A stroke, or cerebrovascular accident, is the rapid loss of brain function (electrical/chemical communications between neurons and target cells) due to disturbance in the blood supply to the brain [[1]]. This can be due to ischemia (lack of blood flow) caused by blockage (thrombosis, arterial embolism), or a hemorrhage (broken blood vessel due to high pressure or a tumor) (Fig. 1 [[2]]). Brain cells (neurons) can stay alive for 4 to 6 minutes without oxygen. After that cells begin to die. One will lose consciousness in 10 seconds after the loss of blood supply to the brain [[3]]. As a result, the affected area of the brain cannot function, which might result in an inability to move one or more limbs on one side of the body, inability to understand or formulate speech, or an inability to see one side of the visual field. A stroke is a medical emergency and can cause permanent neurological damage and death [1]. It is the second leading cause of death in Australia after coronary heart disease. One stroke was happened in every 10 minutes in 2012 and 1 in 6 people will have a stroke in their lifetime in Australia [[4]].

 

The brain is the most important and complicated organ in the body in terms of control and sense of the body and social activities. The brain is about 2% of body in weight while it uses around 20% oxygen/blood of the body [3]. The brains of all species are composed primarily of two broad classes of cells: neurons (for communication) and glial cells (for support and wound healing [[5]]). A human brain contains 15–33 billion neurons, each connected by axons (nerve fiber) and synapses (nerve connection structure where neurotransmitter molecules are released) to several thousand other neurons to form the neural network for the complicated functions of the brain (Fig.2, [[6]]). In general, neurons in most part of the brain do not reproduce after birth (except for the areas of hippocampus and olfactory bulb, which relate to the memory and smell functions respectively). If they are damaged, they cannot be regenerated. Glial cells are different: they can be regenerated after wound throughout the lifespan [6]. However, glial cells don’t transmit nerve signals. Although glial cells have the potential to differentiate into neurons [[7],[8]] and set up new neural networks for the brain functions along with the reconstruction of the other unwound neural network [[9],[10]], these regeneration and reconstruction may or may not successful and take a long time and need a proper molecular environment [[11],[12]] and stimulations [[13]]. Therefore, the functional recovery after stroke is difficult.

 

 

 

 

Due to the complicated functions of the human brain (motor, sensory, orientation, language, memory, thought, etc.) and the functional regions in the brain, stroke occurred in the different area will cause different symptoms and signs (Table-1, Fig. 3[[14]]).

 

 

 

Table-1: Symptoms and signs after stroke in some important areas of the brain [6].

Regions of the brain

Symptoms and signs after stroke in the area

Cerebrum, or cortex, is the largest part of the human brain, divided into four lobes: frontal lobe, parietal lobe, occipital lobe, and temporal lobe.

Affect functions depending on the section involved: Frontal Lobe- associated with reasoning, planning, parts of speech, movement, emotions, and problem solving.

Parietal Lobe- associated with movement, orientation, recognition, perception of stimuli.

Occipital Lobe- associated with visual processing.

Temporal Lobe- associated with perception and recognition of auditory stimuli, memory, and speech [[15]].

Medulla, along with the spinal cord.

Loss of wide variety of sensory and motor functions

Pons, directly above the medulla.

Affect functions of sleep, respiration, swallowing, bladder function, equilibrium, eye movement, facial expressions, and posture.

Hypothalamus, a small region at the base of the forebrain.

Affect functions of sleep and wake cycles, eating and drinking, hormone release, and many other critical biological functions

Thalamus, situated between the cerebral cortex and midbrain.

Affect functions of information interactions between the two cerebral hemispheres, motivation, several types of "consummatory" behaviors, including eating, drinking, defecation, and copulation.

Cerebellum, a separate structure attached to the bottom of the brain, behind pons.

Affect motor control, cognitive functions such as attention and language, and fear and pleasure responses.

Optic tectum, also called superior colliculus, a major component of midbrain.

Affect the sensation and movement of the eyes.

Hippocampus, a part of the cerebral cortex, located in the medial temporal lobe.

Affect functions of behavioral control, short/long-term memory and spatial navigation [[16]].

Basal ganglia, at the base of the forebrain, connected with the cerebral cortex and thalamus.

Cause movement disorders and motivation problems, such as loss of action to hunger, reward and punishment.

"Silent" regions of the brain, the regions that do not cause a noticeable change in an afflicted person’s motor function, speech, pain, or the sense of touch.

No any outward symptoms noticeable, typically detected via the use of neuroimaging such as MRI. Silent strokes are estimated to occur at five times the rate of symptomatic strokes and place the patient at increased risk for symptomatic strokes in the future [1].

Since stroke is a medical emergency situation, for people at risk, if there is a sudden problem of facial expression, arm lifting and speech/understanding, call for medical aids immediately [4].

