Insular Involvement Is Associated with QT Prolongation: ECG Abnormalities in Patients with Acute Stroke

The ECG abnormalities in persons with chronic disorders of consciousness

We aimed to investigate the electrocardiogram (ECG) features in persons with chronic disorders of consciousness (DOC, ≥ 29 days since injury, DSI) resulted from the most severe brain damages. The ECG data from 30 patients with chronic DOC and 18 healthy controls (HCs) were recorded during resting wakefulness state for about five minutes. The patients were classified into vegetative state (VS) and minimally conscious state (MCS). Eight ECG metrics were extracted for comparisons between the subject subgroups, and regression analysis of the metrics were conducted on the DSI (29-593 days). The DOC patients exhibit a significantly higher heart rate (HR, p = 0.009) and lower values for SDNN (p = 0.001), CVRR (p = 0.009), and T-wave amplitude (p < 0.001) compared to the HCs. However, there're no significant differences in QRS, QT, QTc, or ST amplitude between the two groups (p > 0.05). Three ECG metrics of the DOC patients-HR, SDNN, and CVRR-are significantly correlated with the DSI. The ECG abnormalities persist in chronic DOC patients. The abnormalities are mainly manifested in the rhythm features HR, SDNN and CVRR, but not the waveform features such as QRS width, QT, QTc, ST and T-wave amplitudes.

Stroke-Related Visceral Alterations: A Voxel-Based Neuroanatomic Localization Study

OBJECTIVE

Functional and morphologic changes in extracranial organs can occur after acute brain injury. The neuroanatomic correlates of such changes are not fully known. Herein, we tested the hypothesis that brain infarcts are associated with cardiac and systemic abnormalities (CSAs) in a regionally specific manner.

METHODS

We generated voxelwise p value maps of brain infarcts for poststroke plasma cardiac troponin T (cTnT) elevation, QTc prolongation, in-hospital infection, and acute stress hyperglycemia (ASH) in 1,208 acute ischemic stroke patients prospectively recruited into the Heart-Brain Interactions Study. We examined the relationship between infarct location and CSAs using a permutation-based approach and identified clusters of contiguous voxels associated with p < 0.05.

RESULTS

cTnT elevation not attributable to a known cardiac reason was detected in 5.5%, QTc prolongation in the absence of a known provoker in 21.2%, ASH in 33.9%, and poststroke infection in 13.6%. We identified significant, spatially segregated voxel clusters for each CSA. The clusters for troponin elevation and QTc prolongation mapped to the right hemisphere. There were 3 clusters for ASH, the largest of which was in the left hemisphere. We found 2 clusters for poststroke infection, one associated with pneumonia in the left and one with urinary tract infection in the right hemisphere. The relationship between infarct location and CSAs persisted after adjusting for infarct volume.

INTERPRETATION

Our results show that there are discrete regions of brain infarcts associated with CSAs. This information could be used to bootstrap toward new markers for better differentiation between neurogenic and non-neurogenic mechanisms of poststroke CSAs. ANN NEUROL 2023;94:1155-1163.

Testing the nonclinical Comprehensive In Vitro Proarrhythmia Assay (CiPA) paradigm with an established anti-seizure medication: Levetiracetam case study

Levetiracetam (LEV), a well-established anti-seizure medication (ASM), was launched before the original ICH S7B nonclinical guidance assessing QT prolongation potential and the introduction of the Comprehensive In Vitro Proarrhythmia Assay (CiPA) paradigm. No information was available on its effects on cardiac channels. The goal of this work was to "pressure test" the CiPA approach with LEV and check the concordance of nonclinical core and follow-up S7B assays with clinical and post-marketing data. The following experiments were conducted with LEV (0.25-7.5 mM): patch clamp assays on hERG (acute or trafficking effects), NaV 1.5, CaV 1.2, Kir 2.1, KV 7.1/mink, KV 1.5, KV 4.3, and HCN4; in silico electrophysiology modeling (Virtual Assay® software) in control, large-variability, and high-risk human ventricular cell populations; electrophysiology measurements in human induced pluripotent stem cell (hiPSC)-derived cardiomyocytes and dog Purkinje fibers; ECG measurements in conscious telemetered dogs after single oral administration (150, 300, and 600 mg/kg). Except a slight inhibition (<10%) of hERG and KV 7.1/mink at 7.5 mM, that is, 30-fold the free therapeutic plasma concentration (FTPC) at 1500 mg, LEV did not affect any other cardiac channels or hERG trafficking. In both virtual and real human cardiomyocytes, and in dog Purkinje fibers, LEV induced no relevant changes in electrophysiological parameters or arrhythmia. No QTc prolongation was noted up to 2.7 mM unbound plasma levels in conscious dogs, corresponding to 10-fold the FTPC. Nonclinical assessment integrating CiPA assays shows the absence of QT prolongation and proarrhythmic risk of LEV up to at least 10-fold the FTPC and the good concordance with clinical and postmarketing data, although this does not exclude very rare occurrence of QT prolongation cases in patients with underlying risk factors.

