Techniques in neuropathology

The primary objective for a neuropathologist is the characterization of the tissue that is being assessed and thus all available techniques ranging from naked-eye examination to assessment of genetic/epigenetic characteristics are currently applied. What is observed in the tissue obtained from a diseased subject is compared with what is observed in a healthy individual and, based on the outcome, neuropathologic definitions of diseases are constructed. Thus, with the naked eye a neuropathologist can confirm that a hemorrhage is observed in the brain, by histologic examination that the hemorrhage is caused by alterations in the brain vessels and, since 1954, applying Congo red dye neuropathologists have been able to state that congophilic angiopathy is detected. Since 1984, applying immunohistochemical methods neuropathologists have been able to verify that the protein seen in the vessel walls is β-amyloid and by genetic/epigenetic analysis eventual mutation or modifications of genome might be detected. The development of new techniques is staggering and throughout this book the authors have listed techniques currently applied while assessing various disease-related hallmark lesions. In the following a general summary of techniques applied is given.