STUDY - Technical - New Dacian's Medicine
Memory
loss and Dementia (1)
Translation Draft
Dementia is a serious and common problem that affects a very large number of people. 10% of people over 70 and 20 to 40% of those over 85 years of age have clinically identifiable memory loss.
Dementia is a syndrome with many causes. A simple definition of dementia is: a deterioration in cognitive ability that disturbs the performance of daily activities, previously successfully performed. Memory is the most common and important cognitive ability lost.
Other mental faculties may also be affected, such as attention, judgment, comprehension, orientation, learning ability, to calculate or solve problems, mood and behavior.
Agitation or withdrawal itself, hallucinations, delirium, insomnia or loss of inhibition are also common. People with mental retardation and psychosis can become demented if there is a decline in intellectual functions.
Many of the common forms of dementia are progressive, but some are static and invariable. Dementia is a chronic disease, while delirium is an acute confusional state, associated with a change in consciousness (ranging from lethargy to agitation).
Memory is a complex function of the brain that has fascinated philosophy and scientists for centuries. It is regarded today as a mental process that uses several storage units of different capacities and durations: 1. sensory (visual/ iconic and auditory/ "in echo") lasting up to 2 seconds, the possible brain localizations being at the level of the visual and auditory cortex, respectively, 2. immediate (primary/working) duration of up to 30 seconds, with a storage capacity greater than sensory memory, with a capacity limited to about 5 to 10 items, with probable location in the perisylvian cortex, frontal lobe, 3. (secondary/reference) with minutes/ weeks/ months, with a storage capacity greater than immediate memory, with probable location in the hippocampus, the mamilotalamic tract, the dorsomedial thalamus, 4. declarative (explicit/ episodic), without presentable details but easily associable with 5. semantics (implicit/ procedural), with probable localization in the tonsil, cerebellum, association cortex, frontal lobe and others and 6. long-term (reference) duration of months, years, with probable localization at the level of the association cortex and its network elements.
Immediate memory is extremely vulnerable to distraction, requiring attention and alertness to retain. She is frequently tested at the patient's bedroom asking her to remember a few figures, in increasing order and then decreasing. Recent or secondary memory has been called "short-term" as well as "long-term".
By entering a memory unit, the information undergoes a variable duration consolidation process. Secondary memory is usually tested in the clinic asking the patient to recall three words after the passage of 3 to 5 minutes.
Remote memory (declarative and semantic), or long-lasting, stores information over a period of weeks until the end of life and contains most of personal knowledge and experiences. Some information appears to be stored correctly for an indefinite time, while others fade or are distorted.
Memory functions are: recording (coding or acquisition), retention (storing or consolidating), establishing and recovering (decoding or remembering). Recording and remembrance are conscious processes. Animal experiences have shown that long-term memory requires the synthesis of new proteins, and the stabilization process probably involves physical changes in neural synapses.
Several additional memory classifications are sometimes used in psychology, especially as a reference to the content or usefulness of stored information. Relationship memory refers to an archiving system that contains recent and older information obtained from previous experiences. Work memory refers to an active process that is continuously renewed through current experience. Episodic memory contains information about events that occurred in specific times and places. Semantic memory contains facts, associations, principles and invariable data (e.g. state capitals and the number of days in a week). Declarative (explicit) memory refers to data in relation to the world and personal events of the past, which must be consciously recovered in order to be evoked. Procedural (implicit) memory, on the other hand, is involved in learning and retaining a skill or procedure, such as riding a bicycle, dressing or driving. Skills stored in the procedural memory become automatisms and do not require conscious recovery.
Finally, the term "executive function" refers to the mental activities involved in planning, initiation and adaptation behaviors. It is considered the central organizational function of the brain that determines the systematic activity, performed with a purpose. Executive functions are active in unusual situations where automatic or reflex behavior is not appropriate. It is assumed that the anatomical and physiological substrates of executive function are located in the frontal lobes. Executive function deficits occur frequently in dementia patients.
Now we can move on to functional and pathogenic anatomy. Dementia occurs through disturbance of the brain neural circuits and is the result of the combination of the total number of neurons affected and their specific location.
The anatomical basis of memory was initially clarified by studying Korsakoff syndrome of thamine/alcohol deficiency and the consequences of temporal lobe surgery to treat epilepsy.