Inter-sleep stage variations in corrected QT interval differ between obstructive sleep apnea patients with and without stroke history

Obstructive sleep apnea (OSA) is related to the progression of cardiovascular diseases (CVD); it is an independent risk factor for stroke and is also prevalent post-stroke. Furthermore, heart rate corrected QT (QTc) is an important predictor of the risk of arrhythmia and CVD. Thus, we aimed to investigate QTc interval variations in different sleep stages in OSA patients and whether nocturnal QTc intervals differ between OSA patients with and without stroke history. 18 OSA patients (apnea-hypopnea index (AHI)≥15) with previously diagnosed stroke and 18 OSA patients (AHI≥15) without stroke history were studied. Subjects underwent full polysomnography including an electrocardiogram measured by modified lead II configuration. RR, QT, and QTc intervals were calculated in all sleep stages. Regression analysis was utilized to investigate possible confounding effects of sleep stages and stroke history on QTc intervals. Compared to patients without previous stroke history, QTc intervals were significantly higher (β = 34, p<0.01) in patients with stroke history independent of age, sex, body mass index, and OSA severity. N3 sleep (β = 5.8, p<0.01) and REM sleep (β = 2.8, p<0.01) increased QTc intervals in both patient groups. In addition, QTc intervals increased progressively (p<0.05) towards deeper sleep in both groups; however, the magnitude of changes compared to the wake stage was significantly higher (p<0.05) in patients with stroke history. The findings of this study indicate that especially in deeper sleep, OSA patients with a previous stroke have an elevated risk for QTc prolongation further increasing the risk for ventricular arrhythmogenicity and sudden cardiac death.

Sex Hormone-Specific Neuroanatomy of Takotsubo Syndrome: Is the Insular Cortex a Moderator?

Takotsubo syndrome (TTS), a transient form of dysfunction in the heart’s left ventricle, occurs predominantly in postmenopausal women who have emotional stress. Earlier studies support the concept that the human circulatory system is modulated by a cortical network (consisting of the anterior cingulate gyrus, amygdala, and insular cortex (Ic)) that plays a pivotal role in the central autonomic nervous system in relation to emotional stressors. The Ic plays a crucial role in the sympathovagal balance, and decreased levels of female sex hormones have been speculated to change functional cerebral asymmetry, with a possible link to autonomic instability. In this review, we focus on the Ic as an important moderator of the human brain–heart axis in association with sex hormones. We also summarize the current knowledge regarding the sex-specific neuroanatomy in TTS.

Cerebral-Cardiac Syndrome and Diabetes: Cardiac Damage After Ischemic Stroke in Diabetic State

Cerebral-cardiac syndrome (CCS) refers to cardiac dysfunction following varying brain injuries. Ischemic stroke is strongly evidenced to induce CCS characterizing as arrhythmia, myocardial damage, and heart failure. CCS is attributed to be the second leading cause of death in the post-stroke stage; however, the responsible mechanisms are obscure. Studies indicated the possible mechanisms including insular cortex injury, autonomic imbalance, catecholamine surge, immune response, and systemic inflammation. Of note, the characteristics of the stroke population reveal a common comorbidity with diabetes. The close and causative correlation of diabetes and stroke directs the involvement of diabetes in CCS. Nevertheless, the role of diabetes and its corresponding molecular mechanisms in CCS have not been clarified. Here we conclude the features of CCS and the potential role of diabetes in CCS. Diabetes drives establish a “primed” inflammatory microenvironment and further induces severe systemic inflammation after stroke. The boosted inflammation is suspected to provoke cardiac pathological changes and hence exacerbate CCS. Importantly, as the key element of inflammation, NOD-like receptor pyrin domain containing 3 (NLRP3) inflammasome is indicated to play an important role in diabetes, stroke, and the sequential CCS. Overall, we characterize the corresponding role of diabetes in CCS and speculate a link of NLRP3 inflammasome between them.

The Mysterious Island: Insula and Its Dual Function in Sleep and Wakefulness

In the recent sleep studies, it was shown that afferentation of many cortical areas switches during sleep to the interoceptive one. However, it was unclear whether the insular cortex, which is often considered as the main cortical visceral representation, maintains the same effective connectivity in both states of vigilance, or processes interoceptive information predominantly in one state. We investigated neuronal responses of the cat insular cortex to electrical stimulations of the intestinal wall delivered during wakefulness and natural sleep. Marked increase was observed in the number of insular neurons responding to this stimulation in sleep comparing to wakefulness, and enlarged amplitudes of evoked local field potentials were found as well. Moreover, most of the cells responding to intestinal stimulation in wakefulness never responded to identical stimuli during sleep and vice versa. It was also shown that applied low intensity intestinal stimulations had never compromised sleep quality. In addition, experiments with microstimulation of the insular cortex and recording of intestinal myoelectric activity demonstrated that effective insula-to-gut propagation also happened only during sleep. On the other hand, the same insular stimulations in wakefulness led to contractions of orofacial muscles. The evoked face movements gradually disappeared in the course of sleep development. These findings demonstrate that pattern of efficient afferent and efferent connections of the insular cortex changes with transition from wakefulness to sleep.

