Insular Damage Research Articles

Neuroimaging of autobiographical memory in dementia with Lewy bodies: a story of insula.

Although deficits in learning and retrieving new information are well characterized in dementia with Lewy bodies, autobiographical memory has never been explored in this disease. Yet, autobiographical memory impairments are a pervasive feature of dementia, well characterized in other neurodegenerative diseases. Moreover, autobiographical memory corresponds to an extension over time of the self, which we hypothesize is altered in dementia with Lewy bodies and impairment of which could be linked to the insular atrophy occurring from an early stage of the disease. In this study, we sought to characterize autobiographical memory impairments and explore their neural correlates in dementia with Lewy bodies, on the assumption that insular damage could impact the self, including its most elaborate components, such as autobiographical memory. Twenty patients with prodromal to mild dementia with Lewy bodies were selected to participate in this exploratory study along with 20 healthy control subjects. The Autobiographical Interview was used to assess autobiographical memory. Performances were compared between patients and control subjects, and an analysis across life periods and recall conditions was performed. 3D magnetic resonance images were acquired for all participants, and correlational analyses were performed in the patient group using voxel-based morphometry. The behavioural results of the Autobiographical Interview showed that autobiographical memory performances were significantly impaired in dementia with Lewy body patients compared to control subjects in a temporally ungraded manner, for both the free recall and the specific probe conditions (P < 0.0001), though with greater improvement after probing in the patient group. Furthermore, autobiographical memory impairments were correlated with grey matter volume within right insular cortex, temporoparietal junction, precuneus, putamen, left temporal cortex, bilateral parahippocampus and cerebellum, using a threshold of P = 0.005 uncorrected. The behavioural results confirm the existence of temporally ungraded autobiographical memory impairments in dementia with Lewy bodies, from the early stage of the disease. As we expected, neuroimaging analysis revealed a role for the insula and the precuneus in autobiographical memory retrieval, two regions associated with elementary aspects of the self, among other brain regions classically associated with autobiographical memory, such as medial temporal lobe and temporoparietal junction. Our findings provide important insights regarding the involvement of the insula in the self and suggest that insular damage could lead to a global collapse of the self, including its more elaborated components, such as autobiographical memory.

Ischemic insular damage and stress ulcer in patients of acute ischemic stroke.

Stress ulcer (SU) is a common complication in patients with acute ischemic stroke. The relationship of infarction location and the incidence of SU was unclear. Herein, we aim to investigate the association between ischemic insular damage and the development of SU. Data were retrieved from the SPARK study (Effect of Cardiac Function on Short-Term Functional Prognosis in Patients with Acute Ischemic Stroke). We included the patients who had experienced an ischemic stroke within 7 days. The diagnosis of SU was based on clinical manifestations, including hematemesis, bloody nasogastric tube aspirate, or hematochezia. Evaluation of ischemic insular damage was conducted through magnetic resonance imaging. Cyclo-oxygenase regression analysis and Kaplan-Meier survival curves were used to assess the relationship between ischemic insular damage and the occurrence of SU. Among the 1357 patients analyzed, 110 (8.1%) developed SUs during hospitalization, with 69 (6.7%) experiencing infarctions in the anterior circulation. After adjusting for potential confounders, patients with ischemic insular damage exhibited a 2.16-fold higher risk of developing SUs compared to those without insular damage (p=.0206). Notably, among patients with infarctions in the anterior circulation, those with insular damage had a 2.21-fold increased risk of SUs (p=.0387). Moreover, right insular damage was associated with a higher risk of SUs compared to left insular damage or no insular damage (p for trend=.0117). Kaplan-Meier curves demonstrated early separation among groups, persisting throughout the follow-up period (all p<.0001). This study identified a significant independent correlation between ischemic insular damage, particularly on the right side, and the development of SU during hospitalization, indicating the need to consider prophylactic acid-suppressive treatment for patients with ischemic insular damage.

