Myocardial bridging of the left anterior descending coronary artery is associated with reduced myocardial perfusion reserve: a 13N-ammonia PET study.

Myocardial Bridging (MB) refers to the band of myocardium that abnormally overlies a segment of a coronary artery. This paper quantitatively evaluates the influence of MB of the left anterior descending artery (LAD) on myocardial perfusion of the entire left ventricle. We studied 131 consecutive patients who underwent hybrid rest/stress 13N-ammonia positron emission tomography (PET) and coronary computed tomography angiography (CCTA) due to suspected myocardial ischemia. Patients with previous myocardial infarction and/or significant coronary artery disease (≥ 50% stenosis) were excluded. Myocardial perfusion measurements were compared between patients with and without LAD-MB. Additionally, we evaluated the relationship between anatomical characteristics (length and depth) of LAD-MB and myocardial perfusion measurements. 17 (13%) patients presented a single LAD-MB. Global myocardial perfusion reserve (MPR) was lower in patients with LAD-MB than in patients without LAD-MB (1.9 ± 0.5 vs. 2.3 ± 0.6, p < 0.01). Global stress myocardial blood flow (MBF) was similar in patients with and without LAD-MB (2.2 ± 0.4 vs. 2.3 ± 0.7 ml/g/min, p = 0.40). Global rest MBF was higher in patients with LAD-MB than in patients without LAD-MB (1.2 ± 0.3 vs. 1.0 ± 0.2 ml/g/min, p < 0.01). Global rest MBF, stress MBF, and MPR quantifications were similar in patients with superficial and deep LAD-MB (all p = NS). We did not find any correlation between length and global rest MBF, stress MBF nor MPR (r = - 0.14, p = 0.59; r = 0.44, p = 0.07; and r = 0.45, p = 0.07 respectively). Quantitative myocardial perfusion suggests that LAD-MB may be related to impaired perfusion reserve, an indicator of microvascular dysfunction. Anatomical characteristics of LAD-MB were not related to changes in myocardial perfusion.

Difference in CXCR4 expression between sporadic and VHL-related hemangioblastoma.

Central nervous system hemangioblastomas occur sporadically and in patients with von Hippel-Lindau (VHL) disease due to a VHL germline mutation. This mutation leads to enhanced transcription of chemokine receptor 4 (CXCR4), its ligand (CXCL12) and vascular endothelial growth factor A (VEGFA). We aimed to determine in VHL-related and sporadic hemangioblastomas CXCR4, CXCL12, and VEGFA protein expression and to correlate this to hemangioblastoma size and expression in normal surrounding tissue. 27 patients with a hemangioblastoma were included for analysis of immunohistochemistry of tissue, MRI and DNA. Hemangioblastomas overexpress CXCR4, CXCL12, and VEGFA compared to normal surrounding tissue. In sporadic hemangioblastomas the mean percentage of CXCR4 positive hemangioblastoma cells was 16 %, SD 8.4, in VHL-related hemangioblastomas 8 %, SD 4.4 (P = 0.002). There was no relation between preoperative tumor size and CXCR4 or CXCL12 expression. Compared to normal surrounding tissue CXCR4, CXCL12, and VEGFA were overexpressed in hemangioblastomas. Most interestingly, sporadic hemangioblastomas overexpress CXCR4 compared to VHL-related hemangioblastoma.

Regional distribution of cerebral white matter lesions years after preeclampsia and eclampsia.

OBJECTIVE: To assess the distribution of cerebral white matter lesions in women who had eclampsia, preeclampsia, or normotensive pregnancies. The pathophysiology of these lesions, more often seen in formerly eclamptic and preeclamptic women, is unclear but may be related to a predisposition for vascular disease, the occurrence of the posterior reversible encephalopathy syndrome, or both while pregnant. Assessing the distribution of such lesions may give insight into their pathophysiology and possible consequences. METHODS: This retrospective cohort study determined the presence, severity, and location of white matter lesions on cerebral magnetic resonance imaging scans of 64 formerly eclamptic, 74 formerly preeclamptic, and 75 parous control women. RESULTS: Formerly preeclamptic and eclamptic women have white matter lesions more often (34.4% [n=47] compared with 21.3% [n=16]; P<.05) and more severely (0.07 compared with 0.02 mL; P<.05) than parous women in a control group. In all women, the majority of lesions was located in the frontal lobes followed by the parietal, insular, and temporal lobes. CONCLUSION: White matter lesions are more common in women with prior pregnancies complicated by preeclampsia or eclampsia compared with parous women in a control group. In no group does regional white matter lesion distribution correspond to the occipitoparietal edema distribution seen in posterior reversible encephalopathy syndrome.

Three cases of bipartition of the atlas.

