Assessing the effects of age on long white matter tracts using diffusion tensor tractography

By Simon W. Davis, Nancy A. Dennis, Norbou Buchler, Leonard E. White, David J. Madden, Roberto Cabeza. NeuroImage, 2009

468 citations recorded by the source corpus.

Aging is associated with significant white matter deterioration and this deterioration is assumed to be at least partly a consequence of myelin degeneration. The present study investigated specific predictions of the myelodegeneration hypothesis using diffusion tensor tractography. This technique has several advantages over other methods of assessing white matter architecture, including the possibility of isolating individual white matter tracts and measuring effects along the whole extent of each tract. The study yielded three main findings. First, age-related white matter deficits increased gradually from posterior to anterior segments within specific fiber tracts traversing frontal and parietal, but not temporal cortex. This pattern inverts the sequence of myelination during childhood and early development observed in previous studies and lends support to a “last-in-first-out” theory of the white matter health across the lifespan. Second, both the effects aging on white matter and their impact on cognitive performance were stronger for radial diffusivity (RD) than for axial diffusivity (AD). Given that RD has previously been shown to be more sensitive to myelin integrity than AD, this second finding is also consistent with the myelodegeneration hypothesis. Finally, the effects of aging on select white matter tracts were associated with age difference in specific cognitive functions. Specifically, FA in anterior tracts was shown to be primarily associated with executive tasks and FA in posterior tracts mainly associated with visual memory tasks. Furthermore, these correlations were mirrored in RD, but not AD, suggesting that RD is more sensitive to age-related changes in cognition. Taken together, the results help to clarify how age-related white matter decline impairs cognitive performance.

Subfields: Cognitive Neuroscience, Radiology, Nuclear Medicine and Imaging

View Paper: https://www.semanticscholar.org/paper/6808a343925c0bbd654e7fe231ff99c8cc9210a1

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Cognitive Neuroscience

In Radiology, Nuclear Medicine and Imaging

Citations in the corpus

Life-span changes of the human brain white matter: diffusion tensor imaging (DTI) and volumetry. (2010, background): “…well documented (O'Sullivan et al. 2001; Head et al. 2004; Pfefferbaum et al. 2005; Salat, Tuch, Greve, et al. 2005; Charlton et al. 2006; Sullivan and Pfefferbaum 2006; Ardekani et al. 2007; Grieve et al. 2007; Abe et al. 2008; Hugenschmidt et al. 2008; Davis et al. 2009; Kennedy and Raz 2009a).”
Tractography - where do we go from here? (2011, unknown): “Tractometry has been used to study brain development (Eluvathingal et al., 2007; Huang, 2010), ageing (Davis et al., 2009; Hasan et al., 2010; Hsu et al., 2010; Michielse et al., 2010; Sala et al., 2010), clinical markers (Ciccarelli et al., 2008; Johansen-Berg, 2010; Johansen-Berg and Behrens,…”
Tract Profiles of White Matter Properties: Automating Fiber-Tract Quantification (2012, methodology): “Recent reports have emphasized the utility of analyzing diffusion properties along the tract trajectory in healthy brain anatomy [24,25], development [26], aging [27], and clinical conditions [28–32].”
Growing together and growing apart: Regional and sex differences in the lifespan developmental trajectories of functional homotopy (2010, methodology): “This ordering is consistent with a “last-in-firstout” aging effect, which has been described previously for measures of white matter integrity (Raz, 2000; Davis et al., 2009).”
Motor control and aging: links to age-related brain structural, functional, and biochemical effects. (2010, unknown): “…along an anterior to posterior gradient, such that fractional anisotropy is lowest and diffusivity is highest in anterior relative to posterior fiber bundles for older adults (Davis et al., 2009; O'Sullivan et al., 2001; Salat et al., 2005; Sullivan et al., in press; Zahr et al., 2009).”
Partial volume effect as a hidden covariate in DTI analyses (2011, background): “The interest by many researchers in these bundles has resulted in an abundance of information about diffusion changes, and thus valuable reference material for this study (Davis et al., 2009; Huster et al., 2009; Jones et al., 2006; Lebel et al., 2008; Malykhin et al., 2008; Salat et al., 2005).”
White matter damage and cognitive impairment after traumatic brain injury (2010, unknown): “A similar relationship between frontal connectivity and executive function has been observed in studies of normal ageing, where, in older adults, reduced integrity in tracts connecting frontal regions predicts executive dysfunction (O’Sullivan et al., 2001; Davis et al., 2009; Perry et al., 2009).”
Plasticity of Brain Networks in a Randomized Intervention Trial of Exercise Training in Older Adults (2010, unknown): “…age has the greatest impact on structural integrity of the frontal and medial temporal cortices and progressively lesser impact on posterior brain regions such as the parietal and occipital cortices (O’Sullivan et al., 2001; Raz et al., 2005; Davis et al., 2009; Fjell et al., 2009).”
Bilingualism: Consequences for Mind and Brain (2012, background): “This evidence suggests that bilingualism is associated with better maintenance of white matter structures in the course of normal aging [113].”