What Is a Stroke?

A stroke is a medical emergency that occurs when something (usually a blood clot) interrupts the blood supply to a part of the brain, or when a blood vessel inside of the brain bursts.

Brain tissue is very sensitive to the lack of blood supply.

Brain cells start to die within minutes, without the proper blood perfusion.

If it is left untreated, it can lead to brain damage, disabilities and even death.

Stroke survivors usually experience a tremendous change of lifestyle, since their cognitive, mobility and speech functions suddenly become impaired.

 

Signs and Symptoms

The onset of symptoms is usually very sudden. It occurs seconds to minutes after the blood supply is cut off.

Symptoms can vary, depending on the affected area of the brain.

However, the most common ones are:

• Difficulties in understanding speech, slurring of words and sometimes, even confusion.
• Arm and leg paralysis or numbness (usually on one side of the body).
• Drooping of the face.
• Blurred, blackened, or double vision in one or both eyes, accompanied by vomiting and the loss of consciousness.

 

Causes of Stroke

There are three main types of strokes: ischemic (about 80% of all strokes), hemorrhagic and transient ischemic attack (TIA).

They all have their own distinctive sub-types and characteristics.

We will discuss each of them.

Ischemic strokes occur when an artery in the brain becomes clogged, either by a thrombus (thrombotic stroke) or an embolus (embolic stroke).

A thrombus forms in an artery inside the brain, when an atherosclerotic deposit blocks the blood supply.

An embolus, on the other hand, forms away from the brain (usually in the heart) and is carried away and eventually lodged in narrow brain arteries.

Hemorrhagic strokes are a consequence of a brain blood vessel leak or rupture.

There are many causes of this type of stroke.

However, the two most common are hypertension and brain aneurysms.

Transient ischemic stroke (TIA or mini-stroke) is similar to an ischemic stroke, but the decrease in blood supply is temporary and doesn’t lead to permanent brain damage.

 

PEMF and Stroke

Stroke therapy is either surgical or pharmacological. It is aimed at removing the cause, whether it’s arterial blockage or hemorrhage.

Since most stroke victims have some kind of disability, rehabilitation is an important aspect of post-stroke treatment.

Stroke rehabilitation involves a multidisciplinary approach.  It includes physiotherapy, speech therapy and pharmacotherapy.

It can also include methods of alternative healing. An excellent example is Pulsed Electromagnetic Field Therapy (PEMF).

The research suggests that it can improve the survival of neurons, following the ischemia.

PEMF devices work by creating a magnetic field that can enhance cellular functions, improve blood supply and have a neuro-regenerative effect.

PEMF is most effective in improving speech and motor functions.

Speech usually recovers first, which drastically improves the patient’s quality of life and enables him to express his needs and feelings.

It also allows him to explain whether he’s in pain.

Used together with physiotherapy, PEMF can also restore motor functions.

PEMF therapy should be used on the opposite side of the brain from the affected limbs.

This is because the opposite side of the brain controls the motor functions in the body.

PEMF therapy is also known for its ability to help restore damaged vision in stroke victims.

Since PEMF has a neuro-protective effect, it can be successfully used as a method for people with chronic strokes.

While PEMF can be very effective in successful post-stroke rehabilitation, it is not a cure.

It should only be used as a part of a multidisciplinary approach that  also includes physiotherapy, speech and occupational therapy.

Although it has virtually no side effects, it shouldn’t be used in people with a pacemaker or implanted cardioverter-defibrillator (ICD).

During the procedure, the high intensity, low frequency pulsed electromagnetic fields are typically used.

The key is to use gentle pulses (usually 1 Hz) to the brain in order to stimulate the damaged brain cells, while not hurting the surrounding healthy tissue.

The initial treatment duration should be 20-30 minutes, focusing on the opposite side of the affected limbs.

PEMF Research

When PEMF is applied to the head area, it is called Repetitive Transcranial Magnetic Stimulation (rTMS).

