Neurologists need to be aware of rare CAAri, according to Northern Irish study

Irish Neurology Association 57th Annual Meeting, Virtual, 27-28 May 2021

The second session on the second day of the meeting was on the topic of cognitive and parkinson’s disease. During this session Dr Rachel Todd, Neurology Specialist Registrar, Royal Victoria Hospital, Belfast, presented
her study of cerebral amyloid angiopathy (CAAri)-related inflammation in Northern Ireland.

Dr Todd’s study was an epidemiological, clinical and radiological one spanning 10 years from 2011 to 2021, which aimed to reveal the incidence and prevalence of CAAri across Northern Ireland, to identify the range of clinical and radiological features and, further, to identify treatments given (if any) along with clinical outcomes. It is one of the first of its kind in western countries.

Cerebral amyloid angiopathy-related inflammation (CAAri) is a subtype of cerebral amyloid angiopathy (CAA), which is less reported. Although it has been recognised for 25 years, there remains a paucity of epidemiological data on the conditions. Observational reports on randomised control trials of effective therapy are only beginning to emerge, however, as yet there is no evidence of effective therapy in affected patients.

CAAri usually presents with subacute cognitive decline, seizures, focal deficit and headaches in patients over the age of 40 years. CAAri relies on pathology for a definite diagnosis. However, MRI would reveal asymmetric unifocal or multifocal WMH lesions, which extend to the immediately subcortical white matter. Corticosubcortical haemorrhagic lesions, cerebral microbleed, cerebral microbleed or cortical superficial siderosis may also be seen.

In the study a variety of treatments were used, including steroids in isolation, steroids with rituximab, steroids with mycophenolate mofetil, and steroids with cyclophosphamide. Over the course of the study, some patients experienced relapses, although Dr Todd noted that the numbers involved were too small to draw inferences. Although this is a rare condition, with an incidence of approximately one per million population per year, Dr Todd asserted that it is certainly a
condition which neurologists “need to be aware of”.