Abnormal visual and olfactory sensations during radiation therapy: a prospective study.

PURPOSE: Patients sometimes report phosphene and phantosmia during radiation therapy (RT). However, the detail features and related factors are not well understood. Our prospective study aimed to investigate the characteristics of phantosmias and phosphenes, to identify factors that influence the occurrence, intensity and hedonic (pleasantness/unpleasantness) ratings of such sensations during RT. METHODS: We included a total of 106 patients (37 women), who underwent RT in regions of the brain, ear, nose, throat (ENT), and other areas of the body for a duration of 43 ± 5 days. Medical history and treatment parameters were collected in a structured medical interview. Olfactory function was measured using the Sniffin' Stick Odor Identification Test at baseline. Phantosmia and phosphene were recorded weekly based on a self-report questionnaire. RESULTS: There were 37% of the patients experiencing phantosmias, 51% experiencing phosphenes, and 29% simultaneously experiencing both sensations. Phosphenes were typically perceived as a flashily blue, white and/or purple light, phantosmias were typically perceived as a chemical-like, metallic or burnt smell. Younger age (F = 7.81, p < 0.01), radiation in the brain region (χ2 = 14.05, p = 0.02), absence of taste problems (χ2 = 10.28, p = 0.01), and proton RT (χ2 = 10.57, p = 0.01) were related to these abnormal sensations. History of chemical/dust exposure predicted lower intensity (B = -1.52, p = 0.02) and lower unpleasantness (B = 0.49, p = 0.03) of phantosmia. In contrast, disease (tumor) duration (B = 0.11, p < 0.01), food allergy (B = 2.77, p < 0.01), and epilepsy (B = -1.50, p = 0.02) influence phosphenes intensity. Analgesics intake predicted a higher pleasantness of the phosphenes (B = 0.47, p < 0.01). CONCLUSIONS: Phantosmias and phosphenes are common during RT. The treatment settings and individual arousal level influence the occurrence, intensity and hedonic of such abnormal sensations. Phantosmias and phosphenes may involve more central neural than peripheral mechanism, and they could be elicited with activation of areas that are not regarded to be part of the olfactory or visual network.

Self-assessment of olfactory function using the "Sniffin' Sticks".

BACKGROUND: A precise and reliable test of the olfactory function is indispensable for the diagnosis of the olfactory disorder (OD). Despite of this, in a clinical context, often there is no place in daily routine for time-consuming procedures. This study aimed to examine if the assessment of olfactory function using the "Sniffin' Sticks" is suitable for self-assessment. METHODS: Participants comprised 84 healthy control subjects (HC) and 37 OD patients. The "Sniffin' Sticks" test battery consisting of odor threshold (T), discrimination (D) and identification (I) tests was used for self- and assisted assessments. To save time, we applied the 8-item wide step version of the T test and the 8-item D test, whereas the I task remained the same as the original version. The whole test included two sessions, with each session comprising a self-assessment part performed by the participants themselves, and an assisted-assessment part performed by the examiner. RESULTS: Sniffin' Sticks self-assessment was efficient in distinguishing between self-reported HC subjects and OD patients (p's < 0.01), and the scores did not differ significantly from the assisted-assessment (p's > 0.05). In the self-administered I and TDI tests, there was a moderate to excellent test-retest reliability (ICC = 0.51-0.93, p's < 0.01), and a strong to excellent correlation with the assisted assessment (r = 0.71-0.92, p's < 0.01). However, the self-administered T and D tests only exhibited low to moderate test-retest reliability (ICC = 0.30-0.72, p's < 0.05) and correlations with the assisted test (r = 0.31-0.62, p's < 0.05). CONCLUSIONS: The Identification self-test is appropriate to be solely applied, and is therefore an easy-to-use alternative for olfactory screening in a larger segment of patients. The whole "Sniffin' Sticks" self-test also shows good measurement properties and is therefore a suitable backup in clinical practice, but improvement is needed due to the simplified D and T self-test.

Olfactory impairment as an early marker of Parkinson's disease in REM sleep behaviour disorder: a systematic review and meta-analysis.

Olfactory impairment and rapid eye movement sleep behaviour disorder (RBD) are prodromal symptoms of Parkinson's disease (PD) that may be associated with each other. This review aims to investigate the significance of olfaction in the diagnosis and prognosis of patients with RBD and to assess moderating factors affecting olfactory performance. We searched articles on olfaction in RBD and PD in five electronic databases. We identified 32 studies for the systematic review and used 28 of those, including 2858 participants for meta-analysis. Results revealed significant deficits in odour identification (g=-1.80; 95% CI: -2.17 to -1.43), threshold (g=-1.29; 95% CI: -1.67 to -0.91), discrimination (g=-1.08; 95% CI: -1.28 to -0.87) and overall olfactory function (g=-1.64; 95% CI: -1.94 to -1.35) in patients with RBD. Except for the Unified Parkinson's Disease Rating Scale Part III scores, none of the known moderating variables (including age, sex, disease duration and years of education) accounted for the olfactory function heterogeneity in patients with RBD. We identified similar olfactory impairments in patients with RBD and patients with PD (either with or without underlying RBD). These findings suggest that olfactory impairment may be a sensitive and stable diagnostic biomarker of RBD and appears to be useful for identifying patients with idiopathic RBD at high risk for early conversion to PD.