Bearing in mind that PEMF is essentially the same as rTMS, there is considerable available and ongoing research demonstrating the benefits of this treatment in tissue healing, which can be applied to post-stroke patients.

Most of the research papers used PEMF/rTMS, in combination with conventional methods of physical therapy, which supports using these two methods together for the optimal recovery of the patient.

 

The effects of rTMS/PEMF on motor recovery in early stroke patients

A study with the title of Effects of high- and low-frequency repetitive transcranial magnetic stimulation on motor recovery in early stroke patients: Evidence from a randomized controlled trial with clinical, neurophysiological and functional imaging assessments (1)  sought to assess the effects of rTMS/PEMF on motor recovery in early stroke patients.

This study was conducted in China on 60 hospitalized post-stroke patients (within two weeks after the first onset of symptoms) with motor deficits.

In addition to physical therapy, the patients received either High-frequency (HF) rTMS/PEMF, Low-frequency (LF) rTMS/PEMF or placebo.

The measure of success was a motor impairment score (Fugl-Meyer) that was evaluated before, immediately after rTMS/PEMF and three months after the treatment.

The cortical excitability and functional magnetic resonance imaging (fMRI) data were also collected, before and after the application of rTMS/PEMF.

The researchers found that the overall motor improvement was significantly greater in the group that was treated with rTMS/PEMF than in the untreated group.

It was also found that the HF rTMS/PEMF increased cortical excitability and motor-evoked fMRI activation in the opposite motor areas, while the LF rTMS/PEMF decreased these two parameters.

The scientists believe that with the modulation of motor activation of the brain cortex, the motor function is improved during the early stroke phases.

 

The effects of rTMS/PEMF on walking and balance function

This systematic review and meta-analysis with the title Effects of Repetitive Transcranial Magnetic Stimulation on Walking and Balance Function after Stroke: A Systematic Review and Meta-Analysis (2) was published in the American Journal of Physical Medicine and Rehabilitation.

As the study’s name suggests, the objective was to determine the effect of rTMS/PEMF on walking and balance function in stroke patients, by comprehensively searching databases (MEDLINE, EMBASE, CINAHL, etc.) for randomized control trials (RCT).

Only the RCTs with the lower limb function as keywords were selected.

The main outcomes of the study were balance and motor function, walking speed and cortical excitability.

After the analysis of nine selected studies, the results only showed a significant effect of rTMS/PEMF on walking speed.

No effects were found for motor and balance function and cortical excitability.

This research shows that rTMS/PEMF, especially when used on the same side of the brain as the affected limb, can significantly improve walking speed.

However, further research and larger sample sizes are required to fully understand the effects of rTMS/PEMF on walking and balance function in stroke patients.

 

The effects of rTMS/PEMF on upper limb function

The research paper Short- and Long-term Effects of Repetitive Transcranial Magnetic Stimulation on Upper Limb Motor Function after Stroke: a Systematic Review and Meta-Analysis (3) was conducted in collaboration with U.S. and Chinese research.

The objective of the study was to evaluate the long-term and short-term effects of rTMS/PEMF on upper limb recovery following a stroke, by searching the databases (MEDLINE, PubMed, Cochrane, etc.) for RCTs that mentioned the effects of rTMS/PEMF on motor recovery of upper limbs.

The research included 904 participants in 34 studies. It showed that both short- and long-term manual dexterity were improved after rTMS/PEMF treatment.

The effect was stronger, when rTMS/PEMF was applied in the acute stroke phase, after five sessions of rTMS/PEMF treatment and in cases of cortical stroke.

The adverse effects, headache and anxiety, were mentioned in only three studies.

This research paper showed that the rTMS/PEMF is most effective when used in the following cases: in the acute stroke phase, in subcortical lesions, as a five session treatment and as an intermittent theta burst stimulation.

 

The benefits of rTMS/PEMF in speech recovery

This case report was conducted at the Department of Rehabilitation Medicine, Huashan Hospital, Shanghai, China.

The name of the research paper is rTMS treatments combined with speech training for a conduction aphasia patient: A case report with MRI study (4).

