Differential Hemispheric Lateralization of Emotions and Related Display Behaviors: Emotion-Type Hypothesis

Automatic processing of unattended mean emotion: Evidence from visual mismatch responses

The mean emotion from multiple facial expressions can be extracted rapidly and precisely. However, it remains debated whether mean emotion processing is automatic which can occur under no attention. To address this question, we used a passive oddball paradigm and recorded event-related brain potentials when participants discriminated the changes in the central fixation while a set of four faces was presented in the periphery. The face set consisted of one happy and three angry expressions (mean negative) or one angry and three happy expressions (mean positive), and the mean negative and mean positive face sets were shown with a probability of 20% (deviant) and 80% (standard) respectively in the sequence, or the vice versa. The cluster-based permutation analyses showed that the visual mismatch negativity started early at around 92 ms and was also observed in later time windows when the mean emotion was negative, while a mismatch positivity was observed at around 168-266 ms when the mean emotion was positive. The results suggest that there might be different mechanisms underlying the processing of mean negative and mean positive emotions. More importantly, the brain can detect the changes in the mean emotion automatically, and ensemble coding for multiple facial expressions can occur in an automatic fashion without attention.

Clinical characteristics and management of functional neurological disorders (FND) mimicking stroke in emergency settings: a functional stroke mimic cases

Background

FNDs mimicking a stroke represent a growing challenge in the emergency department (ED). A comprehensive diagnostic approach involving clinical evaluation and neuroimaging is essential to differentiate stroke from mimics. The safety profile of thrombolysis justifies its use where FNDs cannot be ruled out. This approach highlights the need for more precise diagnostic tools and protocols to improve patient care and reduce unnecessary treatments. Distinguishing FNDs from actual cerebrovascular events is critical yet difficult, particularly under time constraints. Given the urgency and potential severity of strokes, intravenous thrombolysis is frequently administered even when FNDs cannot be definitively excluded.

Methods

This retrospective study analyzed data of participants admitted to the Trieste University Hospital Stroke Unit between January 2018 and December 2022, focusing on those presenting with sudden-onset focal neurological deficits mimicking a stroke, with some presenting within the reperfusion treatment window (<4.5 h from symptoms onset). We obtained detailed clinical evaluations and neuroimaging, and administered thrombolytic therapy in selected cases.

Results and discussion

We included 84 participants presenting with stroke mimics (average age of 45 yo) predominantly female (65.5%). Most common presentations: hemiparesis or hemisensory loss (75%), speech disorder (10.7%), vertigo/gait disorders (4.8%). History of psychiatric disorders was found in 32.1% of cases, and 48.8% had prior neurological disease or stroke risk factors. Advanced neuroimaging was performed in 43 cases yielding normal or non-specific results. Thrombolysis was safely administered in 31%. Patients mostly recovered within the first 24 h from admission (44.7%). We compared this FND's sample with 291 patients with mild ischemic stroke (NIHSS ≤7).

The effects of real vs simulated high altitude on associative memory for emotional stimuli

INTRODUCTION

This study aimed to investigate the effects of normobaric hypoxia (NH) and hypobaric hypoxia (HH) on associative memory performance for emotionally valenced stimuli.

METHODS

Two experiments were conducted. In Study 1, n = 18 undergraduates performed an associative memory task under three NH conditions (FiO2= 20.9 %, 15.1 %, 13.6 %) using a tent with a hypoxic generator. In Study 2, n = 20 participants were assessed in a field study at various altitudes on the Himalayan mountains, including the Pyramid Laboratory (5000 m above sea level), using functional Near-Infrared Spectroscopy (fNIRS) and behavioral assessments.

RESULTS

Study 1 revealed no significant differences in recognition accuracy across NH conditions. However, Study 2 showed a complex relationship between altitude and memory for emotionally valenced stimuli. At lower altitudes, participants more accurately recognized emotional stimuli compared to neutral ones, a trend that reversed at higher altitudes. Brain oxygenation varied with altitude, indicating adaptive cognitive processing, as revealed by fNIRS measurements.

CONCLUSIONS

These findings suggest that hypoxia affects associative memory and emotional processing in an altitude-dependent manner, highlighting adaptive cognitive mechanisms. Understanding the effects of hypobaric hypoxia on cognition and memory can help develop strategies to mitigate its impact in high-altitude and hypoxic environments.

