Table 3.

Summary of structural MRI studies examining cognitive status subgroups.

Author (year)	Sample age (n)	Structural modality	Effect of Cognitive Status
			Frontal		MTL		Posterior		Whole brain
			YO	OO	YO	OO	YO	OO	YO	OO
Volumetry & Morphometry
Stricker et al. (2011)	60–91 (230)	Cortical thickness			+	o	+	o
Barkhof et al. (2007)	85–105 (132)	Volume				+
Gosche et al. (2002)	87–93 (56)	Volume				+
Lopez et al. (2014)	72–96 (183)	Volume			+	+
Yang et al. (2016b)	71–103 (244)	Volume	+	+	+	+	+	+
Holland et al. (2012)	65–90 (723)	Volume			+	+	+	o	+	o
Rosano et al. (2012)	M=83 (258)	Δ Volume				−
White matter hyperintensities & Microstructure
Rosano et al. (2012)	M=83 (258)	Δ MD		−				−
Zamboni et al. (2019)	20–102 (566)	WMH, FA, MD	+	o					+	o
Polvikoski et al. (2010)	85–104 (132)	WMH		+
Tanskanen et al. (2013)	85–105 (123)	WMH								o
Yang et al. (2016b)	71–103 (244)	WMH							o	o
Rosano et al. (2012)	M=83 (258)	Δ WMH								o

Notes. For each structural modality and brain region, symbols indicate observations of better (+), worse (−), or no difference (o) in brain structure (i.e., smaller volume, more white matter hyperintensities [WMH], higher diffusivity for cognitively normal younger-old (YO) and/or oldest-old (OO) age groups relative to those with cognitive impairment or Alzheimer’s disease and other dementias. Volumetry and morphometry studies are sorted by age effects in the medial temporal lobe (MTL). WMH and microstructure studies are sorted by age effects in the frontal lobe followed by the whole brain. FA = fractional anisotropy, MD = mean diffusivity, Δ = longitudinal change.