According to the bio-medical model there are four main causes of brain dysfunction:
1. Anatomical abnormalities or damage
2. Lack of oxygen or glucose
3. Electrolyte imbalance
4. Neurotransmitter deregulation; the imbalance of brain chemistry
Anatomical abnormalities or damage result from brain injury due to trauma, brain tumors, or problem in brain development. The damage can disrupt functions of any portion of the brain, or the tracts which carry information between parts of the brain. Injury to the frontal lobes, for example, can result in lack of judgment or foresight, impulsiveness and euphoria.
Lack of oxygen occurs when the blood flow to the brain is slowed down or if the person does not get enough oxygen into the blood. Alterations in blood flow have been related to dementia (senility), schizophrenia, as well as various problems following head injury. Lack of glucose occurs when there is insufficient food intake for a period of time.
Electrolytic induced psychosis, due to below normal levels of sodium, chloride, potassium, and magnesium in the diet can be the cause of delusions and hallucinations as well as stupor and mania. Illnesses that may be related to calcium deregulation include anxiety disorders and mania. (See Hair Tissue Mineral Analysis)
Neurotransmitter deregulation, not all causes of which can be identified at this time, can be caused by a variety of sources including use of substances such as alcohol, nicotine, street drugs, huffing, caffeine and carbon monoxide. Some over the counter drugs and prescription drugs can also have major effects on neurotransmitters.
Caffeine has been linked to depression in people who are prone to depression. Diets high in sugar and fat do not provide the nutrients needed for the body to manufacture the various neurotransmitters.
Neurotransmitter deregulation results in serious difficulty with information processing and coping with daily life stresses. An important part of recovery is learning more about the daily stressors in life; and ways to more effectively cope with them.
The five major neurotransmitters are:
Dopamine: Believed to be related to how clear, without delusions or paranoia, we think. Too much dopamine in certain areas of the brain is viewed as one of the major problems in schizophrenia.
Serotonin: A mediator of impulsive and aggressive behavior. Too little serotonin leads to greater impulsivity and aggression.
Acetylcholine: Mood stability. People with a tendency towards depression have a heightened depressive response to increases in acetylcholine or similar neurotransmitters.
Norepinephrine (also called Noradrenaline): How sensitive or reactive people are to events, people or other stimuli in their environment. Too little Norepinephrine is believed to lead to depression and decreased interaction with others. Too much leads to irritability, over reactivity or an extreme reaction to the environment.
G -Amino -n- Butyric Acid (GABA): Involves restraint.
Fifteen different receptors have been found for serotonin (involved with depression), five for dopamine (implicated in schizophrenia), and six for Norepinephrine (involved with both anxiety disorders and depression).
…our brains are a kind of archaeological dig site, with a series of settlements stacked one on top of the other. The deeper you dig, the farther you go back in time. At the deepest level lies the reptilian brain, also known as the brain stem, controlling the body’s basic metabolic functions, like heart rate and breathing. The brain stem is all primitive instinct and repetition, incapable of emotional complexity or anything resembling genuine thought.
The second layer...is known as the ... limbic system. This is the seat of emotion and memory, comprising chiefly the amygdala, the hippocampus, and the hypothalamus. Our primary emotions – love and fear, sadness and joy- emerge from this region, coloring incoming stimuli with the emotional valences we’ve associated with past events …
Stacked on top of the brain stem and the limbic system is the neocortex, the two hemisphere of which spread across the surface of the brain …This is the most distinctly human component of the brain’s architecture. .. When we alter our immediate actions because of long-term interests, when we communicate in complex sentences, when we engage in abstract thought-indeed, when we display most of the hallmarks of human intelligence, we’re most often using our neocortex.
..from Mind Wide Open by Steven Johnson, published by Simon & Schuster
There are more than 100 billion cells in every human brain. The largest organ in the body, weighing about three pounds, it constitutes just 2% of the body’s weigh, but consumes 20% of the body’s blood supply.
BRAIN CELL (illustrations by Jim Lamoreux)
Information is passed between cells by means of chemical messengers; the neurotransmitters. A cell receives a message from another cell at a dendritic branch which is attached to a dendritic spine (A on the diagram) which causes a wave of excitement which travels along the cell body (B). Should the wave of energy have enough power to get over the Axon Hillock (C) it travels down the axon (D) and gets amplified by the myelin sheath (E). Cells develop the glial cells which create the myelin sheath only by use. A cell which is rarely used will not amplify a signal. It then sends a signal to other cells using the axon terminals (F) by sending out more neurotransmitters. The neuro-transmitters which aren’t picked up by nearby brain cells eventually are picked up by the blood stream, and become hormones, which compared to brain cells, are slow acting.