A historical approach to models of emotional laterality

In this paper I discuss the main models that have tried to explain brain asymmetries for emotions. The first models, based on clinical observations, proposed either a general right hemisphere dominance for emotions (the'right hemisphere') model or a different specialization of the right hemisphere for negative and of the left hemisphere for positive emotions (the'valence' model). In more recent times new models, based on partly modified versions of the previous ones have been proposed. The revised version of the 'valence' model, labeled the 'approach-avoidance' model maintained that hemispheric asymmetries are not related to the valence of the emotional stimulus but to the motivational (approach vs avoidance) system that is engaged by that stimulus. On the contrary, revised versions of the 'right hemisphere' hypothesis proposed graded versions of this model, maintaining that only some kinds or some levels of emotions are clearly right lateralized. One version of these models (the'emotion type hypothesis') assumed that only elementary basic emotions should be subsumed by the right hemisphere, wheres more complex social emotions should be subtended by the left hemisphere. The other version (the 'schematic level of emotion hypothesis') assumed that the right hemisphere should subsume only the basic 'schematic' level of emotions, characterized by an automatic and unconscious processing, whereas the more propositional and conscious 'conceptual' level could be less lateralized or subsumed by the left hemisphere. This last model is supported by the obsevation that the right hemisphere reveals a modus operandi (i.e. a prevalence of the 'automatic' over the 'intentional' and of the 'unconscious' over the 'conscious' functional processing) that is typical of the 'schematic level of emotions.

Neural consequences of 5-Hz transcranial alternating current stimulation over right hemisphere: An eLORETA EEG study

INTRODUCTION

Transcranial alternating current stimulation (tACS) at 5-Hz to the right hemisphere can effectively alleviate anxiety symptoms. This study aimed to explore the neural mechanisms that drive the therapeutic benefits.

METHODS

We collected electroencephalography (EEG) data from 24 participants with anxiety disorders before and after a tACS treatment session. tACS was applied over the right hemisphere, with 1.0 mA at F4, 1.0 mA at P4, and 2.0 mA at T8 (10-10 EEG convention). With eLORETA, we transformed the scalp signals into the current source density in the cortex. We then assessed the differences between post- and pre-treatment brain maps across multiple spectra (delta to low gamma) with non-parametric statistics.

RESULTS

We observed a trend of heightened power in alpha and reduced power in mid-to-high beta and low gamma, in accord with the EEG markers of anxiolytic effects reported in previous studies. Additionally, we observed a consistent trend of de-synchronization at the stimulating sites across spectra.

CONCLUSION

tACS 5-Hz over the right hemisphere demonstrated EEG markers of anxiety reduction. The after-effects of tACS on the brain are intricate and cannot be explained solely by the widely circulated entrainment theory. Rather, our results support the involvement of plasticity mechanisms in the offline effects of tACS.

Genetic variation in endocannabinoid signaling: Anxiety, depression, and threat- and reward-related brain functioning during the transition into adolescence

BACKGROUND

The endocannabinoid system modulates neural activity throughout the lifespan. In adults, neuroimaging studies link a common genetic variant in fatty acid amide hydrolase (FAAH C385A)-an enzyme that regulates endocannabinoid signaling-to reduced risk of anxiety and depression, and altered threat- and reward-related neural activity. However, limited research has investigated these associations during the transition into adolescence, a period of substantial neurodevelopment and increased psychopathology risk.

METHODS

This study included FAAH genotype and longitudinal neuroimaging and neurobehavioral data from 4811 youth (46% female; 9-11 years at Baseline, 11-13 years at Year 2) from the Adolescent Brain Cognitive DevelopmentSM Study. Linear mixed models examined the effects of FAAH and the FAAH x time interaction on anxiety and depressive symptoms, amygdala reactivity to threatening faces, and nucleus accumbens (NAcc) response to happy faces during the emotional n-back task.

RESULTS

A significant main effect of FAAH on depressive symptoms was observed, such that depressive symptoms were lower across both timepoints in those with the AA genotype compared to both AC and CC genotypes (p's<0.05). There were no significant FAAH x time interactions for anxiety, depression, or neural responses (p's>0.05). Additionally, there were no main effects of FAAH on anxiety or neural responses (p's>0.05).

CONCLUSIONS

Our findings add to emerging evidence linking the FAAH C385A variant to lower risk of psychopathology, and extend these findings to a developmental sample. In particular, we found lower depressive symptoms in FAAH AA genotypes compared to AC and CC genotypes. Future research is needed to characterize the role of the FAAH variant and the eCB system more broadly in neurodevelopment and psychiatric risk.

