Subarachnoid extension of lobar hemorrhage on acute/subacute MRI is associated with cerebral amyloid angiopathy criteria.

Subarachnoid hemorrhage extension (SAHE) in the acute phase of cerebral amyloid angiopathy (CAA)-related lobar hemorrhage (LH) assessed by CT is very frequent. Recently, SAHE, together with finger-like projections on CT and ApoE4, has been used in a prediction model for histopathologically proven CAA showing excellent discrimination. Our aim was to analyze SAHE on MRI in the acute and subacute phase of LH in patients with and without associated hemorrhagic features supportive of CAA (i.e. chronic LH, cortical superficial siderosis [CSS], and strictly lobar cerebral microbleeds [CMB]). We retrospectively studied SAHE on MRI performed in the acute and subacute phase (within 21 days) in a cohort of consecutive patients with acute LH recruited between January 2012 and April 2018. Sixty-eight acute LH patients (35 men and 33 women, mean age 74 [range 50-89]) were analyzed. Mean delay between symptom onset and MRI was 3.8 days, and 32 patients underwent MRI within 24 h. Based on MRI, 51 patients were classified as probable CAA and 17 patients without probable CAA. Both groups were comparable regarding age, sex, time of MRI performance, MRI field strength, and acute LH volume. Overall, SAHE was observed in 46 (68%) patients, including 39 (76%) patients with probable CAA and 7 (41%) patients without probable CAA (p = 0.015). SAHE presence was also associated with larger LH volumes. During the work-up in the acute/subacute phase of patients with acute LH, in addition to T2*-weighted imaging in search for other hemorrhagic features (chronic LH, CSS, or lobar CMB) evoking probable underlying CAA etiology, search for SAHE on adapted MRI sequences (FLAIR and T2*-weighted imaging) seems to be interesting because of the association with the presence of probable CAA criteria.

Small obliquely oriented cortical cerebellar infarctions are associated with cardioembolic stroke.

BACKGROUND: A revised classification of cerebellar infarctions (CI) may uncover unrecognized associations with etiologic stroke subtypes. We hypothesized that obliquely oriented small cortical cerebellar infarction (SCCI) representing end zone infarctions on MRI would be associated with cardiac embolism. METHODS: We retrospectively analyzed consecutive stroke patients recruited between January-December 2016 in our center. Analyzed baseline characteristics: sex, age, cardiovascular risk factors, history of stroke or atrial fibrillation (AF). TOAST classification was used for determining stroke subtype. Acute infarction location (anterior/posterior/mixed anterior-posterior circulation), acute uni- or multiterritorial infarction, and acute or chronic CI/SCCI/non-SCCI were assessed by MRI, and vertebrobasilar stenosis/occlusion by vessel imaging. Pre-specified analysis was also performed in patients without known high cardioembolic risk (known AF history or acute multiterritorial infarction). RESULTS: We included 452 patients (CI in 154, isolated SCCI in 55, isolated non-SCCI in 50, and mixed SCCI/non-SCCI in 49). Both SCCI and non-SCCI were associated with AF history (SCCI, p = 0.021; non-SCCI, p = 0.004), additional acute posterior circulation infarction (p < 0.001 both CI-subtypes), multiterritorial infarctions (SCCI, p = 0.003; non-SCCI, p < 0.001) and cardioembolic more frequent than large-artery atherosclerosis origin (p < 0.001 for both CI-subtypes). SCCI was associated with older age (p < 0.001), whereas non-SCCI was associated with stroke history (p = 0.036) and vertebrobasilar stenosis/occlusion (p = 0.002). SCCI were older (p = 0.046) than non-SCCI patients, had less frequently prior stroke (p < 0.001), and more frequent cardioembolic infarction (p = 0.025). In patients without known high cardioembolic risk (n = 348), SCCI was strongly associated with subsequent cardioembolism diagnosis (OR 3.00 [CI 1.58-5.73, p < 0.001]). No such association was present in non-SCCI. CONCLUSIONS: Acute or chronic SCCI are strongly associated with a cardioembolic origin.

Anatomical relationship between carotid artery and styloid and hyoid bones in patients showing unintended head rotation on CTA.

Styloid process length and styloid/hyoid bone proximity to the internal carotid artery (ICA) have been implicated in certain carotid pathologies (e.g. carotid artery dissection). Neck movement or trauma may contribute to some of these carotid pathologies. Styloid/hyoid bone to ICA distances have never been systematically analyzed in regard to head rotation and head flexion-extension. We studied axial slices on computed tomography angiograms of 103 nondissection patients showing > 1° head rotation. We measured the distance between ICA and the hyoid bone (HICA) and the closest point and the tip of the styloid bone (SCICA and STICA, respectively), the length of the styloid, and the angle of head rotation and head flexion-extension. STICA distances were significantly smaller on the right as compared to the left side in both the right and the left rotating patient groups (right STICA, 4.4 mm for the right rotating group and 6.4 mm for the left rotating group, p = 0.0091; left STICA, 5.1 mm for the right rotating group and 6.9 for the left rotating group, p = 0.034). No significant differences were observed for SCICA and HICA distances between right and left rotating groups, and head flexion-extension did not altered significantly SCICA, STICA, or HICA distances. Both right- and left-sided head rotation seems to be associated with decreased right-sided and increased the left-sided styloid tip to internal carotid artery distances. This has to be studied and confirmed in single patient analyses using more severe head rotation and flexion-extension angles.

