Epilepsy

    Epilepsy is a brain disorder which effects the brain in many areas and different ways. Usually consisting of series of seizures, within the first few moments of the attack, you will lose consciousness and control of you. Twitching, falling to the floor, moving without control, drooling, and even loss of bladder control are symptoms that occur during tonic-clonic seizures, but there are many other different types of seizures which have shared and different symptoms. This disease was believed to be first described by the Babylonians some 3000 years ago, and the word epilepsy is the Greek word meaning- attack.

    Deep inside your brain are ganglia, which are clusters of interconnecting neurons and other neural cells.  When these begin to malfunction, seizures are sparked. Through the signaling, your average neuron will send 8 impulses per second, but a patient of seizure will have his/her neurons signaling 500x’s per second. And this occurs 100x’s a day for most epileptic patients. 

    Epilepsy, thankfully, is not contagious, nor caused by brain retardation. And again thankfully, most seizures do not damage the brain of those with epilepsy, and any changes to the brain caused by this disease are subtle. But there is no permanent cure for epilepsy at the moment. Many epileptics are normal people in terms of intellectuality. And 1 in 100 people will have epilepsy in their life time (2 million people in the USA). 20% of people who have epilepsy are immune to medication and suffer more than the rest 80% whose symptoms are controlled to some extent by modern medication.  Epilepsy, in most cases, is chronic; nevertheless, there is a high chance for children who spontaneously develop epilepsy, to get rid of it by the time they graduate into adulthood.

    The reason people get epilepsy are many- abnormal brain development or neural paths, to some brain diseases which cause neural cells to malfunction. Other reasons include an excessively large production of neurotransmitters, consequently, increasing neural activity to a point to where a seizure may start. And the same increase in activity of the brain occurs, in some cases, while trying to patch itself from a trauma, or a stroke. And in other cases, glia (glial cells), which affect neural processing while layering myelin (this substance speeds signaling), have known to cause epilepsy. Layering too much myelin can cause seizures. 

    Although half the occurrences of epilepsy have no known cause, researchers are looking into many different reasons trying to find solutions. Traumas, infection, and other threats to the brain.

Parkinson’s disease (PD)

    Both chronic and Progressive, Parkinson’s disease is a movement disorder which commences when dopamine producing cells, in the substantia nigra, begin to malfunction and die over time. Dopamine is a chemical messenger in your body which transmits signals to parts of the brain that coordinate and initiate movement. And in the course of one’s suffering of Parkinson’s disease, these dopamine cells are terminated for unexplained reasons. Their rate of death then picks up consequently stumping the quantity of dopamine production.

    It is estimated that 1 million or so Americans suffer from Parkinson’s, and more than 75% of those victims are diagnosed after reaching the age of 50.  Although the cause is unknown and no major cure is currently present, there are medicating and surgery options to reduce the effect of the symptoms.

    Although there are common symptoms shared by the diseased people, there are many more symptoms that vary and are different between people. The progression of the disease varies in speed between all. Some might suffer more, for their progression is rapid, while others will suffer at a lesser rate, but over a longer time when their symptom worsening is at a slow progression. Such commonly shared sympyoms consist of

1.       Constant shaking tremor of limbs, Face Muscles, and Jaw

    When the disease hasn’t developed as much in one’s brain, 7 out of 10 experience a constant tremor in their hands and legs (sometimes in the face and jaw). It is described as a “beating” movement. It is known as a resting tumor since it occurs more often when the muscle is relaxed.

This indicates that the tremor usually is present after a loss of activity. As the disease progresses more and more, so does the tremor. It will even spread to different parts of the body.

2.       Slowness of movement (Bradykinesia)

    In this symptom, your voluntary muscle movements are slowed down, and they begin to slow down drastically as the disease progresses and worsens. Many will have problems, even with having the ability to start movements. When this is added to stiffening limbs (also a symptom of Parkinson’s) the amount of times a patient stumbles or falls increases. They might even find themselves getting stuck, this is when they cannot begin or stop walking/moving.

3.       Loss of balance and coordination

4.       Stiffness in limbs and trunk

    This is a symptom that includes the stiffness of muscles or inflexibility of them. Because of  the “rigityness” of the muscles, it decreases the rate and length your muscles can stretch to, for it decreases muscle contraction and relaxation. It will even cause cramps in addition to searing pains.

