Hereditary cerebral haemorrhage with amyloidosis, Dutch type (HCHWA-D): clinicopathological studies.

Clinical and neuropathological findings are reported in 63 patients with hereditary cerebral haemorrhage with amyloid angiopathy. Patients had mostly recurrent strokes, and at least 80% of these were haemorrhages. Almost a third of the patients died within a year of their first and only recorded haemorrhage, half of them within two weeks. This angiopathy was restricted to the cerebral and cerebellar cortex and its covering leptomeninges. As the most important consequence, haemorrhagic infarcts and haemorrhages occurred in the subcortical white matter--that is, the region most vulnerable to impaired cortical circulation. Further development of these subcortical lesions gives rise to the fatal haemorrhages seen at necropsy. In so far as dementia occurs this is likely to result from multiple microinfarcts or haemorrhages. In most cases preamyloid lesions or diffuse plaques and early plaques were seen. No other type of plaque or neurofibrillary degeneration was found. The plaques occur in conjunction with the angiopathy, but may not occur even when the angiopathy is severe. In one patient plaques were totally absent. Angiopathy and plaques may be the result of the same mutation, the expression of which is governed by tissue factors or phenotypic differences between individual subjects.