Cerebral perfusion and diffusion in stroke: Association with aphasia severity in the early phases of recovery

Persistent Link:
http://hdl.handle.net/10150/279956
Title:
Cerebral perfusion and diffusion in stroke: Association with aphasia severity in the early phases of recovery
Author:
Fridriksson, Julius
Issue Date:
2002
Publisher:
The University of Arizona.
Rights:
Copyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.
Abstract:
The purpose of this study was to investigate the relationship between aphasia severity and cerebral perfusion and lesion size in stroke. Nine subjects with acute ischemic stroke were examined within 24 hours of symptom onset and six were reexamined at one-month post-stroke. Examination included aphasia testing, testing of face discrimination ability, administration of the National Institutes of Health Stroke Scale, and perfusion MRI (PI), diffusion MRI (DWI), and T2-weighted MRI (T2-MRI). Subjects with a variety of aphasia types and a large range of aphasia severity participated in the study. MR images were visually inspected to verify perfusion and diffusion abnormalities. Perfusion abnormality was quantified by calculating a perfusion signal ratio of the affected hemisphere over the whole image (left/whole = ratio). Lesion volume was calculated from the DWI and T2-MRI. A perfusion abnormality larger than a DWI lesion was observed in 8 of 9 subjects. Minimal lesions were observed on DWI in three of the subjects while their PI revealed significant perfusion abnormality. Correlation coefficients (Spearman) between aphasia severity and hypoperfusion were significant in the acute stage and again at one-month post-stroke. Five of six subjects that were reexamined at one-month post-stroke experienced significant aphasia recovery. Visual inspection of their PI scans suggests that aphasia recovery was accompanied by increase in cerebral perfusion. The correlation between aphasia severity and lesion size was not statistically significant in the acute stage or at one-month post-stroke. Consequently, it is probable that cerebral hypoperfusion is a better predictor of aphasia severity and recovery in early stroke than lesion volume.
Type:
text; Dissertation-Reproduction (electronic)
Keywords:
Health Sciences, Speech Pathology.
Degree Name:
Ph.D.
Degree Level:
doctoral
Degree Program:
Graduate College; Speech and Hearing Sciences
Degree Grantor:
University of Arizona
Advisor:
Holland, Audrey L.

Full metadata record

DC FieldValue Language
dc.language.isoen_USen_US
dc.titleCerebral perfusion and diffusion in stroke: Association with aphasia severity in the early phases of recoveryen_US
dc.creatorFridriksson, Juliusen_US
dc.contributor.authorFridriksson, Juliusen_US
dc.date.issued2002en_US
dc.publisherThe University of Arizona.en_US
dc.rightsCopyright © is held by the author. Digital access to this material is made possible by the University Libraries, University of Arizona. Further transmission, reproduction or presentation (such as public display or performance) of protected items is prohibited except with permission of the author.en_US
dc.description.abstractThe purpose of this study was to investigate the relationship between aphasia severity and cerebral perfusion and lesion size in stroke. Nine subjects with acute ischemic stroke were examined within 24 hours of symptom onset and six were reexamined at one-month post-stroke. Examination included aphasia testing, testing of face discrimination ability, administration of the National Institutes of Health Stroke Scale, and perfusion MRI (PI), diffusion MRI (DWI), and T2-weighted MRI (T2-MRI). Subjects with a variety of aphasia types and a large range of aphasia severity participated in the study. MR images were visually inspected to verify perfusion and diffusion abnormalities. Perfusion abnormality was quantified by calculating a perfusion signal ratio of the affected hemisphere over the whole image (left/whole = ratio). Lesion volume was calculated from the DWI and T2-MRI. A perfusion abnormality larger than a DWI lesion was observed in 8 of 9 subjects. Minimal lesions were observed on DWI in three of the subjects while their PI revealed significant perfusion abnormality. Correlation coefficients (Spearman) between aphasia severity and hypoperfusion were significant in the acute stage and again at one-month post-stroke. Five of six subjects that were reexamined at one-month post-stroke experienced significant aphasia recovery. Visual inspection of their PI scans suggests that aphasia recovery was accompanied by increase in cerebral perfusion. The correlation between aphasia severity and lesion size was not statistically significant in the acute stage or at one-month post-stroke. Consequently, it is probable that cerebral hypoperfusion is a better predictor of aphasia severity and recovery in early stroke than lesion volume.en_US
dc.typetexten_US
dc.typeDissertation-Reproduction (electronic)en_US
dc.subjectHealth Sciences, Speech Pathology.en_US
thesis.degree.namePh.D.en_US
thesis.degree.leveldoctoralen_US
thesis.degree.disciplineGraduate Collegeen_US
thesis.degree.disciplineSpeech and Hearing Sciencesen_US
thesis.degree.grantorUniversity of Arizonaen_US
dc.contributor.advisorHolland, Audrey L.en_US
dc.identifier.proquest3050317en_US
dc.identifier.bibrecord.b42724090en_US
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