Surgical Resection and Cellular Proliferation Index Predict Prognosis for Patients with Papillary Glioneuronal Tumor: Systematic Review and Pooled Analysis.

BACKGROUND: Although the World Health Organization classifies papillary glioneuronal tumor (PGNT) as a grade I tumor, several malignant cases have been reported. In this study, we examined the clinical and prognostic characteristics of PGNT. METHODS: PubMed, Embase, and institutional databases were queried for patient-level reports of PGNT, resulting in identification of 138 cases. Descriptive and Kaplan-Meier survival analyses were conducted. The threshold of significance was 0.05. RESULTS: The mean age at presentation was 26.9 ± 16.3 years, and the incidence was higher in males (1.42:1). Tumors with a high Ki-67 index (≥5) were more likely to exhibit perilesional edema and ring enhancement on magnetic resonance imaging, trending toward significance (P = 0.114 and 0.113, respectively). Compared with tumors with a low Ki-67 index (<5), those with a high Ki-67 index were more likely to be treated with subtotal resection (STR) than with gross total resection (GTR) (Kruskal-Wallis test, P = 0.006) and with radiation therapy (χ2 test, P = 0.010). At 5 years post-treatment, PGNT had a mean progression-free survival (PFS) of 85.9 ± 3.9%. Males had a better 5-year PFS than females (94.0 ± 3.4% vs. 74.8 ± 7.8%; Mantel-Cox test, P = 0.002). Two-year PFS was higher after GTR than after STR (91.9 ± 3.6% vs. 46.7 ± 21.4%; Mantel-Cox test, P < 0.001). A low Ki-67 index was associated with a higher 5-year PFS compared with a high Ki-67 index (94.8 ± 3.6% vs. 55.6 ± 12.9%; Mantel-Cox test, P < 0.001). CONCLUSIONS: PGNT is a benign tumor of young adults, but can present atypically as high grade. Male sex, low cellular proliferation, and maximal surgical resection are positive prognostic indicators for PGNT.

Human preferences for symmetry: subjective experience, cognitive conflict and cortical brain activity.

This study examines the links between human perceptions, cognitive biases and neural processing of symmetrical stimuli. While preferences for symmetry have largely been examined in the context of disorders such as obsessive-compulsive disorder and autism spectrum disorders, we examine various these phenomena in non-clinical subjects and suggest that such preferences are distributed throughout the typical population as part of our cognitive and neural architecture. In Experiment 1, 82 young adults reported on the frequency of their obsessive-compulsive spectrum behaviors. Subjects also performed an emotional Stroop or variant of an Implicit Association Task (the OC-CIT) developed to assess cognitive biases for symmetry. Data not only reveal that subjects evidence a cognitive conflict when asked to match images of positive affect with asymmetrical stimuli, and disgust with symmetry, but also that their slowed reaction times when asked to do so were predicted by reports of OC behavior, particularly checking behavior. In Experiment 2, 26 participants were administered an oddball Event-Related Potential task specifically designed to assess sensitivity to symmetry as well as the OC-CIT. These data revealed that reaction times on the OC-CIT were strongly predicted by frontal electrode sites indicating faster processing of an asymmetrical stimulus (unparallel lines) relative to a symmetrical stimulus (parallel lines). The results point to an overall cognitive bias linking disgust with asymmetry and suggest that such cognitive biases are reflected in neural responses to symmetrical/asymmetrical stimuli.