Tau and TDP-43 accumulation of the basal nucleus of Meynert in individuals with cerebral lobar infarcts or hemorrhage

A previous study reported that a massive cerebral infarct in the territory of the middle cerebral artery (MCA) may be associated with development of neurofibrillary tangles (NFTs) in the ipsilateral basal nucleus of Meynert (BNM). We analyzed 19 cases of an MCA territory infarct and 12 with a putaminal hemorrhage (mean age 82.5 years; female/male ratio 8/23; mean time from stroke onset to autopsy 4182 days). In both groups, 74–100% had a significantly higher rate of phosphorylated tau immunoreactive or Gallyas Braak silver stain-positive neurons on the BNM-affected side than on the BNM-unaffected side. These NFTs were immunoreactive for anti-RD3 and anti-RD4 antibodies, and a triple-band pattern was observed by immunoblot analysis with anti-tau antibody. Most NFTs might be formed within the 5–10 years after stroke onset. There were significantly more TAR DNA-binding protein 43 (TDP43) immunoreactive structures on the BNM-affected side than on the BNM-unaffected side. We showed that many NFTs with TDP43-immunoreactive structures were observed in the ipsilateral BNM associated with a massive cerebral infarct in the MCA territory or a putaminal hemorrhage.