    But often in PD, there are secondary symptoms that are soon to follow. Speech issues such as slurred or stuttering talking habits, a stooped posture (such as leaning forward or backwards) are all caused by a lack of muscle control. There are many more symptoms to follow. More speech changes, loss of facial expression, difficulty in swallowing/drooling, pain, dementia/confusion, constipation, skin problems, depression, fear/anxiety, memory losses/hard time thinking, loss of energy, fatigue, and even urinary problems.

    The cause of Parkinson’s is yet to be solved, chemicals, and mechanisms have been suggested to cause an increasing amount of cell death.  These include…

Oxidative damage (due to stress)

Unstable molecules whose toxic effects are believed to be caused by oxidation are theorized to contribute to cell death, consequently leading to Parkinson’s. Oxidation, in the brain, is hypothesized to cause death and increase damage in tissues. As a result, antioxidants are now to be used as an attempt to slow down the disease.

Mitochondial dysfunction

In our cells, we have small organelles known as mitochondria which break down food suplements and convert it to energy for cell usage. An increasing dysfunction of the mitochondria were found in scientific research to cause cell death to accelerate. So in this theory, scientisits are now investigating if this plays a role in Parkinson’s disease.

Excitotoxicity

Excitotoxicity is the result of an over production of neurotransmitters leading to an increase of cell death. This cause has already been found in Parkinsons’s. Finding a way to now balance the production of neurotransmitants may be able to cause less cases of the disease and slow it down.

There are also genetic factors in which it has been found that 15%-25% of all patients have relatives who have had Parkinson’s . Again, after scientific study, it has been found that there is a defective gene, uncommonly found in families to which Parkinson’s disease may be inherited. 

Other causes include environmental factors which include rural living toxins such as MPTP which cause death to dopmaine and slow down its production.

Credits: Brain disorders source book.

The Organization of the Human Nervous System

    I think of it this way. Cells. Multiple cells make up tissues. Multiple tissues make up organs and organ systems consist of multiple organs. Similarly, the nervous system is organized in the same way. Neurons and axons make up nerves, nerves make up neural circuits, and neural circuits create neural systems. Neural circuits which share similar tasks, come together to make neural systems.

  

    Such neural systems include sensory systems (observe and process information about the environments like the visual system, auditory system etc.) and the motor systems (reactions to certain input information. They include reflexes and counter balancing some moves).  Associational systems are composed of large numbers of cells and circuits which are located between both motor and sensory systems. Associational systems also carry out some of the most intricate processes and brain functions.

    As you know, the Central Nervous System (CNS) is composed of the brain (all 4 regions), and the spinal cord. And then, there is also the peripheral nervous system (PNS) which is all the cranial nerves which branch off the brain, and the many nerves which branch off the spinal cord. The PNS also includes sensory neurons which link sensory receptors (parts of sensory neurons which receive sensory information) to circuits in the CNS (missed information about neural circuits? Click here to view my previous post about them).

    The movement (motor) portion of the PNS is divided into 2 branches which both rely on one another in various ways. There is the somatic motor division which consists of nerves and axons which connect the brain and spinal cord to skeletal muscles. And, an autonomic nervous system which controls smooth muscles (which are muscles that move with conscious control ex: Biceps) and involuntary muscles. Both are crucial for survival, as they provide you, your muscle controls and gland controls to live. Without the somatic motor system, the autonomic system cannot move arms and legs, and without your autonomic system, you will need to keep remembering to execute many of your involuntary muscle movements!

    The neurons which lie within the PNS are located in ganglia which are lumps of nerve cells and supporting cells. Bundles of peripheral axons come together to make nerves, just like how thread is made of many thin fibers bundled and twisted. Those fibers are like axons. In nerves, all-around the body, lie glia. The only glia in the periphery though, are Schwann cells which lie layers of Myelin to help speed up neural messages.

In the PNS it is ganglia but in the CNS it is known as nuclei. Local accumulations of cells in the CNS are known as nuclei (not to get confused with the other meaning of nuclei – control center in most cells. Nuclei are found throughout the CNS, including the Spinal cord and division of the main area of the brain. In addition, there are cortices (cortex-singular) which are flat sheets of nerve cells. 

Tracts in the CNS consist of axons, just like those in the PNS. And those tracts that cross the midline division of the brain are called commissures. The area that contains axons, tracts, and commissures is known as white matter (named so because of its color due to its heavy content of myelin). On the other hand, gray matter is the large clumps of cell bodies and neuropil (click here for more info about neuropil). It is located in the brain and spinal cord.

Neural Circuits

Neural Circuits

  Neural Circuits have different and unique tasks that process different information and are organized and arranged in specific ways. In addition, they control our senses, moods, movement, etc. The connection format is what distinguishes the circuits. These connections are made of thick lumps of dendrites and axons and glia, which are known as neuropil.