QTc Prolongation in Patients with Dementia and Mild Cognitive Impairment: Neuropsychological and Brain Imaging Correlations

The QTc interval is the electrocardiographic manifestation of ventricular depolarization and repolarization. This marker is often prolonged in acute and chronic neurological conditions. The cause of the cerebrogenic QT prolongation remains unclear. The aim of the study was to analyze the relation between QTc interval and the degree of cognitive impairment and structural brain imaging changes in patients with dementia and mild cognitive impairment (MCI). To this aim, 269 patients were screened, of whom 61 met one or more exclusion criteria. The remaining 208 patients (56 control subjects, 44 patients with MCI, and 108 with dementia) were recruited. Eighty-five patients using drugs causing prolongation of QT interval were further excluded. The QT interval was measured manually in all 12 leads by a single blinded observer, assuming the longest QT value adjusted for heart rate by using the Bazett's formula. All patients underwent a structural brain imaging and the following measures were obtained: the bicaudate ratio and the periventricular hyperintensity and deep white matter hyperintensity using the modified Fazekas scale. Prolonged QTc interval was prevalent in 1) patients with dementia, especially in those with moderate-severe degree; 2) subjects with impairment of praxis and attention, low functional status, and behavioral symptoms; 3) patients with global and temporal atrophy and with higher scores on the Fazekas or leukoaraiosis scales. Degenerative and vascular processes might play a main role in QTc interval prolongation because of the damage to brain areas involved in the control of the autonomic cardiac nervous system.

Relationship of QTc Interval Prolongation with Acute Ischemic Stroke

Introduction:

Many electrocardiographic (ECG) changes have been observed after strokes. We analyzed the QTc interval prolongation following stroke.

Aim:

The study aimed to assess if the prolongation in QTc interval is related to the occurrence of acute ischemic stroke.

Methods:

This cross-sectional study was conducted from July to December 2018. We included 100 consecutive patients with first-ever ischemic stroke who were admitted to our emergency department, who were age-matched and gender-matched with a control group of 100 non-stroke patients that visited our outpatients department for diseases other than cerebrovascular or cardiovascular ones. A single 12-lead resting ECG examination was done in all patients at the time of their emergency department admission.

Results:

No significant difference between the two groups regarding the age distribution and mean age was found. 56.5% of the sample were males but the difference was not significant between both gender groups. The main presenting symptoms of stroke cases were right-sided weakness (47%), left-sided weakness (36%), and right-sided weakness and aphasia (10%). 34% of the cases had prolonged QTc interval while none of the controls had a prolonged interval (p-value<0.001). No significant difference was observed among stroke patients concerning gender (p-value=0.584).

Conclusion:

Our findings support many previous studies on the brain-heart interaction during acute ischemic strokes and reinforce previous conclusions that assessment of the QTc interval might aid to stratify morbidity and mortality risks in patients with acute ischemic stroke. To accomplish the acute stroke effects on QTc interval prolongation, we need further larger size analytic studies.

The Relationship Between QT Interval and Intra-Hospital Mortality in patients with Spontaneous Intracranial Hemorrhage

Introduction:

Repolarization abnormalities such as prolongation of QT interval and changes in ST segment and T wave are the most usual electrocardiogram (ECG) changes in patients with intracranial hemorrhage (ICH). It has recently been recommended that prolonged QTc interval raises the risk of death due to malignant ventricular arrhythmias or sudden cardiac death.

Objective:

The goal of this study was to evaluate the relationship between QT interval and death in patients with ICH.

Method:

This cross-sectional study was performed on patients with ICH who referred during 2015–2017 to Poursina Hospital, Rasht, Iran. The QT interval was manually measured based on the BAZETT formula. Max QT and Max QTc and QT dispersion were the variables evaluated by the ECG of the patients. The outcome under the study was the death or survival of patients during hospitalization.

Results:

Finally, 466 cases with the mean age of 69±12 years were studied of whom 68.7% were male. The average QT-Max interval was 350.4±56.5 milliseconds, and the average QTc-Max was 583.6±57.6 msec. Totally, 22.7% of the patients died. There was a significant statistical relationship between QTc-MAX and death (p=0.001). However, there was no statistically significant relationship between QT-MAX and the outcome (p=0.593).

Conclusion:

It is likely that, prolonged QT interval is correlated with in-hospital mortality of patients with ICH. Therefore, it can be expected that assessing ECG abnormalities, especially prolonged QTc could be valuable in these patients.

