Insular ischemic stroke: clinical presentation and outcome

Isolated insular stroke: topography is the answer with respect to outcome and cardiac involvement

Background and purpose

Isolated insular strokes (IIS) are a rare occurrence due to the frequent concomitant involvement of adjacent territories, supplied by the M2 segment of the middle cerebral artery (MCA), and clinical aspects are sometimes contradictory. We aimed to describe clinical and radiological characteristics of a pure IIS case series, focusing on its functional outcome and cardiac involvement.

Methods

We identified 15 isolated insular ischemic strokes from a pool of 563 ischemic strokes occurred between January 2020 and December 2021. Data collection consisted of demographic and baseline clinical characteristics, comorbidities, electrocardiograms, echocardiograms, stroke topography and etiology, reperfusive treatments, and outcome measures. Descriptive statistical analysis was carried out.

Results

Newly detected cardiovascular alterations were the prevalent atypical presentation. Cardioembolism was the most frequent etiology. Most of patients had major neurological improvement at discharge and good outcome at 3-months follow-up.

Discussion and conclusion

IIS are extremely rare, representing according to our study about 2.6% ischemic strokes cases per year, and patients have peculiar clinical manifestations, such as dysautonomia and awareness deficits. Our data suggest the possibility for these patients to completely recover after acute ischemic stroke notwithstanding the pivotal role of the insula in cerebral connections and the frequent association with MCA occlusion. Moreover, given the central role of the insula in regulating autonomic functions, newly detected cardiac arrhythmias must be taken into consideration, as well as a full diagnostic work-up for the research of cardioembolic sources. To our knowledge, this is the largest monocentric case series of IIS and it might be useful for future systematic reviews.

Clinical and Imaging Features Associated with the Utilization of Comfort Measures Only in Acute Ischemic Stroke

Objectives: Up to 10% of acute ischemic stroke (AIS) patients can die in the first 30 days. Older age and a higher National Institutes of Health Stroke Scale (NIHSS) score are associated with transition to comfort measures only (CMO) in AIS. There are insufficient data on specific stroke etiology, infarct location, or vascular territory for the association of AIS with the use of CMO. We therefore evaluated the clinical and imaging factors associated with utilization of CMO and their outcomes. Methods: AIS patients seen in an academic comprehensive stroke center in the United States between July 1, 2015, and June 30, 2016, were subgrouped based on the use of CMO orders (CMO vs. non-CMO) during hospitalization. Clinical, laboratory, and imaging data were analyzed. Multivariable logistic regression analysis was performed, adjusting for pertinent covariates. Results: The study consisted of 296 patients, 27 (9%) patients were transitioned to CMO. Compared with non-CMO patients, those with CMO were older (mean ± standard deviation: 66 ± 15 vs. 75 ± 11 years, p = 0.002). Hemorrhagic transformation of AIS was more likely in CMO (17% vs. 41%, p = 0.0030) compared with non-CMO patients. On multivariate analysis, severe stroke measured by the NIHSS score (odds ratio [OR] = 1.2; 95% confidence interval [CI] = 1.1-1.4), infarction of the insular cortex (OR = 12.9; 95% CI = 1.4-118.4), and presence of cerebral edema with herniation (OR = 9.4; 95% CI = 2.5-35.5) were associated with transition to CMO. Conclusions: The presence of severe stroke, infarction of the insular cortex, and cerebral edema with herniation were associated with utilization of CMO in AIS. Impairment of multiple neurological functions served by the insular cortex could play a role in transition to CMO.

Safety of an operculoinsulectomy in the language-dominant hemisphere for refractory epilepsy

BACKGROUND

Operculoinsular cortectomy is increasingly recognized as a therapeutic avenue for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform this type of procedure because of feared neurological complications, especially in the language-dominant hemisphere, as the insula is involved in speech and language processes. The goal of this retrospective study is to quantify the incidence and types of speech and language deficits associated with operculoinsulectomies in the dominant hemisphere for language, and to identify factors associated with these complications.

METHODS

Clinical, imaging, and surgical data of all patients who had an operculoinsulectomy for refractory epilepsy at our center between 1998 and 2018 were reviewed. Language lateralization was determined by functional magnetic resonance imaging (fMRI) and/or Wada test. Speech and language assessments were carried out by neurosurgeons, neurologists, neuropsychologists and/or speech language pathologists, before surgery, during the first week after surgery, and at least 6 months after surgery.

RESULTS

Amongst 44 operculoinsulectomies, 13 were performed in the language-dominant hemisphere. 46% of these patients presented with transient aphasia post-surgery. However, a few months later, the patients' performances on language assessments were not statistically different from before surgery, thus suggesting a complete recovery of speech and language functions.

