The vanishing of the ACoA syndrome after aneurysmal subarachnoid haemorrhage: New era, different management, fewer problems?

Historically, a specific set of symptoms has been related to the rupture and repair of anterior communicating artery (ACoA) aneurysms. These consequences were defined as the ‘ACoA syndrome’ and included observations of severe memory loss, confabulation and personality or behavioural changes. These observations correspond to neuropsychological impairments in memory, executive functions and social cognition. However, in more recent studies, the existence of such a distinct syndrome has been called into question. We aimed to investigate the existence of the ACoA syndrome, by combining analysis of our own data with a systematic review of the literature. Memory, executive functions and social cognition of subarachnoid haemorrhage patients with ACoA aneurysms (N = 28) were compared to patients with aneurysms in other locations (N = 66). Results showed no significant differences. Subsequently, a systematic review of the existing literature on the ACoA syndrome was performed using Embase and PubMed until October 2022. Studies that investigated cognitive functions after rupture and repair of ACoA aneurysms were included. The search yielded 847 unique entries and after screening titles and abstracts, 648 records were excluded. 199 full-text articles were assessed for eligibility and 55 articles were included. Evidence was found for the ACoA syndrome in studies between 1960 and 2000, with impairments in memory and executive problems in the majority of studies. However, the majority of studies from 2000 did not demonstrate a distinct ACoA syndrome, although neuropsychological measurements improved. This coincides with the changes in the management of ACoA aneurysms over the past decades, such as the emergence of endovascular treatment and improvement of neurointensive care. Therefore, we hypothesize that the management techniques of ACoA aneurysms until around 2000, i.e. mainly conventional clipping, could be related to the presence of symptoms of the ACoA syndrome.