Injuries in Korsakoff syndrome, located in the mammalian bodies, dorsomedial talamic shards and hypothalamus, have demonstrated the importance of these areas in learning, evocation and recognition. Unilateral surgery on the temporal lobe, in epilepsy, produces mild to moderate amnesia for both verbal and nonverbal information. Bilateral excision of the medial temporal lobe, comprising the hippocampal formation, parahypocampic gyrus and part of the tonsil, produces a severe anterograde disorder of learning, i.e. an inability to store new information, frequently accompanied by a preservation of the ability to recall the old ones.
Components of the medial temporal lobe memory system are the hippocampus and the surrounding cortex, including the entorial, peririne and parahippocampal regions. This system includes a circular neural circuit from the entorinal cortex into the dentate gyrus (CA3 and CA1 neurons of the hippocampus to the subiculum and back into the entorinal cortex), severely altered circuit in Alzheimer's disease (BA).
This system is fast, with limited capacity and performs an essential function when learning and organizing declarative memory. Its role continues after learning, over a long period of reorganization and consolidation through which the memory stored in the neocortex eventually becomes independent of the memory system of the medial temporal lobe.
This process, by which the charge of storing long-lasting (permanent) memory is gradually taken over by the neocortex, always leaves the medial temporal lobe system available for the purchase of new information. Recent functional brain imaging studies have shown that memory and learning involve many of the cortex regions that process sensory information and control motor stimuli.
The forms of perceptual and motor learning that can occur without conscious memories are mediated in part by the contraction and expansion of representations in the motor and sensory cortex. For example, a study has shown that the cortical representation of the fingers of the left hand of stringed instrument interpreters is higher than in the control group, suggesting that representations of different parts of the body in the primary human somatosensory cortex depend on their use and the changes you have placed to meet the current needs of the individual's experience.
There are discrete cortical regions where information about the object (such as words that designate colors, animals, tools or action) is organized as a distributive system in which the characteristics of an object are located near the cortical regions that mediate the perception of those attributes. Thus, the cortical areas active during the identification of the object are dependent, in part, on the intrinsic properties of the object. procedural memory (default) seems to involve centers outside the hippocampus, such as the amygdala, cerebellum and sensory cortex.
From a biochemical point of view, the cholinergic system plays an important role in memorization. Anticholinergic agents, such as atropine or scopolamine, interfere with memory functions. It is known that acetylcholine-transferase (the enzyme that catalyzes the formation of acetylcholine) and nicotinic cholinergic receptors are deficient in the context of patients with BA.
The brains of BA patients show severe neuronal loss in the basal nucleus of Meynert, a major source of cholinergic stimuli to the cortex. These data are the basis for the use of thacryon (a cholinesterase inhibitor) in the treatment of BA, the modest benefit being probably achieved by the increase in the level of ed acetylcholine available. Behaviour and mood are modulated by noradergic, serotonin and dopaminergic pathways and it has been found that norepinephrine levels are low in the locus coeruleus in the brain stem of PATIENTS with BA. It is postulated that neutrophins also play a role in memorization, in part through the preservation of cholinergic neurons.
Most diseases that cause dementia do not have very limited regions of anatomology. Diseases like BA appear to be a reflection of relatively diffuse neural damage in the cerebral cortex, while dementia after multiple infarctions associated with recurrent strokes produces several focused lesions, spread erratically in the cerebral cortex. Diffuse white matter damage can interrupt intracerebral connections and cause dementia syndromes, such as those associated with leukodystrophy, multiple sclerosis and Binswanger's disease.
Also, subcortical structures, such as the caudate nucleus, putamen, thalamus and black substance modulate cognitive functions and behavior through mechanisms that are not yet known. Some researchers distinguish between types of cortical and subcortical dementia. Cortical dementia, such as BA or Pick's disease, is mainly present as memory loss and is commonly associated with aphasia or language disorders.
Patients with subcortical dementia, such as Huntington's disease (BH), are less likely to have memory and language problems and more likely attention, judgment and behavioural difficulties. Both the anatomical and clinical characteristics of cortical and subcortical dementias largely overlap, these two types being difficult to differentiate.