Cerebral Amyloid Angiopathy and Cerebral Amyloid Angiopathy-Related Inflammation: Comparison of Hemorrhagic and DWI MRI Features.

BACKGROUND: Cerebral amyloid angiopathy (CAA) can be associated with primary vasculitis of small/medium-sized leptomeningeal and cortical arteries, called CAA-related inflammation (CAA-ri). OBJECTIVE: To compare hemorrhagic and diffusion-weighted imaging (DWI) MRI features in CAA and CAA-ri. METHODS: We prospectively scored in a consecutive CAA and CAA-ri cohort: presence/number of chronic intracerebral hemorrhage (ICH), cerebral microbleeds (CMB), and cortical superficial siderosis (CSS) on initial T2*-weighted imaging, and DWI lesions on both initial and follow-up imaging. In a subgroup, ApoE, CSF, and 18F-florbetaben-positron emission tomography (FBB-PET) were also analyzed. RESULTS: In CAA-ri, CMB presence was more frequent (100% versus 40%, p < 0.001) and CMB numbers higher (mean 137 versus 8, p < 0.001). No difference was observed for chronic ICH or CSS. DWI lesions were more frequent in acute compared to chronic CAA-ri (p = 0.025), whereas no such difference was observed between acute and chronic CAA (p = 0.18). Both ApoE4 (genotyping available in 22 CAA-ri and 48 CAA patients) carriers and homozygosity were more frequent in CAA-ri (48% versus 19% [p = 0.014] and 32% versus 2% [p < 0.001] respectively). CSF biomarker analyses (performed in 20 CAA-ri and 45 CAA patients) showed lower Aß42 levels in CAA-ri compared to CAA (median 312 versus 422 pg/mL, p = 0.0032). FBB-PET (performed in 11 CAA-ri and 20 CAA patients) showed higher standardized uptake value ratios in CAA-ri compared with CAA, only significant when the pons was used as reference (p = 0.037). CONCLUSION: Compared to CAA, CAA-ri was associated with higher CMB numbers, more frequent ApoE4 carriers and homozygotes, lower CSF Aß42 levels, and more severe amyloid load on FBB-PET.

Infratentorial Cerebral Microbleeds in Patients with Cerebral Amyloid Angiopathy.

BACKGROUND: Cerebral microbleeds (CMBs) observed in hypertension-related arteriolosclerosis tend to occur in the supratentorial deep gray matter, whereas those in cerebral amyloid angiopathy (CAA) typically show a supratentorial lobar distribution. Recently, superficial spontaneous cerebellar intracerebral hemorrhage has been shown to be associated with strictly lobar CMBs. Few data exist on infratentorial CMBs in CAA. The purpose of this study was to describe the incidence, number, and characteristics of infratentorial CMBs in patients with CAA. METHODS: We performed a retrospective analysis of data derived from a prospectively recruited cohort of patients with possible or probable CAA according to the Boston criteria. RESULTS: A total of 115 patients with CAA (59% with CMBs) were analyzed. Eighteen percent of all patients with CAA had at least 1 infratentorial CMB. For patients with CMBs, presence and median CMB number were as follows: brainstem, 8% and 1; deep cerebellum, 4% and 1; superficial cerebellum, 10% and 1.5. Brainstem or deep cerebellum CMB was associated with the presence of and with higher numbers of supratentorial deep gray matter CMBs (P < .001 for both) and with hypertension (P = .048), whereas superficial cerebellar CMB was associated with the presence of and with higher numbers of supratentorial lobar CMBs (P < .001 for both). CONCLUSIONS: Based on our study, superficial cerebellar CMBs (in low numbers when present) seem to be a CAA-related phenomenon observed in a minority of patients who have CAA with a relatively high supratentorial lobar CMB load.

Characterizing Deep White Matter Hyperintensities in Patients with Symptomatic Isolated Cortical Superficial Siderosis.

BACKGROUND: In patient with cerebral amyloid angiopathy (CAA) presenting with lobar hemorrhage (LH), magnetic resonance imaging (MRI) white matter hyperintensities (WMH) tend to be predominant in posterior regions with the "multiple subcortical spots" WMH pattern as the most frequent topographical WMH pattern. Our aim was to analyze WMH severity and topographical distribution in patients with cortical superficial siderosis (CSS). METHODS: We retrospectively analyzed MRIs from consecutive symptomatic isolated (i.e., without LH) CSS and LH-CAA (with or without associated CSS) patients. We analyzed baseline clinical characteristics including age, history of hypertension, diabetes, hypercholesterolemia, and pre-existing cognitive deficit. The presence of lobar microbleeds (MB) was scored on T2*. FLAIR (fluid-attenuated inversion recovery) WMH severity (using the Fazekas scale) and topographical distribution (using [slightly modified] earlier described WMH patterns) were analyzed and compared between both groups. RESULTS: Twenty CSS and 63 LH-CAA patients were analyzed. Baseline clinical characteristics were similar between both groups, except for hypercholesterolemia less frequently present in the CSS group (P = .026). Lobar MB were significantly less frequently present in the CSS group (P < .01), and CSS was more frequently focal in the CSS group compared with LH-CAA patients with associated CSS (P = .03). Mean Fazekas scale was significantly lower in CSS patients (P = .011). WMH patterns did not differ between both groups, with the multiple subcortical spots pattern as the most frequently observed pattern. CONCLUSIONS: Relative severe WMH scores and similar topographical distribution in CSS patients argue for WMH as a CAA-related feature in these patients with isolated CSS, adding level of evidence that isolated CSS could correspond to early manifestations of CAA.