that is supplied by this artery is at risk of suffering a stroke. However, different parts of our brains are more dedicated to specific functions. For example, certain areas are more responsible for controlling the movement of limb muscles, others more related to speech, and so on. So depending on the area where the stroke occurs, that function regulated by that brain region may be affected. So, let’s say that the stroke occurs in the region that coordinates the muscles of the limbs on one side of the body. After the vascular accident, “some people may have difficulty reaching and picking up objects, walking, and even performing personal care activities such as buttoning a blouse”, Thaiana explains.

A stroke occurs when there is blockage or rupture of an artery in the brain. Source: https://enableme.org.au/Resources/Types-of-stroke

According to the World Health Organization (WHO), stroke is considered the second leading cause of death and the third leading cause of disability worldwide. Furthermore, 70% of strokes and 87% of stroke-related deaths occur in low- and middle-income countries. These stats make stroke not only a global public health issue but also a problem of social inequality. “Stroke is one of the conditions that most affect people, being responsible for a high mortality rate and disability for survivors. It affects the health, social relations, and economic condition of the population,” clarifies Thaiana.

Source: Our World in Data

Stroke treatment usually occurs in two phases. The first aims to lessen the extent of the damage caused by the vascular accident. Patients are treated with medications or, in some cases, surgery, and must be done as soon as the accident occurs. But stroke can have a very compromising effect on one type of brain cell, the neurons. And the problem is that such a type of brain cell does not regenerate. And if these cells of a certain area die, the functions performed by these regions will most likely be impaired. So, in the second phase of treatment, the rehabilitation, different therapies, such as physiotherapy or speech therapy, are applied to help restore the lost functions. And the sooner they are applied, the better for the patient.

Commonly, the sequelae of a stroke are treated with more conventional methods. For instance, manual physiotherapy or kinesiotherapy (a set of therapeutic exercises that aid in recovery by strengthening and stretching the muscles). But, many times, the patients’ recovery is not as effective, and there is a need to add other therapies to the process. This is where Thaiana’s Master’s thesis project comes in. In her research, she investigated the application of a technique called transcranial direct current stimulation (tDCS) together with physical training.

Usually, when a stroke occurs, the lesion leads to cellular damage in one side of the brain. Thus, there is a hypothesis, supported by different pieces of evidence, that this ends up generating an imbalance of activation and inhibition between one cerebral hemisphere, where the stroke lesion occurred, and the other. In this context, tDCS, the technique used by Thaiana in her project, aims to restore the balance between the two sides of the brain. In such therapy, two electrodes are placed on the individual’s head. Through a very low-intensity electric current, the electrodes contribute to the activation or inhibition of the affected brain area. One of the electrodes is called the anode and the other cathode. In her project, Thaiana used the following configuration: “the anode is applied to the side of the brain lesion to stimulate regions near the lesion and favor better performance in activities with the affected side. The cathode is applied to the contralateral (opposite) hemisphere to inhibit the dominance relationships that the healthy hemisphere exerts over the injured side.”

Transcranial direct current stimulation (tDCS), the technique used in Thaiana’s experiment with stroke patients. Source: Rosa and Lisanby, 2011

But how could tDCS help in stroke recovery? Thaiana based her study on the hypothesis that this technique would help reorganize the brain and, as a consequence, modulate brain activity. Such a process is referred to as neuroplasticity. “In this process, the brain area that suffered the circulatory lesion undergoes a series of “tissue repair” in areas close to the damage to decrease the sequelae of the vascular accident. Since it is not possible to fully recover the injured tissue, neuroplasticity allows the brain to adapt, even with limitations, the important functions, such as the movement of body members. Studies suggest that tDCS is a neuroplasticity-promoting tool that can stimulate this brain adaptation. What can this represent? Improvement of movements and functions previously impaired by the injury, such as being able to walk, being able to pick up objects with the impaired hand, being able to feed oneself, among other possible gains.”

tDCS has already been tested in stroke patients, but it is not yet a common therapeutic practice. Although the technique has the potential to treat vascular disease, “the evidence [regarding the mechanisms of action of tDCS] is limited, considering the small samples and the methodology of the studies. For tDCS to become a practice in the rehabilitation of stroke, it is necessary to perform properly controlled, blinded clinical trials (where the patient doesn’t know if he or she is receiving a true or false stimulus). Then we would know whether the intervention is beneficial or not”, Thaiana explains. Because of this lack of more studies, she adds, “[the] professional councils, national and international organizations have been cautious about proposing the intervention as a possible therapeutic pathway.”

It should be noted that many of the studies that support the hypotheses that tDCS affects neuroplasticity, and that it could help stroke patients recover were done with a low number of participants. So more studies like Thaiana’s, which investigate the effect of tDCS on the brain itself, but also how to use the technique to treat diseases like stroke are very important. However, because it is a promising, cheap, and non-invasive technique (requiring no surgery or skin incision, and no contact with mucosa or internal body cavity), the therapy offers very advantageous qualities that could help to treat stroke. Even more so in a context where stroke is more common in countries with low or middle incomes.

The results of the Master’s project of the Brazilian scientist were not published yet. But they were already submitted to a scientific journal. Thus, we hope to hear about them in a near future. Besides her academic activities, she has been trying new vegetarian recipes and learning how to make animations. “In the future, I hope to use this tool to communicate my academic activities to the general public”, she says.

When asked about who her references are, Thaiana mentions a strong female presence in her career. “Professors like Raimunda Hermelinda, Renata Jucá, and Lidiane Lima motivated me to see health care and clinical decision making from a scientific and individualized perspective. In my Master’s, without a doubt, my co-supervisor Ivani Brys was my reference. With her I had the opportunity to develop my skills in scientific thinking and learn about the world of neuroscience,” she says.

Thank you very much, Thaiana, for sharing your story and your research! We hope you will also inspire not only other girls and women, but everyone, with your dedication to caring for others based on scientific evidence.

Follow Thaiana’s career here.

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