Personality systems interactions theory: an integrative framework complementing the study of the motivational and volitional dynamics underlying adjustment to chronic pain

In the endeavor to advance our understanding of interindividual differences in dealing with chronic pain, numerous motivational theories have been invoked in the past decade. As they focus on relevant, yet different aspects of the dynamic, multilevel processes involved in human voluntary action control, research findings seem fragmented and inconsistent. Here we present Personality Systems Interactions theory as an integrative meta-framework elucidating how different motivational and volitional processes work in concert under varying contextual conditions. PSI theory explains experience and behavior by the relative activation of four cognitive systems that take over different psychological functions during goal pursuit. In this way, it may complement existing content-related explanations of clinical phenomena by introducing a functional, third-person perspective on flexible goal management, pain acceptance and goal maintenance despite pain. In line with emerging evidence on the central role of emotion regulation in chronic pain, PSI theory delineates how the self-regulation of positive and negative affect impacts whether behavior is determined by rigid stimulus-response associations (i.e., habits) or by more abstract motives and values which afford more behavioral flexibility. Along with testable hypotheses, multimodal interventions expected to address intuitive emotion regulation as a central process mediating successful adaptation to chronic pain are discussed.

What impact can brain stimulation interventions have on borderline personality disorder?

INTRODUCTION

Borderline personality disorder (BPD) is a severe mental disorder characterized by emotion dysregulation, impulsivity, neuropsychological impairment, and interpersonal instability, presenting with multiple psychiatric comorbidities, functional disability and reduced life expectancy due suicidal behaviors.

AREAS COVERED

In this perspective, the authors explore the application of noninvasive brain stimulation (NIBS) (rTMS, tDCS, and MST) in BPD individuals by considering a symptom-based approach, focusing on general BPD psychopathology, impulsivity and neuropsychological impairments, suicidality and depressive/anxious symptoms, and emotion dysregulation.

EXPERT OPINION

According to a symptoms-based approach, NIBS interventions (particularly rTMS and tDCS) are promising treatment options for BPD individuals improving core symptoms such as emotional and behavioral dysregulation, neuropsychological impairments and depressive symptoms. However, the heterogeneity of stimulation protocols and of assessment tools used to detect these changes limits the possibility to provide definitive recommendations according to a symptom-based approach. To implement such armamentarium in clinical practice, future NIIBS studies should further consider a lifespan perspective due to clinical variability over time, the role of psychiatric comorbidities affecting BPD individuals and the need to combine NIBS with specialized psychotherapeutic approaches for BPD patients and with functional neuroimaging studies.

Improving Neuroplasticity through Robotic Verticalization Training in Patients with Minimally Conscious State: A Retrospective Study

In disorders of consciousness, verticalization is considered an effective type of treatment to improve motor and cognitive recovery. Our purpose is to investigate neurophysiological effects of robotic verticalization training (RVT) in patients with minimally conscious state (MCS). Thirty subjects affected by MCS due to traumatic or vascular brain injury, attending the intensive Neurorehabilitation Unit of the IRCCS Neurolesi (Messina, Italy), were included in this retrospective study. They were equally divided into two groups: the control group (CG) received traditional verticalization with a static bed and the experimental group (EG) received advanced robotic verticalization using the Erigo device. Each patient was evaluated using both clinical scales, including Levels of Cognitive Functioning (LCF) and Functional Independence Measure (FIM), and quantitative EEG pre (T0) and post each treatment (T1). The treatment lasted for eight consecutive weeks, and sessions were held three times a week, in addition to standard neurorehabilitation. In addition to a notable improvement in clinical parameters, such as functional (FIM) (p < 0.01) and cognitive (LCF) (p < 0.01) outcomes, our findings showed a significant modification in alpha and beta bands post-intervention, underscoring the promising effect of the Erigo device to influence neural plasticity and indicating a noteworthy difference between pre-post intervention. This was not observed in the CG. The observed changes in alpha and beta bands underscore the potential of the Erigo device to induce neural plasticity. The device's custom features and programming, tailored to individual patient needs, may contribute to its unique impact on brain responses.

