Table 3.

Percentage differences in hippocampal subfield volumes (left and right considered separately) between healthy controls, tAD early-onset Alzheimer's disease patients, and PCA early-onset Alzheimer's disease patients estimated using linear regression models (co-variates = age, gender & TIV).

		tAD vs HC		PCA vs HC		tAD vs PCA
		Mean % differencea	p-value	Mean % differencea	p-value	Mean % differenceb	p-value
CA1	L	−15%	<0.001**	−2%	0.49	−12%	0.001**
	R	−13%	<0.001**	−6%	0.12	−8%	0.049*
CA2/3	L	−15%	<0.001**	−3%	0.51	−12%	0.017*
	R	−19%	<0.001**	−10%	0.019*	−10%	0.052
CA4	L	−19%	<0.001**	−8%	0.041*	−12%	0.004*
	R	−15%	<0.001**	−10%	0.004*	−5%	0.17
Pre-subiculum	L	−16%	<0.001**	−16%	0.002**	0%	0.99
	R	−12%	<0.001**	−15%	0.003*	+3%	0.59
Subiculum	L	−18%	<0.001**	−10%	0.019*	−9%	0.045*
	R	−17%	<0.001**	−16%	<0.001**	−1%	0.77
Tail	L	−24%	<0.001**	−6%	0.26	−18%	0.002**
	R	−16%	<0.001**	−5%	0.21	−11%	0.017*
Para-subiculum	L	−13%	0.036	−13%	0.1	0%	0.99
	R	−11%	0.15	−7%	0.41	−3%	0.76
GCMLDG	L	−20%	<0.001**	−11%	0.007*	−11%	0.017*
	R	−16%	<0.001**	−12%	<0.001**	−5%	0.26
Molecular layer	L	−18%	<0.001**	−9%	0.013*	−10%	0.008*
	R	−17%	<0.001**	−12%	<0.001**	−5%	0.15
HATA	L	−22%	<0.001**	−10%	0.076	−13%	0.039*
	R	−22%	<0.001**	−21%	<0.001**	−2%	0.78
Total volume	L	−19%	<0.001**	−9%	0.01*	−11%	0.002**
	R	−16%	<0.001**	−11%	<0.001**	−6%	0.089

Key: TIV = total intracranial volume; GCMLDG = Molecular and Granule Cell Layers of the Dentate Gyrus; HATA = Hippocampal Amygdala Transition Area; PCA = posterior cortical atrophy; tAD = typical Alzheimer's disease; *p ≤.05 – standard statistical threshold; **p ≤ 0.0025 – Bonferroni corrected threshold;

^aExpressed as percentage of mean unadjusted volume for relevant subfield in healthy control participants;

^bExpressed as percentage of mean unadjusted volume for relevant subfield in PCA patients.