PENETRATING GUNSHOTS TO THE HEAD AND LACK OF INTERMEDIATE INCAPACITATION .2. REVIEW OF CASE-REPORTS

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 in capacitation. However, in the last century numerous publications repor ted sustained capability to act following penetrating gunshot wounds o f 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 su stained capability to act are present in cases where the additional wo unding resulting from the special wound ballistic qualities of the hea d (see companion paper) are minimized. Thus, more than 70% of the guns used fired slow and lightweight bullets: 6.35 mm Browning, .22 rimfir e or extremely ineffective projectiles (ancient, inappropriate or self made). A centre-fire rifle or a shotgun from close range were never em ployed in cases involving intracerebral tracts. A coincidence of sever al lucky circumstances made sustained capability to act possible in tw o cases of military centre-fire rifle bullets passing longitudinally b etween the frontal lobes without direct contact with brain tissue. Onl y two large handguns resulting in intracerebral wounding were used: on e firing a .38 special bullet, which solely wounded the base of the ri ght temporal lobe and one firing a .45 lead bullet, which seriously in jured the left frontal lobe but whose trajectory was limited to the an terior fossa of the skull. Of the trajectories, 28% were outside the n eurocranium. At least 70% of the craniocerebral tracts passed above th e anterior fossa of the skull, wounding the frontal parts of the brain . Apart from a neurophysiological approach, this preference can be exp lained 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 th e brain located in its ''shadow'' relative to the trajectory against c avitational tissue displacement and associated overpressures. This is particularly true of the brain stem. Intracerebral trajectories not lo cated above the anterior fossa were caused by slow and lightweight bul lets 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 inj ury to the brain stem, the diencephalon, the cerebellum or major paths of motor conduction and only one grazing shot of the anterior parts o f the nucleus caudatus (basal ganglia) were described. Morphological s igns of high intracranial pressure peaks (cortical contusion zones, in direct skull fractures, perivascular haemorrhages) and secondary missi les were poorly documented. It is suggested that these findings are at least very rare and not obvious in cases of sustained capability to a ct.