Monday, April 28, 2008
blocking the sympathetic system - treatment for social phobia
The connection between psyche and sympathetic nervous system
Timo Telaranta M.D., Ph.D. and Paivi Pohjavaara M.D., Privatix Clinic, Tampere, Finland
In the central nervous system the arousal requires the brain stem, the thalamus and the cortex, attention is maintained in the right frontal lobe; the formation of memories happens in the medial temporal lobe, certain diencephalic nuclei and the basal forebrain. The amygdala rates the emotions of an experience. The limbic system is the centre of the human drives, their regulation requires an intact frontal cortex. The injury in the frontal lobe impairs the executive functions as motivation and attention. The sympathomedullary system and locus coerulaeus are activated in depression, mania, panic disorder and acute phases of schizophrenia. The autonomic nervous system is one of the most important mediators between the mind and the body. It has two roles in this function: the role in basic metabolic function as in energy storage and release, in the control of exocrine secretion and thus intake, in conservation, loss, and transformation of energy the role in behaviour, where the hypothalamus is involved in alert and defense reactions.
The sympathetic system is defined as an energy consumption system and the parasympathetic system is an energy conserving and balancing force. The sympathomedullary system is activated in various mental disorders. The biopsychosocial model is clearly seen in the social phobia. The "fight or flight " response of the sympathetic system can also be seen in the physical signs of the social phobia when the patient is in the centre of attention. With sympathetic overload the patient starts to fear the triggering situations and avoid them. The need-adaptive approach adjusts treatment plans of socially phobic patients who haven't had any help of medication and psychotherapy. It seems possible to treat their symptoms and cut the vicious circle of social phobia blocking the sympathetic system in the upper thoracic level with a surgical procedure. If a patient with the social phobia hasn't had any help of conventional treatment methods such as medication and psychotherapy, the sympathetic block could be a treatment of choice for them
Timo Telaranta M.D., Ph.D. and Paivi Pohjavaara M.D., Privatix Clinic, Tampere, Finland
In the central nervous system the arousal requires the brain stem, the thalamus and the cortex, attention is maintained in the right frontal lobe; the formation of memories happens in the medial temporal lobe, certain diencephalic nuclei and the basal forebrain. The amygdala rates the emotions of an experience. The limbic system is the centre of the human drives, their regulation requires an intact frontal cortex. The injury in the frontal lobe impairs the executive functions as motivation and attention. The sympathomedullary system and locus coerulaeus are activated in depression, mania, panic disorder and acute phases of schizophrenia. The autonomic nervous system is one of the most important mediators between the mind and the body. It has two roles in this function: the role in basic metabolic function as in energy storage and release, in the control of exocrine secretion and thus intake, in conservation, loss, and transformation of energy the role in behaviour, where the hypothalamus is involved in alert and defense reactions.
The sympathetic system is defined as an energy consumption system and the parasympathetic system is an energy conserving and balancing force. The sympathomedullary system is activated in various mental disorders. The biopsychosocial model is clearly seen in the social phobia. The "fight or flight " response of the sympathetic system can also be seen in the physical signs of the social phobia when the patient is in the centre of attention. With sympathetic overload the patient starts to fear the triggering situations and avoid them. The need-adaptive approach adjusts treatment plans of socially phobic patients who haven't had any help of medication and psychotherapy. It seems possible to treat their symptoms and cut the vicious circle of social phobia blocking the sympathetic system in the upper thoracic level with a surgical procedure. If a patient with the social phobia hasn't had any help of conventional treatment methods such as medication and psychotherapy, the sympathetic block could be a treatment of choice for them
Psychosurgery
In the early 20th century, a medical treatment for mental illness, first developed by Portuguese neurologist Egas Moniz, involved damaging the pathways connecting the frontal lobe to the limbic system. Frontal lobotomy (sometimes called frontal leucotomy) successfully reduced distress but at the cost of often blunting the subject's emotions, volition and personality. The indiscriminate use of this psychosurgical procedure, combined with the severe side effects and dangerous nature of the operation gained it a bad reputation and the frontal lobotomy has largely died out as a psychiatric treatment.
More precise psychosurgical procedures are still occasionally used, although are now very rare occurrences. They may include procedures such as the anterior capsulotomy (bilateral thermal lesions of the anterior limbs of the internal capsule) or the bilateral cingulotomy.
More precise psychosurgical procedures are still occasionally used, although are now very rare occurrences. They may include procedures such as the anterior capsulotomy (bilateral thermal lesions of the anterior limbs of the internal capsule) or the bilateral cingulotomy.
Poor regulation of dopamine pathways has been associated with schizophrenia
A report from the National Institute of Mental Health says a gene variant that reduces dopamine activity in the prefrontal cortex is related to poorer performance and inefficient functioning of that brain region during working memory tasks, and to slightly increased risk for schizophrenia.