    
    Although different, many have the same characteristics and similar ways processes are carried out. Preeminent is the direction and way that information travels in all circuits. The direction information flows is key to the distinction of the circuit.The 2 types of preeminent is afferent and efferent. Neurons that carry information from the Peripheral nervous system (PNS)(check my post about peripheral nervous system and central nervous system here for more information here) to the central nervous system are called afferent neurons, but those who carry information away from the CNS to the PNS branches, are classified as  efferent neurons. And there are 

    Interneurons (local circuit neurons) which only participate in short-distance routes which their axons extend.

    An example of a neural circuit is the myotatic spinal reflex, also known as knee-jerk reflex. Afferent and efferent play the role of the reflex. When you get your reflexes tested, you get a hammer tap test. This is what, if you have normal reflexes, triggers the knee-jerk reflex.

    So, here is how it works. The process begins after the hammer has tapped your knee. This stretches your tendon which then stretches the sensory receptors in your extensor muscles (the sensory receptor is the pink little dot on the extensor muscles in this diagram). You can see a blue line, a sensory axon, which is afferent. This axon carries the message of the hammer tap to the purple interneuron and the red motor axon. Now, the interneuron stops the yellow flexor muscle motor axon from moving the flexor muscle. Instead, the flexor muscle relaxes.

    Now, the red extensor muscles axon carries the message to the extensor muscles, which then contracts the muscle. Finally, the leg extends.
Credits: Neuroscience 4th edition

Stroke

 About 550,000 Humans suffer from this Brain Scorching Disease every year. That means someone suffers from this disease every minute. But  to who why, how, and when does stroke occur? You are just about to find out.

    Stroke is not one disease but has many branches. And each branch has a name based on how it forms. These names include Brain Attacks, cerebrovascular accidents (CVA's), hemorrhagic stroke, etc. But all of these strokes have one thing in common. It is on blood shortage in the Brain. Those who suffer stroke are usually above the age of 55 or so. Stroke in children is extremely rare. Stroke can lead to paralysis, mental, or physical damages in the brain and even to death within a few hours if not treated.

 The most common form of stroke is know as cerebral thrombosis  This is when an artery in the brain is blocked and blood flow stops. An important flow of oxygen and nutrients is cut off by a clot. And because of this, million of cells die instantly. Depending on which part of the brain the blood doesn't reach effects the damage type. 

Cerebral embrosis occurs whenever there is a blood clot elsewhere in the body and that artery leads up to the brain. There also the supply of nutrients and oxygen is cut off.
And many more such as hemorrhages where blood vessels burst open in the brain and and a massive session of blood clots and internal bleeding occur. These occur when a patient has high blood pressure.

    There are many more reasons why stroke forms, one includes atherosclerosis (hardening of the arteries) sickle cell anemia, migraine drug abuse and many more.

    Some symptoms of stroke include dizziness, weakness, lack of consciousness or like what my grandfather faced, vomiting, paralysis on a particular side of the body right/left and a loss of balance and coordination. If you put hot water on his left leg he won’t feel anything, but if you put cold water on the same leg of his, he will feel a painful burning sensation.

Although the large number of 550,000 people who suffer of stroke every year, the death rates and stroke rates have plummeted because of a more sophisticated supply of medicine and education on stroke. Medicines such as t-PA have been introduced dispersing blood clots rapidly within 1-3 hours. But a patient with stroke must consult a doctor immediately, for the amount of damage to the brain increases with every minute left untreated. 


    And now, my grandfather has lost much of his balance and coordination as well as control of some body parts.He is lucky to live and so are many people now thanks to medicines. 

There are many diseases which increase the chance of getting stroke. These include diabetes, blood cholesterol levels, high blood pressure, heart diseases and etc.

But of all the risks, hypertension is the greatest. There are also multiple risk factors for stroke including smoking, which doubles your chances of getting stroke. "It is responsible for a greater percentage of the total number of strokes in young adults than in older adults." (Brain Disorders Sourcebook)

Blood pressure diseases such as hypertension, multiply the chance of you getting stroke by 6x's. An entire 3^rd of the adult population have hypertension, and 40-70 percent of which are senior citizens. The systolic pressure (max blood pressure for the left artery of the heart) should be 120mm and a diastolic (blood pressure between heartbeats) of 80mm is considered normal.

