Assistant Professor

Department of Physiotherapy

Rama Institute of Paramedical Sciences

 Kanpur, Uttar Pradesh, India 

Introduction:

As we all know, brain is a very complex and very intense sort of organ which tends to change according to the functions and the sort of information processed by it.  Through its varied functions it has been stated by various authors that this organ is the only organ present in human body capable for producing the changes in normal anatomical structures contained within this cranial cavity without hampering the normal physiological actions of the brain considering various activities that are considered normal. These changes do not alter the normal mechanics of the working of brain but make them either better or transform them into activities that are way relevant to the functionings. These structures tend to undergo these changes because of varied reasons. These changes are thus a result static and dynamic alterations to the brain and the structures within making an overall change in the functioning of the brain. The core structural aspect of the grain constitutes of the presence of white matter and grey matter within the brain and the cranial cavity which is embedded by a diversified form of neurons and neuroglial cells. These neurons and neuroglial cells perform different functions and serve as varied functions depending upon their structure and the location of these structures which governs a major aspect of their functioning and their degeneration as well. These structures not only provide the brain with their optimal functions but also tends to deviate the structures from their normal (considered) functioning.

The use of electrical stimulations to treat anomalies of Brain dates back to 1967 by Wisconsin colleagues, Shealy, Mortimer and Resnik which was initially used to treat the patients having pain syndromes or painful diseases. Better results depicted by various such researches,  engaged the researchers to investigate further the use of these stimulations in the field of neurological physiotherapy and treat anomalies regarding the brain. 

Anatomical Review of the Brain:

Brain is a complex yet very crucial system of the body governing the basic and advanced functions of the human body mechanics. This structure is composed of neuron and their cell bodies with axons which helps determine the function and various aspects of various parts of the brain with respect to the neuron or the neuroglial cells present within that particular space. Not only this the masses of grey matter contained within the white matter region of the brain give immense knowledge about the working pattern and physiology behind each and every activity governed by the brain or regulated directly or indirectly by the brain structures. Brain contains small and large nuclei which are collectively called as the ganglionic cells which perform various functions of the central nervous system. These nuclei not only govern the activities of the body but also perform functions of transferring of the information or the stimulus from one part of the brain to another.

Another structure which performs the same function of transferring of information from one site of the grain to another are collectively termed as fibres or tracts. These fibres or tracts are present in various regions of the brain and act as a linkage between the two cerebral hemispheres, between the forebrain and the midbrain, midbrain and hindbrain and the hindbrain and the forebrain as well. These connections form a strong and easy way of executing complex functions which require involvement of more than one lobe or segments. These fibres include the commissural fibres, projection fibres, ascending – descending tracts, etc. These structures are crucial for sustenance of normal daily activities executed by a living organism. Another important structure which need to be dealt regrading these stimulations and the these structures is the presence of shock absorbing fluid CSF (Cerebro-Spinal Fluid). CSF tends to absorb the chock endowed upon the skull and the brain tissues and helps to combat these structures from the atmospheric pressure as well. In disorders where there is involvement of the CSF or the midline between the two cerebral hemisphere there occurs a phenomena of CSF production and its absorption for better functioning of the brain tissues.

1. This Figure shows the various regions of the Brain

Functions of the Brain:

These structures perform various functions of the brain such as cognitive functions which include memory, reasoning, thinking, intellectual properties, intellectual thinking, abstract thinking, writing, reading, etc. Along with these functions, brain performs various other functions such as sensory, motor and sensorimotor components. These intellectual properties and functions are also a varied part of the intellectual and coordinated function of the brain functions. These changes with reference to any activity or physiology is termed as Neuroplasticity. Neuroplasticity is a term used to define a process which tends to change the structure and activity of the brain with the effect of various stimulations or associated factors which tend to increase or decrease the activity of the brain cells and thus create a modified or mutated form of stimulation or activity.

These neuroplastic activities tend to enhance the efficiency and proficiency of the activities which is a result of various modifications altering the mechanics. This brain in spite of being a crucial and prone to trauma organ, has many insights of the activities undertaken and knowledge gained. The total investigations held on activities of brain in past recent years have been suggestive that the knowledge we acquire regarding the functions are not completely understood. Apart from these functions there are several other functions served by various parts of the brain some of which include involuntary actions which do not require individual’s concern to happen and are considered normal under general circumstances such as swallowing, perception, understanding of the language and speech spoken by someone and to respond to that stimulus in an appropriate manner, to make use of their thinking reasoning and intellectual activities in responding to any stimulus, seeing what comes around and responding according are some of the major functions dealt by the brain. Some other functions in detail are explained in the figure given below:

2. Functions of the Brain according to the locations

Neuromodulations:

Modulating the neural structures and nervous tissues to the extent that there is stimulation of the neurons or neuromuscular junctions producing excitation at the level of inducing the sodium potassium pump which cause further translocation of the electrical signals within the neural axon. Neuromodulation refers to the procedure which is opted by various physiotherapists to target a single site at the neuron or superficial site where the neuronal excitability is achieved to the maximum. The regions which need to be focused directly can be targeted directly through application of these stimulations causing the associated networks to get excited as well for better results.

