Relation between the size of patent foramen ovale and the volume of acute cerebral ischemic lesion in young patients with cryptogenic ischemic stroke.

BACKGROUND: Patent foramen ovale (PFO) closure is superior to medical therapy alone to prevent stroke recurrence in selected patients. Small cortical infarcts and large right to left shunts seem to identify patients who will benefit most from closure. We aimed to study the correlation between the size of the PFO and the volume of cerebral ischemic lesions in young patients with cryptogenic ischemic stroke. METHODS: PFO dimensions and acute ischemic lesion volume of 20 patients, aged<55 years, were analyzed with transesophageal echocardiography and brain magnetic resonance imaging, respectively. The association between the volume of ischemic lesions with the length of PFO, maximum separation between septum primum and septum secundum, and the combination of the twos was explored. RESULTS: A direct statistically significant correlation was found between cerebral lesion volume and maximum separation of septum primum and septum secundum (p=0.047). Length of PFO showed a non-significant trend towards an inverse correlation with lesion volume (p=0.603). Multiple linear regression analysis showed that cerebral lesion volume was dependent directly on maximum separation and inversely on length of PFO (regression coeff. -0,837; p= 0.057; 2,536, p=0.006, respectively). CONCLUSIONS: These data suggest that even small PFO might be pathogenetic in case of small cerebral infarcts and that large cerebral infarcts might be PFO related if the shunt is large. If confirmed, the combination of detailed characteristics of PFO with the volume of cerebral infarct could be integrated in a new score to select patients who would take real advantage from a percutaneous closure.

Association between carotid artery dissection and vascular tortuosity: a case-control study.

PURPOSE: We aimed to verify if vascular tortuosity (VT) may represent a risk factor for spontaneous epiaortic vessel dissection (sEVD) in young adult patients. METHODS: We identified 304 patients aged under 55 years consecutively admitted for acute cerebrovascular events to our Stroke Unit. After checking the possibility to perform a 3D reconstruction of epiaortic vessels on CT-angiography images, we selected and compared fifty patients with sEVD (cases) with fifty-one patients without dissection (controls). VT of carotid and vertebral arteries was measured on reconstructions evaluating the vascular tortuosity index (VTI), calculated according to a specific algorithm, and the presence of kinking and coiling. Differences between groups were analyzed by Student-t test for numeric variables and chi-square test for categoric ones. A ROC curve analysis was used to look for a VTI threshold value beyond which the risk of dissection was significantly increased. RESULTS: VTI was significantly higher in cases than in controls only considering carotid arteries (p = 0.029); cases did not have a significantly higher rate of kinking and coiling than controls (p = 0.059 and 0.077, respectively). We have found a significant VTI threshold value of 27.9% (under curve area = 61.6%, p = 0.04) only for carotid artery dissection. CONCLUSION: VT appears to be associated with an increased risk of dissection for the carotid district but not for the vertebral one. The different structure, embryogenesis, and pathophysiology of dissection between the two districts could explain this finding. VTI threshold as carotid artery dissection predictor deserves confirmation in larger studies.

Prognostic role of intrathecal IgM synthesis in multiple sclerosis: Results from a clinical series.

BACKGROUND: There is emerging evidence that intrathecal IgM synthesis (ITMS) is a risk factor for conversion to clinically defined multiple sclerosis (CDMS) in clinically isolated syndrome (CIS) patients. OBJECTIVES: The objective of this study is to verify the prognostic role of ITMS as a risk factor for the second clinical attack in patients after the first demyelinating event. METHODS: Monocentric observational study performed on prospectively acquired clinical data and retrospective evaluation of magnetic resonance imaging (MRI) data. ITMS was assessed according to Reiber's non-linear function. We compared time to the second attack by using Kaplan-Meier curves and performed adjustment by Cox regression analysis. RESULTS: Demographics and clinical data were collected prospectively in a cohort of 68 patients. ITMS occurred in 40% (27/68) of patients who had a higher T1-hypointense lesion load at brain MRI (p = 0.041). In multivariate Cox regression analysis (adjusted for age, sex, baseline Expanded Disability Status Scale, IgG oligoclonal bands and disease-modifying treatment exposure), relapsing-remitting multiple sclerosis (MS) patients with ITMS were at higher risk to experience a second clinical attack (adjusted hazard ratio (aHR) = 6.3, 95% confidence interval (CI) = 2.1-18.4, p = 0.001). CONCLUSION: Together with previous studies, our findings support the role of ITMS as a prognostic biomarker in MS.

Central vein sign differentiates Multiple Sclerosis from central nervous system inflammatory vasculopathies.

