Podcast
Questions and Answers
What type of neurons in SI are primarily responsible for encoding stimulus intensity related to pain?
What type of neurons in SI are primarily responsible for encoding stimulus intensity related to pain?
- Nociceptive neurons (correct)
- Somatosensory neurons
- Motoneurons
- Interneurons
What aspect of pain perception is suggested to be reflected by nociceptive neurons in SII?
What aspect of pain perception is suggested to be reflected by nociceptive neurons in SII?
- Direct pain sensitivity
- Attention and learning related to pain-evoking stimuli (correct)
- Somatotopic organization of pain
- Emotional response to pain
What phenomenon was observed regarding reaction times to painful stimuli on the left side?
What phenomenon was observed regarding reaction times to painful stimuli on the left side?
- Loss of short-latency responses (correct)
- Increased short-latency responses
- Bimodal distribution of reaction times
- Immediate detection of first pain
In the context of pain localization, what does the study of Campbell and LaMotte primarily focus on?
In the context of pain localization, what does the study of Campbell and LaMotte primarily focus on?
What does the term 'somatotopically organized' imply about nociceptive neurons in monkeys?
What does the term 'somatotopically organized' imply about nociceptive neurons in monkeys?
What is the main finding regarding pain perception in the patient with a postcentral stroke?
What is the main finding regarding pain perception in the patient with a postcentral stroke?
Which part of the brain is responsible for the lateral pain system?
Which part of the brain is responsible for the lateral pain system?
What is the role of Ad-fibers in pain perception according to the content?
What is the role of Ad-fibers in pain perception according to the content?
What evidence was presented for the lateral pain system's involvement in pain sensation?
What evidence was presented for the lateral pain system's involvement in pain sensation?
Which components are suggested to diverge at the thalamic level in pain processing?
Which components are suggested to diverge at the thalamic level in pain processing?
In the context of the study, what does the medial pain system primarily consist of?
In the context of the study, what does the medial pain system primarily consist of?
What physiological aspect does the study highlight about the lateral pain system?
What physiological aspect does the study highlight about the lateral pain system?
What does the integrity of peripheral somatosensory pathways suggest about the median nerve?
What does the integrity of peripheral somatosensory pathways suggest about the median nerve?
What was the wavelength of the laser used in the stimulation?
What was the wavelength of the laser used in the stimulation?
During the evaluation, how was the pain threshold determined?
During the evaluation, how was the pain threshold determined?
How were the reaction times measured during the painful laser stimuli application?
How were the reaction times measured during the painful laser stimuli application?
What sensory examination results indicated damage on the left side in the patient?
What sensory examination results indicated damage on the left side in the patient?
What did the term 'thermaesthesia' refer to in the clinical examination?
What did the term 'thermaesthesia' refer to in the clinical examination?
What was the intended outcome of the patient lifting the index finger during testing?
What was the intended outcome of the patient lifting the index finger during testing?
How often were the interstimulus intervals varied during the reaction time measurement?
How often were the interstimulus intervals varied during the reaction time measurement?
What was the pain threshold for the right hand as mentioned in the study?
What was the pain threshold for the right hand as mentioned in the study?
What limitations were present in prior clinical examinations of pain perception?
What limitations were present in prior clinical examinations of pain perception?
What term describes the painful sensations experienced by patients in the study?
What term describes the painful sensations experienced by patients in the study?
At what intensity did patients begin to describe a 'clearly unpleasant' feeling?
At what intensity did patients begin to describe a 'clearly unpleasant' feeling?
Which area of the brain was indicated to be involved in pain processing according to functional imaging studies?
Which area of the brain was indicated to be involved in pain processing according to functional imaging studies?
What was the mean reaction time for the right index finger lift in the study?
What was the mean reaction time for the right index finger lift in the study?
What type of stimulation method was used in the study to selectively activate pain afferents?
What type of stimulation method was used in the study to selectively activate pain afferents?
What was a noted effect of increased pain associated with functional imaging studies?
What was a noted effect of increased pain associated with functional imaging studies?
What critical factor interfered with understanding the concept of pain structures in humans?
What critical factor interfered with understanding the concept of pain structures in humans?
What was the maximum intensity at which no pain sensation could be elicited in the left hand?
What was the maximum intensity at which no pain sensation could be elicited in the left hand?
What sensory response was notably absent in the tested left hand?
What sensory response was notably absent in the tested left hand?
Which type of discrimination was significantly affected in the left hand during sensory testing?
Which type of discrimination was significantly affected in the left hand during sensory testing?
What conclusion can be drawn regarding painful stimuli detection in relation to SI and SII integrity?
What conclusion can be drawn regarding painful stimuli detection in relation to SI and SII integrity?
Which sensory testing result was normal for the right hand?
Which sensory testing result was normal for the right hand?
What does the presence of hypalgesia in the patient suggest?
What does the presence of hypalgesia in the patient suggest?
What was the result of motor testing for the sensory impaired left hand?
What was the result of motor testing for the sensory impaired left hand?
Which part of the brain is suggested to be crucial for pain perception according to previous lesion studies?
Which part of the brain is suggested to be crucial for pain perception according to previous lesion studies?