Thank you, and tomorrow is a day...
Dementia is a serious and common problem that affects a very large number of people. 10% of people over 70 and 20 to 40% of those over 85 years of age have clinically identifiable memory loss.
Dementia is a syndrome with many causes. A simple definition of dementia is: a deterioration in cognitive ability that disturbs the performance of daily activities, previously successfully performed. Memory is the most common and important cognitive ability lost.
Other mental faculties may also be affected, such as attention, judgment, comprehension, orientation, learning ability, to calculate or solve problems, mood and behavior.
Agitation or withdrawal itself, hallucinations, delirium, insomnia or loss of inhibition are also common. People with mental retardation and psychosis can become demented if there is a decline in intellectual functions.
Many of the common forms of dementia are progressive, but some are static and invariable. Dementia is a chronic disease, while delirium is an acute confusional state, associated with a change in consciousness (ranging from lethargy to agitation).
Memory is a complex function of the brain that has fascinated philosophy and scientists for centuries. It is regarded today as a mental process that uses several storage units of different capacities and durations: 1. sensory (visual/ iconic and auditory/ "in echo") lasting up to 2 seconds, the possible brain localizations being at the level of the visual and auditory cortex, respectively, 2. immediate (primary/working) duration of up to 30 seconds, with a storage capacity greater than sensory memory, with a capacity limited to about 5 to 10 items, with probable location in the perisylvian cortex, frontal lobe, 3. (secondary/reference) with minutes/ weeks/ months, with a storage capacity greater than immediate memory, with probable location in the hippocampus, the mamilotalamic tract, the dorsomedial thalamus, 4. declarative (explicit/ episodic), without presentable details but easily associable with 5. semantics (implicit/ procedural), with probable localization in the tonsil, cerebellum, association cortex, frontal lobe and others and 6. long-term (reference) duration of months, years, with probable localization at the level of the association cortex and its network elements.
Immediate memory is extremely vulnerable to distraction, requiring attention and alertness to retain. She is frequently tested at the patient's bedroom asking her to remember a few figures, in increasing order and then decreasing. Recent or secondary memory has been called "short-term" as well as "long-term".
By entering a memory unit, the information undergoes a variable duration consolidation process. Secondary memory is usually tested in the clinic asking the patient to recall three words after the passage of 3 to 5 minutes.
Remote memory (declarative and semantic), or long-lasting, stores information over a period of weeks until the end of life and contains most of personal knowledge and experiences. Some information appears to be stored correctly for an indefinite time, while others fade or are distorted.
Memory functions are: recording (coding or acquisition), retention (storing or consolidating), establishing and recovering (decoding or remembering). Recording and remembrance are conscious processes. Animal experiences have shown that long-term memory requires the synthesis of new proteins, and the stabilization process probably involves physical changes in neural synapses.
Several additional memory classifications are sometimes used in psychology, especially as a reference to the content or usefulness of stored information. Relationship memory refers to an archiving system that contains recent and older information obtained from previous experiences. Work memory refers to an active process that is continuously renewed through current experience. Episodic memory contains information about events that occurred in specific times and places. Semantic memory contains facts, associations, principles and invariable data (e.g. state capitals and the number of days in a week). Declarative (explicit) memory refers to data in relation to the world and personal events of the past, which must be consciously recovered in order to be evoked. Procedural (implicit) memory, on the other hand, is involved in learning and retaining a skill or procedure, such as riding a bicycle, dressing or driving. Skills stored in the procedural memory become automatisms and do not require conscious recovery.
Finally, the term "executive function" refers to the mental activities involved in planning, initiation and adaptation behaviors. It is considered the central organizational function of the brain that determines the systematic activity, performed with a purpose. Executive functions are active in unusual situations where automatic or reflex behavior is not appropriate. It is assumed that the anatomical and physiological substrates of executive function are located in the frontal lobes. Executive function deficits occur frequently in dementia patients.
Now we can move on to functional and pathogenic anatomy. Dementia occurs through disturbance of the brain neural circuits and is the result of the combination of the total number of neurons affected and their specific location.
The anatomical basis of memory was initially clarified by studying Korsakoff syndrome of thamine/alcohol deficiency and the consequences of temporal lobe surgery to treat epilepsy.