CONCLUSION

Temporary aphasias after operculoinsulectomy for refractory epilepsy in the language-dominant hemisphere are frequent, but eventually subside. Potential mechanisms underlying this recovery are discussed.

Morphological profiles of fatigue in Sarcoidosis patients

INTRODUCTION

Sarcoidosis is a chronic inflammatory disease often associated with chronic fatigue. Prevalence of fatigue can be measured via neuropsychological testing. Its pathophysiology is insufficiently understood. Structural analysis might help with the development of novel treatment methods.

METHODS

We recruited 30 sarcoidosis patients whose fatigue severity and depressive symptom presence was measured through validated neuropsychological self-assessment. T1-weighted structural images were acquired and VBM preprocessing was conducted. Total scores of these tests and subscales were correlated through multiple regression analysis to the brain morphometry.

RESULTS

Fatigue severity positively correlated with gray matter volumes in the striatum, the cingulate cortex and the cerebellum and negatively in the parietal and temporal lobe and posterior insula. Subscale analysis indicated a correlation between cognitive fatigue and striatum involvement as well as between physical and psychosocial fatigue and cerebellar alterations.

DISCUSSION

Structural analysis delineated two structural patterns associated with the presence of fatigue. One such pattern mainly seemed to involve structures with a focus on decision-making processes while the other indicated alterations in regions vital for perception. Fatigue seems to be a heterogeneous disease, where varying dimensions of reported symptoms correlate with different patterns of structural changes.

[A case of hemichorea due to insular and parietal cortical infarctions]

A 70-year-old man visited our hospital with a chief complaint of involuntary movements, diagnosed as chorea, involving the right upper and lower limbs. Brain MRI showed acute cerebral infarctions involving the left insular and parietal cortices. Chorea is usually due to dysfunction of components of the basal ganglia pathways, such as the caudate nucleus or subthalamic nucleus, and is rarely caused by lesions of the insular or parietal cortex. Here, we describe a case of cerebral infarctions in the left insular and parietal cortices and chorea of the right limbs, and discuss the relationship between the mechanism of chorea and insular and parietal cortical lesions.

Clinical presentation of strokes confined to the insula: a systematic review of literature

BACKGROUND AND PURPOSE

The insular cortex serves a wide variety of functions in humans, ranging from sensory and affective processing to high-level cognition. Hence, insular dysfunction may result in several different presentations. Ischemic strokes limited to the insular territory are rare and deserve a better characterization, to be quickly recognized and to receive the appropriate treatment (e.g. thrombolysis).

METHODS

We reviewed studies on patients with a first-ever acute stroke restricted to the insula. We searched in the Medline database the keywords "insular stroke" and "insular infarction", to identify previously published cases. Afterwards, the results were divided depending on the specific insular region affected by the stroke: anterior insular cortex (AIC), posterior insular cortex (PIC) or total insula cortex (TIC). Finally, a review of the clinical correlates associated with each region was performed.

RESULTS

We identified 25 reports including a total of 49 patients (59.7 ± 15.5 years, 48% male) from systematic review of the literature. The most common clinical phenotypes were motor and somatosensory deficits, dysarthria, aphasia and a vestibular-like syndrome. Atypical presentations were also common and included dysphagia, awareness deficits, gustatory disturbances, dysautonomia, neuropsychiatric or auditory disturbances and headache.

CONCLUSIONS

The clinical presentation of insular strokes is heterogeneous; however, an insular stroke should be suspected when vestibular-like, somatosensory, speech or language disturbances are combined in the same patient. Further studies are needed to improve our understanding of more atypical presentations.

The effect of insular cortex lesion on hyperacusis-like behavior in rats

Background and objectives: Hyperacusis is hypersensitivity and extreme response to the intensity of sound that is tolerable in normal subjects. The mechanisms underlying hyperacusis has not been well understood, specially the role of insular cortex. The aim of this study is to investigate the role of insular cortex in hyperacusis like behavior. Material and methods: The number of 33 male wistar rats weighting 170-250 gr were allocated randomly in three groups; control, sham, and insular lesion. Auditory startle responses (ASR) to different intensities of stimuli (70, 80, 90, 100, and110 dB without background noise as well as 110 dB in the presence of 70, 80 dB background noise) were measured before and up to four weeks after intervention. Results: Data analyses showed an increase in ASR to 100 dB stimulus without background noise one week after insular lesion, and increased responses to other intensities two weeks after lesion. Furthermore, there was a decrease in ASR to 110 dB stimulus with 80 dB background noise two weeks after insular lesion. However, no significant difference was observed in 70 dB background noise. The changes in ASR lasts at least four weeks.Conclusion: The findings indicated that there was an increase in ASR in the absence of background noise following cortical excititoxic lesion limited to insular cortex, while there was a decrease in responses in the presence of background noise which suggests possible increased sensitivity to sound loudness as a hyperacusis-like phenomenon. The study showed a significant relationship between insular cortex lesion and ASR in rats.