Association of the Timing of Atrial Fibrillation Detection and Insular Involvement With the Risk of Embolic Events After Acute Ischemic Stroke.

Atrial fibrillation (AF) detected after insular stroke might arise from autonomic and inflammatory mechanisms triggered by insular damage, and be associated with a low embolic risk. We assessed the association of the timing of AF detection and insular involvement with the risk of embolic events after acute ischemic stroke. Acute ischemic stroke patients with AF who underwent brain magnetic resonance imaging at baseline were enrolled. Patients were classified according to the timing of AF detection (AF detected after stroke [AFDAS] or known AF [KAF]) and insular involvement. The primary outcome was embolic events defined as recurrent ischemic stroke, transient ischemic attack, and systemic embolism within 90 days. Of 1,548 patients, 360 had AFDAS with insular cortex lesions (+I), 409 had AFDAS without insular cortex lesions (-I), 349 had KAF+I, and 430 had KAF-I. Cumulative incidence rates of embolic events at 90 days in patients with AFDAS+I, AFDAS-I, KAF+I, and KAF-I were 0.8%, 3.5%, 4.9%, and 3.3%, respectively. Patients with AFDAS-I (adjusted hazard ratio 5.04, 95% confidence interval 1.43-17.75), KAF+I (6.18, 1.78-21.46), and KAF-I (5.26, 1.48-18.69) had a significantly higher risk of embolic events than those with AFDAS+I. Acute ischemic stroke patients with AFDAS and insular cortex lesions had a lower risk of embolic events than those who had AFDAS without insular cortex lesions or those with KAF, regardless of insular involvement. ANN NEUROL 2024;95:338-346.

Me, Myself and My Insula: An Oasis in the Forefront of Self-Consciousness.

The insula is a multiconnected brain region that centralizes a wide range of information, from the most internal bodily states, such as interoception, to high-order processes, such as knowledge about oneself. Therefore, the insula would be a core region involved in the self networks. Over the past decades, the question of the self has been extensively explored, highlighting differences in the descriptions of the various components but also similarities in the global structure of the self. Indeed, most of the researchers consider that the self comprises a phenomenological part and a conceptual part, in the present moment or extending over time. However, the anatomical substrates of the self, and more specifically the link between the insula and the self, remain unclear. We conducted a narrative review to better understand the relationship between the insula and the self and how anatomical and functional damages to the insular cortex can impact the self in various conditions. Our work revealed that the insula is involved in the most primitive levels of the present self and could consequently impact the self extended in time, namely autobiographical memory. Across different pathologies, we propose that insular damage could engender a global collapse of the self.

Effects of emotional valence and intensity on cognitive and affective empathy after insula lesions.

The insula plays a central role in empathy. However, the complex structure of cognitive (CE) and affective empathy (AE) deficits following insular damage is not fully understood. In the present study, patients with insular lesions (n = 20) and demographically matched healthy controls (n = 24) viewed ecologically valid videos that varied in terms of valence and emotional intensity. The videos showed a person (target) narrating a personal life event. In CE conditions, subjects continuously rated the affective state of the target, while in AE conditions, they continuously rated their own affect. Mean squared error (MSE) assessed deviations between subject and target ratings. Patients differed from controls only in negative, low-intensity AE, rating their own affective state less negative than the target. This deficit was not related to trait empathy, neuropsychological or clinical parameters, or laterality of lesion. Empathic functions may be widely spared after insular damage in a naturalistic, dynamic setting, potentially due to the intact interpretation of social context by residual networks outside the lesion. The particular role of the insula in AE for negative states may evolve specifically in situations that bear higher uncertainty pointing to a threshold role of the insula in online ratings of AE.