It is believed that the shape of the neurotransmitters allows their message to be received at the cell’s dendritic branches. Heroin seems to have a close enough shape on the cellular level to Serotonin, which is associated with pleasure, to fit into the serotonin receptors and send out strong messages of pleasure and enjoyment to the rest of the brain. Cocaine and methamphetamines fit into the receptor for Norepinephrine while marijuana fits into one of the lesser known neurotransmitters, Anandamine, which is also the receptor for chocolate. Alcohol fits into the receptor for GABA. The brain believes it has more than enough of these neuro-transmitters and shuts down production. This is believed to be the reason for the strong withdrawal symptoms experienced by many who use these drugs, and an underlying cause of addiction.
Aside from many unknowns the disruption of the ordinary flow of information between brain cells can be caused by:
A. Insufficient production of neurotransmitters. This may be due to drug use, inadequate diet, poor digestion, minimal or no waves of excitement being generated or other unknowns.
B. Too many neurotransmitters. While not a great deal is known about this, one of the possibilities is that the myelin sheathing is causing unnecessary amplification of brain signals, resulting in the cell sending out more than a sufficient quantity of neurotransmitters.
C. Misshapen receptors. Analysis of brain tissue in persons who had schizophrenia has shown a modestly different shape of some receptors for the neurotransmitter dopamine.
D. Misshapen transmitters. Neurotransmitters formed, for some unknown reason, slightly differently.
E. Same cell pick ups. For some reason, perhaps due to misshaped cells, or extra long Axon terminals, some cells pick up neurotransmitters that they sent out. The class of drugs, known as reuptake inhibitors, act to decrease this phenomenon.
The brain has many components. The following are the functions, as well as the most common clinical effects when each portion of the brain is not functioning as it should. Many different parts of the brain work together to produce complex behavior. There is no one center for the emotions, just as there is no one center for driving, or anything complicated. Various interactions across different brain areas are needed for complex behaviors.
CORTEX(fig. 1)
Interpreting, processing, and integrating sensory and motor functions.
Errors in processing sight, taste, touch, smell, hearing and movement can result in inappropriate responses, the inability to distinguish objects by touch, hallucinations, delusions and bizarre behavior. In-coordination and lack of control of motor aspects of muscle movement; disturbance in balance; strange eye movements.
LIMBIC AREA(fig. 2)
(Consists of portions of the frontal, parietal, and temporal lobes; sometimes referred to as the limbic system.) Collectively plays an important role in learning, memory and emotions. Co-ordinates visceral (instinctual) responses with motivational states; interprets smell; regulates emotional responses such as anger, fear, pleasure, sorrow, rage, and sexual arousal.
Excessive emotional responses to new stimuli. Increased eating and drinking of fluids. Changes in taste preferences. Inability of emotions to reach consciousness. Decreased ability of cognition to affect emotion. Unable to integrate the behavioral expression of emotion and motivation. Decreased ability of central rewards system to respond to basic drives and instincts.
FRONTAL LOBES (fig. 2)
(Part of Limbic area) Decision making, planning for future actions and control of movement.
Inappropriate or uninhibited behavior. Impulsiveness, inability to evaluate and control emotions, judgment, and conduct. Emotional impoverishment. Irritability, lack of motivation, ambition, and/or responsibility. Difficulty with all cognitive functions, especially attention, concentration, memory and follow through. Difficulty with the motor aspects of speech (words are garbled). Difficulty with written communication. Difficulty with abstract thinking.
The frontal lobes consist of the frontal, pre-frontal lobes and the ventromedial cortex. Individuals who have a propensity for spontaneous anti-social behavior (behavior without thinking before the act) have been found to have smaller, less active left pre-frontal lobes. Mental exercises, the use of imagination and meditation, have been shown to increase the size and activity of the left pre- frontal lobe, and have resulted in individuals being able to reduce anti-social behavior.
Activity in the left pre-frontal lobe is also associated with the feelings of happiness, enthusiasm, joy, and alertness. Heightened activity in the right frontal lobe is associated with an increase in what are viewed as the negative emotions.
When the ventromedial cortex is more active, activity in the amygdala is decreased. When the ventromedial cortex is damaged, unregulated emotional behavior is the typical result.
TEMPORAL LOBES(fig. 2)
(Part of limbic area) Hearing, learning, complex memory, and emotions.
Difficulty controlling sexual and aggressive drives. Memory impairment; inability to recall stored information or to have newly learned information reach long term storage in hippocampus. Difficulty with production and analysis of speech. Difficulty attaching meaning to spoken words. Difficulty recognizing own emotions. Confusion about masculinity/femininity (Not to be confused with sexual orientation). Auditory hallucinations.