Transient naming deficits associated with insular lesions in a patient with encephalitis

We describe a patient with acute herpes simplex encephalitis with left-hemispheric hippocampal, parahippocampal and insular lesions. Although prototypic language areas were unaffected, the patient suffered from an inability to name objects or animals displayed on pictures. This deficit was transient and gradually disappeared 8 weeks after the initial diagnosis. Our findings are in line with a previous report showing similar deficits in a patient with a comparable lesion pattern and support the hypothesis that left insular lesions can produce severe naming deficits. Using FDG-PET we ruled out that functional deactivation in classical language areas account for the observed naming deficits.

Operculoinsular cortectomy for refractory epilepsy. Part 2: Is it safe?

OBJECTIVE

Operculoinsular cortectomy (also termed operculoinsulectomy) is increasingly recognized as a therapeutic option for perisylvian refractory epilepsy. However, most neurosurgeons are reluctant to perform the technique because of previously experienced or feared neurological complications. The goal of this study was to quantify the incidence of basic neurological complications (loss of primary nonneuropsychological functions) associated with operculoinsular cortectomies for refractory epilepsy, and to identify factors predicting these complications.

METHODS

Clinical, imaging, and surgical data of all patients investigated and surgically treated by our team for refractory epilepsy requiring an operculoinsular cortectomy were retrospectively reviewed. Patients with tumors and encephalitis were excluded. Logistic regression analysis was used for uni- and multivariate statistical analyses.

RESULTS

Forty-four operculoinsular cortectomies were performed in 43 patients. Although postoperative neurological deficits were frequent (54.5% of procedures), only 3 procedures were associated with a permanent significant neurological deficit. Out of the 3 permanent deficits, only 1 (2.3%; a sensorimotor hemisyndrome) was related to the technique of operculoinsular cortectomy (injury to a middle cerebral artery branch), while the other 2 (arm hypoesthesia and hemianopia) were attributed to cortical resection beyond the operculoinsular area. With multivariate analysis, a postoperative neurological deficit was associated with preoperative insular hypometabolism on PET scan. Postoperative motor deficit (29.6% of procedures) was correlated with fewer years of neurosurgical experience and frontal operculectomies, but not with corona radiata ischemic lesions. Ischemic lesions in the posterior two-thirds of the corona radiata (40.9% of procedures) were associated with parietal operculectomies, but not with posterior insulectomies.

CONCLUSIONS

Operculoinsular cortectomy for refractory epilepsy is a relatively safe therapeutic option but temporary neurological deficits after surgery are frequent. This study highlights the role of frontal/parietal opercula resections in postoperative complications. Corona radiata ischemic lesions are not clearly related to motor deficits. There were no obvious permanent neurological consequences of losing a part of an epileptic insula, including on the dominant side for language. A low complication rate can be achieved if the following conditions are met: 1) microsurgical technique is applied to spare cortical branches of the middle cerebral artery; 2) the resection of an opercula is done only if the opercula is part of the epileptic focus; and 3) the neurosurgeon involved has proper training and experience.

Insula stroke: the weird and the worrisome

Infarction of the insula is a common scenario with large tissue-volume strokes in the middle cerebral artery territory. Considered to be part of the central autonomic network, infarction of this region is associated with autonomic disturbances, in particular cardiovascular dysregulation. Risk of aspiration following stroke is also associated with involvement of the insula, consistent with its purported participation in complex functions of the mouth and pharynx. Strokes restricted to the insula are rare and present with a broad range of symptoms that offer a window of insight into the diverse functionality of the insular cortex. Chemosensory, autonomic, vestibular, auditory, somatosensory, language and oropharyngeal functional deficits are all recognised, among others. Long-term sequelae are unknown but profound symptoms, such as hemiparesis, are usually transient. Understanding the patterns of dysfunction highlighted provides the basis for future strategies to optimise stroke management on the discovery of insula involvement.

