Cerebral amyloid angiopathy-related inflammation: clinical features and treatment response in a case series

INTRODUCTION

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is an entity characterised by an inflammatory response to β-amyloid deposition in the walls of cerebral microvessels.

METHODS

We conducted a retrospective review of a series of patients with a diagnosis of CAA-ri according to histopathological study findings or clinical-radiological diagnostic criteria.

RESULTS

The study included 7 patients (5 men) with a mean age of 79 years. Disease onset was acute or subacute in 6 patients. The most frequent symptoms were cognitive impairment (n = 6), behavioural alterations (n = 5), epileptic seizures (n = 5), focal neurological signs (n = 4), and headache (n = 2). Cerebrospinal fluid was abnormal in 3 patients (lymphocytic pleocytosis and high protein levels). The most frequent MRI findings were microbleeds (n = 7), subcortical white matter hyperintensities on T2-FLAIR sequences (n = 7), and leptomeningeal enhancement (n = 6). Lesions were bilateral in 3 patients and most frequently involved the parieto-occipital region (n = 5). Amyloid PET studies were performed in 2 patients, one of whom showed pathological findings. Two patients underwent brain biopsy, which confirmed diagnosis. All patients received immunosuppressive therapy. An initially favourable clinical-radiological response was observed in all cases, with 2 patients presenting radiological recurrence after treatment withdrawal, with a subsequent improvement after treatment was resumed.

CONCLUSIONS

Early diagnosis of CAA-ri is essential: early treatment has been shown to improve prognosis and reduce the risk of recurrence. Although a histopathological study is needed to confirm diagnosis, clinical-radiological criteria enable diagnosis without biopsy.

Cerebral amyloid angiopathy-related inflammation: clinical features and treatment response in a case series

INTRODUCTION

Cerebral amyloid angiopathy-related inflammation (CAA-ri) is an entity characterised by an inflammatory response to β-amyloid deposition in the walls of cerebral microvessels.

METHODS

We conducted a retrospective review of a series of patients with a diagnosis of CAA-ri according to histopathological study findings or clinical-radiological diagnostic criteria.

RESULTS

The study included 7 patients (5 men) with a mean age of 79 years. Disease onset was acute or subacute in 6 patients. The most frequent symptoms were cognitive impairment (n = 6), behavioural alterations (n = 5), epileptic seizures (n = 5), focal neurological signs (n = 4), and headache (n = 2). Cerebrospinal fluid was abnormal in 3 patients (lymphocytic pleocytosis and high protein levels). The most frequent MRI findings were microbleeds (n = 7), subcortical white matter hyperintensities on T2-FLAIR sequences (n = 7), and leptomeningeal enhancement (n = 6). Lesions were bilateral in 3 patients and most frequently involved the parieto-occipital region (n = 5). Amyloid PET studies were performed in 2 patients, one of whom showed pathological findings. Two patients underwent brain biopsy, which confirmed diagnosis. All patients received immunosuppressive therapy. An initially favourable clinical-radiological response was observed in all cases, with 2 patients presenting radiological recurrence after treatment withdrawal, with a subsequent improvement after treatment was resumed.

CONCLUSIONS

Early diagnosis of CAA-ri is essential: early treatment has been shown to improve prognosis and reduce the risk of recurrence. Although a histopathological study is needed to confirm diagnosis, clinical-radiological criteria enable diagnosis without biopsy.

[The glymphatic system and its involvement in disorders of the nervous system]

The central nervous system was thought to be devoid of lymphatics. Recently, the existence of an authentic brain lymphatic system, known as the glymphatic system, composed of paravascular channels penetrating arterial and venous brain vessels and dural lymphatics cleaning the interstitial space, has been demonstrated. Aquaporin-4, located in astrocyte feet attached to the paravascular spaces, plays a key role in the clearance of waste molecules, such as beta-amyloid or tau proteins. The activity of this system is increased during sleep, mainly in the slow wave phase and while sleeping on one side, and with exercise, and is reduced with aging. Even though data are still preliminary, the glymphatic system could be decisively involved in the pathophysiology of neurological disorders such as neurodegenerative and demyelinating diseases, normal pressure hydrocephalus, stroke or certain headaches. The discovery of this system should provide new opportunities for the treatment of these neurological disorders.