Table 2 Relevant differential diagnoses of CAA-ri
From: Diagnosis, pathomechanisms and therapy of cerebral amyloid angiopathy-related inflammation (CAA-ri)
Category | Disease(s) | Clinical + radiological characteristics |
|---|---|---|
Vascular | Sporadic CAA | Diagnosis by modified Boston criteria Symmetric WMH Normal levels of anti-Aβ autoantibodies Neuropathology: absence of peri-/ transmural vascular inflammation |
PRES syndrome | Causes: hypertension, (pre)eclampsia, immunosuppressives, cytotoxic therapies, systemic autoinflammatory diseases FLAIR-hyperintense bilateral symmetric lesions, mainly in occipital lobe \(\pm\) posterior parts of the parietal/ temporal lobes and frontal region Mostly subcortical location of lesions | |
RCVS | Younger patient cohort (~ 42 years) Thunderclap headache \(\pm\) focal neurological signs and epileptic seizures Cerebral angiography: ‘string of beads’ pattern MRI: symmetric reversible brain edema (comparable to PRES), infarctions in ‘watershed regions’, ICH of variable size with cortical predominance, subarachnoid hemorrhage | |
Autoinflam-matory | PACNS | Younger patient cohort (onset ~ 4th decade) Lumbar puncture: frequent (80–90%) presence of decent lymphocytic pleo-cytosis + elevated protein concentration DSA: possible ‘vessel beading’ MRI: pronounced leptomeningeal en-hancement, multifocal lesions, vessel wall enhancement + thickening in black blood sequences |
Neoplastic | Low-grade glioma | T1: solid without enhancement, T2: hyperintense signal DWI: no significant diffusion restriction |
Infectious | PML | Hyperintense, multifocal FLAIR lesions, frequently in frontal + parieto-occipital lobes Absence of microbleeds in T2* GRE/ SWI sequence Elevated JC virus PCR results |