[Ultrastructural pathology of mechanical skeletal muscle damage]

Haemorrhages into the back and auxiliary breathing muscles after death by hanging

We describe and discuss haemorrhages discovered in the back and auxiliary breathing muscles of a population of cases of suicidal death by hanging. Intramuscular haemorrhages were present in approximately 30% of the cases. Pre-existing illnesses with an increased tendency to bleed or an anticoagulant medication did not exist; corresponding skin and subcutaneous fatty tissue structures were intact in each case. In cases of death by hanging, the occurrence of muscle haemorrhages of this type may be explained pathophysiologically by the occurrence of increased respiratory exertions and/or seizures during the hanging process. Although the results of our study do not indicate an obligatory autopsy finding, evidence of internal haemorrhaging into the back and auxiliary breathing muscles may be called upon following consideration of differential diagnostic aspects as a further diagnostic indication of vital hanging.

Light microscopical investigations on structural changes of skeletal muscle as artifacts after postmortem stimulation

Samples of skeletal muscle were taken from 20 human corpses where mechanical or electrical stimulation had been carried out up to 8h postmortem (hpm) in order to estimate the time since death. The stimulation had caused an idiomuscular bulge or tetanic contraction of the muscle tissue at this location. The muscle samples were examined for structural changes of the fibers by light microscopy. A comparison with control muscle samples taken contralaterally from the same corpse, showed that the findings previously interpreted as being of intravital origin, e.g. destruction of fiber integrity, invagination and contraction bands, could also be due to postmortem alterations. It is hypothesized that structural changes to the muscle fibers can, in general, be produced as long as the manifestation time is shorter than the supravital phase after the time of force impact.

Immunohistochemical alterations after muscle trauma

The proteins fibrin, fibrinogen, fibronectin and complement C5b-9 were investigated in mechanically damaged skeletal muscle. An accumulation of fibrin, fibrinogen and fibronectin could be observed immediately after intra-vital trauma in damaged fibre zones, later an accumulation at the torn edges of the fibres. The accumulation of complement C5b-9 began one hour after trauma. After post mortem trauma no positive reactions could be observed for any of the proteins. The degree of expression of these proteins can therefore be used to differentiate between vital and postmortem muscle damage as well as the estimation of wound age in the early antemortem time period.