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Regional brain morphometry predicts memory rehabilitation outcome after traumatic brain injury.

Strangman GE, O'Neil-Pirozzi TM, Supelana C, Goldstein R, Katz DI, Glenn MB - Front Hum Neurosci (2010)

Bottom Line: Fifty individuals with TBI of all severities who reported having memory difficulties first underwent structural MRI scanning.We identified several brain regions that provided significant predictions of rehabilitation outcome, including the volume of the hippocampus, the lateral prefrontal cortex, the thalamus, and several subregions of the cingulate cortex.The prediction range of regional brain volumes were in some cases nearly equal in magnitude to prediction ranges provided by pretest scores on the outcome variable.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Harvard Medical School Boston, MA, USA.

ABSTRACT
Cognitive deficits following traumatic brain injury (TBI) commonly include difficulties with memory, attention, and executive dysfunction. These deficits are amenable to cognitive rehabilitation, but optimally selecting rehabilitation programs for individual patients remains a challenge. Recent methods for quantifying regional brain morphometry allow for automated quantification of tissue volumes in numerous distinct brain structures. We hypothesized that such quantitative structural information could help identify individuals more or less likely to benefit from memory rehabilitation. Fifty individuals with TBI of all severities who reported having memory difficulties first underwent structural MRI scanning. They then participated in a 12 session memory rehabilitation program emphasizing internal memory strategies (I-MEMS). Primary outcome measures (HVLT, RBMT) were collected at the time of the MRI scan, immediately following therapy, and again at 1-month post-therapy. Regional brain volumes were used to predict outcome, adjusting for standard predictors (e.g., injury severity, age, education, pretest scores). We identified several brain regions that provided significant predictions of rehabilitation outcome, including the volume of the hippocampus, the lateral prefrontal cortex, the thalamus, and several subregions of the cingulate cortex. The prediction range of regional brain volumes were in some cases nearly equal in magnitude to prediction ranges provided by pretest scores on the outcome variable. We conclude that specific cerebral networks including these regions may contribute to learning during I-MEMS rehabilitation, and suggest that morphometric measures may provide substantial predictive value for rehabilitation outcome in other cognitive interventions as well.

No MeSH data available.


Related in: MedlinePlus

Depiction of the relationship between HVLT delayed correct recall score at posttest 2 versus the volume of (A) the hippocampus, and (B) the posterior dorsal cingulate gyrus. Simple least-squares lines are plotted; detailed regression results appear in Tables 4 and 5.
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Figure 3: Depiction of the relationship between HVLT delayed correct recall score at posttest 2 versus the volume of (A) the hippocampus, and (B) the posterior dorsal cingulate gyrus. Simple least-squares lines are plotted; detailed regression results appear in Tables 4 and 5.

Mentions: From our a priori regions of interest, we found a significant positive relationship between hippocampal volume (pooling across left and right hemispheres) and HVLT outcome at posttest 2 (p = 0.007; cf. Table 4 and Figure 3A). The regression coefficient for hippocampal volume was 1.056 per 1 cm3 (1,000 mm3) of tissue, whereas that for the HVLT pretest score was 0.53; thus a 1-unit change in pretest was roughly equivalent to a 0.5 cm3 change in hippocampal volume in terms of predicting HVLT at posttest 2. Over the full range of hippocampal volumes (1.335–5.182 cm3), the hippocampal volume term predicted a range of 4.1 points on the HVLT, or 34% of the full-scale (12 point) range. For comparison, the HVLT pretest score predicted a range of 6.38 points, or 53% of the full-scale HVLT range. The hippocampal prediction model also included a significant effect of age, whereby older individuals had better rehabilitation outcomes (1.6 points on HVLT across the span of four decades), and marginal effects of injury severity (severities greater than mild tended towards an average 0.85 point decrease in HVLT at outcome). Other results from our six regions of interest with volume terms exhibiting p < 0.05 appear in Table 5. This included the mFG which exhibited modest predictive value for HVLT at posttest 2 (coefficient = 0.27 on a 7.633 cm3 range) as well as at posttest 1, and the supramarginal gyrus, which predicted both HVLT and RBMT outcomes, but only at posttest 1.


Regional brain morphometry predicts memory rehabilitation outcome after traumatic brain injury.

