Biomedical subjects
Publications and source records attributed to B Karger.
A man committed suicide with a modified signal pen gun and a .22 lr HV HP bullet. The contact shot to the left chest led to a conventional entrance wound. The projectile from the unconventional weapon caused a penetrating wound and was not deformed instead of the expected perforation and deformation. The smooth-bore barrel did not leave characteristic firing marks on the bullet.
There are two distinct mechanisms of ballistic injury. Crushing of tissue resulting in a permanent tract is the primary factor in wounding of most tissues and most body regions. Temporary cavitation causes radial tissue displacement and subsequent shearing, compression and especially stretching of tissue analogous to blunt trauma. In contrast to the effect in elastic tissue, temporary cavitation can contribute substantially to wounding of inelastic tissue, such as the brain. This is the case in penetrating gunshot wounds to the head. Additionally, the penetration of the bony cranium can produce secondary missiles in the form of bone or bullet fragments and a tendency of the bullet to deformation and early yaw. Most important, wounding resulting from temporary cavitation is greatly augmented by the confined space provided by the unyielding walls of the skull. Bone contact and enhanced effects of temporary cavitation result in an enlarged zone of disintegrated tissue and in high intracranial peak pressures. Morphological signs of powerful intracranial pressure effects are cortical contusion zones, indirect skull fractures and perivascular haemorrhages remote from the tract. Depending on ballistic and anatomical parameters, the intracranial effect varies from slightly more severe injury than in isolated soft tissue to an "explosive" type of injury with comminuted fractures of the skull and laceration of the brain. Incapacitation is the physiologically based inability to perform complex and longer lasting movements independent of consciousness or intention. Immediate incapacitation is possible following cranio-cerebral gunshot wounds or wounds that disrupt the upper cervical spinal cord only. Rapid incapacitation can be produced by massive bleeding from major vessels or the heart. Immediate incapacitation is the result of primary intracranial effects of the bullet. A mechanism similar to commotion cerebri applied extracranially does not exist in cases of penetrating gunshot wounds to the head.
Because of the enhanced intracranial tissue disruption (see companion paper) and the functional significance of the central nervous system, penetrating gunshot wounds of the head commonly result in immediate incapacitation. However, in the last century numerous publications reported sustained capability to act following penetrating gunshot wounds of the head. These are reviewed. A large number of case reports had to be excluded from re-examination because of doubtful capability to act or lack of morphological documentation. There remained 53 case reports from 42 sources for systematic analysis. Favourable conditions for sustained capability to act are present in cases where the additional wounding resulting from the special wound ballistic qualities of the head (see companion paper) are minimized. Thus, more than 70% of the guns used fired slow and lightweight bullets: 6.35 mm Browning, .22 rimfire or extremely ineffective projectiles (ancient, inappropriate or selfmade). A centre-fire rifle or a shotgun from close range were never employed in cases involving intracerebral tracts. A coincidence of several lucky circumstances made sustained capability to act possible in two cases of military centrefire rifle bullets passing longitudinally between the frontal lobes without direct contact with brain tissue. Only two large handguns resulting in intracerebral wounding were used: one firing a .38 special bullet, which solely wounded the base of the right temporal lobe and one firing a .45 lead bullet, which seriously injured the left frontal lobe but whose trajectory was limited to the anterior fossa of the skull. Of the trajectories, 28% were outside the neurocranium. At least 70% of the craniocerebral tracts passed above the anterior fossa of the skull, wounding the frontal parts of the brain. Apart from a neurophysiological approach, this preference can be explained by the fact that the base of the anterior cranial fossa and the sella turcica area serve as a bony barrier protecting the parts of the brain located in its "shadow"' relative to the trajectory against cavitational tissue displacement and associated overpressures. This is particularly true of the brain stem. Intracerebral trajectories not located above the anterior fossa were caused by slow and lightweight bullets preferring one temporal lobe. Additionally, one parietal and one occipital lobe were each injured once by a very ineffective projectile and by a 7.65-mm bullet reduced in velocity. Not a single case of injury to the brain stem, the diencephalon, the cerebellum or major paths of motor conduction and only one grazing shot of the anterior parts of the nucleus caudatus (basal ganglia) were described. Morphological signs of high intracranial pressure peaks (cortical contusion zones, indirect skull fractures, perivascular haemorrhages) and secondary missiles were poorly documented. It is suggested that these findings are at least very rare and not obvious in cases of sustained capability to act.
