Objectives: No prior study has reported on the cortical activation pattern in hemiparetic patients with a pontine infarct. The aim of this study was to investigate the cortical activation pattern of hemiparetic patients with a pontine infarct, using functional MRI scanning (fMRI). Subjects and Method: Fifteen consecutive patients who showed severe weakness at onset due to a pontine infarct were recruited. The motor function was assessed at the time of the onset of stroke and fMRI scanning was performed (on average 8.9 months after stroke onset). The fMRI was performed during a motor task of timed hand grasp-release movements. From the fMRI, the laterality index was calculated to assess the relative activity in the ipsilateral versus the contralateral primary sensorimotor cortex (SM1). Results: All patients except for 2 (bilateral SM1 activation) showed contralateral SM1 activation without ipsilateral SM1 activation associated with the affected hand movements. The average laterality index for the affected hand movements among all patients was 0.97. Conclusions: The fMRI results showed that primarily the contralateral SM1 was activated during affected hand movements. Therefore, it appears that the motor function of the affected hand, in patients with a pontine infarct, recovers mainly via the lateral corticospinal tract.

Keywords:
Magnetic resonance imaging, functional, Pons, Stroke, Infarct, Motor recovery
1.
Carey LM, Seitz RJ: Functional neuroimaging in stroke recovery and neurorehabilitation: conceptual issues and perspectives. Int J Stroke 2007;2:245–264.
2.
Dietrichs E: Brain plasticity after stroke – implications for post-stroke rehabilitation (in Norwegian). Tidsskr Nor Laegeforen 2007;127:1228–1231.
3.
Jones TA, Allred RP, Adkins DL, Hsu JE, O’Bryant A, Maldonado MA: Remodeling the brain with behavioral experience after stroke. Stroke 2009;40:S136–S138.
4.
Calautti C, Baron JC: Functional neuroimaging studies of motor recovery after stroke in adults: a review. Stroke 2003;34:1553–1566.
5.
Platz T, Kim IH, Engel U, Kieselbach A, Mauritz KH: Brain activation pattern as assessed with multi-modal EEG analysis predict motor recovery among stroke patients with mild arm paresis who receive the arm ability training. Restor Neurol Neurosci 2002;20:21–35.
6.
Feydy A, Carlier R, Roby-Brami A, Bussel B, Cazalis F, Pierot L, Burnod Y, Maier MA: Longitudinal study of motor recovery after stroke: recruitment and focusing of brain activation. Stroke 2002;33:1610–1617.
7.
Cho SH, Shin HK, Kwon YH, Lee MY, Lee YH, Lee CH, Yang DS, Jang SH: Cortical activation changes induced by visual biofeedback tracking training in chronic stroke patients. Neurorehabilitation 2007;22:77–84.
8.
Jang SH: A review of motor recovery mechanisms in patients with stroke. Neurorehabilitation 2007;22:253–259.
9.
Kwon YH, Lee MY, Park JW, Kang JH, Yang DS, Kim YH, Ahn SH, Jang SH: Differences of cortical activation pattern between cortical and corona radiata infarct. Neurosci Lett 2007;417:138–142.
10.
Shelton FN, Reding MJ: Effect of lesion location on upper limb motor recovery after stroke. Stroke 2001;32:107–112.
11.
Chen CL, Tang FT, Chen HC, Chung CY, Wong MK: Brain lesion size and location: Effects on motor recovery and functional outcome in stroke patients. Arch Phys Med Rehabil 2000;81:447–452.
12.
Luft AR, Waller S, Forrester L, Smith GV, Whitall J, Macko RF, Schulz JB, Hanley DF: Lesion location alters brain activation in chronically impaired stroke survivors. Neuroimage 2004;21:924–935.
13.
Furlan M, Marchal G, Viader F, Derlon JM, Baron JC: Spontaneous neurological recovery after stroke and the fate of the ischemic penumbra. Ann Neurol 1996;40:216–226.
14.
Witte OW: Lesion-induced plasticity as a potential mechanism for recovery and rehabilitative training. Curr Opin Neurol 1998;11:655–662.
15.
Oldfield RC: The assessment and analysis of handedness: the Edinburgh Inventory. Neuropsychologia 1971;9:97–113.
16.
Demeurisse G, Demol O, Robaye E: Motor evaluation in vascular hemiplegia. Eur Neurol 1980;19:382–389.
17.
Council MR: Aids to Examination of the Peripheral Nervous System. London, HM Stationery Office, 1976.
18.
Fujii Y, Nakada T: Cortical reorganization in patients with subcortical hemiparesis: neural mechanisms of functional recovery and prognostic implication. J Neurosurg 2003;98:64–73.
19.
Cunha IT, Lim PA, Henson H, Monga T, Qureshy H, Protas EJ: Performance-based gait tests for acute stroke patients. Am J Phys Med Rehabil 2002;81:848–856.
20.
Cramer SC, Nelles G, Schaechter JD, Kaplan JD, Finklestein SP, Rosen BR: A functional MRI study of three motor tasks in the evaluation of stroke recovery. Neurorehabil Neural Repair 2001;15:1–8.
21.
Jang SH, Cho SH, Kim YH, Kwon YH, Byun WM, Lee SJ, Park SM, Chang CH: Cortical activation changes associated with motor recovery in patients with precentral knob infarct. Neuroreport 2004;15:395–399.
22.
Dassonville P, Lewis SM, Zhu XH, Ugurbil K, Kim SG, Ashe J: Effects of movement predictability on cortical motor activation. Neurosci Res 1998;32:65–74.
23.
Yousry TA, Schmid UD, Alkadhi H, Schmidt D, Peraud A, Buettner A, Winkler P: Localization of the motor hand area to a knob on the precentral gyrus. A new landmark. Brain 1997;120:141–157.
24.
Kwak R, Kadoya S, Suzuki T: Factors affecting the prognosis in thalamic hemorrhage. Stroke 1983;14:493–500.
25.
Binkofski F, Seitz RJ, Arnold S, Classen J, Benecke R, Freund HJ: Thalamic metabolism and corticospinal tract integrity determine motor recovery in stroke. Ann Neurol 1996;39:460–470.
26.
Ahn YH, You SH, Randolph M, Kim SH, Ahn SH, Byun WM, Yang DS, Jang SH: Peri-infarct reorganization of motor function in patients with pontine infarct. Neurorehabilitation 2006;21:233–237.
27.
Kim JS, Lee JH, Im JH, Lee MC: Syndromes of pontine base infarction. A clinical-radiological correlation study. Stroke 1995;26:950–955.
28.
Bassetti C, Bogousslavsky J, Barth A, Regli F: Isolated infarcts of the pons. Neurology 1996;46:165–175.
29.
Kumral E, Bayulkem G, Evyapan D: Clinical spectrum of pontine infarction. Clinical-MRI correlations. J Neurol 2002;249:1659–1670.
30.
Jang SH: Aberrant pyramidal tract in the medial lemniscus of the brainstem in a patient with a pontine infarct: diffusion tensor tractography study. J Neurol Neurosurg Psychiatry 2009;80:243–244.
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2010
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