Haemorrhagic transformation in ischaemic stroke is more frequent than clinically suspected – A neuropathological study

Abstract

ObjectivesThe vast majority of literature on the frequency of the haemorrhagic transformation of ischaemic stroke is based on imaging studies. The purpose of the present study was to assess the added value of autopsy and neuropathological analysis in a neurology centre with emphasis on acute stroke care. MethodsWe retrospectively analysed the findings of 100 consecutive brain autopsies followed by detailed clinical correlation. ResultsThe clinical diagnosis was confirmed by neuropathology in every patient with intracerebral haemorrhage and with non-cerebrovascular neurological disorders (e.g. primary tumours, metastases, infections). At admission 64 patients (age 62 years, SD 6.5) were diagnosed with acute ischaemic stroke. In 10 of these patients (16%) haemorrhagic transformation was diagnosed clinically by a second CT. In 24 cases (38%) haemorrhagic transformation was detected only at autopsy. The distribution of haemorrhagic transformation in our material was the following: small petechiae in 26.5%, more confluent petechiae in 29.4%, ≤ 30% of the infarcted area with some mild space-occupying effect in 29.4% and > 30% of the infarcted area with significant space-occupying effect or clot remote from infarcted area in 14.7%. Most of the PH1-2 transformations developed in thrombolysed patients and all of the PH2 type transformations were diagnosed already clinically. ConclusionsWe demonstrated that haemorrhagic transformation is frequent and often undiscovered in vivo. Our findings underline the importance of post-mortem neuropathological examination also in the era of advanced imaging techniques and prove that autopsy is the ultimate yardstick of our diagnostic and therapeutic efforts. The high number of haemorrhagic transformations diagnosed only after death is an important novel finding with clinical implications.

Haemorrhagic transformation following ischaemic stroke: A retrospective study

“…Studies from Singapore and south east Asian populations suggest that the frequency of haemorrhagic stroke is higher than in the Caucasian population 22 , however the overall frequency of ischaemic stroke remains high in Asian populations 23 . As compared to our data, in earlier studies by Hornig et al, HT was observed in 28 out of 65 patients (43%) over a four-week period 3 , and the frequency of HT was 29% in one neuropathological study 4 . The percentage of HT in studies of stroke patients varies from 6.4 to 43% 7,11,15,17,[24][25][26][27][28][29] .…”

Discrepancies between clinical and autopsy findings in patients who had an acute stroke

“… 24 25 In an earlier autopsy study conducted at our clinic (in 64 patients with cerebral ischaemia), we found haemorrhagic transformation of an infarct in 38% of the patients. 26 This proportion was similar in the present study (in over half thousand patients): we found a rate of 35%. A haemorrhagic transformation of an infarct increases both early and late mortality after ischaemic stroke.…”

“…The incidence rate reported in literature only depends on whether CT-reported transformations (13%–43%) or asymptomatic/symptomatic cases (0.6%–20%) were considered 24 25. In an earlier autopsy study conducted at our clinic (in 64 patients with cerebral ischaemia), we found haemorrhagic transformation of an infarct in 38% of the patients 26. This proportion was similar in the present study (in over half thousand patients): we found a rate of 35%.…”

The role of the blood–brain barrier during neurological disease and infection

“…Increased BBB permeability leading to cerebral oedema [ 68 , 79 ] and haemorrhagic transformation [ 80 , 81 ] are common complications of ischaemic stroke, which can impact the outcome of these patients with potential serious and life-threatening consequences [ 82 ]. A series of factors or events in combination or in sequence can lead to BBB disruption in ischaemic stroke.…”