PARIETAL LOBES(fig. 2)
(Part of limbic area) Receiving and identifying sensory information from tactile receptors. Ability to picture something in the mind’s eye.
Inability to recognize sensations from the skin including pain, touch, and temperature changes. Body image disturbances. Inability to recognize body parts. Impaired spatial abilities, loss of ability to visualize three dimensions. Denial of illness (Anosognosia). Difficulty dressing. Impaired left /right orientation (Gets lost easily). Impaired association and sensory aspects of speech. Inability to recognize written words. Inability to recognize relationship of body to environment. Loss of ability to evaluate muscular activity; unable to sense pain from an uncomfortable body position. Loss of memory association; unable to learn from the past; loss of ability to apply previous learning to the present and future.
OCCIPITAL LOBES (fig. 3)
All aspects of vision.
Disturbed spatial orientation; difficulty with physical and environmental boundaries. Visual illusions; visual hallucinations. Simulated hysteria. Loss of visual memory; loss of object constancy (unable to recognize objects, people, places by sight). Loss of ability to understand the meaning of written words.
HIPPOCAMPUS(fig. 3)
Receives input from the para-limbic areas; hypothalamus, amygdala, and septial regions. Involved with the endocrine system. (Thyroid, Adrenal gland, pancreas, ovaries, testis) Regulation of the immune system, and memory storage. Essential for the appreciation of the context of events.
Difficulty with behavioral arousal. Many short and long term memory problems. Inability to discriminate and inhibit behavioral responses. May generate epileptic discharges. Inability to process complex sensory information. Difficulty acquiring new learning.
AMYGDALA(fig.3)
Located in the anterior inferior temporal lobe. Interacts with the olfactory bulb, brainstem, hypothalamus, and neocortex. Implicated in sampling physical aspects of the environment. Helps coordinate the actions of the autonomic and endocrine systems and is involved in emotions, especially fear and anxiety.
Inability to attach motivational and autonomic significance to sensory stimuli. Over and/or under response to anxiety and fear. Unable to compare incoming and previously experienced stimuli. Unable to discriminate responses based on consequences of past experiences. A highly active amygdala impairs ability to turn off negative thoughts and emotions.
HYPOTHALAMUS(fig. 3)
Has an extensive connection with the thalamus, midbrain, and some cortical areas. It also appears to have a role in the control of biological rhythms and immune system regulation. Mediates emotions and fear, anger, pleasure, and contentment.
Disorders of appetite. Disorders of water balance. Difficulty responding to visceral stimuli. Disorders of sexual functioning and behavior. Disorders of pituitary hormonal secretions. Disorders of thermoregulation. Disorders of emotional expression of anger, rage, placidity, pleasure, fear, and social attraction even when survival depends on these emotions. Difficulty regulating vital functions of blood pressure due to inability to respond to water and salt content of blood. Abnormal sleep/wake cycle.
BASAL GANGLIA
Located at the base of each hemisphere, they receive input from all four lobes, but have output only to the frontal cortex via the thalamus. Major activities include the planning of movement and all cognitive functions.
Thought process disorders. Disorders of affect. Disorders of cognition. Parkinson’s disease, Huntington’s disease. Extra-pyramidal movements (involuntary movements, such as tremors, rocking, and movement of limbs) from psychotropic drugs.
THALAMUS
Monitors, processes, integrates, and distributes almost all sensory and motor information going to the cerebral cortex by connecting cerebral cortex, basal ganglia, hypothalamus, and brain stem.
Inability to regulate and integrate levels of awareness. Difficulty integrating the emotional aspects of sensory experiences. Unable to have an impression of the agreeableness (or disagreeableness) of a sensation. Hyper/hypo sensitivity to pain.
BRAIN STEM
Includes Midbrain, Pons and Medulla Oblongata. The spinal cord mediates sensations and motor control of the trunk and limbs, whereas the brain stem is concerned with sensation from skin and joints in the head, neck, face and specialized senses, such as taste, hearing, and balance. The brain stem also controls the muscles of the head and neck.
Disorders of midbrain cause problems with the direct control of eye movements as well as in the motor control of skeletal muscles and the relay of sight and hearing to the cortex. The regulations of breathing, vomiting, and hiccoughing involve the medulla as does the relay of impulses between brain and spinal cord.
RETICULAR FORMATION (RAS)
Coordinates the planning, timing, and patterning of skeletal muscles contractions during movement. Maintains equilibrium by receiving input about balance from the inner ear. Maintains posture and helps coordinate head and eye movements.
Difficulty learning motor skills. Problems regulating the force and range of movements. Disorders of balance, coordination. Difficulty walking upright.
