Cortical Reorganization in Primary Somatosensory Cortex in Patients With Unilateral Chronic Pain

2009 ◽  
Vol 10 (8) ◽  
pp. 854-859 ◽  
Author(s):  
Nuutti Vartiainen ◽  
Erika Kirveskari ◽  
Katariina Kallio-Laine ◽  
Eija Kalso ◽  
Nina Forss
Keyword(s):  
Chronic Pain ◽  
Somatosensory Cortex ◽  
Cortical Reorganization ◽  
Primary Somatosensory Cortex

In vivo two-photon calcium imaging of neuronal activities in primary somatosensory cortex in inflammatory chronic pain

2009 ◽  
Vol 65 ◽  
pp. S179
Author(s):  
Kei Eto ◽  
Hiroaki Wake ◽  
Hitoshi Ishibashi ◽  
Mami Noda ◽  
Junichi Nabekura
Keyword(s):  
Chronic Pain ◽  
Somatosensory Cortex ◽  
Calcium Imaging ◽  
Primary Somatosensory Cortex ◽  
Two Photon

Changes in Intrinsic Properties of Pyramidal Neurons in Adult Rat S1 During Cortical Reorganization

2005 ◽  
Vol 94 (1) ◽  
pp. 501-511 ◽  
Author(s):  
Peter W. Hickmott
Keyword(s):  
Somatosensory Cortex ◽  
Pyramidal Neurons ◽  
Cortical Reorganization ◽  
Primary Somatosensory Cortex ◽  
Membrane Properties ◽  
Intrinsic Properties ◽  
Adult Rat ◽  
Layer 2 ◽  
Cortical Circuit

Peripheral denervation causes significant changes in the organization of developing or adult primary somatosensory cortex (S1). However, the basic mechanisms that underlie reorganization are not well understood. Most attention has been focused on possible synaptic mechanisms associated with reorganization. However, another important determinant of cortical circuit function is the intrinsic membrane properties of neurons in the circuit. Here we document changes in the intrinsic properties of pyramidal neurons in cortical layer 2/3 in adult rat primary somatosensory cortex (S1) after varying durations of forepaw denervation. Denervation of the forepaw induced a rapid and sustained shift in the location of the border between the forepaw and lower jaw representations of adult S1 (reorganization). Coronal slices from the reorganized region were maintained in vitro and the intrinsic properties of layer 2/3 pyramidal neurons of S1 were determined using whole cell recordings. In general, passive membrane properties were not affected by denervation; however, a variety of active properties were. The most robust changes were increases in the amplitudes of the fast and medium afterhyperpolarization (AHP) and an increase in the interval between action potentials (APs). Additional changes at some durations of denervation were observed for the AP threshold. These observations indicate that changes in intrinsic properties, mostly reflecting a decrease in overall excitation, may play a role in changes in cortical circuit properties during reorganization in adult S1, and suggest a possible role for AHPs in some of those changes.

Cortical Motor Activation Patterns Following Hand Transplantation and Replantation

2005 ◽  
Vol 30 (5) ◽  
pp. 530-533 ◽  
Author(s):  
C. BRENNEIS ◽  
W. N. LÖSCHER ◽  
K. E. EGGER ◽  
T. BENKE ◽  
M. SCHOCKE ◽  
...  
Keyword(s):  
Motor Cortex ◽  
Somatosensory Cortex ◽  
Cortical Reorganization ◽  
Cortical Activation ◽  
Primary Somatosensory Cortex ◽  
Activation Pattern ◽  
Hand Transplantation ◽  
Activation Patterns ◽  
Hand Replantation

We studied cortical activation patterns by functional MRI in a patient who received bilateral hand transplantation after amputation 6 years ago and in a patient who had received unilateral hand replantation within 2 hours after amputation. In the early postoperative period, the patient who had had the hand transplantation revealed strong activation of a higher motor area, only weak activation of the primary sensorimotor motor cortex and no activation of the primary somatosensory cortex. At 1-year follow-up, a small increase in primary sensorimotor motor cortex activation was observed. Activation of the primary somatosensory cortex was only seen at the 2 year follow-up. By contrast, after hand replantation, the activation pattern was similar to that of the uninjured hand within 6 weeks. This included activation of the primary sensorimotor motor cortex, higher motor areas and primary somatosensory cortex. Transplantation after long-standing amputation results in cortical reorganization occurring over a 2-year period. In contrast, hand replantation within a few hours preserves a normal activation pattern.

Postcentral Topectomy for Pain Relief: A Historical Review and Possible Improvements

2020 ◽  
Vol 2 (1) ◽  
Author(s):  
Timothy Challener ◽  
Oleg Favorov
Keyword(s):  
Chronic Pain ◽  
Somatosensory Cortex ◽  
Primary Motor Cortex ◽  
Historical Review ◽  
Transitional Zone ◽  
Primary Somatosensory Cortex ◽  
Successful Outcome ◽  
Cortical Region ◽  
Area 3A ◽  
Surgical Teams

Postcentral topectomy is a neurosurgical procedure, practiced in the mid-20th century, in which surgical ablations of the primary somatosensory cortex were used as a therapeutic means of treating patients suffering from intractable chronic pain. While successful in curing some—but not all—patients, the procedure was poorly understood and eventually became displaced by methods that more consistently stopped patient complaints of pain, such as opiates and frontal lobotomies. However, a more recent discovery of a nociresponsive region in the transitional zone between the primary somatosensory cortex and the primary motor cortex (lying in Brodmann Area 3a anterior to its better known proprioceptive region) raises the possibility that the outcome of postcentral topectomy depended in each patient on whether the ablation extended deep enough into the central sulcus to remove this cortical region. Here we review every postcentral topectomy case we could find in the neurosurgical literature in order to evaluate its past effectiveness and to reassess its potential in light of modern knowledge of the cerebral cortex. We found 17 full-text reports from 16 different surgical teams describing outcomes of the procedure in 27 patients. Among those, in only 5 patients the procedure either failed to abolish the targeted chronic pain or the pain returned to its preoperational levels several weeks or months after the surgery. In the other 22 patients, their pain stayed abolished or at least significantly reduced as of the last evaluation by the treating physician (which was one year or more for 9 patients). We propose that the probability of a successful outcome might be brought to near 100% by selective targeting—guided by functional imaging—of the nociresponsive region in Area 3a. 

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