The Thermal Sensitivity Test in Evaluating Outcome after Peripheral Nerve Injury

The purpose of this study was to evaluate the ability to discriminate temperatures in patients following peripheral nerve injury. Knowing that temperature sensibility is mediated by different receptors, the scores were compared to other functional hand scores in order to determine whether the ability to discriminate temperatures is restored to a different extent compared with other commonly evaluated hand function modalities. The test was performed using the NTE-2 device (Physitemp Instruments Inc., 154 Huron Avenue, Clifton, New Jersey, USA). Out of 57 patients, 27 had normal thermal discrimination scores, and 9 could not tell the temperatures apart in the differences set on the measuring device. Overall, patients with better thermal discrimination had also better hand function as evaluated with different methods. However, some patients who did regain the ability to differentiate temperatures correctly did not have any measurable return of hand function in other tests. Thermal discrimination scores correlated similarly with different functional scores, except for vibration sensibility, which did not show any significant correlation. The development and severity of cold intolerance seem to be unrelated to temperature sense.

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SUR1, newly expressed in astrocytes, mediates neuropathic pain in a mouse model of peripheral nerve injury

Molecular Pain ◽

10.1177/17448069211006603 ◽

2021 ◽

Vol 17 ◽

pp. 174480692110066

Author(s):

Orest Tsymbalyuk ◽

Volodymyr Gerzanich ◽

Aaida Mumtaz ◽

Sanketh Andhavarapu ◽

Svetlana Ivanova ◽

...

Keyword(s):

Spinal Cord ◽

Neuropathic Pain ◽

Sciatic Nerve ◽

Peripheral Nerve ◽

Dorsal Horn ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Thermal Sensitivity ◽

Gradual Improvement ◽

Pain Behaviors

Background Neuropathic pain following peripheral nerve injury (PNI) is linked to neuroinflammation in the spinal cord marked by astrocyte activation and upregulation of interleukin 6 (IL -6 ), chemokine (C-C motif) ligand 2 (CCL2) and chemokine (C-X-C motif) ligand 1 (CXCL1), with inhibition of each individually being beneficial in pain models. Methods Wild type (WT) mice and mice with global or pGfap-cre- or pGFAP-cre/ERT2-driven Abcc8/SUR1 deletion or global Trpm4 deletion underwent unilateral sciatic nerve cuffing. WT mice received prophylactic (starting on post-operative day [pod]-0) or therapeutic (starting on pod-21) administration of the SUR1 antagonist, glibenclamide (10 µg IP) daily. We measured mechanical and thermal sensitivity using von Frey filaments and an automated Hargreaves method. Spinal cord tissues were evaluated for SUR1-TRPM4, IL-6, CCL2 and CXCL1. Results Sciatic nerve cuffing in WT mice resulted in pain behaviors (mechanical allodynia, thermal hyperalgesia) and newly upregulated SUR1-TRPM4 in dorsal horn astrocytes. Global and pGfap-cre-driven Abcc8 deletion and global Trpm4 deletion prevented development of pain behaviors. In mice with Abcc8 deletion regulated by pGFAP-cre/ERT2, after pain behaviors were established, delayed silencing of Abcc8 by tamoxifen resulted in gradual improvement over the next 14 days. After PNI, leakage of the blood-spinal barrier allowed entry of glibenclamide into the affected dorsal horn. Daily repeated administration of glibenclamide, both prophylactically and after allodynia was established, prevented or reduced allodynia. The salutary effects of glibenclamide on pain behaviors correlated with reduced expression of IL-6, CCL2 and CXCL1 by dorsal horn astrocytes. Conclusion SUR1-TRPM4 may represent a novel non-addicting target for neuropathic pain.

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Thermo-sensitive TRP channels in peripheral nerve injury: A review of their role in cold intolerance

Journal of Plastic Reconstructive & Aesthetic Surgery ◽

10.1016/j.bjps.2013.12.014 ◽

2014 ◽

Vol 67 (5) ◽

pp. 591-599 ◽

Cited By ~ 5

Author(s):

S. Kambiz ◽

L.S. Duraku ◽

J.C. Holstege ◽

S.E.R. Hovius ◽

T.J.H. Ruigrok ◽

...

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Trp Channels ◽

Cold Intolerance

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FLEXOR TENDON AND PERIPHERAL NERVE REPAIR

Hand Surgery ◽

10.1142/s021881040200087x ◽

2002 ◽

Vol 07 (01) ◽

pp. 83-100 ◽

Cited By ~ 11

Author(s):

Judith A. Bell Krotoski

Keyword(s):

Peripheral Nerve ◽

Nerve Injury ◽

Peripheral Nerve Injury ◽

Flexor Tendon ◽

Nerve Repair ◽

Hand Function ◽

Tendon Injury ◽

Finger Movement ◽

Flexor Tendon Injury ◽

Direct Injury

Any restoration of hand function following tendon and nerve injury has to include the repair or replacement of the hand's ability to perform a great many tasks. It is hard at first to appreciate fully the loss that occurs with flexor tendon injury. With loss of flexor tendons operating at the fingers or thumb, they cannot be fully closed and the hand is impaired for grasp and release as it interfaces with objects. But, sensibility can also be compromised from tendon injury even without direct injury to nerve, as object recognition in the absence of vision requires finger movement. When peripheral nerve injury is combined with flexor tendon injury, sensibility is directly impaired. There is a loss in the sense of finger or thumb position, pain, temperature, and touch/pressure recognition, in addition to the tendon injury.

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