Lesion characteristics driving right-hemispheric language reorganization in congenital left-hemispheric brain damage

Pre- or perinatally acquired ("congenital") left-hemispheric brain lesions can be compensated for by reorganizing language into homotopic brain regions in the right hemisphere. Language comprehension may be hemispherically dissociated from language production. We investigated the lesion characteristics driving inter-hemispheric reorganization of language comprehension and language production in 19 patients (7-32years; eight females) with congenital left-hemispheric brain lesions (periventricular lesions [n=11] and middle cerebral artery infarctions [n=8]) by fMRI. 16/17 patients demonstrated reorganized language production, while 7/19 patients had reorganized language comprehension. Lesions to the insular cortex and the temporo-parietal junction (predominantly supramarginal gyrus) were significantly more common in patients in whom both, language production and comprehension were reorganized. These areas belong to the dorsal stream of the language network, participating in the auditory-motor integration of language. Our data suggest that the integrity of this stream might be crucial for a normal left-lateralized language development.

The regional neuronal activity in left posterior middle temporal gyrus is correlated with the severity of chronic aphasia

BACKGROUND

Aphasia is one of the most disabling cognitive deficits affecting >2 million people in the USA. The neuroimaging characteristics of chronic aphasic patients (>6 months post onset) remain largely unknown.

OBJECTIVE

The objective of this study was to investigate the regional signal changes of spontaneous neuronal activity of brain and the inter-regional connectivity in chronic aphasia.

MATERIALS AND METHODS

Resting-state blood oxygenation level-dependent functional magnetic resonance imaging (fMRI) was used to obtain fMRI data from 17 chronic aphasic patients and 20 healthy control subjects in a Siemens Verio 3.0T MR Scanner. The amplitude of low-frequency fluctuation (ALFF) was determined, which directly reflects the regional neuronal activity. The functional connectivity (FC) of fMRI was assessed using a seed voxel linear correlation approach. The severity of aphasia was evaluated by aphasia quotient (AQ) scores obtained from Western Aphasia Battery test.

RESULTS

Compared with normal subjects, aphasic patients showed decreased ALFF values in the regions of left posterior middle temporal gyrus (PMTG), left medial prefrontal gyrus, and right cerebellum. The ALFF values in left PMTG showed strong positive correlation with the AQ score (coefficient r=0.79, P<0.05). There was a positive FC in chronic aphasia between left PMTG and left inferior temporal gyrus (BA20), fusiform gyrus (BA37), and inferior frontal gyrus (BA47\45\44).

CONCLUSION

Left PMTG might play an important role in language dysfunction of chronic aphasia, and ALFF value might be a promising indicator to evaluate the severity of aphasia.

Ictal fear: Associations with age, gender, and other experiential phenomena

PURPOSE

The aim of this study was to determine the relationship of fear to other auras and to gender and age using a large database.

METHODS

The Epilepsy Phenome/Genome Project (EPGP) is a multicenter, multicontinental cross-sectional study in which ictal symptomatology and other data were ascertained in a standardized series of questionnaires then corroborated by epilepsy specialists. Auras were classified into subgroups of symptoms, with ictal fear, panic, or anxiety as a single category.

RESULTS

Of 536 participants with focal epilepsy, 72 were coded as having ictal fear/panic/anxiety. Reviewing raw patient responses, 12 participants were deemed not to have fear, and 24 had inadequate data, leaving 36 (7%) of 512 with definite ictal fear. In univariate analyses, fear was significantly associated with auras historically considered temporal lobe in origin, including cephalic, olfactory, and visceral complaints; déjà vu; and derealization. On both univariate and multivariate stepwise analyses, fear was associated with jamais vu and auras with cardiac symptoms, dyspnea, and chest tightening. Expressive aphasia was associated with fear on univariate analysis only, but the general category of aphasias was associated with fear only in the multivariate model. There was no age or gender relationship with fear when compared to the overall population with focal epilepsy that was studied under the EPGP. Patients with ictal fear were more likely to have a right hemisphere seizure focus.

CONCLUSIONS

Ictal fear was strongly associated with other auras considered to originate from the limbic system. No relationship of fear with age or gender was observed.

Isolated left posterior insular infarction and convergent roles in verbal fluency, language, memory, and executive function

The posterior insular cortex-a complex structure interconnecting various brain regions for different functions-is a rare location for ischemic stroke. We report a patient with isolated left posterior insular infarction who presented with multiple cognitive impairment, including impairment in semantic and phonemic verbal fluency.

Smoking cessation behaviors three months following acute insular damage from stroke

BACKGROUND

Recent evidence suggests that the insular cortex may play an important role in cognitive and emotional processes that facilitate drug use but it is unclear whether changes to the insula would result in sustained abstinence. To better understand the role of the insula in maintaining abstinence, we examined quitting patterns in smokers with acute damage to their insula relative to other regions.

DESIGN

Prospective cohort study with 3month follow-up, beginning June 2013 and ending May 2014.