Not always the results of neuromodulation are acquired according to the results desired by the researchers, many a time higher excitation of the neurons causes local inactivation of those neurons at that particular site. This inactivation in turn activates the GABAergic inhibitory neurons which stimulate the dissociation and disposal of the excitation signals causing no effect of the stimulations. These hyper-activation of the neurons causes the membrane potentials to increase abruptly and then decreases to the level that it ends the further excitation of the neurons. Apart from higher stimulations, prolonged excitation of the higher frequencies also tends to induce depression of the electrical signal transfer at that site causing electrical burden and hyperpolarization at that site.

Neuroplasticity:

These neuroplastic changes can be brought upon by various physiotherapeutic and electrotherapeutic modalities. These changes can be dealt with various obsolete treatment managements. These changes could be elicited by various stimulations. Especially cases dealt with physiotherapeutic interventions these days, electrical stimulations to alter the neuroplasticity content within the brain structures. These electrical stimulations cause the electrical activity within the neurons and the axons of the neurons along with the synapses to mould their activity according to their stimulations and their excitation coupling mechanics. The electrical mechanisms which are altered produce some sort of altered mechanics which not only changes the pattern of stimulations being received by the brain but also tends to alter the final product of these stimulations. Another crucial part of these stimulations is these are given at a proper intensity and set pattern which requires in depth knowledge of the brain structures and functions which helps the researcher or the physiotherapist to gain in depth knowledge of the result being evaluated and the reason behind such results.

There have been many researches in the field of Neurological disorders and physiotherapy interventions prevalent in this field that use of many physiotherapeutic modalities can alter the physiology of normal procedures. These modalities in way one or the other regulate the mechanisms being followed by the brain making some dreadful serious conditions treat along side basic physiotherapeutic interventions. It has been evident in many articles that use of electrical stimulations can make the signals in the brain undergo changes that are crucial in producing evident alterations within the normal physiology of the brain activities. These stimulations or electrical signals are sent through a varied form of modes that are capable of delivering this type of stimulus to the grain tissues.

Electrical Stimulations:

Through a long time, it was seen that physiotherapists along with researchers have been using stimulation methods for dealing with various anomalies of the brain or human body. These stimulations were firstly used in the form of electrical excitation mechanisms through the modality called TENS or Trans Electrical Nerve Stimulation which provides the stimulation in form of electrical current to the damaged or under trauma neural tissues superficially. These stimulations are rendered through the surface of the skin, nearest to the site of pain or radiation of pain caused by damage to the neural components. After TENS, electrical stimulations were used in form of various other modalities which rendered current and electrical stimulation to treat various anomalies of the soft tissues.

Electrical stimulations like IFT, EMG, etc, have been used to treat disease and symptoms arising from varied injuries and trauma. These electrical stimulations through electrical activity within the body tend to alter the mechanics within the body. These altered mechanics stimulate the changes needed to treat diseases and acquire knowledge of the outcomes possible when the changes are produced with a respective goal. These stimulations are thus a boon for the better treatment and effective outcome reporting. Apart from stimulating the peripheral parts of the human body, researches have now been keen on assessing whether these stimulations could work for better outcomes in cases with involvement of brain lesions and brain disorders. Stimulations to be applied at the brain and brain lobes must be evaluated to see its effects on the various brain lesions and brain activities.

Brain Stimulations:

Stimulations to the brain or brain tissues whether stimulated deeply within the tissue or stimulated superficially from the scalp. These may produce alteration in the activity of the brain or cause desired action regarding the treatment of a particular disease related to the brain. The stimulations or the electrical signals rendered to the brain structures produce a synonymous electrical activity creating a physiological process which is necessary to treat any condition along side physiotherapy. In various researches there have been evidence that stimulating the brain tissues is not only considered as an alternative by the physiotherapist or the electrotherapeutic assistants but it is also considered as an alternative by the surgeons and neurophysiologists. In many countries this practise of stimulating the brain is considered a very ancient practise targeting an appropriate type of response guided by the doctors.

These stimulations however, are thought to be of great importance while dealing with conditions that require keener and prolonged observations of the nursing staff and doctors. Especially diseases which require prolonged hospitalization of the patients or require round the clock observation of the patients without stimulations. These interventions are however of varied procedures and varied importance. It is not necessary that these interventions are always up taken for a safer option or the lesser taken pathway. These brain modulating interventions are chose because in recent researches they have depicted a quite sustainable and satisfactory response of the patients undergoing brain stimulations for various reasons. There have been a keen interest of the researches in this particular field of neuro-physiotherapy and neuro-surgical physiotherapy interventions. Through various researches it has been evidently proved that electrical stimulations could also benefit patients in treatment during and after surgical procedures in various cases. These stimulations were initially rendered to patients in clinical type of settings which induced better results when used in combination with motor task training also termed as Dual motor task training schedules for patients suffering from longer ailments and anomalies involving higher mental function degradation which ultimately leads to entire dependency of the patients on their care takers or family members.