OBJECTIVES: In multiple sclerosis (MS), magnetic resonance imaging (MRI) is a sensitive tool for detecting white matter lesions, but its diagnostic specificity is still suboptimal; ambiguous cases are frequent in clinical practice. Detection of perivenular lesions in the brain (the "central vein sign") improves the pathological specificity of MS diagnosis, but comprehensive evaluation of this MRI biomarker in MS-mimicking inflammatory and/or autoimmune diseases, such as central nervous system (CNS) inflammatory vasculopathies, is lacking. In a multicenter study, we assessed the frequency of perivenular lesions in MS versus systemic autoimmune diseases with CNS involvement and primary angiitis of the CNS (PACNS). METHODS: In 31 patients with inflammatory CNS vasculopathies and 52 with relapsing-remitting MS, 3-dimensional T2*-weighted and T2-fluid-attenuated inversion recovery images were obtained during a single MRI acquisition after gadolinium injection. For each lesion, the central vein sign was evaluated according to consensus guidelines. For each patient, lesion count, volume, and brain location, as well as fulfillment of dissemination in space MRI criteria, were assessed. RESULTS: MS showed higher frequency of perivenular lesions (median = 88%) than did inflammatory CNS vasculopathies (14%), without overlap between groups or differences between 3T and 1.5T MRI. Among inflammatory vasculopathies, Behçet disease showed the highest median frequency of perivenular lesions (34%), followed by PACNS (14%), antiphospholipid syndromes (12%), Sjögren syndrome (11%), and systemic lupus erythematosus (0%). When a threshold of 50% perivenular lesions was applied, central vein sign discriminated MS from inflammatory vasculopathies with a diagnostic accuracy of 100%. INTERPRETATION: The central vein sign differentiates inflammatory CNS vasculopathies from MS at standard clinical magnetic field strengths. Ann Neurol 2018;83:283-294.

Leptomeningeal gadolinium enhancement across the spectrum of chronic neuroinflammatory diseases.

OBJECTIVE: To assess the prevalence and the specificity of leptomeningeal enhancement (LME) on postcontrast T2-fluid-attenuated inversion recovery (FLAIR) MRI in multiple sclerosis (MS) compared to a variety of inflammatory and noninflammatory neurologic conditions assessed in 2 academic research hospitals. METHODS: On 3T postcontrast T2-FLAIR images, the presence of focal gadolinium enhancement was evaluated in the leptomeningeal compartment in 254 people with non-MS neurologic conditions or neurotropic viral infections. Based on their clinical diagnosis, patients were grouped as follows: (1) other-than-MS inflammatory neurologic diseases; (2) noninflammatory neurologic diseases; (3) human T-lymphotropic virus (HTLV)-infected; (4) HIV-infected; (5) healthy volunteers. RESULTS: LME was detected in 56/254 non-MS cases (22%) vs 74/299 (25%) of MS cases. LME was nearly 4-fold more frequent in non-MS inflammatory neurologic conditions (18/51 cases, 35%) than in noninflammatory neurologic conditions (3/38, 8%) and healthy volunteers (5/66, 8%). The highest prevalence of LME was detected in HTLV infection (17/38 cases, 45%), particularly in the setting of HTLV-associated myelopathy (14/25 cases, 56%). LME also frequently occurred in HIV infection (13/61 cases, 21%). Unlike in MS, LME is not associated with lower brain and cortical volumes in non-MS inflammatory neurologic conditions, including HTLV and HIV infection. CONCLUSIONS: Despite its relevance to MS pathogenesis and cortical pathology, LME is not specific to MS, occurring frequently in non-MS inflammatory neurologic conditions and especially in those patients with HTLV-associated myelopathy. Overall, this strengthens the notion that LME localizes inflammation-related focal disruption of the blood-meninges barrier and associated scarring.

Gadolinium-based MRI characterization of leptomeningeal inflammation in multiple sclerosis.

OBJECTIVE: To determine the frequency and nature of leptomeningeal contrast enhancement in multiple sclerosis (MS) via in vivo 3-tesla postcontrast T2-weighted, fluid-attenuated inversion recovery (FLAIR) MRI and 7-tesla postmortem MRI-pathology correlation. METHODS: Brain MRI, using the postcontrast T2-weighted, FLAIR technique, was prospectively collected in 299 MS cases and 37 age-matched neurologically healthy controls. Expert raters evaluated focal gadolinium enhancement in the leptomeningeal compartment. Two progressive MS cases came to autopsy after in vivo MRI characterization. Pathologic and immunohistochemical examination assessed the association of enhancement with leptomeningeal inflammation and adjacent cortical demyelination. RESULTS: Focal contrast enhancement was detected in the leptomeningeal compartment in 74 of 299 MS cases (25%) vs 1 of 37 neurologically healthy controls (2.7%; p = 0.001). Enhancement was nearly twice as frequent (p = 0.009) in progressive MS (39/118 cases, 33%) as in relapsing-remitting MS (35/181, 19%). Enhancing foci generally remained stable throughout the evaluation period (up to 5.5 years). Pathology showed perivascular lymphocytic and mononuclear infiltration in the enhancing areas in association with flanking subpial cortical demyelination. CONCLUSION: Leptomeningeal contrast enhancement occurs frequently in MS and is a noninvasive, in vivo marker of inflammation and associated subpial demyelination. It might therefore enable testing of new treatments aimed at eliminating this inflammation and potentially arresting progressive MS.