Injuries in Korsakoff syndrome, located in the mammalian bodies, dorsomedial talamic shards and hypothalamus, have demonstrated the importance of these areas in learning, evocation and recognition. Unilateral surgery on the temporal lobe, in epilepsy, produces mild to moderate amnesia for both verbal and nonverbal information. Bilateral excision of the medial temporal lobe, comprising the hippocampal formation, parahypocampic gyrus and part of the tonsil, produces a severe anterograde disorder of learning, i.e. an inability to store new information, frequently accompanied by a preservation of the ability to recall the old ones.
Components of the medial temporal lobe memory system are the hippocampus and the surrounding cortex, including the entorial, peririne and parahippocampal regions. This system includes a circular neural circuit from the entorinal cortex into the dentate gyrus (CA3 and CA1 neurons of the hippocampus to the subiculum and back into the entorinal cortex), severely altered circuit in Alzheimer's disease (BA).
This system is fast, with limited capacity and performs an essential function when learning and organizing declarative memory. Its role continues after learning, over a long period of reorganization and consolidation through which the memory stored in the neocortex eventually becomes independent of the memory system of the medial temporal lobe.
This process, by which the charge of storing long-lasting (permanent) memory is gradually taken over by the neocortex, always leaves the medial temporal lobe system available for the purchase of new information. Recent functional brain imaging studies have shown that memory and learning involve many of the cortex regions that process sensory information and control motor stimuli.
The forms of perceptual and motor learning that can occur without conscious memories are mediated in part by the contraction and expansion of representations in the motor and sensory cortex. For example, a study has shown that the cortical representation of the fingers of the left hand of stringed instrument interpreters is higher than in the control group, suggesting that representations of different parts of the body in the primary human somatosensory cortex depend on their use and the changes you have placed to meet the current needs of the individual's experience.
There are discrete cortical regions where information about the object (such as words that designate colors, animals, tools or action) is organized as a distributive system in which the characteristics of an object are located near the cortical regions that mediate the perception of those attributes. Thus, the cortical areas active during the identification of the object are dependent, in part, on the intrinsic properties of the object. procedural memory (default) seems to involve centers outside the hippocampus, such as the amygdala, cerebellum and sensory cortex.
From a biochemical point of view, the cholinergic system plays an important role in memorization. Anticholinergic agents, such as atropine or scopolamine, interfere with memory functions. It is known that acetylcholine-transferase (the enzyme that catalyzes the formation of acetylcholine) and nicotinic cholinergic receptors are deficient in the context of patients with BA.
The brains of BA patients show severe neuronal loss in the basal nucleus of Meynert, a major source of cholinergic stimuli to the cortex. These data are the basis for the use of thacryon (a cholinesterase inhibitor) in the treatment of BA, the modest benefit being probably achieved by the increase in the level of ed acetylcholine available. Behaviour and mood are modulated by noradergic, serotonin and dopaminergic pathways and it has been found that norepinephrine levels are low in the locus coeruleus in the brain stem of PATIENTS with BA. It is postulated that neutrophins also play a role in memorization, in part through the preservation of cholinergic neurons.
Most diseases that cause dementia do not have very limited regions of anatomology. Diseases like BA appear to be a reflection of relatively diffuse neural damage in the cerebral cortex, while dementia after multiple infarctions associated with recurrent strokes produces several focused lesions, spread erratically in the cerebral cortex. Diffuse white matter damage can interrupt intracerebral connections and cause dementia syndromes, such as those associated with leukodystrophy, multiple sclerosis and Binswanger's disease.
Also, subcortical structures, such as the caudate nucleus, putamen, thalamus and black substance modulate cognitive functions and behavior through mechanisms that are not yet known. Some researchers distinguish between types of cortical and subcortical dementia. Cortical dementia, such as BA or Pick's disease, is mainly present as memory loss and is commonly associated with aphasia or language disorders.
Patients with subcortical dementia, such as Huntington's disease (BH), are less likely to have memory and language problems and more likely attention, judgment and behavioural difficulties. Both the anatomical and clinical characteristics of cortical and subcortical dementias largely overlap, these two types being difficult to differentiate.
Thank you, and tomorrow is a day...
All the best and health in
all!
Dorin, Merticaru