What type of stimuli evoked a normal response in the tests for the right hand?
What type of stimuli evoked a normal response in the tests for the right hand?
Which stimulus did the sensory impaired left hand show no reaction to?
Which stimulus did the sensory impaired left hand show no reaction to?
In the testing, which of the following sensory modalities had a perfect score in the right hand?
In the testing, which of the following sensory modalities had a perfect score in the right hand?
Flashcards
Pain perception dissociation
Pain perception dissociation
The ability to feel pain without being able to discriminate its location or intensity.
Lateral pain system
Lateral pain system
A pathway in the brain that is involved in processing the discriminative aspects of pain.
Medial pain system
Medial pain system
A brain pathway for emotional aspects of pain, such as unpleasantness.
First pain
First pain
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Second pain
Second pain
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Postcentral stroke
Postcentral stroke
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Pain affect without pain sensation
Pain affect without pain sensation
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What is a Tm:YAG laser used for?
What is a Tm:YAG laser used for?
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What is a thermonociceptive stimulus?
What is a thermonociceptive stimulus?
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What is a von Frey-hair stimulus?
What is a von Frey-hair stimulus?
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What does 'pallaesthesia' mean?
What does 'pallaesthesia' mean?
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What is graphaesthesia?
What is graphaesthesia?
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What is stereognosia?
What is stereognosia?
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What is two-point discrimination?
What is two-point discrimination?
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What is a somatosensory evoked potential?
What is a somatosensory evoked potential?
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What is the function of the parietal operculum?
What is the function of the parietal operculum?
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Proprioception
Proprioception
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Pallaesthesia
Pallaesthesia
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Hypoaesthesia
Hypoaesthesia
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Anaesthesia
Anaesthesia
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Two-point discrimination
Two-point discrimination
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Sharp-dull discrimination
Sharp-dull discrimination
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Graphaesthesia
Graphaesthesia
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Stereognosia
Stereognosia
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Motor reaction
Motor reaction
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Central sulcus
Central sulcus
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Sensory-discriminative pain
Sensory-discriminative pain
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Somatotopic organization
Somatotopic organization
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SI and SII
SI and SII
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Nociceptive neurons
Nociceptive neurons
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Bimodal distribution
Bimodal distribution
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Thermonociceptive stimulus
Thermonociceptive stimulus
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SI and SII involvement in pain
SI and SII involvement in pain
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What is the limitation of using non-selective pain stimuli?
What is the limitation of using non-selective pain stimuli?
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Laser stimulation for studying pain
Laser stimulation for studying pain
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Pain threshold
Pain threshold
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Why are reaction times important in pain studies?
Why are reaction times important in pain studies?
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What is the impact of lesion extent on pain perception?
What is the impact of lesion extent on pain perception?
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Influence of clinical presentation on pain research
Influence of clinical presentation on pain research
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Why is it important to study pain perception?
Why is it important to study pain perception?
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Study Notes
Pain Affect Without Pain Sensation
- A 57-year-old male patient with a right-sided postcentral stroke exhibited a dissociation between pain perception's discriminative and affective components.
- The study demonstrated a dependence of sensory-discriminative pain and initial pain sensations on the integrity of the lateral pain system. This is the first such demonstration in humans.
Introduction
- The brain's pain processing involves a lateral and medial pain system.
- The lateral system includes the lateral thalamus, primary and secondary somatosensory cortices.
- The medial system includes the medial thalamus and anterior cingulate cortex.
- The lateral system is associated with sensory-discriminative aspects of pain.
- The medial system is associated with emotional/motivational aspects.
- Evidence from prior research in monkeys supports the association between the lateral system and sensory-discriminative pain. However, human lesion studies haven't definitively confirmed this.
Case Report
- The patient experienced a cardioembolic stroke affecting the right postcentral gyrus and parietal operculum (including the hand area of SI and SII).
- The MRI confirmed the lesion location.
- The patient showed sensory deficits on the left side, but preserved sensory function on the right. A notable absence of pain sensation despite preserved pain affect in the patient was observed.
- Thermonociceptive stimuli (laser) were used to assess and quantify pain perception. Pain thresholds were considerably higher in the affected (left) arm.
- Stimulation of the right hand (unaffected) showed a bimodal distribution of reaction times, whereas the left (affected) hand exhibited prolonged latency responses.
Discussion
- The observed dissociation between pain sensation and pain affect indicates the separate role of the lateral pain system and SI/SII in pain perception. Sensory-discriminative elements of pain are directly related to the integrity of SI and/or SII.
- Pain affect and the ability to detect painful stimuli do not require these structures.
- Cutaneous laser stimulation was a critical component in the study, as it selectively activated thermonociceptors, and thereby separated pain pathways from other sensory signals. Previous studies used nonspecific stimuli, thus potentially masking the specific functions of different pain pathways.
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Description
Explore the complex interplay between the sensory-discriminative and affective components of pain perception. This quiz delves into the lateral and medial pain systems and their roles in processing pain, particularly in relation to a case study of a stroke patient. Gain insights into how brain regions contribute to different aspects of pain experiences.