Autologous hematopoietic stem cell transplantation in multiple sclerosis: a phase II trial.

OBJECTIVE: To assess in multiple sclerosis (MS) the effect of intense immunosuppression followed by autologous hematopoietic stem cells transplantation (AHSCT) vs mitoxantrone (MTX) on disease activity measured by MRI. METHODS: We conducted a multicenter, phase II, randomized trial including patients with secondary progressive or relapsing-remitting MS, with a documented increase in the last year on the Expanded Disability Status Scale, in spite of conventional therapy, and presence of one or more gadolinium-enhancing (Gd+) areas. Patients were randomized to receive intense immunosuppression (mobilization with cyclophosphamide and filgrastim, conditioning with carmustine, cytosine-arabinoside, etoposide, melphalan, and anti-thymocyte globulin) followed by AHSCT or MTX 20 mg every month for 6 months. The primary endpoint was the cumulative number of new T2 lesions in the 4 years following randomization. Secondary endpoints were the cumulative number of Gd+ lesions, relapse rate, and disability progression. Safety and tolerability were also assessed. Twenty-one patients were randomized and 17 had postbaseline evaluable MRI scans. RESULTS: AHSCT reduced by 79% the number of new T2 lesions as compared to MTX (rate ratio 0.21, p = 0.00016). It also reduced Gd+ lesions as well as the annualized relapse rate. No difference was found in the progression of disability. CONCLUSION: Intense immunosuppression followed by AHSCT is significantly superior to MTX in reducing MRI activity in severe cases of MS. These results strongly support further phase III studies with primary clinical endpoints. The study was registered as EUDRACT No. 2007-000064-24.

Sample-size calculations for short-term proof-of-concept studies of tissue protection and repair in multiple sclerosis lesions via conventional clinical imaging.

BACKGROUND: New multiple sclerosis (MS) lesion activity on magnetic resonance imaging (MRI) can test immunomodulatory therapies in proof-of-concept trials. Comparably powerful endpoints to assess tissue protection or repair are lacking. OBJECTIVE: The objective of this paper is to report sample-size calculations for assessment of new lesion recovery. METHODS: In two sets of six active MS cases, new lesions were observed by monthly MRI for approximately 12 months. Averages and quartiles of normalized (proton density/T1/T2 weighted) and quantitative (T1/T2 and mean diffusivity maps for dataset 1, T2 and magnetization transfer ratio maps for dataset 2) measures were used to compare the lesion area before lesion appearance to afterward. A linear mixed-effects model incorporating lesion- and participant-specific random effects estimated average levels and variance components for sample-size calculations. RESULTS: In both datasets, greatest statistical sensitivity was observed for the 25th percentile of normalized proton density-weighted signal. At 3T, using new lesions ⩾15 mm(3), as few as nine participants/arm may be required for a six-month placebo-controlled add-on trial postulating a therapeutic effect size of 20% and statistical power of 90%. CONCLUSION: Lesion recovery is a powerful outcome measure for proof-of-concept clinical trials of tissue protection and repair in MS. The trial design requires active cases and is therefore best implemented near disease onset.

Low intensity lympho-ablative regimen followed by autologous hematopoietic stem cell transplantation in severe forms of multiple sclerosis: A MRI-based clinical study.

BACKGROUND: Autologous hematopoietic stem cell transplantation (AHSCT) has been successfully used to treat aggressive forms of multiple sclerosis (MS) that are unresponsive to approved therapies. In the last years, in view of the risk of mortality related to the procedure, the utilization of low-intensity conditioning regimens has been considered. OBJECTIVE: To report magnetic resonance imaging (MRI) and clinical data in a small cohort of patients treated with a low-intensity lympho-ablative regimen, followed by AHSCT. METHODS: Seven patients affected by relapsing-remitting MS (RRMS) underwent AHSCT, with cyclophosphamide 120 mg/kg in 2 days as the conditioning regimen; and were then followed with serial MRI evaluations until 36 months, with clinical evaluations until 60 months. RESULTS: The mean number of gadolinium (Gd)-enhancing lesions significantly decreased after treatment, but a complete suppression of inflammatory activity was not obtained. No deaths occurred, but every patient developed adverse events, although not severe. After 5 years of follow-up, two patients remained stable, one patient markedly improved and four patients had a mild progression of the disease. Only one patient experienced a relapse after treatment. CONCLUSION: A low-intensity conditioning regimen with AHSCT has a profound effect on MRI inflammation and relapses, but is not able to completely abrogate MRI activity and disease progression of aggressive RRMS.