Postoperative 'STEMI' in Intracerebral Hemorrhage due to Arteriovenous Malformation: A Case Report and Review of Literature

Electrocardiogram (ECG) changes suggestive of cardiac ischemia are frequently demonstrated in patients with ischemic stroke and subarachnoid hemorrhage. However, little is known of such changes particularly acute ST segment myocardial infarction (STEMI) in patients with intracerebral hemorrhage (ICH), especially after neurosurgery. We present a patient with intraparenchymal hemorrhage due to cerebral arteriovenous malformation (AVM) who exhibited acute STEMI after neurosurgery. Serial cardiac biomarkers and echocardiograms were performed which did not reveal any evidence of acute myocardial infarction. The patient was managed conservatively from cardiac stand point with no employment of anticoagulants, antiplatelet therapy, fibrinolytic agents, or angioplasty and recovered well with minimal neurological deficit. This case highlights that diffuse cardiac ischemic signs on the ECG can occur in the setting of an ICH after neurosurgery, potentially posing a difficult diagnostic and management conundrum.

Prevalence and Prognostic Features of ECG Abnormalities in Acute Stroke: Findings From the SIREN Study Among Africans

BACKGROUND

Africa has a growing burden of stroke with associated high morbidity and a 3-year fatality rate of 84%. Cardiac disease contributes to stroke occurrence and outcomes, but the precise relationship of abnormalities as noted on a cheap and widely available test, the electrocardiogram (ECG), and acute stroke outcomes have not been previously characterized in Africans.

OBJECTIVES

The study assessed the prevalence and prognoses of various ECG abnormalities among African acute stroke patients encountered in a multisite, cross-national epidemiologic study.

METHODS

We included 890 patients from Nigeria and Ghana with acute stroke who had 12-lead ECG recording within first 24 h of admission and stroke classified based on brain computed tomography scan or magnetic resonance imaging. Stroke severity at baseline was assessed using the Stroke Levity Scale (SLS), whereas 1-month outcome was assessed using the modified Rankin Scale (mRS).

RESULTS

Patients' mean age was 58.4 ± 13.4 years, 490 were men (55%) and 400 were women (45%), 65.5% had ischemic stroke, and 85.4% had at least 1 ECG abnormality. Women were significantly more likely to have atrial fibrillation, or left ventricular hypertrophy with or without strain pattern. Compared to ischemic stroke patients, hemorrhagic stroke patients were less likely to have atrial fibrillation (1.0% vs. 6.7%; p = 0.002), but more likely to have left ventricular hypertrophy (64.4% vs. 51.4%; p = 0.004). Odds of severe disability or death at 1 month were higher with severe stroke (AOR: 2.25; 95% confidence interval: 1.44 to 3.50), or atrial enlargement (AOR: 1.45; 95% confidence interval: 1.04 to 2.02).

CONCLUSIONS

About 4 in 5 acute stroke patients in this African cohort had evidence of a baseline ECG abnormality, but presence of any atrial enlargement was the only independent ECG predictor of death or disability.

QTc interval in patients with multiple sclerosis: an inference from the insula of Reil?

BACKGROUND AND PURPOSE

The aim of this study was to investigate the correlation between the duration of the QTc interval and the brain lesion load at the level of the structures involved in superior autonomic control (insula, cingulate cortex and amygdala-hippocampus) in multiple sclerosis (MS) patients.

METHODS

Thirty-one consecutive patients with relapsing-remitting MS were recruited. The QT interval was measured manually in all 12 leads by a single blinded observer, with the longest QT value adjusted for heart rate by using the Bazett's formula. All patients performed a brain magnetic resonance imaging (MRI) scan including three-dimensional double inversion recovery and three volumetric fast-field echo sequences. The following MRI measures were obtained: (i) global and regional cortical thickness (CTh); (ii) white matter lesion load volume; (iii) cortical damage blindly assessed by a trained observer who assigned, on the basis of the number of cortical lesions, a score from 0 to 5 for each of the brain areas analysed.

RESULTS

In all, 16% of the patients had an increased QTc interval. The QTc interval was correlated with disease duration, cortical insular lesion volume and grey matter lesion volume in the three examined areas and inversely correlated with global and insular CTh.

CONCLUSIONS

An increased QTc interval in patients with MS may have a cerebral origin possibly driven by involvement of the insular cortex. With the recent introduction in clinical practice of treatments with potential cardiac effects such as fingolimod, the recognition of a long QTc interval could be clinically crucial and should encourage appropriate electrocardiographic monitoring in order to prevent the risk of malignant ventricular pro-arrhythmia and iatrogenic sudden death.

Prolonged Corrected QT Interval as a Predictor of Clinical Outcome in Acute Ischemic Stroke

BACKGROUND

This study aimed to investigate changes of corrected QT (QTc) interval during acute ischemic stroke and its correlation with high-sensitivity troponin I (hsTnI), brain natriuretic peptide (BNP), neurological outcome, and 1-year mortality.

METHODS

We registered electrocardiogram in 69 patients immediately after admission to the intensive care unit and then after 24 and 48 hours. Computed tomography was performed on admission to determine brain infarct size and localization. Neurological outcome was assessed by modified Rankin scale (mRS) at discharge.