SETTING

Three acute care hospitals in Rochester, NY.

PARTICIPANTS

One-hundred-fifty-six current smokers hospitalized for acute ischemic stroke; 38 with insular infarctions and 118 with non-insular infarctions, assessed by 3 neuroradiologists.

MEASUREMENTS

Self-reported smoking status (seven-day point prevalence and continuous abstinence), complete abstinence from any nicotine product, and disruption of smoking addiction (defined by criteria on smoking status, difficulty of quitting, and urge) were assessed at three months post-stroke. Time to relapse (in days) after discharge was also assessed.

RESULTS

Insular damage was associated with increased odds of three-month continuous abstinence (OR=3.71, 95% CI: 1.59, 8.65) and complete cessation from any nicotine product (OR=2.72, 95% CI: 1.19, 6.22). Average time to relapse was longer in the insular-damaged group (17.50days, SD=19.82) relative to non-insular damage (10.42days, SD=18.49). Among quitters, insular damage was also associated with higher relative odds of experiencing a disruption of addiction compared to non-insular damage (adjusted OR=5.60, 95% CI: 1.52, 20.56).

CONCLUSIONS

These findings support the potential role of the insular cortex in maintaining smoking and nicotine abstinence. Further research is needed to establish whether the insula may be a novel target for smoking cessation interventions.

Hyperacusis following unilateral damage to the insular cortex: a three-case report

The insula is a multisensory area involved in various brain functions, including central auditory processing. However, its specific role in auditory function remains unclear. Here we report three cases of persistent hypersensitivity to auditory stimuli following damage to the insular cortex, using behavioral and neurophysiological measures. Two patients who complained of auditory disturbance since they suffered an isolated unilateral insular stroke, and one epileptic patient who underwent right insular resection for control of drug-resistant seizures, were involved in this study. These patients, all young adult women, were tested for auditory function more than one year after brain injury, and were compared to 10 healthy control participants matched for age, sex, and education. The assessment included pure-tone detection and speech detection in quiet, loudness discomfort levels, random gap detection, recognition of frequency and duration patterns, binaural separation, dichotic listening, as well as late-latency auditory event-related potentials (ERPs). Each patient showed mild or moderate hyperacusis, as revealed by decreased loudness discomfort levels, which was more important on the side of lesion in two cases. Tests of temporal processing also revealed impairments, in concordance with previous findings. ERPs of two patients were characterised by increased amplitude of the P3b component elicited during a two-tone auditory oddball detection task. This study is the first to report cases of persistent hyperacusis following damage to the insular cortex, and suggests that the insula is involved in modulating the perceived intensity of the incoming auditory stimuli during late-stage processing.

Language disturbances associated to insular and entorhinal damage: study of a patient affected by herpetic encephalitis

The herpes simplex encephalitis (HSE) patient reported in this study presented a left hemisphere lesion limited to the left insula and to the left anterior parahippocampal region. The patient was followed longitudinally, focusing on the aphasia type, the language recovery, and the integrity of semantic representations. The language deficit was of fluent type, without phonological impairment, and showed a good but incomplete recovery after four months. A semantic impairment was possible at the onset, but recovered quickly and did not present a disproportionate impairment of living categories.

Dyscalculia, dysgraphia, and left-right confusion from a left posterior peri-insular infarct

The Gerstmann syndrome of dyscalculia, dysgraphia, left-right confusion, and finger agnosia is generally attributed to lesions near the angular gyrus of the dominant hemisphere. A 68-year-old right-handed woman presented with sudden difficulty completing a Sudoku grid and was found to have dyscalculia, dysgraphia, and left-right confusion. Magnetic resonance imaging (MRI) showed a focus of abnormal reduced diffusivity in the left posterior insula and temporoparietal operculum consistent with acute infarct. Gerstmann syndrome from an insular or peri-insular lesion has not been described in the literature previously. Pathological and functional imaging studies show connections between left posterior insular region and inferior parietal lobe. We postulate that the insula and operculum lesion disrupted key functional networks resulting in a pseudoparietal presentation.

[Multimodal imaging protocols and their predictive role in acute stroke functional outcome]

Brain imaging plays a central role in the assessment of patients with acute ischemic stroke. Within a few minutes, modern multimodal imaging protocols can provide one with comprehensive information about prognosis, management, and outcome of the disease, and may detect changes in the intracranial structures reflecting severity of the ischemic injury depicted by four Ps: parenchyma (of the brain), pipes (i.e., the cerebral blood vessels), penumbra, and permeability (of the blood brain barrier). In this article, we have reviewed neuroradiological predictors of stroke functional outcome in the light of the aforementioned four Ps.