Ann Rehabil Med.  2018 Aug;42(4):495-501. 10.5535/arm.2018.42.4.495.

Changes in Intracortical Excitability of Affected and Unaffected Hemispheres After Stroke Evaluated by Paired-Pulse Transcranial Magnetic Stimulation

• Seo HY
• Kim GW
• Won YH
• Park SH
• Seo JH
• Ko MH

• KMID: 2420040
• DOI: http://doi.org/10.5535/arm.2018.42.4.495

Abstract

OBJECTIVE
To assess the altered pattern of intracortical excitability of the affected and unaffected hemispheres in stroke patients using paired-pulse transcranial magnetic stimulation (TMS).
METHODS
We evaluated intracortical inhibition (ICI) and intracortical facilitation (ICF) in both hemispheres at acute and subacute stages of 103 stroke patients using paired-pulse TMS. The patients were divided into two groups: mild-to-moderate patients whose motor evoked potential (MEP) was recorded in the affected hemisphere; and severe patients whose MEP was not recorded in the affected hemisphere.
RESULTS
In mild-to-moderate patients, the value of ICI in the affected hemisphere was increased from 70.3% to 77.9% and the value of ICI in the unaffected hemisphere was decreased from 74.8% to 70.3% with eventual progression in acute to subacute stages of stroke. In severe patients, the value of ICI in the unaffected hemisphere was increased from 65.4% to 75.6%. The changes in ICF were not significantly different in this study.
CONCLUSION
We conclude that the unaffected hemisphere was more disinhibited than the affected hemisphere in acute phase of mild-to-moderate stroke, and the affected hemisphere was more disinhibited in the subacute stage. The unaffected hemisphere was inhibited in severe cases in acute-to-subacute phases of stroke. This finding facilitates appropriate neuromodulation of acute-to-subacute phases in mild-to-severe stroke patients.

Keyword

Transcranial magnetic stimulation; Cortical excitability; Stroke

MeSH Terms

Evoked Potentials, Motor
Humans
Stroke*
Transcranial Magnetic Stimulation*

Figure

• 

  Fig. 1. Comparison of the changes in intracortical excitability of cerebral hemisphere. AH, affected hemisphere; UH, unaffected hemisphere; T1, 1st assessment session; T2, 2nd assessment session. *p<0.05.

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