Dopamine-sensitive neurons in the cerebral cortex are found primarily in the frontal lobes. The dopamine system is associated with pleasure, long-term memory, planning and drive. Dopamine tends to limit and select sensory information arriving from the thalamus to the fore-brain. Poor regulation of dopamine pathways has been associated with schizophrenia.
The so-called executive functions of the frontal lobes involve the ability to recognize future consequences resulting from current actions, to choose between good and bad actions (or better and best), override and suppress unacceptable social responses, and determine similarities and differences between things or events.
The frontal lobes also play an important part in retaining longer term memories which are not task-based. These are often memories with associated emotions, derived from input from the brain's limbic system, and modified by the higher frontal lobe centers to generally fit socially acceptable norms (see executive functions above). The frontal lobes have rich neuronal input from both the alert centers in the brain-stem, and from the limbic regions.
Dopamine-sensitive neurons in the cerebral cortex are found primarily in the frontal lobes. The dopamine system is associated with pleasure, long-term memory, planning and drive. Dopamine tends to limit and select sensory information arriving from the thalamus to the fore-brain. Poor regulation of dopamine pathways has been associated with schizophrenia.
The so-called executive functions of the frontal lobes involve the ability to recognize future consequences resulting from current actions, to choose between good and bad actions (or better and best), override and suppress unacceptable social responses, and determine similarities and differences between things or events.
The frontal lobes also play an important part in retaining longer term memories which are not task-based. These are often memories with associated emotions, derived from input from the brain's limbic system, and modified by the higher frontal lobe centers to generally fit socially acceptable norms (see executive functions above). The frontal lobes have rich neuronal input from both the alert centers in the brain-stem, and from the limbic regions.
Orthostatic Intolerance
The normal response for a change in body position, results in a stabilization to the upright position in approximately sixty seconds. During this process, the normal change in heart rate would include an increase in heart rate of 10 to 15 beats per minute, and an increase in diastolic pressure of 10 mm Hg, with only a slight change in systolic pressure.
For those who are afflicted with Orthostatic Intolerance, there is an excessive increase in heart rate upon standing, resulting in the cardiovascular system working harder to maintain blood pressure and blood flow to the brain.
Upright posture also brings about a neurohumoral response, involving a change in the levels of vasopressin, renin, angiotensin and aldosterone levels - all of which are involved in the regulation of blood pressure.
Additionally, arterial baroreceptors, particularly those in the carotid sinus area, play an important role in the regulation of blood pressure and the response to positional changes. As the heart pumps blood to the body, the left atrium is passively filled with blood as a result of the force exerted by venous blood pressure. The baroreceptors in the left atrium respond, proportionately, to the pressure exerted by this venous blood pressure. Thus, a drop in venous blood pressure will trigger a compensatory response to increase blood pressure.
Any disruption in any of these processes, or their coordination, can result in an inappropriate response to an upright position, and can lead to a series of symptoms.
The symptoms for these conditions may include the following:
Excessive Fatigue
Exercise Intolerance
Recurrent Syncope or Near Syncope
Dizziness
Nausea
Tachycardia
Palpitations
Visual Disturbances
Tremulusness
Weakness - most noticeable in the legs
Chest Discomfort
Shortness of Breath
Mood Swings
Migraines and Other Headaches
Gastrointestinal Problems
National Dysautonomia Research Foundation
http://ndrf.org/orthostat.htm
For those who are afflicted with Orthostatic Intolerance, there is an excessive increase in heart rate upon standing, resulting in the cardiovascular system working harder to maintain blood pressure and blood flow to the brain.
Upright posture also brings about a neurohumoral response, involving a change in the levels of vasopressin, renin, angiotensin and aldosterone levels - all of which are involved in the regulation of blood pressure.
Additionally, arterial baroreceptors, particularly those in the carotid sinus area, play an important role in the regulation of blood pressure and the response to positional changes. As the heart pumps blood to the body, the left atrium is passively filled with blood as a result of the force exerted by venous blood pressure. The baroreceptors in the left atrium respond, proportionately, to the pressure exerted by this venous blood pressure. Thus, a drop in venous blood pressure will trigger a compensatory response to increase blood pressure.
Any disruption in any of these processes, or their coordination, can result in an inappropriate response to an upright position, and can lead to a series of symptoms.
The symptoms for these conditions may include the following:
Excessive Fatigue
Exercise Intolerance
Recurrent Syncope or Near Syncope
Dizziness
Nausea
Tachycardia
Palpitations
Visual Disturbances
Tremulusness
Weakness - most noticeable in the legs
Chest Discomfort
Shortness of Breath
Mood Swings
Migraines and Other Headaches
Gastrointestinal Problems
National Dysautonomia Research Foundation
http://ndrf.org/orthostat.htm
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