Podcast
Questions and Answers
What component of pain perception is affected by the integrity of the lateral pain system?
What component of pain perception is affected by the integrity of the lateral pain system?
Which area of the brain is primarily associated with the lateral pain system?
Which area of the brain is primarily associated with the lateral pain system?
What type of stimulus was used in the clinical examination of the patient?
What type of stimulus was used in the clinical examination of the patient?
What is the dual pathway for pain perception mediated by?
What is the dual pathway for pain perception mediated by?
Signup and view all the answers
Which cortical areas are mainly involved in the lateral pain system?
Which cortical areas are mainly involved in the lateral pain system?
Signup and view all the answers
What was the age of the male patient who suffered from the postcentral stroke?
What was the age of the male patient who suffered from the postcentral stroke?
Signup and view all the answers
What is the primary function of the medial pain system?
What is the primary function of the medial pain system?
Signup and view all the answers
What was the pain threshold measured for the right hand?
What was the pain threshold measured for the right hand?
Signup and view all the answers
What effect does cutaneous laser stimulation have in the study?
What effect does cutaneous laser stimulation have in the study?
Signup and view all the answers
What is a significant limitation in assessing human pain perception mentioned in the content?
What is a significant limitation in assessing human pain perception mentioned in the content?
Signup and view all the answers
At what intensity did the patient describe a 'clearly unpleasant' sensation?
At what intensity did the patient describe a 'clearly unpleasant' sensation?
Signup and view all the answers
What was the mean reaction time for right index finger lift?
What was the mean reaction time for right index finger lift?
Signup and view all the answers
What are the two components of pain perception that the study aimed to differentiate?
What are the two components of pain perception that the study aimed to differentiate?
Signup and view all the answers
What role does the lateral pain system play according to the study's findings?
What role does the lateral pain system play according to the study's findings?
Signup and view all the answers
What was the initial health status of the patient presented in the case report?
What was the initial health status of the patient presented in the case report?
Signup and view all the answers
What type of stroke did the patient experience?
What type of stroke did the patient experience?
Signup and view all the answers
What was observed in the patient's motor functions following the stroke?
What was observed in the patient's motor functions following the stroke?
Signup and view all the answers
What does the phrase 'first and second pain' refer to in the context of this study?
What does the phrase 'first and second pain' refer to in the context of this study?
Signup and view all the answers
What methodological approach was lacking evidence in humans based on the study?
What methodological approach was lacking evidence in humans based on the study?
Signup and view all the answers
What type of imaging was performed on the patient after the stroke?
What type of imaging was performed on the patient after the stroke?
Signup and view all the answers
Which area of the brain was affected by the stroke described in the case report?
Which area of the brain was affected by the stroke described in the case report?
Signup and view all the answers
What type of sensation was absent when thermal stimuli were applied to the patient?
What type of sensation was absent when thermal stimuli were applied to the patient?
Signup and view all the answers
Which testing method indicated normal sensory function in the right hand?
Which testing method indicated normal sensory function in the right hand?
Signup and view all the answers
What was the score of the left hand in sharp-dull discrimination testing?
What was the score of the left hand in sharp-dull discrimination testing?
Signup and view all the answers
Which area of the brain is crucially important for pain perception according to the content?
Which area of the brain is crucially important for pain perception according to the content?
Signup and view all the answers
What does the table suggest about the patient's ability to perform sensory tests on the left hand?
What does the table suggest about the patient's ability to perform sensory tests on the left hand?
Signup and view all the answers
What technology was used for controlled, selective thermonociceptive stimuli?
What technology was used for controlled, selective thermonociceptive stimuli?
Signup and view all the answers
What sensory test showed a normal result in the patient's right hand?
What sensory test showed a normal result in the patient's right hand?
Signup and view all the answers
What was the method used to determine pain thresholds on the dorsum of feet and hands?
What was the method used to determine pain thresholds on the dorsum of feet and hands?
Signup and view all the answers
What suggests an interaction between the medial and lateral pain system in the patient?
What suggests an interaction between the medial and lateral pain system in the patient?
Signup and view all the answers
What was the criterion for defining the pain threshold during the study?
What was the criterion for defining the pain threshold during the study?
Signup and view all the answers
Which sensory test had the highest score for the left hand?
Which sensory test had the highest score for the left hand?