BACKGROUND CONTEXT: A bipartite atlas is a rare coincidental finding, and it is reported in only 0.1% of the general population. It is a congenital disorder characterized by incomplete fusion of the anterior and the posterior arches of C1, and it is important to differentiate it from a Jefferson fracture. STUDY DESIGN/SETTING: Case report and literature review. PURPOSE: To report three cases of patients with bipartition of the atlas with a focus on imaging. To review the literature on these fusion defects, the embryologic basis, and the differentiation from a Jefferson fracture. METHODS: We report three cases of patients with a bipartite atlas as a coincidental finding in a trauma setting. The bipartite atlas was assessed by multidetector computed tomography (CT). The first case, for example, describes a 36-year-old patient who was struck by a moped. The CT of the skull showed a bipartite atlas as an additional finding. The embryologic development of C1 is reviewed and also the imaging features and the management. Furthermore, a CT image of a Jefferson fracture is provided for comparison. RESULTS: The CT scans of the three patients show midline clefts of the anterior and the posterior arches of C1 with similar imaging features: smooth margins lined by cortical bone and no lateral offset. The patients had no neurological symptoms relating to the C1 abnormality, and no follow-up was performed. The clefts at level C1 are the result of the failure of three ossification centers to fuse properly. Anterior and posterior clefts are caused by hypoplasia of the hypochordal bow and lateral parts of the C1 sclerotome, respectively. Because of the risk of instability, assessing atlantoaxial stability is advised. However, patients usually have no symptoms and require no specific treatment. CONCLUSIONS: A bipartite atlas is a rare congenital abnormality, caused by a failure of anterior and lateral ossification centers to fuse. It needs to be differentiated from a Jefferson fracture in a trauma setting. It usually requires no specific treatment.

Long-term visual functioning after eclampsia.

OBJECTIVE: Complete neurocognitive recovery after eclampsia has been questioned with the expression of neurocognitive deficits by affected women and demonstration of cerebral white matter lesions on magnetic resonance imaging years after eclampsia. We hypothesized that formerly eclamptic women may experience impaired vision-related quality of life (QOL) and visual field loss as a result of the presence of such lesions in the cerebral visual areas. METHODS: Using the National Eye Institute Visual Function Questionnaire-39/Nederlands questionnaire, vision-related QOL was compared between formerly eclamptic women and control participants after normotensive pregnancies. Furthermore, in formerly eclamptic women, visual fields were assessed using automated perimetry, and presence of white matter lesions was evaluated using cerebral magnetic resonance imaging. Presence of a relationship between these lesions and National Eye Institute Visual Function Questionnaire-39/Nederlands scores was estimated. RESULTS: Forty-seven formerly eclamptic women and 47 control participants participated 10.1±5.2 and 11.5±7.8 years after their index pregnancy, respectively. Composite scores and 4 out of 12 National Eye Institute Visual Function Questionnaire-39/Nederlands subscale scores were significantly lower in formerly eclamptic women than in control participants (P<.01 for composite scores). This could not be explained by visual field loss, because all formerly eclamptic women who underwent perimetry (n=43) demonstrated intact visual fields. White matter lesions were present in 35.7% of formerly eclamptic women who underwent magnetic resonance imaging (n=42) and were associated with lower vision-related QOL scores (P<.05 for composite scores). CONCLUSION: Formerly eclamptic women express lower vision-related QOL than control participants, which seemed at least partly related to the presence of white matter lesions. However, such women do not have unconscious visual field loss. Vision-related QOL impairment expressed by formerly eclamptic women may therefore be related to problems with higher-order visual functions. LEVEL OF EVIDENCE: II.

Brain lesions several years after eclampsia.

OBJECTIVE: Eclampsia is thought to have no long-term neurological consequences. We aimed to delineate the neurostructural sequelae of eclampsia, in particular brain white matter lesions, utilizing high-resolution 3-Tesla magnetic resonance imaging (MRI). STUDY DESIGN: Formerly eclamptic women were matched for age and year of index pregnancy with normotensive parous controls. The presence and volume of brain white matter lesions were compared between the groups. RESULTS: MRI scans of 39 women who formerly had eclampsia and 29 control women were performed on average 6.4 +/- 5.6 years following the index pregnancy at a mean age of 38 years. Women with eclampsia demonstrated subcortical white matter lesions more than twice as often as compared with controls (41% vs 17 %; odds ratio, 3.3; 95% confidence interval, 1.05-10.61; P = .04). CONCLUSION: Cerebral white matter lesions occur more often in women who formerly had eclampsia compared with women with normotensive pregnancies. The exact pathophysiology underlying these imaging changes and their clinical relevance remain to be elucidated.