Cerebral amyloid angiopathy-related inflammation presenting with steroid-responsive higher brain dysfunction: case report and review of the literature

Abstract

A 56-year-old man noticed discomfort in his left lower limb, followed by convulsion and numbness in the same area. Magnetic resonance imaging (MRI) showed white matter lesions in the right parietal lobe accompanied by leptomeningeal or leptomeningeal and cortical post-contrast enhancement along the parietal sulci. The patient also exhibited higher brain dysfunction corresponding with the lesions on MRI. Histological pathology disclosed β-amyloid in the blood vessels and perivascular inflammation, which highlights the diagnosis of cerebral amyloid angiopathy (CAA)-related inflammation. Pulse steroid therapy was so effective that clinical and radiological findings immediately improved.CAA-related inflammation is a rare disease, defined by the deposition of amyloid proteins within the leptomeningeal and cortical arteries associated with vasculitis or perivasculitis. Here we report a patient with CAA-related inflammation who showed higher brain dysfunction that improved with steroid therapy. In cases with atypical radiological lesions like our case, cerebral biopsy with histological confirmation remains necessary for an accurate diagnosis.

MR Imaging Features of Amyloid-Related Imaging Abnormalities

“…Although the focus of this report is on imaging features of ARIA associated with therapeutic amyloid-modifying agents, similar imaging findings have been noted to occur spontaneously, such as in cerebral amyloid angiopathy. [9][10][11][12][13][14][15] Therapy-related ARIA should be a diagnostic consideration when specific imaging findings are encountered in the appropriate clinical setting-namely, a patient being treated with an amyloid-modifying agent with exclusion of other underlying pathologies. For the most part, clinical history will be of value as the patient will typically be asymptomatic, imaged as part of routine drug study surveillance (ie, safety scan).…”

“…Also of note are reports of spontaneous ARIA-like phenomena in patients with cerebral amyloid angiopathy, described as cerebral amyloid angiopathy-related inflammation, and in AD patients without identifiable underlying cerebral amyloid angiopathy on MR imaging. [9][10][11][12][13][14][15] An underlying endovascular inflammatory component has been described in this condition and may provide an additional potential mechanism involved with the ARIA phenomenon.…”

“…Both AD and cerebral amyloid angiopathy share a common neuropathology relating to the deposition of A␤, which affects arterial wall integrity and interference with perivascular drainage pathways. In this regard, it is interesting to note the imaging similarities between cerebral amyloid angiopathy-related inflammation [12][13][14][15] and ARIA-E associated with amyloid-modifying agents. Both conditions may reveal asymmetric, patchy, or confluent FLAIR hyperintense lesions with little or no enhancement after gadolinium administration and with imaging features suggesting noncytotoxic edema on DWI sequences.…”

Acute Delirium and Sub-acute Cognitive Decline in a Patient with Probable Cerebral Amyloid Angiopathy Related Inflammation

“…However, microbleeds might not be observed in all CAAri cases according to Sakaguchi's review [8]. Brain biopsy should be considered if CAAri is highly suspected from clinical presentation despite absence of microbleeds on brain MRI [8]. Our patient's brain MRI findings revealed confluent areas of asymmetric T2 FLAIR white matter hyperintensities over the bilateral temporal and occipital lobes; and T2 gradient-echo diffuse microbleeds over the bilateral corticalsubcortical junction.…”

“…Microbleeds present as a decreased or absent signal on T2 gradientecho sequences. However, microbleeds might not be observed in all CAAri cases according to Sakaguchi's review [8]. Brain biopsy should be considered if CAAri is highly suspected from clinical presentation despite absence of microbleeds on brain MRI [8].…”