Inhibition of the primary motor cortex and the upgoing thumb sign

A. Nucera; M.R. Azarpazhooh; L. Cardinali; R. Alsubaie; T.C. Chiang; N. Weishaupt; V. Hachinski

doi:10.1016/j.ensci.2017.07.001

Inhibition of the primary motor cortex and the upgoing thumb sign

A. Nucera, M.R. Azarpazhooh, L. Cardinali, R. Alsubaie, T.C. Chiang, N. Weishaupt, V. Hachinski^*

^*Corresponding author for this work

Research output: Contribution to Journal › Article › peer-review

Abstract

Background: The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign.

Methods: Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition.

Results: 10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign.

Conclusion: The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements.

Keywords: Corticospinal tract; Primary motor cortex; Transcranial magnetic stimulation; Upper motor neuron lesions.

Original language	English
Pages (from-to)	31-33
Number of pages	3
Journal	eNeurologicalSci
Volume	8
DOIs	https://doi.org/10.1016/j.ensci.2017.07.001
Publication status	Published - 27 Jul 2017
Externally published	Yes

Bibliographical note

We are grateful to the 10 study volunteers, without whose participation in this study, would not have been possible.

Keywords

Corticospinal tract
Upper motor neuron lesions
Primary motor cortex
Transcranial magnetic stimulation

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Cite this

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title = "Inhibition of the primary motor cortex and the upgoing thumb sign",

abstract = "Background: The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign.Methods: Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60\% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition.Results: 10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign.Conclusion: The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements.Keywords: Corticospinal tract; Primary motor cortex; Transcranial magnetic stimulation; Upper motor neuron lesions.",

keywords = "Corticospinal tract, Upper motor neuron lesions, Primary motor cortex, Transcranial magnetic stimulation",

author = "A. Nucera and M.R. Azarpazhooh and L. Cardinali and R. Alsubaie and T.C. Chiang and N. Weishaupt and V. Hachinski",

note = "We are grateful to the 10 study volunteers, without whose participation in this study, would not have been possible.",

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doi = "10.1016/j.ensci.2017.07.001",

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AU - Nucera, A.

AU - Azarpazhooh, M.R.

AU - Cardinali, L.

AU - Alsubaie, R.

AU - Chiang, T.C.

AU - Weishaupt, N.

AU - Hachinski, V.

N1 - We are grateful to the 10 study volunteers, without whose participation in this study, would not have been possible.

PY - 2017/7/27

Y1 - 2017/7/27

N2 - Background: The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign.Methods: Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition.Results: 10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign.Conclusion: The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements.Keywords: Corticospinal tract; Primary motor cortex; Transcranial magnetic stimulation; Upper motor neuron lesions.

AB - Background: The upgoing thumb sign has been frequently observed in patients with minor strokes and transient ischemic attacks as an indicator of brain involvement. We assessed the effect of primary motor cortex (M1) inhibition in the development of the upgoing thumb sign.Methods: Used repetitive Transcranial Magnetic Stimulation (rTMS, 1 Hz frequency for 15 min, 1s ISI, 900 pulses) at 60% of resting motor threshold to inhibit the right or left primary motor cortex of 10 healthy individuals. Participants were examined before and after rTMS by a neurologist who was blind to the site of motor cortex inhibition.Results: 10 neurological intact participants (5 women/5 men) were recruited for this study. 2 cases were excluded due to pre-existing possible thumb signs. After the inhibition of the primary motor cortex, in 6 subjects out of 8, we observed a thumb sign contralateral to the site of primary motor cortex inhibition. In one subject an ipsilateral thumbs sign was noted. In another case, we did not find an upgoing thumb sign.Conclusion: The upgoing thumb sign is a subtle neurological finding that may be related to the primary motor cortex or corticospinal pathways involvements.Keywords: Corticospinal tract; Primary motor cortex; Transcranial magnetic stimulation; Upper motor neuron lesions.

KW - Corticospinal tract

KW - Upper motor neuron lesions

KW - Primary motor cortex

KW - Transcranial magnetic stimulation

U2 - 10.1016/j.ensci.2017.07.001

DO - 10.1016/j.ensci.2017.07.001

M3 - Article

SN - 2405-6502

VL - 8

SP - 31

EP - 33

JO - eNeurologicalSci

JF - eNeurologicalSci

ER -

Inhibition of the primary motor cortex and the upgoing thumb sign

Abstract

Bibliographical note

Keywords

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