Olfaction is a Marker of Severity but Not Diagnosis in Anorexia Nervosa: a Systematic Review and Meta-Analysis.

Researchers have examined if olfaction is a sensitive biomarker of anorexia nervosa, but considerable heterogeneity across studies makes it difficult to reach a consensus. This review and meta-analysis sought to clarify if olfaction is altered in individuals with anorexia nervosa and explore potential moderators of olfaction in this population. We performed quantitative and qualitative analyses of olfactory function in individuals with anorexia nervosa compared with healthy controls. A random effect model was used to estimate pooled effect sizes, and meta-regression was conducted to identify potential moderators. We found that individuals with anorexia nervosa had largely intact olfactory function compared with healthy controls in terms of threshold (g = -0.09, 95% confidence interval [CI] (-0.65,0.47), p = 0.757), identification (g = -0.06, 95% CI (-0.32,0.20), p = 0.642), and overall olfactory function (g = -0.47, 95% CI (-1.02,0.07), p = 0.090). Discrimination was different from control (g = -0.51, 95% CI (-0.97,-0.05), p = 0.029). However, after sensitivity analysis, the pooled effect size was nonsignificant in discrimination. Olfactory sensitivity covaried with anorexia nervosa severity, body mass index (BMI) positively moderated olfactory threshold score (ß = 0.79, 95% CI (0.18,1.41), p = 0.020) in individuals with anorexia nervosa. Disease duration negatively moderated olfactory threshold score (ß = -0.21, 95% CI (-0.40,-0.03), p = 0.034). The results suggest that olfaction is not a sensitive marker of anorexia nervosa diagnosis, but olfactory sensitivity may be a useful indicator of anorexia nervosa severity.

Well-being in patients with olfactory dysfunction.

This cross-sectional, retrospective study aimed to investigate the differences in well-being among patients with olfactory disorder (OD) with quantitative and/or qualitative olfactory dysfunctions, and to identify factors associated with well-being (WB). We included 470 OD patients. WB (WHO-5 questionnaire), quantitative olfactory function (Sniffin' Sticks) and qualitative dysfunction were assessed. Overall, 35% of the OD patients reported a poor WB, higher than 22% of the normative data in general population. For quantitative function, anosmia patients showed lower WB scores than hyposmia and normosmia patients (all p's < 0.03). For qualitative dysfunction, patients with severe parosmia showed lower WB scores than patients without and with less severe parosmia (p's < 0.01). Regarding OD causes in hyposmic patients, post-infectious patients showed poorer WB than idiopathic patients (p = 0.01); sinonasal patients had lower WB than post-traumatic and idiopathic patients (all p's < 0.04). There was a weak but significant positive correlation between WB score and Threshold test score (r = 0.11, p = 0.02). Hierarchical regression analyses showed that women gender, Threshold and overall Sniffin' Sticks scores (TDI) significantly predicted WB score in OD patients. Our results implied that quantitative and qualitative dysfunction is associated with WB. However, only patients with severe dysfunction showed significantly lower WB. While this needs to be better understood, in order to improve well-being, in these patients it appears to be highly important to improve olfactory function, and here especially olfactory sensitivity.

Joint-Channel-Connectivity-Based Feature Selection and Classification on fNIRS for Stress Detection in Decision-Making.

Stress is one of the contributing factors affecting decision-making. Therefore, early stress recognition is essential to improve clinicians' decision-making performance. Functional near-infrared spectroscopy (fNIRS) has shown great potential in detecting stress. However, the majority of previous studies only used fNIRS features at the individual level for classification without considering the correlations among channels corresponding to the brain, which may provide distinguishing features. Hence, this study proposes a novel joint-channel-connectivity-based feature selection and classification algorithm for fNIRS to detect stress in decision-making. Specifically, this approach integrates feature selection and classifier modeling into a sparse model, where intra- and inter-channel regularizers are designed to explore potential correlations among channels to obtain discriminating features. In this paper, we simulated the decision-making of medical students under stress through the Trier Social Stress Test and the Balloon Analog Risk Task and recorded their cerebral hemodynamic alterations by fNIRS device. Experimental results illustrated that our method with the accuracy of 0.961 is superior to other machine learning methods. Additionally, the stress correlation and connectivity of brain regions calculated by feature selection have been confirmed in previous studies, which validates the effectiveness of our method and helps optimize the channel settings of fNIRS. This work was the first attempt to utilize a sparse model that simultaneously considers the sparsity of features and the correlation of brain regions for stress detection and obtained an admirable classification performance. Thus, the proposed model might be a useful tool for medical personnel to automatically detect stress in clinical decision-making situations.

