Validating the TeleStroke Mimic Score: A Prediction Rule for Identifying Stroke Mimics Evaluated Over Telestroke Networks

Reviewing migraine-associated pathophysiology and its impact on elevated stroke risk

Migraine affects up to 20 percent of the global population and ranks as the second leading cause of disability worldwide. In parallel, ischemic stroke stands as the second leading cause of mortality and the third leading cause of disability worldwide. This review aims to elucidate the intricate relationship between migraine and stroke, highlighting the role of genetic, vascular, and hormonal factors. Epidemiological evidence shows a positive association between migraine, particularly with aura, and ischemic stroke (IS), though the link to hemorrhagic stroke (HS) remains inconclusive. The shared pathophysiology between migraine and stroke includes cortical spreading depression, endothelial dysfunction, and genetic predispositions, such as mutations linked to conditions like CADASIL and MELAS. Genetic studies indicate that common loci may predispose individuals to both migraine and stroke, while biomarkers such as endothelial microparticles and inflammatory cytokines offer insights into the underlying mechanisms. Additionally, hormonal influences, particularly fluctuations in estrogen levels, significantly impact migraine pathogenesis and stroke risk, highlighting the need for tailored interventions for women. The presence of a patent foramen ovale (PFO) in migraineurs further complicates their risk profile, with device closure showing promise in reducing stroke occurrence. Furthermore, white matter lesions (WMLs) are frequently observed in migraine patients, suggesting potential cognitive and stroke risks. This review hopes to summarize the links between migraine and its associated conditions and ischemic stroke, recognizing the profound implications for clinical management strategies for both disorders. Understanding the complex relationship between migraine and ischemic stroke holds the key to navigating treatment options and preventive interventions to enhance overall patient outcomes.

Frequency and Characteristics of Non-Neurological and Neurological Stroke Mimics in the Emergency Department

BACKGROUND

Stroke mimics are common in the emergency department (ED) and early detection is important to initiate appropriate treatment and withhold unnecessary procedures. We aimed to compare the frequency, clinical characteristics and predictors of non-neurological and neurological stroke mimics transferred to our ED for suspected stroke.

METHODS

This was a cross-sectional study of consecutive patients with suspected stroke transported to the ED of the University Hospital Essen between January 2017 and December 2021 by the city's Emergency Medical Service. We investigated patient characteristics, preclinical data, symptoms and final diagnoses in patients with non-neurological and neurological stroke mimics. Multinominal logistic regression analysis was performed to assess predictors of both etiologic groups.

RESULTS

Of 2167 patients with suspected stroke, 762 (35.2%) were diagnosed with a stroke mimic. Etiology was non-neurological in 369 (48.4%) and neurological in 393 (51.6%) cases. The most common diagnoses were seizures (23.2%) and infections (14.7%). Patients with non-neurological mimics were older (78.0 vs. 72.0 y, p < 0.001) and more likely to have chronic kidney disease (17.3% vs. 9.2%, p < 0.001) or heart failure (12.5% vs. 7.1%, p = 0.014). Prevalence of malignancy (8.7% vs. 13.7%, p = 0.031) and focal symptoms (38.8 vs. 57.3%, p < 0.001) was lower in this group. More than two-fifths required hospitalization (39.3 vs. 47.1%, p = 0.034). Adjusted multinominal logistic regression revealed chronic kidney and liver disease as independent positive predictors of stroke mimics regardless of etiology, while atrial fibrillation and hypertension were negative predictors in both groups. Prehospital vital signs were independently associated with non-neurological stroke mimics only, while age was exclusively associated with neurological mimics.

CONCLUSIONS

Up to half of stroke mimics in the neurological ED are of non-neurological origin. Preclinical identification is challenging and a high proportion requires hospitalization. Awareness of underlying etiologies and differences in clinical characteristics is important to provide optimal care.

Thrombolysis in Stroke Mimics: Comprehensive Stroke Centers vs Telestroke Sites

BACKGROUND

Hyperacute treatment of acute stroke may lead to thrombolysis in stroke mimics (SM). Our aim was to determine the frequency of thrombolysis in SM in primary stroke centers (PSC) dependent on telestroke versus comprehensive stroke centers (CSC).

METHOD

Retrospective review of prospectively collected data from the Quality improvement and Clinical Research (QuICR) registry, the Discharge Abstract Database (DAD), and The National Ambulatory Care Reporting System (NACRS) of consecutive patients treated with intravenous thrombolysis for acute ischemic stroke in Alberta (Canada) from April 2016 to March 2021.

RESULT

A total of 2471 patients who received thrombolysis were included. Linking the QuICR registry to DAD 169 (6.83%) patients were identified as SM; however, on our review of the records, only 112 (4.53%) were actual SM. SMs were younger with a mean age of 61.66 (±16.15) vs 71.08 (±14.55) in stroke. National Institute of Health Stroke Scale was higher in stroke with a median (IQR) of 10 (5-17) vs 7 (5-10) in SM. Only one patient (0.89 %) in SM groups had a small parenchymal hemorrhage versus 155 (6.57%) stroke patients had a parenchymal hemorrhage. There was no death among patients of thrombolysed SM during hospitalization versus 276 (11.69%) in stroke. There was no significant difference in the rate of SM among thrombolysed patients between PSC 27 (5.36%) versus CSC 85 (4.3%) (P = 0.312). The most responsible diagnosis of SM was migraine/migraine equivalent, functional disorder, seizure, and delirium.

CONCLUSION

The diagnosis of SM may not always be correct when the information is extracted from databases. The rate of thrombolysis in SM via telestroke is similar to treatment in person at CSC.