Lateralized deficits in arousal processing after insula lesions: Behavioral and autonomic evidence

A large body of evidence ascribes a pivotal role in emotion processing to the insular cortex. However, the complex structure and lateralization of emotional deficits following insular damage are not understood. Here, we investigated emotional ratings of valence and arousal and skin conductance responses (SCR) to a graded series of emotionally arousing scenes in patients with left (n = 10) or right (n = 9) insular damage and in healthy controls (n = 18). We found a significant reduction in overall SCRs, arousal ratings and valence extremity scores in right-lesioned patients, as compared to left-lesioned patients and healthy controls. The degree of right insular damage was significantly correlated with the degree of arousal, SCR and extremity attenuation. Additional analyses of correlations between subjective arousal ratings resp. SCR and normative arousal ratings revealed that both lesion groups had evaluative and physiological difficulties to discover changes in stimulus arousal. Although no group differences emerged on overall ratings of valence, analysis of correlations between subjective and normative valence ratings displayed markedly reduced accuracy in right-lesioned patients, as compared to left-lesioned patients and healthy controls. Our findings support the hypothesis that the left and right insulae subserve different functions in emotion processing, potentially due to asymmetrical representations of autonomic information in the left and right human forebrain. The right insula may serve as integral node for sympathetic arousal and cognitive-affective processing.

Self, insula and dementia with Lewy bodies

AbstractBackgroundThe objective is to review in the literature evidence of the relationship between the Self, the insular cortex, and Dementia with Lewy bodies (DLB). The notion of “Self” encompasses a subjective part that integrates the most internal bodily phenomena of self‐awareness, and an objective part that sustains autobiographical memory and its most specific details. Modifications of the Self, such as anosognosia and personal identity, or autobiographical memory deterioration, are frequently reported by relatives and noticed by clinicians, jointly with insular atrophy, which occurs early in the course of the disease.MethodWe performed research on PubMed and Google Scholar, using MeSH subheadings and keywords, limited to papers in English; 226 publications contributed to the review. The terms “Lewy bodies”, “Insula”, “Self” and different aspects related to the self, such as “subjective sense of self”, “self‐concept” and “autobiographical memory” were used to denote the themes of interest.ResultThe evidence suggest that insula is a multiconnected brain region involved in processing varied aspects of the self. On the one hand, insula’s posterior part integrates primary interoceptive representations through sensorimotor processes, and on the other hand insula’s anterior part sustains and integrates viscerosensory responses, socio‐emotional processing and cognitive functions, allowing the emergence of self‐awareness. In addition, changes in personal tastes resulting from insular atrophy have been highlighted in DLB. However, there is, to date, little work exploring the different components of the self (i.e. subjective sense of self; self‐concept; autobiographical memory) in DLB.ConclusionBased on our literature review, it seems that no experimental work have ever been performed on the Self in DLB. Numerous aspects related to the Self, from the most primitive to more elaborated ones are worthy of being studied in this affection, whose anatomic peculiarity sets in early insular damage. We intend to investigate these questionings in DLB, compared to Alzheimer disease – which is characterized by an early deterioration of episodic autobiographical memory – and healthy elderly population, by combining behavioral measures and multimodal neuroimaging, with a particular interest for the insular cortex.

Insula and Olfaction: A Literature Review and Case Report

(1) Background: It is well established that the insula is involved in olfaction, though its specific role in olfactory processing remains uncertain. In this paper, we first review the current literature on the insula and olfaction. Then, we describe the case of a 56-year-old man with a left insular cavernoma that caused olfactory disturbances. (2) Results: Structural neuroimaging studies suggest that insular gray matter volume is related to olfactory function, and functional neuroimaging shows that various types of stimuli lead to either lateralized or bilateral insular activations. Studies using electro-cortical stimulation reveal a specific region of the insular cortex, around the central insular sulcus, that could be related to unpleasant odor processing. Previous cases of insular lesions leading to olfactory disturbances suggest that left-sided insular lesions may more frequently lead to olfactory changes. In our patient with a left insular cavernoma, odors that were previously perceived as pleasant started smelling unpleasant and were hard to distinguish. Despite these subjective complaints, olfactory function assessed with the Sniffin’ Sticks test was normal. (3) Conclusions: Current tests may not be sensitive to all types of olfactory impairments associated with insular damage, and further studies should be conducted to develop olfactory tests assessing the hedonic appreciation of odors.