Smaller Hippocampal Volume Is Associated With Reduced Posttraumatic Stress Symptoms in Children With Cancer and Survivors Following a Brief Novel Martial Arts-Based Intervention

PURPOSE

Children with cancer and survivors frequently report posttraumatic stress symptoms (PTSS), which are associated with volumetric changes in stress-sensitive brain regions, including the hippocampus.

METHODS

We examined the impact of a novel, 4-week martial-arts-based meditative intervention on cancer-related PTSS in 18 pediatric patients and survivors and whether baseline hippocampal volumes correlate with PTSS severity and/or PTSS changes over time.

RESULTS

Overall, PTSS did not significantly change from baseline to post-intervention. Smaller hippocampal volume was correlated with more severe re-experiencing PTSS at baseline, and greater reductions in PTSS post-intervention.

CONCLUSIONS

Together, hippocampal volume may be a biomarker of PTSS severity and intervention response. Identifying hippocampal volume as a potential biomarker for PTSS severity and intervention response may allow for more informed psychosocial treatments.

Mainly Visual Aspects of Emotional Laterality in Cognitively Developed and Highly Social Mammals-A Systematic Review

Several studies have shown that emotions are asymmetrically represented in the human brain and have proposed three main models (the 'right hemisphere hypothesis', the 'approach-withdrawal hypothesis' and the 'valence hypothesis') that give different accounts of this emotional laterality. Furthermore, in recent years, many investigations have suggested that a similar emotional laterality may also exist in different animal taxa. However, results of a previous systematic review of emotional laterality in non-human primates have shown that some of these studies might be criticized from the methodological point of view and support only in part the hypothesis of a continuum in emotional laterality across vertebrates. The aim of the present review therefore consisted in trying to expand this survey to other cognitively developed and highly social mammals, focusing attention on mainly visual aspects of emotional laterality, in studies conducted on the animal categories of horses, elephants, dolphins and whales. The 35 studies included in the review took into account three aspects of mainly visual emotional laterality, namely: (a) visual asymmetries for positive/familiar vs. negative/novel stimuli; (b) lateral position preference in mother-offspring or other affiliative interactions; (c) lateral position preference in antagonistic interactions. In agreement with data obtained from human studies that have evaluated comprehension or expression of emotions at the facial or vocal level, these results suggest that a general but graded right-hemisphere prevalence in the processing of emotions can be found at the visual level in cognitively developed non-primate social mammals. Some methodological problems and some implications of these results for human psychopathology are briefly discussed.

Imbalanced motivated behaviors according to motor sign asymmetry in drug-naïve Parkinson's disease

Few studies have considered the influence of motor sign asymmetry on motivated behaviors in de novo drug-naïve Parkinson's disease (PD). We tested whether motor sign asymmetry could be associated with different motivated behavior patterns in de novo drug-naïve PD. We performed a cross-sectional study in 128 de novo drug-naïve PD patients and used the Ardouin Scale of Behavior in Parkinson's disease (ASBPD) to assess a set of motivated behaviors. We assessed motor asymmetry based on (i) side of motor onset and (ii) MDS-UPDRS motor score, then we compared right hemibody Parkinson's disease to left hemibody Parkinson's disease. According to the MDS-UPDRS motor score, patients with de novo right hemibody PD had significantly lower frequency of approach behaviors (p = 0.031), including nocturnal hyperactivity (p = 0.040), eating behavior (p = 0.040), creativity (p = 0.040), and excess of motivation (p = 0.017) than patients with de novo left hemibody PD. Patients with de novo left hemibody PD did not significantly differ from those with de novo right hemibody PD regarding avoidance behaviors including apathy, anxiety and depression. Our findings suggest that motor sign asymmetry may be associated with an imbalance between motivated behaviors in de novo drug-naïve Parkinson's disease.

Affective Prosody and Its Impact on the Neurology of Language, Depression, Memory and Emotions

Based on the seminal publications of Paul Broca and Carl Wernicke who established that aphasic syndromes (disorders of the verbal-linguistic aspects of communication) were predominantly the result of focal left-hemisphere lesions, "language" is traditionally viewed as a lateralized function of the left hemisphere. This, in turn, has diminished and delayed the acceptance that the right hemisphere also has a vital role in language, specifically in modulating affective prosody, which is essential for communication competency and psychosocial well-being. Focal lesions of the right hemisphere may result in disorders of affective prosody (aprosodic syndromes) that are functionally and anatomically analogous to the aphasic syndromes that occur following focal left-hemisphere lesions. This paper will review the deductive research published over the last four decades that has elucidated the neurology of affective prosody which, in turn, has led to a more complete and nuanced understanding of the neurology of language, depression, emotions and memory. In addition, the paper will also present the serendipitous clinical observations (inductive research) and fortuitous inter-disciplinary collaborations that were crucial in guiding and developing the deductive research processes that culminated in the concept that primary emotions and related display behaviors are a lateralized function of the right hemisphere and social emotions, and related display behaviors are a lateralized function of the left hemisphere.

