Improved reconstruction of crossing fibers in the mouse optic pathways with orientation distribution function fingerprinting.

PURPOSE: The accuracy of diffusion MRI tractography reconstruction decreases in the white matter regions with crossing fibers. The optic pathways in rodents provide a challenging structure to test new diffusion tractography approaches because of the small crossing volume within the optic chiasm and the unbalanced 9:1 proportion between the contra- and ipsilateral neural projections from the retina to the lateral geniculate nucleus, respectively. METHODS: Common approaches based on Orientation Distribution Function (ODF) peak finding or statistical inference were compared qualitatively and quantitatively to ODF Fingerprinting (ODF-FP) for reconstruction of crossing fibers within the optic chiasm using in vivo diffusion MRI ( n = 18 $$ n=18 $$ healthy C57BL/6 mice). Manganese-Enhanced MRI (MEMRI) was obtained after intravitreal injection of manganese chloride and used as a reference standard for the optic pathway anatomy. RESULTS: ODF-FP outperformed by over 100% all the tested methods in terms of the ratios between the contra- and ipsilateral segments of the reconstructed optic pathways as well as the spatial overlap between tractography and MEMRI. CONCLUSION: In this challenging model system, ODF-Fingerprinting reduced uncertainty of diffusion tractography for complex structural formations of fiber bundles.

A meta-analysis and systematic review of endovascular thrombectomy versus medical management for acute basilar artery occlusion.

OBJECTIVE: Acute basilar artery occlusion (BAO) is a devastating neurologic event. As endovascular thrombectomy (EVT) became more prevalent for anterior circulation strokes, investigations were conducted in the posterior circulation. Its success in improving outcomes compared to standard medical therapy (SMT) after BAO has been debated. METHODS: We conducted a systematic review and meta-analysis of all randomized controlled trials (RCTs) and observational cohort studies evaluating EVT compared to SMT in acute BAO. We queried PubMed, Embase, and Cochrane for studies. Primary outcome was good functional outcome at 90 days (modified Rankin scale (mRS) ≤ 3). We analyzed studies for risk of bias (ROB) and calculated pooled risk ratios (RRs), odds ratios (ORs), and mean differences (MDs) with 95% confidence intervals (95%CI) using the random effects model for our primary outcome and secondary positive outcomes and harms. RESULTS: We identified four RCTs (991 patients randomized) and three cohort studies (1030 patients treated in-trial) that fit inclusion criteria. Three RCTs had low ROB, one had serious ROB. One cohort study had high ROB, one had moderate ROB, and one had low ROB. EVT was statistically significantly more associated with good functional outcome than SMT in RCTs (RR=1.54, 95%CI=1.16-2.04, p = 0.003) and trended towards significance in cohort studies (RR=2.64, 95%CI=0.87-8.00, p = 0.09). Mean mRS at 90 days was lower in EVT patients in RCTs (MD=-0.65, 95%CI=-1.07--0.22, p = 0.003) though not cohort studies (MD =-0.84, 95%CI=-2.48-0.79, p = 0.31). Symptomatic intracerebral hemorrhage (sICH) was statistically significantly associated with EVT in RCTs (OR=6.36, 95%CI=2.24-18.07, p < 0.001) and statistically non-significantly in cohort studies (OR=4.51, 95CI=1.00-20.33, p = 0.05). Mortality at 90 days was statistically lower with EVT than with SMT in both RCTs (OR=0.76, 95%CI=0.65-0.88, p < 0.001) cohort studies (OR=0.36, 95%CI=0.26-0.50, p < 0.001) CONCLUSION: EVT is associated with greater rates of good functional outcomes and lower rates of death and disability despite higher rates of periprocedural sICH.

Cell specificity of Manganese-enhanced MRI signal in the cerebellum.

Magnetic Resonance Imaging (MRI) resolution continues to improve, making it important to understand the cellular basis for different MRI contrast mechanisms. Manganese-enhanced MRI (MEMRI) produces layer-specific contrast throughout the brain enabling in vivo visualization of cellular cytoarchitecture, particularly in the cerebellum. Due to the unique geometry of the cerebellum, especially near the midline, 2D MEMRI images can be acquired from a relatively thick slice by averaging through areas of uniform morphology and cytoarchitecture to produce very high-resolution visualization of sagittal planes. In such images, MEMRI hyperintensity is uniform in thickness throughout the anterior-posterior axis of sagittal sections and is centrally located in the cerebellar cortex. These signal features suggested that the Purkinje cell layer, which houses the cell bodies of the Purkinje cells and the Bergmann glia, is the source of hyperintensity. Despite this circumstantial evidence, the cellular source of MRI contrast has been difficult to define. In this study, we quantified the effects of selective ablation of Purkinje cells or Bergmann glia on cerebellar MEMRI signal to determine whether signal could be assigned to one cell type. We found that the Purkinje cells, not the Bergmann glia, are the primary of source of the enhancement in the Purkinje cell layer. This cell-ablation strategy should be useful for determining the cell specificity of other MRI contrast mechanisms.

Adverse Childhood Experiences (ACEs) questionnaire and Adult Attachment Interview (AAI): implications for parent child relationships.

Although Adverse Childhood Experiences (ACEs) are linked to increased health problems and risk behaviors in adulthood, there are no studies on the association between ACEs and adults' states of mind regarding their early childhood attachments, loss, and trauma experiences. To validate the ACEs questions, we analyzed the association between ACEs and emotional support indicators and Adult Attachment Interview (AAI) classifications in terms of unresolved mourning regarding past loss or trauma and discordant states of mind in cannot classify (U/CC) interviews. Seventy-five urban women (41 clinical and 34 community) completed a questionnaire on ACEs, which included 10 categories of abuse, neglect, and household dysfunction, in addition to emotional support. Internal psychological processes or states of mind concerning attachment were assessed using the AAI. ACE responses were internally consistent (Cronbach's α=.88). In the clinical sample, 84% reported≥4 ACEs compared to 27% among the community sample. AAIs judged U/CC occurred in 76% of the clinical sample compared to 9% in the community sample. When ACEs were≥4, 65% of AAIs were classified U/CC. Absence of emotional support in the ACEs questionnaire was associated with 72% of AAIs being classified U/CC. As the number of ACEs and the lack of emotional support increases so too does the probability of AAIs being classified as U/CC. Findings provide rationale for including ACEs questions in pediatric screening protocols to identify and offer treatment reducing the intergenerational transmission of risk associated with problematic parenting.