The effects of insular and mesiotemporal lesions on affective information processing: Preliminary evidence from patients with epilepsy surgery

Depressive symptoms and anxiety are common complaints in patients who have had epilepsy surgery. Recent studies have reported disturbances in emotional memory, facial and vocal emotion recognition, and affective learning after temporal lobe and/or insular resection for drug-resistant seizures, suggesting that these regions may be involved in emotional processes underlying psychological symptoms. The insula is a core component of the salience network and is thought to be involved in processing emotions such as disgust, and the role of mesial temporal lobe structures in affective processing is well established. However, to our knowledge, no study has yet investigated whether attentional processing of affective information is altered when these structures are resected as part of an epilepsy surgery. The present study examined the interference control capacity and attentional biases for emotional information in adult patients with epilepsy who underwent temporal lobe resections including the amygdala and hippocampus (n = 15) and/or partial or complete insular resections (n = 16). Patients were tested on an Emotional Stroop test and on a Dot-Probe task using fearful and disgusting pictures and were compared with a healthy control group (n = 30) matched for age, gender, and education. Repeated-measures analyses of variances revealed a significant effect of emotional words on color naming speed in the Emotional Stroop task among insular patients, which was not observed in the other groups. By contrast, the groups did not differ on Dot-Probe task performance. These preliminary findings suggest that insular damage may alter emotional interference control.

SERUM-CORTISOL LEVELS IN SEVERITY OF STROKE

Introduction: Cortisol, an important hormone in the hypothalamic pituitary adrenal axis, has important effects on the metabolism of glucose, protein and lipid[i]. A stress response consists of increased levels of cortisol and catecholamines in the 1st weeks after acute stroke. The cortisol response has been observed in cerebral infarction as well as in intracerebral haemorrhage. Change in serum level of cortisol has been reported in patients with ischemic stroke and studies reported that high levels of this hormone are independently associated with increase in ischemic lesion volume. Also it has been observed that cortisol level in patients with ischemic stroke is associated with significantly increased mortality rate. Increase in the circulating levels of catecholamines was shown in insular damage in experimental stroke suggesting this as a mechanism for the cardiac complications associated with stroke.&#x0D; Patients and Methods: All patients were included in the study who was admitted within 6 hours in the hospital after the episode of stroke. Scandinavian Stroke Scale (SSS)[ii] was monitored in all patients from admission. SSS was performed every 2 hours in the first 24 hours, every 4 hours in the next 48 hours and then daily up to day 7. Blood samples were obtained for routine investigation and estimation of serum cortisol. No patients had blood samples drawn for cortisol determination between 01:00 and 07:00 am.&#x0D; Results: Mean age was observed in the current series was 72.8 ± 12.54 years. There were 34 (53.1%) male and 30(46.9%) female. SSS was observed to be 36 (21-47) on admission. History of hypertension, History of stroke, Diabetes mellitus and Atrial fibrillation was observed in 38(59.4%), 12(18.8%), 24(37.5%) and 11(17.2%) respectively. In univariate logistic regression analysis of the relations to 7 days of mortality, s-cortisol, SSS on admission, and pulse rate reached a significance level. Age, atrial fibrillation, blood glucose, body temperature 12 h after stroke onset, and the presence of early infarctions signs did not reach a significance level of 0.1 in univariate testing. S-cortisol level was higher in patients with insular involvement, 635 nmol/l, in comparison to patients without insular involvement, 589 nmol/l.&#x0D; Conclusion: Adrenal glucocorticoid stress response in acute stroke is harmful. High cortisol levels are associated with the poor outcome and mortality of the patients with stroke.&#x0D; Keywords: Cortisol, HPA, Stroke, SSS