Signup and view all the answers
During clinical examination, the evaluation of the patient's sensory deficits was based on which technique?
During clinical examination, the evaluation of the patient's sensory deficits was based on which technique?
Signup and view all the answers
What phenomenon was detected regarding the proprioceptively impaired left hand?
What phenomenon was detected regarding the proprioceptively impaired left hand?
Signup and view all the answers
What was the patient's score for two-point discrimination on the left hand?
What was the patient's score for two-point discrimination on the left hand?
Signup and view all the answers
Which area of the brain was indicated to have a partial lesion, as suggested by the diminished long latency potentials?
Which area of the brain was indicated to have a partial lesion, as suggested by the diminished long latency potentials?
Signup and view all the answers
What was the effect of stroke on the patient's sensory examination on the right side?
What was the effect of stroke on the patient's sensory examination on the right side?
Signup and view all the answers
The reaction times to painful laser stimuli were measured in what intervals?
The reaction times to painful laser stimuli were measured in what intervals?
Signup and view all the answers
What sensory test involves the ability to discern sharpness or dullness?
What sensory test involves the ability to discern sharpness or dullness?
Signup and view all the answers
What does graphaesthesia test assess?
What does graphaesthesia test assess?
Signup and view all the answers
What type of stimuli was used to evaluate the patient after the stroke?
What type of stimuli was used to evaluate the patient after the stroke?
Signup and view all the answers
Study Notes
Pain Affect Without Pain Sensation
- A 57-year-old male with a right-sided postcentral stroke exhibited a dissociation of pain perception components.
- The patient demonstrated a separation between discriminative (sensory) and affective aspects of pain.
- This case, for the first time in humans, showed a dependence of sensory-discriminative pain and first pain on the integrity of the lateral pain system.
Lateral and Medial Pain Systems
- Cerebral pain processing involves two systems: lateral and medial.
- The lateral system includes the lateral thalamic nuclei, SI (Primary), and SII (Secondary) somatosensory cortices.
- The medial system involves the medial thalamic nuclei and anterior cingulate cortex.
- These systems are anatomically distinct and likely function differently in pain perception.
- The medial system is more strongly associated with the motivational-affective aspects of pain.
First and Second Pain
- Pain is often experienced as two distinct sensations.
- First pain is sharp and pricking, mediated by Aδ fibers.
- Second pain is dull and persistent, mediated by C-fibers.
- The lateral pain system seems to be involved in the representation of first pain.
Key Lesion and Imaging
- The patient's lesion affected the right SI and SII cortices, particularly the hand area.
- MRI confirmed the location of the lesion.
- The location of the lesion in SI and SII supports a critical role for these areas in the sensory-discriminative aspects of pain perception for humans..
Cutaneous Laser Stimulation
- Used to elicit controlled and selective thermonociceptive stimuli.
- This technique is effective in evaluating sensory-discriminative pain components and distinguishing first pain from second pain.
- By applying stimuli at varying intensities, pain thresholds were determined and reaction times were measured.
Sensory Deficits
- The patient exhibited left-sided sensory deficits.
- These included hypaesthesia (reduced sensitivity) and anesthesia (loss of sensitivity) in the foot, leg, face, hand, and left arm.
- Thermal stimuli did not evoke any sensation, indicating a significant sensory impairment.
- Other sensory functions (touch, two-point discrimination, etc) were also impaired on the left side, but pallaesthesia was nearly normal.
Motor Deficits
- Marginal left-sided pronation impairment was noted during arm movement against gravity tests.
- This suggests that other motor functions were mostly spared by the stroke.
Clinical Examination & Testing
- The patient was comprehensively evaluated 5 and 12 days after the stroke.
- Evaluations focused on sensory functions such as light touch, pain, temperature, two-point discrimination, stereognosis.
- Various tools were used to test sensation (von Frey-hairs, test tubes, tuning forks etc.).
- Reaction times to acoustic stimuli were also determined to assess possible delays affecting other functions.
Studying That Suits You
Use AI to generate personalized quizzes and flashcards to suit your learning preferences.
Description
Explore the intricate relationship between pain perception and its components through a case study of a patient with a postcentral stroke. This quiz delves into the lateral and medial pain systems, illustrating their distinct functions in discriminative and affective pain experiences.
