Central intra-lesional iron deposits as a possible novel imaging marker at 7 Tesla MRI in Susac Syndrome - an exploratory study.

BACKGROUND: Susac syndrome (SuS) is a rare autoimmune disease that leads to hearing impairment, visual field deficits, and encephalopathy due to an occlusion of precapillary arterioles in the brain, retina, and inner ear. Given the potentially disastrous outcome and difficulties in distinguishing SuS from its differential diagnoses, such as multiple sclerosis (MS), our exploratory study aimed at identifying potential new SuS-specific neuroimaging markers. METHODS: Seven patients with a definite diagnosis of SuS underwent magnetic resonance imaging (MRI) at 7 Tesla (7T), including T2* weighted and quantitative susceptibility mapping (QSM) sequences. T2 weighted hyperintense lesions were analyzed with regard to number, volume, localization, central vein sign, T1 hypointensity, and focal iron deposits in the center of SuS lesions ("iron dots"). Seven T MRI datasets from the same institute, comprising 75 patients with, among others, MS, served as controls. RESULTS: The "iron dot" sign was present in 71.4% (5/7) of the SuS patients, compared to 0% in our control cohort. Thus, sensitivity was 71.4% and specificity 100%. A central vein sign was only incidentally detected. CONCLUSION: We are the first to demonstrate this type of "iron dot" lesions on highly resolving 7T T2*w and QSM images in vivo as a promising neuroimaging marker of SuS, corroborating previous histopathological ex vivo findings.

Association of statin use and lipid levels with cerebral microbleeds and intracranial hemorrhage in patients with atrial fibrillation: A prospective cohort study.

BACKGROUND: An increased risk of intracranial hemorrhage (ICH) associated with statins has been reported, but data on the relationship between statin use and cerebral microbleeds (CMBs) in patients with atrial fibrillation (AF), a population at high bleeding and cardiovascular risk, are lacking. AIMS: To explore the association between statin use and blood lipid levels with the prevalence and progression of CMBs in patients with AF with a particular focus on anticoagulated patients. METHODS: Data of Swiss-AF, a prospective cohort of patients with established AF, were analyzed. Statin use was assessed during baseline and throughout follow-up. Lipid values were measured at baseline. CMBs were assessed using magnetic resonance imagining (MRI) at baseline and at 2 years follow-up. Imaging data were centrally assessed by blinded investigators. Associations of statin use and low-density lipoprotein (LDL) levels with CMB prevalence at baseline or CMB progression (at least one additional or new CMB on follow-up MRI at 2 years compared with baseline) were assessed using logistic regression models; the association with ICH was assessed using flexible parametric survival models. Models were adjusted for hypertension, smoking, body mass index, diabetes, stroke/transient ischemic attack, coronary heart disease, antiplatelet use, anticoagulant use, and education. RESULTS: Of the 1693 patients with CMB data at baseline MRI (mean ± SD age 72.5 ± 8.4 years, 27.6% women, 90.1% on oral anticoagulants), 802 patients (47.4%) were statin users. The multivariable adjusted odds ratio (adjOR) for CMBs prevalence at baseline for statin users was 1.10 (95% CI = 0.83-1.45). AdjOR for 1 unit increase in LDL levels was 0.95 (95% CI = 0.82-1.10). At 2 years, 1188 patients had follow-up MRI. CMBs progression was observed in 44 (8.0%) statin users and 47 (7.4%) non-statin users. Of these patients, 64 (70.3%) developed a single new CMB, 14 (15.4%) developed 2 CMBs, and 13 developed more than 3 CMBs. The multivariable adjOR for statin users was 1.09 (95% CI = 0.66-1.80). There was no association between LDL levels and CMB progression (adjOR 1.02, 95% CI = 0.79-1.32). At follow-up 14 (1.2%) statin users had ICH versus 16 (1.3%) non-users. The age and sex adjusted hazard ratio (adjHR) was 0.75 (95% CI = 0.36-1.55). The results remained robust in sensitivity analyses excluding participants without anticoagulants. CONCLUSIONS: In this prospective cohort of patients with AF, a population at increased hemorrhagic risk due to anticoagulation, the use of statins was not associated with an increased risk of CMBs.

Apical pulmonary lesions suspected of malignancy visible on neck CT angiography performed for acute stroke: Prevalence, treatment, and clinical implications - the PLEURA study.

BACKGROUND: Computed tomography angiography (CTA) of the supraaortic arteries is commonly used for acute stroke workup and may reveal apical pulmonary lesions (APL). AIM: To determine the prevalence, follow-up algorithms, and in-hospital outcomes of stroke patients with APL on CTA. METHODS: We retrospectively included consecutive adult patients with ischemic stroke, transient ischemic attack, or intracerebral hemorrhage and available CTA at a tertiary hospital between January 2014 and May 2021. We reviewed all CTA reports for the presence of APL. APL were classified as malignancy suspicious or benign appearing based on radiological-morphological criteria. We performed regression analyses to investigate the impact of malignancy suspicious APL on different in-hospital outcome parameters. RESULTS: Among 2715 patients, APL on CTA were found in 161 patients (5.9% [95%CI: 5.1-6.9]; 161/2715). Suspicion of malignancy was present in one third of patients with APL (36.0% [95%CI: 29.0-43.7]; 58/161), 42 of whom (72.4% [95%CI: 60.0-82.2]; 42/58) had no history of lung cancer or metastases. When performed, further investigations confirmed primary or secondary pulmonary malignancy in three-quarters (75.0% [95%CI: 50.5-89.8]; 12/16), with two patients (16.7% [95%CI: 4.7-44.8]; 2/12) receiving de novo oncologic therapy. In multivariable regression, the presence of radiologically malignancy suspicious APL was associated with higher NIHSS scores at 24 h (beta = 0.67, 95%CI: 0.28-1.06, p = 0.001) and all-cause in-hospital mortality (aOR = 3.83, 95%CI: 1.29-9.94, p = 0.01). CONCLUSIONS: One in seventeen patients shows APL on CTA, of which one-third is malignancy suspicious. Further work-up confirmed pulmonary malignancy in a substantial number of patients triggering potentially life-saving oncologic therapy.