The risk factors for stroke include high blood pressure, atrial fibrillation, high blood cholesterol, diabetes, cigarette smoking (active and passive), heavy alcohol consumption and drug use, lack of physical activity, obesity, processed red meat consumption and unhealthy diet [1].

It is very important for people who are having stroke symptoms to get to a hospital as quickly as possible, since the shorter the time, the less the brain tissue damaged, the quicker the functions recovered. The immediate treatments include clot-busting drugs or mechanical clot removal within 4.5 hours for ischemic stroke and a surgery to control the bleeding and reduce the pressure for a hemorrhagic stroke [[17]].

Not like skin wounds, the damage of neurons is very difficult to repair. As introduced above, neurons regeneration and neural network reconstruction takes a long time and needs a proper molecular environment and stimulations. At this point, traditional Chinese medicine (TCM) including acupuncture and Chinese massage shows an effective and widely used role in the stroke recovery [[18],[19]], especially in China, where it reports more patients with stroke than anywhere else in the world [[20]]. The neuroregeneration needs various cytokines. Recent researches on TCM showed that many herbs and acupuncture regulated cytokines [[21],[22]]. For example, the commonly used herb on stroke, Huang Qi, showed a stimulating effect on stromal cell-derived factor 1 (SDF-1) on the rat brain ischemic model and decreased the brain damage due to the ischemia [[23]]. In the senescence accelerated mouse model, 10 cytokines (GM-CSF, IFN-γ, TNFα, IL-1β, IL-2, IL-4, IL-5, IL-6, IL-10 and IL-12) in hippocampus were decreased, while Dan Gui Shao Yao San significantly increased IFN-γ and IL-4; Si Jun Zi Tang significantly increased IFN-γ; Liu Wei Di Huang Tang recovered all 10 cytokines to normal levels, indicating the molecular regulation rationales for the uses of those TCM formulas on Alzheimer's disease [[24]]. Also, acupuncture can regulate TNF-α and IL-6 back to normal for patients with ischemic stroke [[25]].

According to the TCM theory, stroke can be treated by promoting blood circulation and removing blood stasis; resolving blood-stasis and unblocking collaterals; extinguishing wind and unblocking collaterals; smoothing Fu organ and purgation; promoting blood and diuresis; heat-clearing and detoxifying method; supplementing Qi and activating blood circulation; warming yang and activating meridian (Table-2, [[26]]).

 

Table-2. Commonly used Chinese herbs in stroke treatments [26].

Chinese herbs

Functions

Huang Qi (Astragali Radix)

Effects of invigorating Qi and consolidation of superficies, diuresis, detumescence, discharge toxin and pus, regenerating muscle, etc. At present, Astragalus is one of the main herbs for treatment of apoplectic hemiplegia.

Dang Gui (Angelicae Sinensis Radix)

Effects of  nourishing blood to regulate menstruation, promoting blood circulation and relieving pain, discharge toxin and regenerating muscle, relieving cough and asthma. It is widely used in dizziness, arthralgia, numbness, stroke, hemiplegia, palpitation, insomnia and amnesia.

Chuan Xiong (Chuanxiong Rhizoma)

Effects of promoting circulations of blood and Qi, dispelling wind and relieving pain. Chuanxiong has an obvious sedating effect on the central nervous system, and excited effects on medullary respiratory center, vasomotor center and spinal reflex center.

Huai Niu Xi (Achyranthes aspera)

Effects of tonifying the liver and kidney, strengthening bones and muscles, resolving blood-stasis and unblocking collaterals, leading blood downwards.

Guang Di Long (Pheretima asperfillm)

Functions of clearing heat and relieving convulsion, calming liver to stop the wind, clearing and activating the channels and collaterals, relieving asthma, diuresis. Treating stroke hemiplegia, liver Yang headache, fever, mania, convulsion, and rheumatic arthralgia.

Ji Xue Teng (Spatholobi Caulis)

Effects of nourishing blood, invigorating the circulation of blood, dredging collaterals. Main treatments include irregular menstruation, blood deficiency and chlorosis, numbness and paralysis from stroke, rheumatic arthralgia. Modern pharmacological confirmed that Spatholobi Caulis has effects of anticoagulant, promoting fibrinolysis, anti-platelet aggregation, vasodilation, and increasing blood cells and hemoglobin.

Hong Hua (Carthami Flos)

Carthami Flos: Effects of promoting blood and clearing the channels, dispersing blood stasis and relieving pain. It is used for treatments of amenorrhea, dysmenorrhea, lochia, and lump in the abdomen, trauma and injuries. Modern pharmacological discovered that Carthami Flos can inhibit platelet aggregation, increase fibrinolytic enzyme activity, inhibit thrombosis in vitro, promote collateral circulation expansion, increase blood flow in the cerebral ischemic area, thereby reduce brain edema, and has a protective effect on hypoxic ischemic encephalopathy.