30 autogenic and allogenic (homologous) cartilage grafts removed from the middle ear after an average time of 9 years and a maximal time of 25 years were studied by light microscopy. Half of the grafts showed signs of cellular vitality. Degeneration and avital cells are predominant in all grafts. Persisting residual vitality does not influence resorption and matrix necrosis in other areas of the graft. More than two thirds show structural changes by cellular resorption, infraction and vascularisation. These changes appear mainly independent of the time elapsed after transplantation. 5 grafts show bone new formation. Circumscript necrosis of the cartilage matrix was seen in 12 grafts. The study indicates that in comparison to ossicles or alloplastic material cartilage is less advisable to be used for the reconstruction of the ossicular chain due to the unpredictable degradation and loss of form stability.
In this study 130 ossicular middle ear transplants were studied. 33 remained in the middle ear for 10 years or longer, one for 21 years. The majority of the grafts show 5% to 40% bone new formation. Absence of vital bone or subtotal host bone replacement is exceptional. The amount of bone new formation appears independent the implantation time. 75% of the grafts show no bone resorption. In 15% sound transmitting might be impaired due to resorption. Grafts with a high degree of bone new formation show less resorption. 21% of the ossicles have signs of inflammation. Inflammation boosts bone turnover with resorption on one hand and new for resorption. Cholesteatoma is the main cause of resorption and inflammation. The critical phase for resorption of the graft are the first two to three years after transplantation. No considerable difference was found between autografts and allografts (homografts). Histological and metabolical properties of the ossicles seem to be responsible for the stability of the graft. Ossicular grafts have a good longterm stability which makes them very suitable for reconstruction of the ossicular chain.
Two suicides with home-made guns firing conventional ammunition are reported. Three different classes of homemade guns can be distinguished. Special characteristics of the interior and exterior ballistics of the home-made guns caused unusual muzzle imprints, intensive soot deposits at the entrance wounds and on the hands, intensive CO-effects, burns and in one case a skin laceration of the hand holding the weapon. The bullets showed a reduced penetration depth, characteristic firing marks were missing.
A man committed suicide by a contact shot to the left chest from a nail-gun. The nail caused a slit-like entrance wound and a penetrating heart injury. The front side of the nailgun led to an outer "muzzle imprint", the muzzle and the nail to an inner "muzzle imprint". Wound ballistics of nails are discussed.
A case of physical activity following a suicidal gunshot to the head including perforation of the left frontal lobe from a .22 rimfire rifle is reported. Subsequently, the man was able to walk a distance of more than 100 m and to reload manually. The special wound ballistic features of the head leading to increased intracranial projectile effects are discussed and the morphological changes such as cortical contusion zones, intracerebral hemorrhages or indirect skull fractures are explained. The analysis of 38 cases of head shots followed by physical activity reveals that injury to certain CNS-areas or the use of centre fire rifles and large handguns usually excludes a potential for subsequent physical activity. But physical activity is possible if the trajectory is restricted to the frontal brain or one temporal lobe only and if a projectile of low wounding potential has been used for this gunshot.
A multicentre study involving 36 out of 38 German medico-legal Institutes discovered 784 non-natural fatalities among 78,000 external examinations before cremation (1%) in 1995. These included 169 accidents, 16 suicides, 3 homicides and 589 deaths in connection with medical treatment. In the remaining 7 cases, a belated differentiation between homicide and accident was not successful. A linear projection results in 1980 non-natural fatalities among all 197,000 external examinations before cremation. This number includes 8 homicides but due to considerable inhomogeneities, a number of 40 homicides appears to be realistic. Consequently, abolishing the mandatory external examination before cremation would be equivalent to an official renouncement of solving relevant non-natural deaths. In case of a thorough external examination, a total of 18,000 non-natural fatalities including approximately 180 homicides could be detected per year during the first external examinations (n = 885,000).