Extensive immune reconstitution inflammatory syndrome in Fingolimod-associated PML: a case report with 7 Tesla MRI data.

BACKGROUND: Progressive multifocal leukoencephalopathy (PML) is a rare complication of patients treated with fingolimod. CASE PRESENTATION: Routine MRI eventually led to diagnosis of asymptomatic early PML that remained stable after discontinuation of fingolimod. As blood lymphocyte counts normalized, signs of immune reconstitution inflammatory syndrome (IRIS) and renewed MS activity developed. Both, advanced laboratory and ultrahigh field MRI findings elucidated differences between PML and MS. CONCLUSIONS: In our case, early discontinuation of fingolimod yielded a good outcome, lymphocyte counts reflected immune system activity, and paraclinical findings helped to differentiate between PML-IRIS and MS.

Progressive Multifocal Leukoencephalopathy in a Multiple Sclerosis Patient Diagnosed after Switching from Natalizumab to Fingolimod.

Background. Natalizumab- (NTZ-) associated progressive multifocal leukoencephalopathy (PML) is a severe and often disabling infectious central nervous system disease that can become evident in multiple sclerosis (MS) patients after NTZ discontinuation. Recently, novel diagnostic biomarkers for the assessment of PML risk in NTZ treated MS patients such as the anti-JC virus antibody index have been reported, and the clinical relevance of milky-way lesions detectable by MRI has been discussed. Case Presentation and Conclusion. We report a MS patient in whom PML was highly suspected solely based on MRI findings after switching from NTZ to fingolimod despite repeatedly negative (ultrasensitive) polymerase chain reaction (PCR) testing for JC virus DNA in cerebrospinal fluid. The PML diagnosis was histopathologically confirmed by brain biopsy. The occurrence of an immune reconstitution inflammatory syndrome (IRIS) during fingolimod therapy, elevated measures of JCV antibody indices, and the relevance of milky-way-like lesions detectable by (7 T) MRI are discussed.

Widespread inflammation in CLIPPERS syndrome indicated by autopsy and ultra-high-field 7T MRI.

OBJECTIVE: To examine if there is widespread inflammation in the brain of patients with chronic lymphocytic inflammation with pontine perivascular enhancement responsive to steroids (CLIPPERS) syndrome by using histology and ultra-high-field MRI at 7.0T. METHODS: We performed a detailed neuropathologic examination in 4 cases, including 1 autopsy case, and studied 2 additional patients by MRI at 7.0T to examine (1) extension of inflammation to areas appearing normal on 3.0T MRI, (2) potential advantages of 7.0T MRI compared to 3.0T MRI in reflecting widespread inflammation, perivascular pathology, and axonal damage, and (3) the possibility of lymphoma. RESULTS: In the autopsy case, perivascular inflammation dominated by CD4+ T cells was not only detected in the brainstem and cerebellum but also in brain areas with normal appearance on 3.0T MRI, including supratentorial regions and cranial nerve roots. There was no evidence of lymphoma in any of the 4 patients. The 7.0T MRI in clinical remission also revealed supratentorial lesions and perivascular pathology in vivo with contrast-enhancing lesions centered around a small venous vessel. Ultra-high-field MRI at 7.0T disclosed prominent T1 hypointensities in the brainstem, which were not seen on 3.0T MRI. This corresponded to neuropathologic detection of axonal injury in the autopsy case. CONCLUSION: Our findings suggest more widespread perivascular inflammation and postinflammatory axonal injury in patients with CLIPPERS.

Optic radiation damage in multiple sclerosis is associated with visual dysfunction and retinal thinning--an ultrahigh-field MR pilot study.

OBJECTIVE: To investigate posterior visual pathway damage in multiple sclerosis using ultrahigh-field magnetic resonance imaging (MRI) at 7 Tesla (7 T), and to determine its correlation with visual disability and retinal fibre layer (RNFL) damage detectable by optic coherence tomography (OCT). METHODS: We studied 7 T MRI, OCT, functional acuity contrast testing (FACT), and visually evoked potentials (VEP, n = 16) in 30 patients (including 26 relapsing-remitting MS and four clinically isolated syndrome patients) and 12 healthy controls to quantify RNFL thickness, optic radiation lesion volume, and optic radiation thickness. RESULTS: Optic radiation lesion volume was associated with thinning of the optic radiation (p < 0.001), delayed VEP (p = 0.031), and visual disability indicated by FACT (p = 0.020). Furthermore, we observed an inverse correlation between optic radiation lesion volume and RNFL thickness (p < 0.001), including patients without previous optic neuritis (p < 0.001). CONCLUSIONS: Anterior visual pathway damage, but also (subclinical) optic radiation integrity loss detectable by 7 T MRI are common findings in MS that are mutually affected. Given the association between optic radiation damage, visual impairment, and increased VEP latency in this exploratory study of a limited sample size, clinicians should be aware of acute lesions within the optic radiation in patients with (bilateral) visual disturbances. KEY POINTS: • Focal destruction of the optic radiation is detectable by 7 T MRI. • Focal optic radiation damage is common in MS. • Optic radiation damage is associated with RNFL thinning, detectable by OCT. • Optic radiation damage is associated with delayed VEP and visual dysfunction. • RNFL thickness in non-optic neuritis eyes correlates with optic radiation demyelination.