Routine techniques in forensic neuropathology as demonstrated by gunshot injury to the head

It will be vital to the practical activity of every forensic and/or clinical pathologist to be able to answer three questions regarding the reconstruction of a lethal event: the type and cause of death, as well as the survival time. The authors offer an overview of the application of selected morphological techniques in general forensic neuropathology, techniques that provide answers to some of the main questions in forensic neurotraumatology. The methods are illustrated by individual cases of lethal gunshot injury to the head from low velocity handguns. Besides the general forensic tasks of interpretation of the crime scene and postmortem external examination of the victim's body a computed tomography is recommended for documentation and reconstruction of the missile track. The microscopic techniques involve Nissl-stain for neurons, hematoxylin and eosin for delayed ischemic neuronal alterations, microtubule-associated protein (MAP) expression for acute neuronal ischemia, luxol-fast-blue-stain for myelin destruction (and demyelination), silver-stain for axons, beta-amyloid precursor protein (beta-APP) for axonal injury, glial fibrillary acidic protein (GFAP) for astrocytic characterization, naphthol AS-D-chloroacetate esterase for neutrophilic infiltration and CD68-expression for microglial reaction. The pattern of methods lead--in the case of gunshot injury as well as in any traumatic impact to the head--to answers according the extent of tissue destruction (and the cause of death), the biometric reconstruction of the criminal event, and the timing of (gunshot) wounds of the brain. These methods will be indispensable for the preparation of future neuropathological expert reports addressing questions of type of injury, the consequent pathological symptoms, timing of the injury, and the cause of death.