Background: delirium and dementia have been defined as different entities in the literature. Knowledge of the relationship between delirium and dementia which are the major causes of cognitive impairment in the elderly is scanty. There has not been any convincing demonstration of altered cognitive function to chronic cerebral ischemia associated with asymptomatic carotid artery disease and remains a concept which is continuously being debated.
Case presentation: a 79-year-old man with severe asymptomatic carotid artery disease presented with acute delirium. This was followed by three other episodes over a period of 32 months. He was cognitively and functionally normal prior to the first episode and in between the episodes of delirium. Following the fourth episode he exhibited significant cognitive and functional deterioration consistent with dementia. CT scan had shown a small focal hypodense lesion in the right region following the first episode. A duplex scan of the carotid arteries had shown extensive disease of both common carotids and internal carotid arteries. It is surmised that the dementia that followed was the result of a chronic cerebral ischemia resulting from the bilateral carotid artery disease.
Conclusions: if the true role of occlusive carotid artery disease and progressive cognitive decline is acknowledged then early endarterectomy may forestall the disaster. However the optimal treatment choice remains unclear.