Determination of serum troponin levels in patients with acute ischemic stroke

From October 2017 to March 2018, 398 patients with acute ischemic stroke admitted in Department of Neurology, First Hospital of Shanxi Medical University were enrolled in the study, including 59 cases with elevated troponin (cTn) and 339 cases with normal cTn level. Patients were assessed with National institute of Health Stroke Scale (NIHSS), Chinese Ischemic Stroke Subclassification (CISS), Island cortical lesions and related non-neurological diseases. The short-term prognosis was assessed by NIHSS score during 10-15 days in hospital and compared between the two groups. Multivariate regression analysis showed that elevated serum cTn was independently associated with insular cortex damage (OR=2.87, 95%CI:1.26-6.53), NIHSS score at admission (OR=1.08, 95% CI:1.01-1.14), hemorrhagic transformation (OR=6.71, 95% CI:2.21-20.38), cancer (OR=5.04, 95% CI:1.43-17.77), and the level of serum creatinine (OR=1.02, 95%CI:1.01-1.03). Increased serum cTn in acute ischemic stroke is associated with severe neurological deficits, insular cortex damage and non-neurological diseases. Aacute ischemic stroke patients with increased serum troponin have a more severe prognosis. Key words: Troponin; Brain infarction, acute; Hypoxia-ischemia, brain

Insular resection may lead to autonomic function changes

ObjectiveThe aim of this study was to determine if insular damage is associated with markers of autonomic dysfunction. MethodsWe studied patients who underwent temporal lobe and/or insular resections for epilepsy surgery between April 2010 and June 2015 at University Hospitals Cleveland Medical Center (UHCMC). Presurgical T1-weighted MPRAGE, standard T1, T2 and FLAIR sequences were compared with postsurgical MRI by a neuroradiologist and classified as type 0 (no involvement of insula), type 1 (minimal involvement of insular margin), type 2 (insular involvement <25%), and type 3 (insular involvement ≥25%).Analysis of heart rate variability (HRV) was carried out in pre- and postoperative video-electroencephalography (vEEG) recording. Time-domain parameters were calculated: (mean of the RR intervals (MNN), root mean square difference of successive RR intervals (RMSSD), standard deviation of the RR intervals (SDNN), and coefficient of variation (CV)). In addition, frequency-domain parameters were calculated: low frequency (LF), high frequency (HF), and low frequency/high frequency (LF/HF). ResultsTwenty-one patients (14 females) with mean age of 36.2 ± 14.4 years (30; 22–75) were studied. Insular involvement was classified as type 0 (4 patients [19%]), type 1 (9 [43%]), type 2 (7 [33%]), and type 3 (1 [5%]). Significant decrease in RMSSD (p = 0.025) and CV (p = 0.008) was seen in insular damage types 2 and 3 compared with no or minimal insular involvement (types 0 and 1). Right-sided resections were associated with increase in LF power (p = 0.010) and the LF/HF ratio (p = 0.017). ConclusionsThis study indicates that insular resection may lead to autonomic function changes.

Implications of insular cortex laterality for treatment of nicotine addiction

BackgroundDamage to the insula disrupts nicotine-induced cravings and is associated with greater odds of cessation. The role of laterality in regulating these changes is unclear. Neuroimaging studies in cigarette smokers show left hemispheric activation during a period of forced withdrawal and right hemispheric activation after having just smoked. Among current smokers hospitalized for stroke involving their insula, we compared left versus right insular damage and its effect on smoking outcomes. MethodsA total of 37 smokers hospitalized with unilateral insular strokes (14 right, 23 left) were administered questionnaires to assess urge (Questionnaire on Smoking Urges) before (retrospectively) and during hospitalization and 3 months post-stroke, withdrawal during hospitalization (Wisconsin Smoking Withdrawal Scale), and prolonged abstinence at 3 months post-stroke. Crude and adjusted linear regression models were performed controlling for baseline covariates. ResultsRight and left insular-damaged smokers experienced a significant decrease in urge from baseline to hospitalization and three-month follow-up (p < 0.01). Smokers with left-sided insular infarcts relative to right-sided experienced a larger decrease in acute urge (adjusted β=−1.16, 95% CI: −2.59, 0.27, p = 0.11) but not chronically (adjusted β=-0.06, 95% CI: −1.53, 1.40, p = 0.93). Left-sided insular damage was also associated with significantly fewer and less severe withdrawal symptoms during hospitalization (adjusted β=−3.52, 95% CI: −7.01, −0.04, p = 0.05). No differences were noted between groups for prolonged abstinence (p = 0.50). ConclusionsLeft insular adaptations are suggestive to have an impact on acute changes in urge and withdrawal more so than the right insula, however lateral asymmetries did not exist for long-term changes.