Characterizing Treatment Non-responders vs. Responders in Completed Alzheimer's Disease Clinical Trials

Alzheimer's disease (AD) patients have varying responses to AD drugs and there may be no single treatment for all AD patients. Trial after trial shows that identifying non-responsive and responsive subgroups and their corresponding moderators will provide better insights into subject selection and interpretation in future clinical trials. We aim to extensively investigate pre-treatment features that moderate treatment effect of Galantamine, Bapineuzumab, and Semagacestat from completed trial data. We obtained individual-level patient data from ten randomized clinical trials. Six Galantamine trials and two Bapineuzumab trials were from Yale University Open Data Access Project and two Semagacestat trials were from the Center for Global Clinical Research Data. We included a total of 10,948 subjects. The trials were conducted worldwide from 2001 to 2012. We estimated treatment effect using causal forest modeling on each trial. Finally, we identified important pre-treatment features that determine treatment efficacy and identified responsive or nonresponsive subgroups. As a result, patient's pre-treatment conditions that determined the treatment efficacy of Galantamine differed by dementia stages, but we consistently observed that non-responders in Galantamine trials had lower BMI (25 vs 28, P < .001) and increased ages (74 vs 68, P < .001). Responders in Bapineuzumab and Semagacestat trials had lower Aβ42 levels (6.41 vs 6.53 pg/ml, P < .001) and smaller whole brain volumes (983.13 vs 1052.78 ml, P < .001). 6 'positive' treatment trials had subsets of patients who had, in fact, not responded. 4 "negative" treatment trials had subsets of patients who had, in fact, responded. This study suggests that analyzing heterogeneity in treatment effects in "positive" or "negative" trials may be a very powerful tool for identifying distinct subgroups that are responsive to treatments, which may significantly benefit future clinical trial design and interpretation.

P3a amplitude to trauma-related stimuli reduced after successful trauma-focused PTSD treatment

An elevated P3a amplitude to trauma-related stimuli is strongly associated with posttraumatic stress disorder (PTSD), yet little is known about whether this response to trauma-related stimuli is affected by treatment that decreases PTSD symptoms. As an analysis of secondary outcome measures from a randomized controlled trial, we investigated the latency and amplitude changes of the P3a in responses in a three-condition oddball visual task that included trauma-related (combat scenes) and trauma-unrelated (threatening animals) distractors. Fifty-five U.S. veterans diagnosed with combat-related PTSD were randomized to receive either active or sham repetitive transcranial magnetic stimulation (rTMS). All received cognitive processing therapy, CPT+A, which requires a written account of the index trauma. They were tested before and 6 months after protocol completion. P3a amplitude and response time decreases were driven largely by the changes in the responses to the trauma-related stimuli, and this decrease correlated to the decrease in PTSD symptoms. The amplitude changes were greater in those who received rTMS + CPT than in those who received sham rTMS + CPT, suggesting that rTMS plays beneficial role in reducing arousal and threat bias, which may allow for more effective engagement in trauma-focused PTSD treatment.

The Spatiotemporal Dynamics of Facial Movements Reveals the Left Side of a Posed Smile

Humans can recombine thousands of different facial expressions. This variability is due to the ability to voluntarily or involuntarily modulate emotional expressions, which, in turn, depends on the existence of two anatomically separate pathways. The Voluntary (VP) and Involuntary (IP) pathways mediate the production of posed and spontaneous facial expressions, respectively, and might also affect the left and right sides of the face differently. This is a neglected aspect in the literature on emotion, where posed expressions instead of genuine expressions are often used as stimuli. Two experiments with different induction methods were specifically designed to investigate the unfolding of spontaneous and posed facial expressions of happiness along the facial vertical axis (left, right) with a high-definition 3-D optoelectronic system. The results showed that spontaneous expressions were distinguished from posed facial movements as revealed by reliable spatial and speed key kinematic patterns in both experiments. Moreover, VP activation produced a lateralization effect: compared with the felt smile, the posed smile involved an initial acceleration of the left corner of the mouth, while an early deceleration of the right corner occurred in the second phase of the movement, after the velocity peak.