RESULTS

Forty-five (65.2%) patients had prolonged QTc at baseline; only 18 (26.1%) patients had prolonged QTc after 48 hours. Baseline QTc was not associated with neurological outcome (P = .27). However, prolonged QTc after 48 hours was associated with worse mRS at discharge (4.5 [4.0-6.0] versus 2.0 [1.0-3.0]; P < .0001). Patients who deceased during hospitalization (n = 7 [10.1%]) as compared with survivors had more frequently prolonged QTc after 48 hours (38.9 versus 0%; P < .0001), higher level of hsTnI (48.4 [36.1-75.0] versus 8.6 [3.4-26.5]; P = .003), and BNP (334 [224-866] versus 109 [30-190]; P = .014). In univariate analysis, 1-year mortality was associated with prolonged QTc after 48 hours, hsTnI, and BNP. In multivariate analysis, only BNP remained to be associated with 1-year mortality (odds ratio 3.41, 95% confidence interval 1.06-11.03).

CONCLUSIONS

QTc interval in patients with acute ischemic stroke is a dynamic parameter. Prolonged QTc after 48 hours, but not baseline QTc, correlated with neurological outcome and 1-year mortality. Patients with prolonged QTc had higher level of hsTnI.

The pathophysiology of cardiac dysfunction in epilepsy

Alterations in cardiac electrophysiology are an established consequence of long-standing drug resistant epilepsy. Patients with chronic epilepsy display abnormalities in both sinoatrial node pacemaker current as well as ventricular repolarizing current that places them at a greater risk of developing life-threatening cardiac arrhythmias. The development of cardiac arrhythmias secondary to drug resistant epilepsy is believed to be a key mechanism underlying the phenomenon of Sudden Unexpected Death in EPilepsy (SUDEP). Though an increasing amount of studies examining both animal models and human patients have provided evidence that chronic epilepsy can detrimentally affect cardiac function, the underlying pathophysiology remains unclear. Recent work has shown the expression of several key cardiac ion channels to be altered in animal models of genetic and acquired epilepsies. This has led to the currently held paradigm that cardiac ion channel expression may be secondarily altered as a consequence of seizure activity-resulting in electrophysiological cardiac dysfunction. Furthermore, cortical autonomic dysfunction - resulting from seizure activity-has also been suggested to play a role, whereby seizure activity may indirectly influence cardiac function via altering centrally-mediated autonomic output to the heart. In this review, we discuss various cardiac dysrhythmias associated with seizure events-including tachycardia, bradycardia and QT prolongation, both ictally and inter-ictally, as well as the role of the autonomic nervous system. We further discuss key ion channels expressed in both the heart and the brain that have been shown to be altered in epilepsy and may be responsible for the development of cardiac dysrhythmias secondary to chronic epilepsy.

QTc-prolongation in posterior circulation stroke

BACKGROUND AND PURPOSE

To evaluate the relationship between infarct location and QTc-prolongation in patients with posterior circulation strokes.

METHODS

Admission electrocardiograms (ECG) of 131 patients among a prospective sample of 407 consecutive adult patients in the New England Medical Center Posterior Circulation Registry were retrospectively analyzed. The QT interval (ms) was measured and corrected using Bazett's formula (QTcBazett) as well as linear regression functions (QTcLinear). QTcBazett > 440 ms and QTcLinear ≥ 450 ms for men (≥460 ms for women) were considered prolonged. Multivariable linear and logistic regression analyses were used to identify independent predictors of the QTc.

RESULTS

Overall, 34% of patients had a prolonged QTcBazett and 7% had a prolonged QTcLinear noted on the admission ECG. There was a significant association between temporal lobe infarction and QTcBazett and QTcLinear (p < 0.001 for both) in multivariable linear regression analyses adjusting for demographics, ECG parameters, and preadmission medication use. In multivariable logistic regression analysis, temporal lobe infarction emerged as an independent predictor of prolonged QTcBazett (p = 0.009) and QTcLinear (p = 0.008), respectively. Sensitivity analyses excluding patients with transient ischemic attack yielded similar results. Exploratory analyses indicated that patients with temporal lobe infarction had worse functional 30-day outcomes in multivariable logistic regression (p = 0.022). However, there was no significant association between QTc and 30-day functional outcome.

CONCLUSIONS

QTc-prolongation is common after posterior circulation stroke and associated with temporal lobe infarction. Prospective studies are needed to confirm these preliminary findings and to examine potential long-term consequences.

Ictal modulation of cardiac repolarization, but not of heart rate, is lateralized in mesial temporal lobe epilepsy

Objectives

Human and animal studies provided controversial data on asymmetric cortical representation of cardiac function, which may partially be due to different study designs and inter-individual variability. Here, we investigated whether seizure-related changes in heart rate (HR) and cardiac repolarization depend on the side of seizure-activity in people with mesial temporal lobe epilepsy (mTLE).

Methods

To account for inter-individual variability, EEG and ECG data were reviewed from patients with medically refractory mTLE undergoing pre-surgical video-EEG telemetry with at least 2 seizures arising from each hippocampus as assessed by bilateral hippocampal depths electrodes. RR and QT intervals were determined at different timepoints using a one-lead ECG. QT intervals were corrected for HR (QTc) using 4 established formulas.

