Transthyretin amyloid deposition Cerebral transthyretin amyloid deposition 2025-10-26T08:40:29Z Accumulation of misfolded transthyretin protein in brain tissue. Leptomeninges and subarachnoid vessels affected earlier, followed by perforating cortical vessels and subpial deposition, and finally subependymal deposition and involvement of basal ganglia vessels near the ependymal lining. Interestingly, brainstem and spinal cord show early severe involvement, with amyloid subpial deposition already seen in the initial stages. Despite massive CNS amyloid deposition, no parenchymal deposition is found in the cortex or white matter.