B score

Braak score (4 levels) is a semiquantitative measure of severity of neurofibrillary tangle (NFT) pathology (see Braak stage ). Bielschowsky silver stain was used to visualize NFTs in the frontal, temporal, parietal, entorhinal cortex, and the hippocampus. Braak stages were based upon the distribution and severity of NFT pathology. Diagnosis includes algorithm and neuropathologist’s opinion.

Source: https://www.radc.rush.edu/docs/var/detail.htm?category=Pathology&subcategory=Alzheimer%27s+disease&variable=b_score