Table 4.

Staging of Alzheimer's disease‐related neuronal pathology on the basis of density and regional distribution of IHC/AT8 immunopositive neuropil threads. The density is scored on a four step scale 0‐none; +‐some; ++‐moderate; +++ severe (see also Figure 6). Abbreviations: IHC = immunohistochemistry.

Section number	Region		Stage I	Stage II	Stage III	Stage IV	Stage V	Stage VI
Occipital cortex	Area 17		0–+	0–+	0–+	0–+	0–+	++–+++
	Area (18)/19		0–+	0–+	0–+	0–+	++–+++	++–+++
Temporal cortex			0–+	0–+	0–+	++–+++	++–+++	++–+++
Anterior hippocampus	Occipito‐temporal gyrus		0–+	0–+	++–+++	++–+++	++–+++	++–+++
	Entorhinal region	Outer layers	0–+	++–+++	++–+++	++–+++	++–+++	++–+++
		Inner layers	0–+	+–+++	++–+++	++–+++	++–+++	++–+++
	Transentorhinal region		+–+++	++–+++	++–+++	++–+++	++–+++	++–+++
Posterior hippocampus	Occipito‐temporal gyrus		0–+	0–+	++–+++	++–+++	++–+++	++–+++
	Remnants of the entorhinal region	Outer layers	0–+	++–+++	++–+++	++–+++	++–+++	++–+++
		Inner layers	0–+	+–+++	++–+++	++–+++	++–+++	++–+++

In stages I to VI various numbers of IHC/AT8‐labeled neurons are seen, but the presence of IHC/AT8‐positive neurons is not used as a diagnostic criterion. The hallmark lesion for each Braak stage is given in bold.