Subdural hemorrhage, intradural hemorrhage and hypoxia in the pediatric and perinatal post mortem: Are they related? An observational study combining the use of post mortem pathology and magnetic resonance imaging

Abstract Background and purpose Controversies exist over the causes of intradural hemorrhages (IDH), subdural hemorrhages (SDH) and hypoxia. SDH is a recognised finding at perinatal and pediatric autopsy. We describe the occurrence of IDH, SDH, and hypoxia in these deaths using a combined approach of post mortem magnetic resonance imaging (PM MRI), autopsy examination and histology. Material and methods Forty-two cases (1 day to 4 years, mean 6.9 months) underwent PM MRI and autopsy. Two further children (8 and 32 month of age) underwent autopsy only. MRI was conducted with a 1.5 T Magnet with fast spin-echo T2 weighted images, the images were assessed for the presence of SDH, hypoxia and structural abnormalities. Hypoxia was defined by a low signal in the ventrolateral thalami and peri-rolandic regions on MRI. Edema was interpreted as early acute hypoxia. On histology, hypoxia was defined by the presence of hypoxic neurons. Results IDH was seen histologically in 35/39 cases: diffuse in 17 and focal in 18. On the PM MRI focal IDH was not distinguished, and DIDH was only retrospectively suggested as a low signal around the venous sinuses or prominent venous sinuses, predominantly in the posterior falx and tentorium. Confident identification on the MRI was not possible. 12/17 cases with DIDH were less than a week old. SDH was seen in 11 cases on PM MRI. SDH was seen at autopsy in the same 11 cases and in the 2 cases where no PM MRI was performed. DIDH was seen in all these cases on histological examination (except in 1 case where the dura had not been sampled). Acute hypoxia was present in 14/42 cases both on histology and MRI. In 1 case changes of hypoxia were seen on MRI only. In 7 cases the hypoxia was seen on histology only. 12/13 cases with SDH had features of hypoxia. Of the cases with DIDH on histology 14/17 had hypoxia (on MRI, histology, or both). Conclusion IDH and SDH are frequent findings in the perinatal and pediatric autopsy. SDH was associated with a DIDH and was also frequently associated with hypoxia. Focal IDH was not identified at the PM MRI; it was associated with hypoxia (on MRI and/or on histology) in less than a quarter of cases. Our results exhibit an association between IDH, SDH and hypoxia in children dying of natural causes. The highest incidence is seen in the perinatal period.