Strangman GE, O'Neil-Pirozzi TM, Supelana C, Goldstein R, Katz DI, Glenn MB - Front Hum Neurosci (2010)

Depiction of the relationship between HVLT delayed correct recall score at posttest 2 versus the volume of (A) the hippocampus, and (B) the posterior dorsal cingulate gyrus. Simple least-squares lines are plotted; detailed regression results appear in Tables 4 and 5.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2967347&req=5

Figure 3: Depiction of the relationship between HVLT delayed correct recall score at posttest 2 versus the volume of (A) the hippocampus, and (B) the posterior dorsal cingulate gyrus. Simple least-squares lines are plotted; detailed regression results appear in Tables 4 and 5.
Mentions: From our a priori regions of interest, we found a significant positive relationship between hippocampal volume (pooling across left and right hemispheres) and HVLT outcome at posttest 2 (p = 0.007; cf. Table 4 and Figure 3A). The regression coefficient for hippocampal volume was 1.056 per 1 cm3 (1,000 mm3) of tissue, whereas that for the HVLT pretest score was 0.53; thus a 1-unit change in pretest was roughly equivalent to a 0.5 cm3 change in hippocampal volume in terms of predicting HVLT at posttest 2. Over the full range of hippocampal volumes (1.335–5.182 cm3), the hippocampal volume term predicted a range of 4.1 points on the HVLT, or 34% of the full-scale (12 point) range. For comparison, the HVLT pretest score predicted a range of 6.38 points, or 53% of the full-scale HVLT range. The hippocampal prediction model also included a significant effect of age, whereby older individuals had better rehabilitation outcomes (1.6 points on HVLT across the span of four decades), and marginal effects of injury severity (severities greater than mild tended towards an average 0.85 point decrease in HVLT at outcome). Other results from our six regions of interest with volume terms exhibiting p < 0.05 appear in Table 5. This included the mFG which exhibited modest predictive value for HVLT at posttest 2 (coefficient = 0.27 on a 7.633 cm3 range) as well as at posttest 1, and the supramarginal gyrus, which predicted both HVLT and RBMT outcomes, but only at posttest 1.

Bottom Line: Fifty individuals with TBI of all severities who reported having memory difficulties first underwent structural MRI scanning.We identified several brain regions that provided significant predictions of rehabilitation outcome, including the volume of the hippocampus, the lateral prefrontal cortex, the thalamus, and several subregions of the cingulate cortex.The prediction range of regional brain volumes were in some cases nearly equal in magnitude to prediction ranges provided by pretest scores on the outcome variable.

View Article: PubMed Central - PubMed

Affiliation: Department of Psychiatry, Harvard Medical School Boston, MA, USA.

ABSTRACT
Cognitive deficits following traumatic brain injury (TBI) commonly include difficulties with memory, attention, and executive dysfunction. These deficits are amenable to cognitive rehabilitation, but optimally selecting rehabilitation programs for individual patients remains a challenge. Recent methods for quantifying regional brain morphometry allow for automated quantification of tissue volumes in numerous distinct brain structures. We hypothesized that such quantitative structural information could help identify individuals more or less likely to benefit from memory rehabilitation. Fifty individuals with TBI of all severities who reported having memory difficulties first underwent structural MRI scanning. They then participated in a 12 session memory rehabilitation program emphasizing internal memory strategies (I-MEMS). Primary outcome measures (HVLT, RBMT) were collected at the time of the MRI scan, immediately following therapy, and again at 1-month post-therapy. Regional brain volumes were used to predict outcome, adjusting for standard predictors (e.g., injury severity, age, education, pretest scores). We identified several brain regions that provided significant predictions of rehabilitation outcome, including the volume of the hippocampus, the lateral prefrontal cortex, the thalamus, and several subregions of the cingulate cortex. The prediction range of regional brain volumes were in some cases nearly equal in magnitude to prediction ranges provided by pretest scores on the outcome variable. We conclude that specific cerebral networks including these regions may contribute to learning during I-MEMS rehabilitation, and suggest that morphometric measures may provide substantial predictive value for rehabilitation outcome in other cognitive interventions as well.

No MeSH data available.


Related in: MedlinePlus