In vivo imaging of spinal cord atrophy in neuroinflammatory diseases.

OBJECTIVE: Spinal cord atrophy is prominent in chronic progressive neurologic diseases such as human T-cell lymphotropic virus type 1 (HTLV-1)-associated myelopathy/tropical spastic paraparesis (HAM/TSP) and multiple sclerosis (MS). Here we compared the spinal cord cross-sectional area (SCCSA) in HAM/TSP and MS patients to that of healthy volunteers (HVs). METHODS: SCCSA and clinical disability scores were measured in 18 HAM/TSP patients, 4 asymptomatic carriers (ACs) of HTLV-1, 18 MS patients, and 10 HVs from a 3T magnetic resonance imaging. SCCSA measured in patients and ACs were compared to that of HVs and correlated with disability scores. RESULTS: The entire spinal cord in HAM/TSP patients was thin compared to HVs, whereas only the cervical cord in MS patients was thinner than in HVs (p < 0.0001). In HAM/TSP patients, SCCSA extensively correlated with Ambulation Index, whereas only the cervical cord correlated with disease duration (p < 0.05). In MS patients, the SCCSA extensively correlated with Scripps Neurologic Rating Score and the Expanded Disability Status Scale (p < 0.05). One of the 4 ACs showed atrophy in a pattern similar to HAM/TSP. INTERPRETATION: These results are in accordance with the findings that whereas over half of all lesions in an MS cord are seen in the upper cervical cord, most of the pathology in HAM/TSP is seen in the thoracolumbar cord, which in turn may be responsible for the more extensive cord atrophy seen in HAM/TSP. An imaging marker such as SCCSA might serve as a surrogate endpoint in clinical trials, especially to assess the neuroprotective impact of various therapies.

Reversibility of brain lesions in a case of Neuro-Behçet's disease studied by MR diffusion.

Behçet's disease is a multisystem disorder first described in 1937 as a triad of oral and genital ulcerations and uveitis. The etiology is unknown. Involvement of the central nervous system (CNS) occurs in 10-25% of patients. Neuro-Behçet's disease (NBD) can be classified as: (1) parenchymal, with a predilection for brainstem, basal ganglia and thalami involvement, subcortical white matter damage, spinal cord lesions, and meningoencephalitic presentations; (2) vascular, which usually affects major intracranial vessels with frequent involvement of the venous sinuses, cerebral veins and rarely intracranial arteries. Even if not constantly demonstrated in the CNS a vasculitic process involving small blood vessels, including venules, is regarded as an important pathological feature. We describe the case of a patient with NBD studied with conventional and diffusion weighted MR imaging.

Multiple sclerosis: hyperintense dentate nucleus on unenhanced T1-weighted MR images is associated with the secondary progressive subtype.

PURPOSE: To describe the occurrence of abnormal hyperintensity in the dentate nucleus on T1-weighted magnetic resonance (MR) images in patients with multiple sclerosis (MS) as a neuroradiologic sign of gray matter involvement. Presence of the finding was evaluated for association with disability, clinical MS subtype, total lesion volume on T1- and T2-weighted MR images (lesion load), and brain atrophy. MATERIALS AND METHODS: Written informed consent was waived by the Ethics Committee because of the retrospective nature of this single-center Institutional Review Board-approved study. MR examinations of 185 patients with MS were reviewed, and 119 patients were included for analysis. Two neuroimagers, who were blinded to clinical data, assessed the presence of a hyperintense dentate nucleus on T1-weighted MR images. The presence of this radiologic alteration was then evaluated in relation to MS subtype, clinical disability, T1 and T2 lesion load, and whole-brain atrophy measurements. Fisher exact, chi(2), and Mann-Whitney U tests were used to evaluate differences in clinical and imaging features between patients with and those without a T1 hyperintense dentate nucleus. RESULTS: Twenty-three (19.3%) of the 119 patients had a hyperintense dentate nucleus on unenhanced T1-weighted MR images. This finding was related to the secondary progressive subtype of the disease, a higher score on the Expanded Disability Status Scale, a higher brain lesion load, and tissue loss. None of the patients with primary progressive MS had a hypterintense dentate nucleus. CONCLUSION: Hyperintensity of the dentate nucleus may be present on unenhanced T1-weighted MR images of patients with MS and is associated with the secondary progressive disease subtype and with increased clinical disability, lesion load, and brain atrophy.