Abstract WMP63: New Onset Nonvalvular Paroxysmal Atrial Fibrillation After Acute Ischemic Stroke Without Atrial Cardiopathy- to or Not to Anticoagulant

Introduction: Cardiac outcome in acute ischemic stroke (AIS) remains less well understood as do the neuroanatomic correlates of AIS associated myocardial injury. For patients with new onset paroxysmal atrial fibrillation (Afib), anticoagulant therapy is determined based on the CHA 2 DS 2 -VASc score. However, newly diagnosed short-run Afib after AIS could be neurogenic, without an increase in the risk of AIS recurrence. The present study of 68 patients with acute insular infarcts describes cardiac outcomes including newly diagnosed Afib and clinical significance. Methods and Results: Serial measurements of cardiac troponin I (cTnI), EKG, echocardiography (Echo) (some had transesophageal Echo) were conducted in all patients with MRI-confirmed AIS involving insular cortex. The severity of insular damage was measured with diffusion-weighted imaging. Thirty-one patients (46%) had right MCA infarcts involving insular cortex, and 37 patients had left MCA (54%) stroke with insular involvement. Patients with left MCA infarcts had higher cTnI but did not reach statistical significance. By linear regression analysis in either right or left insular AIS, there was a significant correlation between elevated cTnI and the severity of insular injury. Six patients (3 right and 3 left MCA AISs) were found to have transient cardiac dysfunction. Nine out of 68 AIS patients detected new onset transient Afib in the absence of prior heart disease, cardiac arrhythmia, or evidence of atrial myopathy. Five of them are not on anticoagulant therapy due to varied reasons. None of them experienced recurrent major cardiac events, recurrent Afib, or ischemic stroke during the 12-month follow up. Conclusions: Our study shows that either left or right MCA AIS involving the insular cortex may cause cardiac injury including transient Afib. We further demonstrated a correlation between the severity of insular damage and cardiac sequelae. However, there is no increased risk of recurrent ischemic stroke at 1 year in 5 patients with newly diagnosed Afib not on anticoagulant therapy. A long-term study with large number of AIS patients with newly diagnosed Afib is needed to determine if lifelong anticoagulation is required in this particular group of patients with presumed neurogenic Afib.

The study of nicotine addiction abstinence in patients with insular infarction

Objective To investigate the effect of insular on the addiction of nicotine after insular infarction. Methods Totally 35 patients with lesions involving insular infarction were enrolled in insular damage group. The patients matched with the demographic data of the study subjects who did not involve insular infarction were the control group(n=114). All patients were given the internationally popular questionnaire of smoking urges (QSU) and fagerstrom test for nicotine dependence(FTND)during hospitalization, and they were followed up 3 months after stroke.The QSU and the minnesota nicotine withdrawal scale(MNWS) were assessment for patients who did not smoke again and did not relapse, and the QSU and FTND scale were used for the patients who still smoke. Results After 3 months follow-up, the rate of withdrawal from insular damage was 77.14%, and that in non-insular damage was 52.63%(χ2=6.62, P=0.01), and the MNWS in two groups(insular damage patients (0.59±0.97) and non-insular damage patients(1.15±1.29)), the difference was statistically significant (t=-2.00, P=0.04). All subjects were evaluated by questionnaire of smoking urges (QSU), among which QSU score was (19.40±9.63) in insular damage group and (24.47±10.39) in non-insular group, the difference was statistically significant (t=-2.57, P=0.01) . Conclusion Patients with insular lesion are more likely to cause withdrawal of nicotine addiction, suggesting that insular may be involved in cognitive processing of addiction. Key words: Insular infarction; Nicotine; Addiction; Abstinence

Insular damage, new-onset atrial fibrillation and outcome after acute intracerebral hemorrhage.