It shows speech-language improvements in a stroke patient following the rTMS/PEMF treatment.

The report discusses a 39-year-old woman who had a left hemisphere stroke  with resulting speech difficulties.

The patient’s left Broca area in the brain was exposed to 5 Hz rTMS/PEMF for 10 days, in combination with one-month long speech rehabilitation training after the stroke.

In order to assess the functional changes before and after the rTMS/PEMF treatment, functional magnetic resonance imaging (fMRI) and diffusion tensor imaging were used.

Two weeks post-treatment, Western Aphasia Battery language scores were improved, and the gains continued at two and a half months after the treatment.

Post-treatment fMRI indicated a more focused pattern of activation in the left hemisphere, especially in the areas around the stroke lesion, compared to pre-treatment fMRI.

The findings suggest that the combination of rTMS/PEMF and speech therapy significantly improved the speech-language ability of this speech-impaired patient.

This treatment enhanced the functional reorganization of brain tissue.

 

Improvements in microvascular perfusion and tissue oxygenation after PEMF treatment

This 2015 study was published in the prestigious Journal of Neurosurgery.

The study titled Increases in microvascular perfusion and tissue oxygenation via pulsed electromagnetic fields in the healthy rat brain (5), demonstrated the acute effects of PEMF on the brain’s microvascular perfusion and metabolism.

Even though it is well-known that PEMF stimulation can facilitate bone and skin wound healing, the exact mechanism remains unknown.

Some research suggests that the key is nitric oxide (NO), a well-known blood vessel dilatator that also increases the tissue blood flow.

In order to test this hypothesis, the research examined the PEMF effects on the healthy brains of rats, with and without the NO inhibitor.

The research showed that PEMF significantly dilates cerebral arterioles, which then increases capillary flow and enhances tissue oxygenation.

The use of a NOS inhibitor prevented all of these physiological changes.

In the untreated control rats, no changes in these parameters were observed.

This research demonstrated that 30 minutes of PEMF treatment induced the dilation of cerebral arterioles and resulted in an increase in tissue oxygenation that lasted for at least three hours.

It also proved that these effects were mediated by NO, since there were no effects when the NOS inhibition was applied.

Based on these results,  it is possible to conclude that PEMF can be an effective treatment for patients, who suffer from ischemic or traumatic brain injury.

Further research on humans is needed.

 

The aid of rTMS/PEMF in swallowing difficulties

This randomized controlled study with the title Effects of Bilateral Repetitive Transcranial Magnetic Stimulation on Post-Stroke Dysphagia (6) was published with the aim of examining the high-frequency rTMS effects on patients that had swallowing difficulties after a stroke.

The research used a RCT approach with a blinded observer. It divided 35 stroke patients into three groups – a group that received bilateral rTMS/PEMF stimulation, a group with unilateral stimulation and a placebo group.

They also assessed clinical and video-fluoroscopic swallowing functions.

The findings showed that the most effective type of rTMS/PEMF stimulation is bilateral, since that group of patients showed significantly better improvement in swallowing.

Therefore, the scientists concluded that the bilateral 10 Hz rTMS/PEMF exposure of motor cortices that are in charge of swallowing functions, can be used as an additional therapy method for post-stroke swallowing difficulties.

 

Conclusion

A stroke is a life-changing event that unfortunately results in the loss of mobility and cognitive and speech functions.

The successful rehabilitation process involves re-learning in order to return to independent living.

However, this process is usually very slow.

Stroke victims who take part in a stroke rehabilitation program perform much better than those who don’t.

Depending on the level and the type of disability, the physical therapy approach varies, and can include a combination of physical, cognitive and experimental activities.

Exposure to PEMF has virtually no side effects. It is a safe and effective treatment that shows promising results, but only in combination with one of the physical therapy methods.

While it is clear that more research needs to be done on this subject, the use of PEMF should be encouraged after the stroke.

Although the PEMF therapy is most effective right after a stroke, it can be beneficial for up to 10 years, following the first onset of symptoms.