Microstructural characterization of corticospinal tract in subacute and chronic stroke patients with distal lesions by means of advanced diffusion MRI

PURPOSE: The aim of the paper is to evaluate if advanced dMRI techniques, including diffusion kurtosis imaging (DKI) and neurite orientation dispersion and density imaging (NODDI), could provide novel insights into the subtle microarchitectural modifications occurring in the corticospinal tract (CST) of stroke patients in subacute and chronic phases. METHODS: Seventeen subjects (age 68 ± 11 years) in the subacute phase (14 ± 3 days post-stroke), 10 of whom rescanned in the chronic phase (231 ± 36 days post-stroke), were enrolled. Images were acquired using a 3-T MRI scanner with a two-shell EPI protocol (20 gradient directions, b = 700 s/mm2, 3 b = 0; 64 gradient directions, b = 2000 s/mm2, 9 b = 0). DTI-, DKI-, and NODDI-derived parameters were calculated in the posterior limb of the internal capsule (PLIC) and in the cerebral peduncle (CP). RESULTS: In the subacute phase, a reduction of FA, AD, and KA values was correlated with an increase of ODI, RD, and AK parameters, in both the ipsilesional PLIC and CP, suggesting that increased fiber dispersion can be the main structural factor. In the chronic phase, a reduction of FA and an increase of ODI persisted in the ipsilesional areas. This was associated with reduced Fic and increased MD, with a concomitant reduction of MK and increase of RD, suggesting that fiber reduction, possibly due to nerve degeneration, could play an important role. CONCLUSIONS: This study shows that advanced dMRI approaches can help elucidate the underpinning architectural modifications occurring in the CST after stroke. Further follow-up studies on bigger cohorts are needed to evaluate if DKI- and NODDI-derived parameters might be proposed as complementary biomarkers of brain microstructural alterations

WEB-DL endovascular treatment of wide-neck bifurcation aneurysms: short- and midterm results in a European study

BACKGROUND AND PURPOSE: Flow disruption with the WEB-DL device has been used safely for the treatment of wide-neck bifurcation aneurysms, but the stability of aneurysm occlusion after this treatment is unknown. This retrospective multicenter European study analyzed short- and midterm data in patients treated with WEB-DL. MATERIALS AND METHODS: Twelve European neurointerventional centers participated in the study. Clinical data and pre- and postoperative short- and midterm images were collected. An experienced interventional neuroradiologist independently analyzed the images. Aneurysm occlusion was classified into 4 grades: complete occlusion, opacification of the proximal recess of the device, neck remnant, and aneurysm remnant. RESULTS: Forty-five patients (34 women and 11 men) 35-74 years of age (mean, 56.3 \ub1 9.6 years) with 45 aneurysms treated with the WEB device were included. Aneurysm locations were the middle cerebral artery in 26 patients, the posterior circulation in 13 patients, the anterior communicating artery in 5 patients, and the internal carotid artery terminus in 1 patient. Forty-two aneurysms were unruptured. Good clinical outcome (mRS < 2) was observed in 93.3% of patients at the last follow-up. Adequate occlusion (complete occlusion, opacification of the proximal recess, or neck remnant) was observed in 30/37 patients (81.1%) in short-term follow-up (median, 6 months) and in 26/29 patients (89.7%) in midterm follow-up (median, 13 months). Worsening of the aneurysm occlusion was observed in 2/28 patients (7.1%) at midterm follow-up. CONCLUSIONS: The results suggest that the WEB endovascular treatment of wide-neck bifurcation aneurysms offers stable occlusion in a class of aneurysms that are historically unstable. Additionally, our data show that opacification of the WEB recess can be delineated from true neck or aneurysm remnant

ITALIAN MULTICENTER EXPERIENCE WITH FLOW-DIVERTER DEVICES FOR INTRACRANIAL UNRUPTURED ANEURYSM TREATMENT WITH PERIPROCEDURAL COMPLICATIONS\u2014A RETROSPECTIVE DATA ANALYSIS

Introduction: We report the experiences of 25 Italian centers, analyzing intra- and periprocedural complications of endovascular treatment of intracranial aneurysms using Silk (Balt Extrusion, Montmorency, France) and pipeline embolization devices (EV3 Inc, Irvine California). Methods: Two hundred seventy-three patients with 295 cerebral aneurysms, enrolled in 25 centers in Italy and treated with the new flow-diverter devices, were evaluated; 142 patients were treated with Silk and 130 with pipeline (in one case, both devices were used). In 14 (5.2 %) cases devices were used with coils. Aneurysm size was >15 mm in 46.9 %, 5-15 mm in 42.2 %, and <5 mm in 10.8 %. Aneurysm locations were supraclinoid internal carotid artery (ICA) in 163 cases (55.2 %), cavernous ICA in 76 (25.7 %), middle cerebral artery in 11 (3.7 %), PCoA in 6 (2 %), and ACoA in 2 (0.7 %); the vertebrobasilar system accounted for 32 cases (10.8 %) and PCA in 5 (1.7 %). Results: Technical adverse events occurred with 59 patients (21.6 %); 5 patients died after ischemic events, 10 to hemorrhagic complications, and 1 from external ventricular drain positioning. At 1 month, morbidity and mortality rates were 3.7 % and 5.9 %, respectively Conclusion: Our retrospective study confirms that morbidity and mortality rates in treatment with FDD of unruptured wide-neck or untreatable cerebral aneurysms do not differ from those reported in the largest series

Italian multicenter experience with flow-diverter devices for intracranial unruptured aneurysm treatment with periprocedural complications-a retrospective data analysis

Introduction: We report the experiences of 25 Italian centers, analyzing intra- and periprocedural complications of endovascular treatment of intracranial aneurysms using Silk (Balt Extrusion, Montmorency, France) and pipeline embolization devices (EV3 Inc, Irvine California). Methods: Two hundred seventy-three patients with 295 cerebral aneurysms, enrolled in 25 centers in Italy and treated with the new flow-diverter devices, were evaluated; 142 patients were treated with Silk and 130 with pipeline (in one case, both devices were used). In 14 (5.2 %) cases devices were used with coils. Aneurysm size was >15 mm in 46.9 %, 5-15 mm in 42.2 %, and <5 mm in 10.8 %. Aneurysm locations were supraclinoid internal carotid artery (ICA) in 163 cases (55.2 %), cavernous ICA in 76 (25.7 %), middle cerebral artery in 11 (3.7 %), PCoA in 6 (2 %), and ACoA in 2 (0.7 %); the vertebrobasilar system accounted for 32 cases (10.8 %) and PCA in 5 (1.7 %). Results: Technical adverse events occurred with 59 patients (21.6 %); 5 patients died after ischemic events, 10 to hemorrhagic complications, and 1 from external ventricular drain positioning. At 1 month, morbidity and mortality rates were 3.7 % and 5.9 %, respectively Conclusion: Our retrospective study confirms that morbidity and mortality rates in treatment with FDD of unruptured wide-neck or untreatable cerebral aneurysms do not differ from those reported in the largest series