Results

Eighty-two seizures of 15 patients were analyzed. HR increased by ∼30% during hippocampal activity irrespective of the side (p = 0.411). QTc intervals were lengthened to a significantly greater extent during left hippocampal seizures (e.g. difference of QT intervals between preictal and ictal state using Bazett’s formula; left side 32.0±5.3 ms, right side 15.6±7.7 ms; p = 0.016). Abnormal QTc prolongation occurred in 7 of 41 left hippocampal seizures of 4 patients, and only in 2 of 37 right hippocampal seizures of 2 patients.

Conclusions

Seizure-related modulation of cardiac repolarization, but not of HR, appears to depend on the side of ictal activity, strengthening the hypothesis of asymmetric cerebral representation of cardiac function. The clinical relevance of this is unclear, but may indicate an increased risk of abnormal ictal QT prolongation in people with left mTLE.

Cardiovascular and neurological causes of sudden death after ischaemic stroke

Sudden death is an important but widely under-recognised consequence of stroke. Acute stroke can disturb central autonomic control, resulting in myocardial injury, electrocardiographic abnormalities, cardiac arrhythmias, and ultimately sudden death. Experimental and clinical evidence suggests that autonomic imbalance is more frequent after infarcts involving the insular cortex, a crucial region for the control of sympathetic and parasympathetic autonomic functions. Cardiovascular comorbidities increase the risk of cardiac morbidity and mortality after stroke. Thus, many sudden deaths and serious non-fatal cardiac events after stroke are probably due to an interaction between cardiovascular and neurological causes. The exact mechanisms leading to sudden death remain incompletely understood. Further research is needed to investigate the autonomic consequences of acute stroke and to identify patients at high risk of sudden death.

The insular cortex: a review

The human insular cortex forms a distinct, but entirely hidden lobe, situated in the depth of the Sylvian fissure. Here, we first review the recent literature on the connectivity and the functions of this structure. It appears that this small lobe, taking up less than 2% of the total cortical surface area, receives afferents from some sensory thalamic nuclei, is (mostly reciprocally) connected with the amygdala and with many limbic and association cortical areas, and is implicated in an astonishingly large number of widely different functions, ranging from pain perception and speech production to the processing of social emotions. Next, we embark on a long, adventurous journey through the voluminous literature on the structural organization of the insular cortex. This journey yielded the following take-home messages: (1) The meticulous, but mostly neglected publications of Rose (1928) and Brockhaus (1940) are still invaluable for our understanding of the architecture of the mammalian insular cortex. (2) The relation of the insular cortex to the adjacent claustrum is neither ontogenetical nor functional, but purely topographical. (3) The insular cortex has passed through a spectacular progressive differentiation during hominoid evolution, but the assumption of Craig (2009) that the human anterior insula has no homologue in the rhesus monkey is untenable. (4) The concept of Mesulam and Mufson (1985), that the primate insula is essentially composed of three concentrically arranged zones, agranular, dysgranular, and granular, is presumably correct, but there is at present much confusion concerning the more detailed architecture of the anterior insular cortex. (5) The large spindle-shaped cells in the fifth layer of the insular cortex, currently known as von Economo neurons (VENs), are not only confined to large-brained mammals, such as whales, elephants, apes, and humans, but also occur in monkeys and prosimians, as well as in the pygmy hippopotamus, the Atlantic walrus, and Florida manatee. Finally, we point out that the human insula presents a unique opportunity for performing an in-depth comparative analysis of the relations between structure and function in a typical sensory and a typical cognitive cortical domain.

Ischemic-appearing electrocardiographic changes predict myocardial injury in patients with intracerebral hemorrhage

OBJECTIVES

Myocardial injury is common among patients with intracerebral hemorrhage (ICH). However, it is challenging for emergency physicians to recognize acute myocardial injury in this population, as electrocardiographic (ECG) abnormalities are common in this setting. Our objective is to examine whether ischemic-appearing ECG changes predict subsequent myocardial injury in the context of ICH.

METHODS

Consecutive patients with primary ICH presenting to a single academic center were prospectively enrolled. Electrocardiograms were retrospectively reviewed by 3 independent readers. Anatomical areas of ischemia were defined as I and aVL; II, III, and aVF; V(1) to V(4); and V(5) and V(6). Medical record review identified myocardial injury, defined as troponin I or T elevation (cutoff 1.5 and 0.1 ng/mL, respectively), within 30 days.

RESULTS

Between 1998 and 2004, 218 patients presented directly to our emergency department and did not have a do-not-resuscitate/do-not-intubate order; arrival ECGs and troponin levels were available for 206 patients. Ischemic-appearing changes were noted in 41% of patients, and myocardial injury was noted in 12% of patients. Ischemic-appearing changes were more common in patients with subsequent injury (64% vs 37%; P = .02). After multivariable analysis controlling for age and cardiac risk factors, ischemic-appearing ECG changes independently predicted myocardial injury (odds ratio, 3.2; 95% confidence interval, 1.3-8.2). In an exploratory analysis, ischemic-appearing ECG changes in leads I and aVL as well as V(5) and V(6) were more specific for myocardial injury (P = .002 and P = .03, respectively).