The second most common cause for stroke, is Heart Disease. This is because a faltering vain leading up to the brain, could lead to clotting. Abnormal beating of the left artery is a major heart disease in terms of contribution towards stroke. This is known as atrial fibrillation. This affects 2.2million people in the U.S. alone. 15% of people who have stroke have this condition.

Credits- Brain Disorders Sourcebook- Judd, Sandra

Protection of the brain

The protection of the brain is a vital part of your survival. Although brain functions are important and complicated, safety comes first. Without protection to your brains, they can be penetrated and damage at every step you take while walking. 

The brain is found inside a bone shelter called the cranium. The cranium will protect the brain from concussion and many other injuries. Together, the cranium, cheek bones, jaw bones, teeth and etc. form the skull protecting your whole face from injury. The cranium will provide the tough protection of anything trying to penetrate through the bone. But the cranium is not enough to protect the brain, because every hard hit you take to the head will affect the brain through shocks from the cranium.

This is why we also have 3 other layers known as the meninges. These layers are made up of tissue which cover and blanket the surface area of the brain's cerebral cortex as well as the spinal cord.  The three layers are known as dura mater, archanoid, and pia mater. Let's take a closer look at these. 

The dura mater is made of 2 layers of a white-like, non flexible thin wire called the membrane. The outer layer of the dura mater is called the periosteum  An inner layer called the dura makes the outer most inner part of the skull. The dura and the falx(a minor layer) separate both the left and right hemispheres of the brain. And at the same time the dura and the tentorium separate both top and bottom hemispheres.

The second layer know as the archanoid is a thin, delicate layer and unlike the dura mater, it is very elastic, in fact this stretches to cover the entire brain. This layer carries many blood vessels of many different sizes across its wide range. The archanoid serves as a secondary layer and gives the brain more like a transport system for blood vessels. 

The layer of meninges closest to the surface of the brain is known as the pia mater. This carries many blood vessels from the stretchable archanoid deep into the brain. The pia mater is the one which has a bumpy bottom surface to firmly but gently cradle the brain and keep it in place with the support of the other meninges. There is a gap found between the pia mater and the archanoid known as the subarchanoid space. This is were your cerebrospinal fluid flows(CSF).

CSF is found surrounding the brain and the spinal cord. It is a clear and has a similar viscosity to water. This helps cushion the brain including the spinal cord from any injury. The CSF serves other interesting purposes such as flowing out waste. It also serves as a transportation route to transport hormones around to parts of the brain. When CSF builds too much in ventricles, obstructs ventricles, or has problems without absorbing waste you are diagnosed with the condition of hydrocephalus.

So, imagine what it would be like without brain protection, in fact if you didn't have brain protection you couldn't even imagine! You would be receiving concussions every second. So remember every part of the brain and nervous system plays a vital role in your survival, not just boosted thinking where you wouldn't have anything to loose. Credits: Human Brain Diseases a Sourcebook

Regulation of the Body

    The body's basic functions are carefully controlled in order to keep a stable internal system. And while regulating the body the hypothalamus and brain stem are key to our involuntary internal organs. They play many roles such as co operating with chemical messengers(which are your hormones) to keep the body going. Mostly without your you being conscious!

  Regulation of the Heartbeat
    The heart rate is regulated by the autonomic nervous system (ANS). The sympathetic ANS slows down heartbeat while the parasympathetic is related to activity and speeds it up. 
    
    The head quarters for the ANS heart regulation is not found in the cerebular cortex of the brain's main body but it is located in the brain stem. About half way down the brainstem there is an area called the Medulla. The medulla is the sight also for breathing regulation. Nerves branch down from the medulla to the organs under our rib cages.

     The medulla contains a clump of neurons communicate with the cardioregulatory center. In response to the information, the ANS sends signals to the sinoatrial node and the atrioventricular node in the heart. These nodes then set the heart beat to a speed which is suitable to the amount of oxygen coming into the body.

    The Hypothalamus
     The hypothalamus contains many clumps of neurons called nuclei, these are small clusters. These nuclei control regulations of many things like your, eating, body temperature, hormonal levels, wake/sleep cycles and your balance! The hypothalamus is the main coordinating center and even connects to the ANS. Through all these intricate connections out, the hypothalamus plays a huge responsible part. 
    
    It produces vital responses for your survival. 
Ever wondered why you are hungry? Well, that's your hypothalamus notifying you of the possible consequences of not taking food(nutrition) and brings the pain of acids in your stomach to your consciousness. It also plays a party in emotions such as anger.
So know you know that the hypothalamus is vital to your life and even subtle damage could cause the worse consequences and long term(even permanent) consequences throughout your life.
Credits: The human brain by Rita Carter