Multi-Region Microdialysis Imaging Platform Revealed Dorsal Raphe Nucleus Calcium Signaling and Serotonin Dynamics during Nociceptive Pain

In this research, we combined our ultralight micro-imaging device for calcium imaging with microdialysis to simultaneously visualize neural activity in the dorsal raphe nucleus (DRN) and measure serotonin release in the central nucleus of the amygdala (CeA) and the anterior cingulate cortex (ACC). Using this platform, we observed brain activity following nociception induced by formalin injection in the mouse’s hind paw. Our device showed that DRN fluorescence intensity increased after formalin injection, and the increase was highly correlated with the elevation in serotonin release in both the CeA and ACC. The increase in calcium fluorescence intensity occurred during the acute and inflammatory phases, which suggests the biphasic response of nociceptive pain. Furthermore, we found that the increase in fluorescence intensity was positively correlated with mouse licking behavior. Lastly, we compared the laterality of pain stimulation and found that DRN fluorescence activity was higher for contralateral stimulation. Microdialysis showed that CeA serotonin concentration increased only after contralateral stimulation, while ACC serotonin release responded bilaterally. In conclusion, our study not only revealed the inter-regional serotonergic connection among the DRN, the CeA, and the ACC, but also demonstrated that our device is feasible for multi-site implantation in conjunction with a microdialysis system, allowing the simultaneous multi-modal observation of different regions in the brain.

The causal role of the bilateral ventrolateral prefrontal cortices on emotion regulation of social feedback

The ventrolateral prefrontal cortices (VLPFC) are crucial regions involved in voluntary emotion regulation. However, the lateralization of the VLPFC in downregulating negative emotions remains unclear; and whether the causal role of the VLPFC is generalizable to upregulating positive emotions is unexplored. This study used transcranial magnetic stimulation (TMS) to examine the causal relationship between the left/right VLPFC and social emotion reappraisal. One hundred and twenty participants were randomly assigned to either active (left and right VLPFC groups, n = 40/40) or sham (vertex, n = 40) TMS groups. Participants were instructed to passively receive social feedback or use reappraisal strategies to positively regulate their emotions. While the subjective emotional rating showed that the bilateral VLPFC facilitated the reappraisal success, the electrophysiological measure of the late positive potential (LPP) demonstrated a more critical role of the right VLPFC on social pain relief (decreased LPP amplitudes) and social reward magnification (enhanced LPP amplitudes). In addition, the influence of emotion regulation on social evaluation was found to be mediated by the memory of social feedback, indicating the importance of memory in social behavioral shaping. These findings suggest clinical protocols for the rehabilitation of emotion-regulatory function in patients with affective and social disorders.

Toward unraveling the correlates of fatigue in glioma

BACKGROUND

Even though fatigue is one of the most prevalent and burdensome symptoms in patients with glioma, its etiology and determinants are still poorly understood. We aimed to identify which demographic, tumor- and treatment-related characteristics and patient-reported outcome measures (PROMs) are associated with or are predictors of fatigue in glioma.

METHODS

In this retrospective observational study, we included glioma patients with preoperative and postoperative assessments including PROMs on fatigue, depression, cognitive functioning, and health-related quality of life (HRQoL). Linear mixed models were used to identify which clinical factors and PROMs were associated with fatigue and linear multiple regression was used to detect predictors of postoperative fatigue.

RESULTS

In this study, 222 patients were included (78% grade II-III glioma, 22% grade IV). These patients had performed 333 assessments (193 preoperative and 116 one year postoperatively). Of all assessments, 39% was indicative of severe fatigue. Several HRQoL domains, depression, and right-sided tumors were significantly associated with fatigue (marginal R 2 = 0.63). Contrary to common expectations, tumor type, treatment-related factors, and timing of the assessment, were not associated with fatigue. In a subgroup of 70 patients with follow-up assessments, preoperative fatigue, and physical functioning were predictors of postoperative fatigue (adjusted R 2 = 0.31).

CONCLUSION

Fatigue is a complex symptom, which should not solely be attributed to the tumor or its treatment, but is instead related to different aspects of mood and HRQoL. These insights are important in understanding fatigue and could guide symptom management, especially in patients with lower-grade tumors.