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FMRI of working memory impairment after recovery from subarachnoid hemorrhage.

Ellmore TM, Rohlffs F, Khursheed F - Front Neurol (2013)

Bottom Line: Behavioral results indicated a subtle but statistically significant impairment relative to healthy subjects in working memory performance accuracy, which was accompanied by relatively increased blood-oxygen level dependent signal in widespread left and right hemisphere cortical areas during periods of encoding, maintenance, and retrieval.We conclude that deficits in verbal working memory following recovery from (SAH) are accompanied by widespread differences in hemodynamic correlates of neural activity.These differences are discussed with respect to the immediate and delayed focal and global brain damage that can occur following (SAH), and the possibility that this damage induces subcortical disconnection and subsequent decreased efficiency in neural processing.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Program in Behavioral and Cognitive Neuroscience, The City College of New York , New York, NY , USA.

ABSTRACT
Recovery from aneurysmal subarachnoid hemorrhage (SAH) is often incomplete and accompanied by subtle but persistent cognitive deficits. Previous neuropsychological reports indicate these deficits include most prominently memory impairment, with working memory particularly affected. The neural basis of these memory deficits remains unknown and unexplored by functional magnetic resonance imaging (fMRI). In the present study, patients who experienced (SAH) underwent fMRI during the performance of a verbal working memory paradigm. Behavioral results indicated a subtle but statistically significant impairment relative to healthy subjects in working memory performance accuracy, which was accompanied by relatively increased blood-oxygen level dependent signal in widespread left and right hemisphere cortical areas during periods of encoding, maintenance, and retrieval. Activity increases remained after factoring out inter-individual differences in age and task performance, and included most notably left hemisphere regions associated with phonological loop processing, bilateral sensorimotor regions, and right hemisphere dorsolateral prefrontal cortex. We conclude that deficits in verbal working memory following recovery from (SAH) are accompanied by widespread differences in hemodynamic correlates of neural activity. These differences are discussed with respect to the immediate and delayed focal and global brain damage that can occur following (SAH), and the possibility that this damage induces subcortical disconnection and subsequent decreased efficiency in neural processing.

No MeSH data available.


Related in: MedlinePlus

A covariate interaction analysis shows regions that differ as a function of working memory accuracy. Several regions (A–D) exhibited fMRI activity that covaried significantly (p < 0.05) differently between patients and controls as a function of working memory accuracy (E).
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Figure 5: A covariate interaction analysis shows regions that differ as a function of working memory accuracy. Several regions (A–D) exhibited fMRI activity that covaried significantly (p < 0.05) differently between patients and controls as a function of working memory accuracy (E).

Mentions: We next tested the hypothesis that the greater activity elicited in patients could be explained by signal that covaried differently as a function of age and task performance. To do this, we computed MEMA age and percent correct covariate t-maps, and displayed significant BOLD-fMRI changes that differed between groups as a function of age (Figure 4) and performance (Figure 5). These analyses highlighted regions where signal differed differently between groups as a function of the covariate, and no constraint was placed on the direction of the difference. Averaged across all regions and task periods that were found to differ significantly between groups as a function of the age covariate, patients tended to exhibit BOLD-fMRI changes that increased with age while controls showed a decreasing pattern (Figure 4E). For the regions that differed between groups as a function of task accuracy, patients showed a mostly flat relationship while controls showed an average decrease as a function of increasing performance (Figure 5E).


FMRI of working memory impairment after recovery from subarachnoid hemorrhage.

Ellmore TM, Rohlffs F, Khursheed F - Front Neurol (2013)

A covariate interaction analysis shows regions that differ as a function of working memory accuracy. Several regions (A–D) exhibited fMRI activity that covaried significantly (p < 0.05) differently between patients and controls as a function of working memory accuracy (E).
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC3818578&req=5

Figure 5: A covariate interaction analysis shows regions that differ as a function of working memory accuracy. Several regions (A–D) exhibited fMRI activity that covaried significantly (p < 0.05) differently between patients and controls as a function of working memory accuracy (E).
Mentions: We next tested the hypothesis that the greater activity elicited in patients could be explained by signal that covaried differently as a function of age and task performance. To do this, we computed MEMA age and percent correct covariate t-maps, and displayed significant BOLD-fMRI changes that differed between groups as a function of age (Figure 4) and performance (Figure 5). These analyses highlighted regions where signal differed differently between groups as a function of the covariate, and no constraint was placed on the direction of the difference. Averaged across all regions and task periods that were found to differ significantly between groups as a function of the age covariate, patients tended to exhibit BOLD-fMRI changes that increased with age while controls showed a decreasing pattern (Figure 4E). For the regions that differed between groups as a function of task accuracy, patients showed a mostly flat relationship while controls showed an average decrease as a function of increasing performance (Figure 5E).

Bottom Line: Behavioral results indicated a subtle but statistically significant impairment relative to healthy subjects in working memory performance accuracy, which was accompanied by relatively increased blood-oxygen level dependent signal in widespread left and right hemisphere cortical areas during periods of encoding, maintenance, and retrieval.We conclude that deficits in verbal working memory following recovery from (SAH) are accompanied by widespread differences in hemodynamic correlates of neural activity.These differences are discussed with respect to the immediate and delayed focal and global brain damage that can occur following (SAH), and the possibility that this damage induces subcortical disconnection and subsequent decreased efficiency in neural processing.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychology and Program in Behavioral and Cognitive Neuroscience, The City College of New York , New York, NY , USA.

ABSTRACT
Recovery from aneurysmal subarachnoid hemorrhage (SAH) is often incomplete and accompanied by subtle but persistent cognitive deficits. Previous neuropsychological reports indicate these deficits include most prominently memory impairment, with working memory particularly affected. The neural basis of these memory deficits remains unknown and unexplored by functional magnetic resonance imaging (fMRI). In the present study, patients who experienced (SAH) underwent fMRI during the performance of a verbal working memory paradigm. Behavioral results indicated a subtle but statistically significant impairment relative to healthy subjects in working memory performance accuracy, which was accompanied by relatively increased blood-oxygen level dependent signal in widespread left and right hemisphere cortical areas during periods of encoding, maintenance, and retrieval. Activity increases remained after factoring out inter-individual differences in age and task performance, and included most notably left hemisphere regions associated with phonological loop processing, bilateral sensorimotor regions, and right hemisphere dorsolateral prefrontal cortex. We conclude that deficits in verbal working memory following recovery from (SAH) are accompanied by widespread differences in hemodynamic correlates of neural activity. These differences are discussed with respect to the immediate and delayed focal and global brain damage that can occur following (SAH), and the possibility that this damage induces subcortical disconnection and subsequent decreased efficiency in neural processing.

No MeSH data available.


Related in: MedlinePlus