Physiology behind Brain Stimulations:  

The basic physiology behind application of electrical stimulation to the brain regions depends upon two uncommon but efficient phenomenon which are Neuroplasticity and Neuromodulation. These two phenomena explained earlier in the chapter suggest the possible mechanism by which these stimulations effect the brain cells. Through a diversified and explorative studies authors have came to a conclusion that these brain disorders or prolonged hospitalization or dependency on others creates a negative feedback mechanism on various tissues of the body pertaining to the brain cells as well. Since each and every neurological disorder imparts a negative effect on the brain cells, these disorders after a certain period of time initiate to cause atrophy within the brain cells and tissues, forming cerebral atrophy type of symptoms. This atrophy of the brain causes the shock absorbing mechanism of the brain to hamper because of lesser production and absorption of the cerebro-spinal fluid which makes this circulation impaired causing defaults at the various mechanism being governed by it.

Not only impaired CSF circulation imparts negative effect over the shock absorption but in cases where there is presence of well defined midline shift, there occurs a conditions which causes the CSF circulation to be irregular and more on the side which is away from the more content of the cerebral hemisphere. These shifts thus create a negative pressure at the level of hemispheral content which causes the brain activity to cease or get hampered producing enhancement in symptoms and altering the normal mechanics of the brain. These hampered circulations and ceased normal functions create an altered mechanics at the level of cellular activity as well. These cellular activity in turn deviate the activity of the hormones released by the parts of the brain and at times are responsible for direct and indirect consequences in the body. These hormonal changes produce various cellular and microscopic changes at the anatomical level which can tend to increase this deviation of the midline and in turn induce abnormal levels of some important enzymes. Brain’s normal functioning is the outcome of various procedures which occur in simultaneous fashion to make the functioning happen. One of these important mechanisms is the production of the Endothelin within the brain tissues which keeps a check on the physiology normally. Any deviation in the midline or the changes in pressure gradients or disordered circulation of CSF causes this endothelin to function and produce in abundance abruptly hampering the normal physiology of the brain. Stimulation of the production of these endothelins cause significant enhancement in brain disorder symptoms.  

Indications for Brain Stimulations:

These sorts of stimulations are used frequently by physiotherapists and researchers in following conditions:

1. Brain disorders involving midline shift and translocation of the cerebral hemispheres

2. In cases of pain disorders

3.  In cases of psychological pain syndromes

4.  Anxiety and other cognitive anomalies

5.  Epilepsy

6.  Stroke

7.  Alzheimer’s Disease

8.  Brain oedema

Mode of Application:

The mode of administering brain stimulation depends upon the type of stimulation being rendered to the patients. The placement of electrodes which stimulate the tissues is however based on the 10-20 EEG system which demarks each and every part of the brain into various sections depending upon the location to be targeted.

3. 10-20 EEG system for targeting the locations in Brain

Types of Brain Stimulations:

There are broadly two categories in which stimulation activity of the Brain can be categorised. These two sections are:

1.     Invasive Brain Stimulation, and

2.     Non-Invasive Brain Stimulations

Invasive Brain Stimulations: These stimulations are those which are targeted region stimulations based on the correct location inside the brain to be targeted. These are also referred to as Deep Brain Stimulations and are usually carried out by practised Surgeons who open the skull and expose the brain tissue and place the electrodes which stimulate the brain parts at the desired site through surgery. These stimulations since are targeted are quite apt when talking about the precision of the positioning of the electrodes. This procedure requires thorough conscious learning and deep investigation about the type of electrode to be used and the type of stimulation to be rendered. These stimulations since are practised by surgeons and are in direct contact with the brain tissue being stimulated and give rise to various complications which are earlier studied and evaluated by the surgeons before use. Deep brain stimulations in turn require consent of the patients and their family members because the risk of patients being paralysed, drawn into coma or death are high with respect to the other available practise. Earlier these practises were very prevalent but by the introduction of alternative method these are only practised where it becomes completely impossible to target deep seated structures. Various deep brain stimulations include Vagus nerve stimulation, Thalamic stimulation (which stimulated the ganglions in the thalamus region and the substantia nigra region of the brain), etc. These stimulations because of being in constant contact with the tissues provide a focused response.

Non- Invasive Brain Stimulations: these are the type of brain stimulations that do not require the electrodes to be in direct contact with the brain tissues being stimulated. These types of stimulations are rendered superficially without opening the skull and exposing the brain tissues. These stimulations require placement of electrodes at appropriate site of stimulation according to the lobes targeted and the result wanted. These require application of direct current to the scalp for stimulation of the brain regions. Recent studies have found them to be equally effective in producing desired outcomes when compared to deep brain stimulations. However, a bigger drawback is the stimulation of deep-seated brain tissues through these application procedures. The types of stimulations involve Transcranial Direct Current Stimulation, Trans-electrical stimulations, Cranial electrical stimulations, etc depending upon the type of stimulation desired by the physiotherapist or the researcher.

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