Cortical insular damage is associated with cardiac arrhythmias and an increased risk of death. We investigated the influence of insular damage on the outcome of patients with acute intracerebral hemorrhage as well as the frequency and predictors of new-onset atrial fibrillation (nAF). We studied consecutive patients with intracerebral hemorrhage from 2013 to 2016. We identified those patients who underwent continuous electrocardiographic monitoring (≥24 h), known atrial fibrillation and recent ischemic stroke. We prospectively collected demographic data, vascular risk factors, neurological severity, vital signs, radiological data, nAF and mortality at 3 months. Bivariate and multivariate regression analyses were performed. We evaluated 347 patients whose mean age was 73.5 ± 14.0 years (50.7% of them were men). We selected 183 patients to study the frequency and risk factors of nAF (mean age, 69.1 ± 14.7 years; 52.5% of them were men). We observed that 11/183 (6.0%) had nAF. Insular damage [odds ratio (OR), 7.6; 95% confidence interval (CI), 2.1-27.7] was associated with nAF. A total of 138/347 patients died within the first 3 months and insular damage was detected in 99/347 of them. Predictors of death were age (OR, 1.07; 95% CI, 1.04-1.10), blood glucose (OR, 1.00 per mg/dL;, 95% CI, 1.00-1.01), Glasgow Coma Scale score (OR, 0.85; 95% CI, 0.77-0.92), hematoma volume (OR, 1.02 per mL; 95% CI, 1.01-1.04), intraventricular hemorrhage (OR, 1.93; 95% CI, 1.03-3.64) and insular damage (OR, 3.98; 95% CI, 2.00-7.90). The frequency of nAF in our patients was 6.0%. Insular damage was a risk factor for nAF and an independent predictor of death at 3 months.

Abstract TP331: Right Insular Damage is Associated With New Onset Atrial Fibrillation in Patients With Acute Intracerebral Hemorrhage

Introduction: The frequency and risk factors for new-onset atrial fibrillation (nAF) after acute intracerebral hemorrhage (ICH) are uncertain. Hypothesis: By analogy with ischemic stroke, we hypothesized that insular cortex damage may be a risk factor for nAF. Methods: This is an observational study of consecutive patients with spontaneous ICH. All patients underwent continuous bedside cardiac monitoring for at least 24 hours. We excluded patients with previous history of AF, recent myocardial infarction and ischemic stroke. We prospectively collected the following variables: Demographic data (age and sex), traditional vascular risk factors, neurological severity (assessed with the Glasgow scale coma score), vital signs, laboratory and radiological data (localization and volume of the hematoma, concomitant intraventricular or subarachnoid hemorrhage), and detection of nAF. A blind evaluator using an interactive brain atlas assessed the insular cortex damage. Bivariate and multivariate regression analyses were performed to describe nAF risk factors. Results: We included 167 patients who fulfilled the inclusion/exclusion criteria. Mean age was 70.5±14.7 years and 56.8% were men. Cardiac monitoring was initiated after a median of 240 minutes (interquartile range 67-720) of the onset of ICH symptoms. We detected nAF in 9 patients (5.3%). Patients with nAF were older (75.6±13.1 vs 70.5±14.7 years, p=0.30) and most of them were men (8/9 vs 87/158, p=0.07) but these differences did not reach the statistical significance. We observed that right insular cortex damage (3/9 vs 9/158, p=0.019) and any insular cortex damage (5/9 vs 25/158, p=0.010) were more frequent in nAF patients. In the logistic regression analysis right insular cortex damage (OR 8.2; 95% CI 1.7-38.4, p=0.007) was associated with nAF. Conclusion: The frequency of nAF in patients with spontaneous ICH is 5.3%. Insular cortex lesions, probably due to the central autonomous nervous system dysregulation, are associated with nAF. This finding may have important implications in the hemodynamic and antithrombotic management.