Tian Ma (Gastrodiae Rhizoma)

Embellish but not dry; nourishing blood and calming endogenous wind. Modern research has found that Gastrodia has sedative, analgesic, and anticonvulsant effect; can increase cerebral blood flow, decrease cerebral vascular resistance; mild contraction of cerebral blood vessels, increase coronary blood flow.

Shi Chang Pu (Acori Tatarinowii Rhizoma)

Effects of removing dampness and appetizing, eliminating phlegm and inducing resuscitation, improving hearing and eyesight, refreshing and improving the mind. Modern research shows that Acorus tatarinowii can protect the brain from hypoxic brain dysfunction, improve the disturbance of consolidation of memory caused by hypoxia. It showed good therapeutic effects on dementia, stroke plus dementia, cerebral concussion sequela, neurasthenia, myocardial infarction, and aphonia.

Tao Ren (Persicae Semen)

Effects of nourishing blood and removing blood stasis, lubricating intestine and relieving constipation, relieving cough and asthma. Pharmacology showed that the semen persicae extract can significantly increase cerebral blood flow, reduce vascular resistance, and improve the hemodynamic status.

Shao Yao (Paeonia lactiflora)

Smoothing the liver to stop pain, nourishing blood and regulating menstruation, astringing Yin and anti-perspiration. Modern research has found that the peony can decrease blood glucose and total cholesterol levels; dilate blood vessels; inhibit thrombosis and platelet aggregation. It has protective effects on brain edema by ischemic, on blood-brain barrier and brain blood flow. It can reduce the degree of cerebral edema, reduce infarct size and improve neurological symptoms.

Yi Mu Cao (Leonuri Herba)

Effects of promoting blood and regulating the channels, diuresis and detumescence. Its mechanism of promoting blood circulation and removing blood stasis is by improving blood concentration, coagulation and aggregation state through the changes of hemorheology.

In clinics, acupuncture also plays an important role in the recovery treatment of stroke. Since the functions of the nervous system are realized by the neurotransmission of networks, the damage in one point or a small area of the network may be compensated by the signals from the roundabout ways. The stimulations of acupuncture can help to rebuild these roundabout ways. The sooner you get acupuncture after a stroke, the faster your recovery will be. By applying acupuncture to the skin of the scalp above the various regions of the cerebral cortex that have been damaged in an ischemic stroke we can increase blood flow and the metabolic activity of neural cells to help restore normal neural function. This treatment has been used successfully over the last 40 years to help patients suffering from hemiplegic and related neural deficiencies arising from strokes and other cerebral vascular diseases [[27]].

In addition, movement therapies such as Qi Gong (also known as Chi Gung) or Tai Ji (Tai Chi) as well as Chinese massage and nutritional advice can also be recommended to assist the person's treatment in the recovery of a stroke.


Xiaolong Meng

 

References:

[1] Stroke, Wikipedia: http://en.wikipedia.org/wiki/Stroke

 

 

[5] Michael T. Fitch and Jerry Silver: CNS Injury, Glial Scars, and Inflammation. Exp Neurol. 2008 February; 209(2): 294–301.

 

 

[6] Brain, Wikipedia: http://en.wikipedia.org/wiki/Brain

 

 

[7] Sigr?dur Rut Franzdottir et al: Switch in FGF signalling initiates glial differentiation in the Drosophila eye. Nature. Vol 460|6 August 2009| doi:10.1038/nature08167. .

 

 

[8] Stephen C. Noctor et al: Neurons derived from radial glial cells establish radial units in neocortex. Nature 409, 714-720 (8 February 2001) | doi:10.1038/35055553.

 

 

[9] Christian Grefkes and Gereon R. Fink: Reorganization of cerebral networks after stroke: new insights from neuroimaging with connectivity approaches. Brain. 2011 May;134(Pt 5):1264-76. doi: 10.1093/brain/awr033. Epub 2011 Mar 16.

 

 

[10] Carmichael ST: Cellular and molecular mechanisms of neural repair after stroke: making waves. Ann Neurol. 2006 May;59(5):735-42.

 

 

[11] Ohab JJ et al: A neurovascular niche for neurogenesis after stroke. J Neurosci. 2006 Dec 13;26(50):13007-16.

 

 

[13] Andreas R. Luft et al: Treadmill Exercise Activates Subcortical Neural Networks and Improves Walking After Stroke. roke. 2008 Dec;39(12):3341-50. doi: 10.1161/STROKEAHA.108.527531. Epub 2008 Aug 28.

 

 

[16] Function of hippocampus, Wikipedia: http://en.wikipedia.org/wiki/Hippocampus

 

 

[19] TCM for stroke recovery: http://www.eastmountain.ca/stroke.pdf

 

 

[21] Studies of cytokines and TCM: http://www.doc88.com/p-39937916040.html

 

 

[22] Studies of cytokines and TCM: http://www.xiangya.cc/yydt/xs/2010/1105/14339.html