CONCLUSION

In conclusion, although a range of ECG abnormalities can occur after ICH, the finding of ischemic-appearing changes in an anatomical distribution can help predict which patients are having true myocardial injury.

Changes in ventricular repolarization duration during typical daily emotion in patients with Long QT syndrome

OBJECTIVE

Intense emotions are known triggers of sudden cardiac death. However, the effect of typical daily emotion on repolarization has not been examined. We examined whether QT interval changes as a function of typical daily emotion in patients at risk for cardiac events in the context of emotion.

METHODS

We studied 161 patients (n = 114 females; mean age, 35 years) with the congenital form of the Long QT Syndrome during daily activities. Each day for 3 days, a 12-hour Holter recording was completed. Patients were paged ten times per day at random times and rated the intensity of 16 prespecified emotions during the preceding 5 minutes. Measurements of QT interval and interbeat intervals were synchronized with emotion ratings.

RESULTS

Low Arousal Positive Affect was associated with significant increases in QT interval corrected for heart rate (using Fridericia's QTc) (p < .001), whereas higher arousal Activated Positive Affect (p < .001) and Activated Negative Affect (p < .01) were associated with significant decreases in QTc. Changes in QTc as a function of daily emotion ranged from 5-ms increases to 11-ms decreases. High-frequency heart rate variability (vagal tone) was positively correlated with QTc (p < .001). The effects of each positive emotion variable on QTc were greater in LQT2 than LQT1 patients (p < .001).

CONCLUSION

Ventricular repolarization duration (QTc) changes dynamically as a function of daily emotion. These changes are relatively small and do not constitute a risk in themselves. In the context of other risk factors, however, they may contribute to ventricular arrhythmias in vulnerable populations.

Operculo-insular pain (parasylvian pain): a distinct central pain syndrome

Central pain with dissociated thermoalgesic sensory loss is common in spinal and brainstem syndromes but not in cortical lesions. Out of a series of 270 patients investigated because of somatosensory abnormalities, we identified five subjects presenting with central pain and pure thermoalgesic sensory loss contralateral to cortical stroke. All of the patients had involvement of the posterior insula and inner parietal operculum. Lemniscal sensory modalities (position sense, graphaestesia, stereognosis) and somatosensory evoked potentials to non-noxious inputs were always preserved, while thermal and pain sensations were profoundly altered, and laser-evoked potentials to thermo-nocoiceptive stimuli were always abnormal. Central pain resulting from posterior parasylvian lesions appears to be a distinct entity that can be identified unambiguously on the basis of clinical, radiological and electrophysiological data. It presents with predominant or isolated deficits for pain and temperature sensations, and is paradoxically closer to pain syndromes from brainstem lesions affecting selectively the spinothalamic pathways than to those caused by focal lesions of the posterior thalamus. The term 'pseudo-thalamic' is therefore inappropriate to describe it, and we propose parasylvian or operculo-insular pain as appropriate labels. Parasylvian pain may be extremely difficult to treat; the magnitude of pain-temperature sensory disturbances may be prognostic for its development, hence the importance of early sensory assessment with quantitative methods.

Too long or too short? New insights into abnormal cardiac repolarization in people with chronic epilepsy and its potential role in sudden unexpected death

SUMMARY

Sudden unexpected death in epilepsy (SUDEP) is probably caused by periictal cardiorespiratory alterations such as central apnea, bradyarrhythmia, and neurogenic pulmonary edema. These alterations may occur in people with epilepsy and vary in duration and severity. Seizure-related ventricular tachyarrhythmias have also been hypothesized to be involved in SUDEP, but compelling evidence of these, or of predisposition to these, is lacking. Ventricular tachyarrhythmias are facilitated by pathologic cardiac repolarization. Electrocardiography (ECG) indicators of pathologic cardiac repolarization, such as prolongation or shortening of QT intervals as well as increased QT dispersion, are established risk factors for life-threatening tachyarrhythmia and sudden cardiac death (SDC). Abnormalities in cardiac repolarization have recently been described in people with epilepsy. Importantly, periictal ventricular tachycardia and fibrillation have also been reported in the absence of any underlying cardiac disease. Therefore, pathologic cardiac repolarization could promote SCD in people with epilepsy and could be one plausible cause for SUDEP. Herein, we review abnormal cardiac repolarization in people with epilepsy, describe the putative contribution of antiepileptic drugs, and discuss the potential role of pathologic cardiac repolarization in SUDEP. Based on these, measures to reduce the risk of or prevent SUDEP may include antiarrhythmic medication and implantation of cardiac combined pacemaker-defibrillator devices.

Neurotoxic and cardiotoxic effects of cocaine and ethanol

INTRODUCTION

Concurrent abuse of alcohol and cocaine results in the formation of cocaethylene, a powerful cocaine metabolite. Cocaethylene potentiates the direct cardiotoxic and indirect neurotoxic effects of cocaine or alcohol alone.