The effect of social exclusion on intertemporal choice in suicide attempters: A preliminary experimental study.

BACKGROUND: Suicide-related theories and a growing body of evidence suggest that suicidal patients may have a tendency toward "short-sightedness"-the preference for immediate gratification when making intertemporal choice-and that social exclusion may exacerbate this tendency in suicidal patients. The present study examined the intertemporal choice performance of suicide attempters under conditions of social exclusion in a sample of affective disorder patients. METHODS: A total of 64 affective disorder patients (22 non-suicidal patients, 24 single-suicide attempters and 18 multiple-suicide attempters) completed an intertemporal choice task in an exclusion or a non-exclusion condition. Social exclusion was manipulated using the Cyberball paradigm. RESULTS: Non-suicidal patients and single-suicide attempters both exhibited an exaggerated preference for immediate rewards in the exclusion condition compared with the non-exclusion condition; in contrast, the multiple-suicide attempters appeared relatively indifferent to the social exclusion, exhibiting virtually identical preferences for immediate rewards in both the exclusion and non-exclusion conditions. In addition, the multiple-suicide attempters exhibited an exaggerated preference for immediate rewards compared with non-suicidal patients and single-suicide attempters in the non-exclusion condition, while the three groups did not differ in the exclusion condition. CONCLUSIONS: Affective disorder patients with a single or no suicide attempts are more short-sighted after being excluded, while those with multiple suicide attempts appeared consistent short-sightedness in both exclusion and non-exclusion conditions. The study provides preliminary evidence of the role of disadvantageous intertemporal choice in the suicidal process. Future research replicate and extend these findings could have implications for suicide prevention and intervention.

Impulsiveness and suicide in male offenders: Examining the buffer roles of regulatory emotional self-efficacy and flourishing.

OBJECTIVES: Although impulsiveness has been recognized as a risk factor for suicide, few studies have explored how to protect offenders with impulsiveness from the risk of suicide. This study aims to examine the relationships among impulsiveness, suicide risk, regulatory emotional self-efficacy (RESE), and flourishing, focusing on the moderating effects of RESE and flourishing in the relationship between impulsiveness and suicide risk. DESIGN AND METHODS: This is a cross-sectional study of 941 male offenders. All participants were requested to provide some items of demographic information and to complete a package of self-reported questionnaires measuring impulsiveness, suicide risk, RESE, and flourishing. RESULTS: The results indicate that impulsiveness is positively correlated with suicide risk, while RESE and flourishing are negatively correlated with impulsiveness and suicide risk. Most importantly, both RESE and its dimension managing negative affect (NEG) negatively moderate the relationship between impulsiveness and suicide risk. Flourishing and the RESE dimension expressing positive affect (POS) show no significant moderating effect on impulsiveness-suicide risk link. CONCLUSIONS: Regulatory emotional self-efficacy, especially its NEG dimension, can buffer the impact of impulsiveness on suicide risk in male offenders, indicating that these factors might be useful supplements in suicide prevention. PRACTITIONER POINTS: Offender with higher level of RESE and flourishing show lower level of impulsiveness and suicide risk. High level of RESE and its NEG dimension can buffer the effect of impulsiveness on suicide risk. RESE, especially its NEG dimension might be a useful supplement for suicide prevention in offenders with high impulsiveness.

Mindfulness and Suicide Risk in Undergraduates: Exploring the Mediating Effect of Alexithymia.

The present study was designed to examine the relationship between dispositional mindfulness and suicide risk in undergraduates, and it further explored the potential mediating role of alexithymia in this relationship. A total of 2,633 undergraduates completed the Mindful Attention Awareness Scale (MAAS), the Suicidal Behaviors Questionnaire - Revised (SBQ-R), and the 20-item Toronto Alexithymia Scale (TAS-20). The results indicate that mindfulness and suicide risk were negatively correlated, and alexithymia partially mediated the relationship between mindfulness and suicide risk only in the female undergraduates. Moreover, only the difficulty in identifying feelings (DIF) factor of alexithymia mediated the relationship between mindfulness and suicide risk in the female undergraduates. These findings contribute to the potential mechanism that explains the relationship between mindfulness and suicide risk. Furthermore, it is possible to implement mindfulness in the suicide intervention of alexithymic individuals.