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(Stroke. 2004;35:e73.)
© 2004 American Heart Association, Inc.

Letters to the Editor

Re: Interhemispheric Asymmetries of Motor Cortex Excitability in the Postacute Stroke Stage

Ernest H. Friedman, MD

Department of Medicine and Psychiatry, Case Western Reserve University, Cleveland, Ohio

To the Editor:

Cicinelli and others¹ report that intracortical inhibition was reduced in affected hemispheres and normal in the unaffected hemispheres of stroke patients. Neurobiological features are suggested by 2.5- to 3-second delay periods for inhibition shaping the temporal flow of information in the prefrontal cortex,² which represents action sequence boundaries.³

This hypothesis is supported by the association of reduction of blood pressure with longer, less recurrent speech hesitation pauses (SHPs); behavioral correlates of mood, of about 2 seconds linked to prefrontal cortex modulation of dopamine during the delayed alternation task; and optimum response organization and working memory at intermediate dopamine tone in a mediofrontostriatal activation system.

The fact that rate and variability in duration of SHPs, 4.79±2.48 per minute, 1.50±0.33 seconds (mean±SD), correlate with the left and right hemisphere, respectively, suggests that the analysis of SHPs on a time-base² might provide a valuable behavioral parameter in the prognosis and follow-up of patients with monohemispheric stroke.¹

References

1. Cicinelli P, Pasqualetti P, Zaccagnini M, Traversa R, Oliveri M, Rossini PM. Interhemispheric asymmetries of motor cortex excitability in the postacute stroke stage: a paired-pulse transcranial magnetic stimulation study. Stroke. 2003; 34: 2653–2658.[Abstract/Free Full Text]
2. Friedman EH. Re: pulse pressure and risk of Alzheimer disease in persons aged 75 years and older. Stroke. 2003; 34: e107. Letter.[Medline] [Order article via Infotrieve]
3. Fujii N, Graybiel AM. Representation of action sequence boundaries by macaque prefrontal cortical neurons. Science. 2003; 301: 1246–1249.[Abstract/Free Full Text]

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This Article Full Text (PDF) All Versions of this Article: 35/4/e73    most recent 01.STR.0000120957.67484.D2v1 Alert me when this article is cited Alert me if a correction is posted Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Download to citation manager Request Permissions Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Friedman, E. H. Search for Related Content PubMed PubMed Citation Articles by Friedman, E. H.