Abstract TP330: Insular Cortex Lesions are Associated With Early Mortality in Patients With Intracerebral Hemorrhage

Introduction: Insular lesions have been described as an independent predictor of death in acute ischemic stroke. This study was undertaken to determine the influence of insular damage on the mortality of patients with intracerebral hemorrhage (ICH). Hypothesis: Insular cortex lesions are an independent predictor of death in acute ICH. Methods: This is an observational study of consecutive patients with spontaneous acute ICH who were admitted to a tertiary care hospital. The following data were collected prospectively: age, sex, traditional vascular risk factors, vital signs, CT findings (secondary intraventricular hemorrhage, hematoma volume), Glasgow Coma Scale score, time and cause of death within hospitalization. The insular cortex damage (right, left or any) was assessed by a blind evaluator using an interactive brain atlas. The association between insular lesions and mortality was investigated by use of logistic regression and Cox proportional hazards models. Results: We included 276 patients whose mean age was 77±14.3 years; 52.7% of them were men. During a median of 7 days (interquartile range 2-15) of hospitalization, 91 (32.9%) deaths were recorded. We observed 72 (26%) patients with insular cortex lesions (right insula=34, left insula=38). Cox regression analysis showed that age (adjusted hazard ratio [aHR] 1.02, 95% CI 1.00-1.04; p&lt;0.001), Glasgow Coma Scale (aHR 0.84, 95% CI 0.80-0.89; p&lt;0.001), lesion volume (aHR 1.10, 95% CI 1.06-1.15; p&lt;0.001) and any insular damage (aHR 2.19, 95% CI 1.40-3.42, p=0.002) were significant predictors of death within hospitalization. Conclusions: In conclusion, insular cortex lesions adversely influence survival after spontaneous ICH. This finding was observed even after adjustment for other well-known predictors of ICH mortality.

Sex differences in smoking withdrawal, urge, and cessation after stroke-induced insular cortex damage

Sex differences in smoking withdrawal, urge, and cessation after stroke-induced insular cortex damage

Feeling, learning from and being aware of inner states: interoceptive dimensions in neurodegeneration and stroke.

Interoception is a complex process encompassing multiple dimensions, such as accuracy, learning and awareness. Here, we examined whether each of those dimensions relies on specialized neural regions distributed throughout the vast interoceptive network. To this end, we obtained relevant measures of cardiac interoception in healthy subjects and patients offering contrastive lesion models of neurodegeneration and focal brain damage: behavioural variant fronto-temporal dementia (bvFTD), Alzheimer's disease (AD) and fronto-insular stroke. Neural correlates of the three dimensions were examined through structural and functional resting-state imaging, and online measurements of the heart-evoked potential (HEP). The three patient groups presented deficits in interoceptive accuracy, associated with insular damage, connectivity alterations and abnormal HEP modulations. Interoceptive learning was differentially impaired in AD patients, evidencing a key role of memory networks in this skill. Interoceptive awareness results showed that bvFTD and AD patients overestimated their performance; this pattern was related to abnormalities in anterior regions and associated networks sub-serving metacognitive processes, and probably linked to well-established insight deficits in dementia. Our findings indicate how damage to specific hubs in a broad fronto-temporo-insular network differentially compromises interoceptive dimensions, and how such disturbances affect widespread connections beyond those critical hubs. This is the first study in which a multiple lesion model reveals fine-grained alterations of body sensing, offering new theoretical insights into neuroanatomical foundations of interoceptive dimensions.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.