CASE REPORT

A 44-year-old female with history of cocaine and alcohol abuse presented with massive stroke in the emergency department. CT scan revealed extensive left internal carotid artery dissection extending into the left middle and anterior cerebral arteries resulting in a massive left hemispheric infarct, requiring urgent decompressive craniectomy. The patient had a stormy hospital course with multiple episodes of torsades de pointes in the first 4 days requiring aggressive management. She survived all events and was discharged to a nursing home with residual right hemiplegia and aphasia.

CONCLUSION

The combination of ethanol and cocaine has been associated with a significant increase in the incidence of neurological and cardiac emergencies including cerebral infarction, intracranial hemorrhage, myocardial infarction, cardiomyopathy, and cardiac arrhythmias. The alteration of cocaine pharmacokinetics and the formation of cocaethylene have been implicated, at least partially, in the increased toxicity of this drug combination.

[Stroke and atrial fibrillation]

Approximately 80% of all strokes are ischemic, the remaining being hemorrhagic. The major reason for cerebral ischemia is occlusion of a cerebral artery by a cardiac thrombus in a patient with atrial fibrillation. This article focuses on the therapeutic management of patients with cerebral ischemia due to atrial fibrillation and is based on the guidelines of the German Society of Neurology and the European Stroke Organization: Patients with cerebral ischemia and atrial fibrillation require oral anticoagulation with an INR of 2.0-3.0. After a TIA (transient ischemic attack) or minor ischemic stroke, anticoagulation can be initiated within the first week after the stroke. Combination therapy of aspirin and clopidogrel is less effective than oral anticoagulation.

Guidelines for management of ischaemic stroke and transient ischaemic attack 2008

This article represents the update of the European Stroke Initiative Recommendations for Stroke Management. These guidelines cover both ischaemic stroke and transient ischaemic attacks, which are now considered to be a single entity. The article covers referral and emergency management, Stroke Unit service, diagnostics, primary and secondary prevention, general stroke treatment, specific treatment including acute management, management of complications, and rehabilitation.

Telencephalon: Neocortex

The neocortex is an ultracomplex, six-layered structure that develops from the dorsal palliai sector of the telencephalic hemispheres (Figs. 2.24, 2.25, 11.1). All mammals, including monotremes and marsupials, possess a neocortex, but in reptiles, i.e. the ancestors of mammals, only a three-layered neocortical primordium is present [509, 511]. The term neocortex refers to its late phylogenetic appearance, in comparison to the “palaeocortical” olfactory cortex and the “archicortical” hippocampal cortex, both of which are present in all amniotes [509].

Myocardial stress in patients with acute cerebrovascular events

Signs of myocardial involvement are common in patients with acute cerebrovascular events. ST segment deviations, abnormal left ventricular function, increased N-terminal pro-brain natriuretic peptide (NT-proBNP), prolonged QT interval, and/or raised troponins are observed in up to one third of the patients. The huge majority of these findings are fully reversible. The changes may mimic myocardial infarction, but are not necessarily identical to coronary thrombosis. Based on the literature these signs may represent an acute catecholamine release provoked by the cerebrovascular catastrophe itself and not coronary thrombosis. However, all patients with signs of cardiac involvement during acute cerebrovascular events should receive a cardiological follow-up in order to exclude concomitant ischemic heart disease.

Elevated Troponin Levels Are Associated with Sympathoadrenal Activation in Acute Ischaemic Stroke

BACKGROUND

It has been hypothesised that elevated serum troponin levels in acute stroke are due to myocardial damage caused by sympathoadrenal activation, which, in turn, may be due particularly to insular damage. We aimed to determine the factors associated with troponin elevation in ischaemic stroke and the prognostic value of this finding.

METHODS

We studied 222 consecutive acute ischaemic stroke admissions. Serum troponin I and catecholamines were measured. Ischaemic damage on brain computed tomography (CT) scan was graded using the Alberta Stroke Program Early CT Score (ASPECTS). Electrocardiograms were classified using the Minnesota Code and the European Society of Cardiology/American College of Cardiology criteria for acute myocardial infarction. The Rankin scale was recorded at 30 days.

RESULTS

Forty-five patients (20%) had troponin I >0.2 microg/l. These troponin-positive patients had higher epinephrine levels (median 0.27 vs. 0.17 nmol/l; p = 0.0002) and were more likely to have electrocardiograms coded as definite or possible acute myocardial infarction (odds ratio 3.35; 95% CI 1.26-8.93), compared with those with troponin < or = 0.2 microg/l, in univariate analysis. There were no significant associations between troponin I score and ASPECTS or insular damage on brain CT. In logistic regression analyses, elevated troponin was significantly associated with age, elevated serum creatinine and epinephrine; however, increased troponin was not an independent predictor of death or dependency (Rankin >2) at 30 days.

CONCLUSIONS

Raised troponin I is associated with elevation of circulating epinephrine in acute ischaemic stroke. Activation of the sympathoadrenal system may be an important contributor to myocardial damage in these patients. Increased troponin is not associated with insular damage and does not independently predict poor outcome.