Telemedicine in Neuro-Oncology-An Evaluation of Remote Consultations during the COVID-19 Pandemic

In order to minimize the risk of infections during the COVID-19 pandemic, remote video consultations (VC) experienced an upswing in most medical fields. However, telemedicine in neuro-oncology comprises unique challenges and opportunities. So far, evidence-based insights to evaluate and potentially customize current concepts are scarce. To fill this gap, we analyzed >3700 neuro-oncological consultations, of which >300 were conducted as VC per patients' preference, in order to detect how both patient collectives distinguished from one another. Additionally, we examined patients' reasons, suitable/less suitable encounters, VC's benefits and disadvantages and future opportunities with an anonymized survey. Patients that participated in VC had a worse clinical condition, higher grade of malignancy, were more often diagnosed with glioblastoma and had a longer travel distance (all p < 0.01). VC were considered a fully adequate alternative to face-to-face consultations for almost all encounters that patients chose to participate in (>70%) except initial consultations. Most participants preferred to alternate between both modalities rather than participate in one alone but preferred VC over telephone consultation. VC made patients feel safer, and participants expressed interest in implementing other telemedicine modalities (e.g., apps) into neuro-oncology. VC are a promising addition to patient care in neuro-oncology. However, patients and encounters should be selected individually.

Diagnostic accuracy of telestroke consultation: a Louisiana based tele-network experience

Background and purpose

Telestroke has grown significantly since its implementation. Despite growing utilization, there is a paucity of data regarding the diagnostic accuracy of telestroke to distinguish between stroke and its mimics. We aimed to evaluate diagnostic accuracy of telestroke consultations and explore the characteristics of misdiagnosed patients with a focus on stroke mimics.

Methods

We conducted a retrospective study of all the consultations in our Ochsner Health's TeleStroke program seen between April 2015 and April 2016. Consultations were classified into one of three diagnostic categories: stroke/transient ischemic attack, mimic, and uncertain. Initial telestroke diagnosis was compared with the final diagnosis post review of all emergency department and hospital data. Sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV), positive likelihood ratio (LR+) and negative likelihood ratio (LR-) for diagnosis of stroke/TIA versus mimic were calculated. Area under receiver-operating characteristic curve (AUC) analysis to predict true stroke was performed. Bivariate analysis based on the diagnostic categories examined association with sex, age, NIHSS, stroke risk factors, tPA given, bleeding after tPA, symptom onset to last known normal, symptom onset to consult, timing in the day, and consult duration. Logistic regression was performed as indicated by bivariate analysis.

Results

Eight hundred and seventy-four telestroke evaluations were included in our analysis. Accurate diagnosis through teleneurological consultation was seen in 85% of which 532 were strokes (true positives) and 170 were mimics (true negatives). Sensitivity, specificity, PPV, NPV were 97.8, 82.5, 93.7 and 93.4%, respectively. LR+ and LR- were 5.6 and 0.03. AUC (95% CI) was 0.9016 (0.8749-0.9283). Stroke mimics were more common with younger age and female gender and in those with less vascular risk factors. LR revealed OR (95% CI) of misdiagnosis for female gender of 1.9 (1.3-2.9). Lower age and lower NIHSS score were other predictors of misdiagnosis.

Conclusion

We report high diagnostic accuracy of the Ochsner Telestroke Program in discriminating stroke/TIA and stroke mimics, with slight tendency towards over diagnosis of stroke. Female gender, younger age and lower NIHSS score were associated with misdiagnosis.

Thrombolysis of stroke mimics via telestroke

BACKGROUND

The rate of intravenous tissue plasminogen activator (IVtPA) administered to stroke mimics (SM) occurs in 24%-44% of telestroke series.

METHODS

We reviewed 270 suspected acute ischaemic stroke (AIS) patients who were evaluated by telestroke and received IVtPA from 1 July 2016 to 30 September 2017 at our academic comprehensive stroke centre.

RESULTS

Among 270 AIS patients who received IVtPA via telestroke, 64 (23.7%) were diagnosed with SM. Compared with patients who had a stroke, the SM group was younger (mean age 56.4 vs 68.2, p<0.0001), more likely to be female (60.9% vs 45.6%, p=0.0324) and had longer door-to-needle times (85.3 vs 69.9, p=0.0008). The most common SM diagnoses were migraine 26 (40.6%), conversion disorder 12 (18.8%), encephalopathy 7 (10.9%) and unmasking (9.4%). Among the SM, migraine and conversion disorder were younger compared with the other subgroups (p<0.001). Functional exam elements were noted more frequently in conversion disorder (66.7%) and migraine (34.6%), but rare in other diagnoses (p=0.006). Among the SM, 23 (35.9%) had a history of a prior similar episodes, and 15 (23.4%) had a history of more than 5 spells.

CONCLUSIONS

In our telestroke programme, 23.7% of those administered thrombolysis had a final diagnosis of SM.

Pre-hospital transdermal glyceryl trinitrate in patients with stroke mimics: data from the RIGHT-2 randomised-controlled ambulance trial

BACKGROUND

Prehospital stroke trials will inevitably recruit patients with non-stroke conditions, so called stroke mimics. We undertook a pre-specified analysis to determine outcomes in patients with mimics in the second Rapid Intervention with Glyceryl trinitrate in Hypertensive stroke Trial (RIGHT-2).

METHODS

RIGHT-2 was a prospective, multicentre, paramedic-delivered, ambulance-based, sham-controlled, participant-and outcome-blinded, randomised-controlled trial of transdermal glyceryl trinitrate (GTN) in adults with ultra-acute presumed stroke in the UK. Final diagnosis (intracerebral haemorrhage, ischaemic stroke, transient ischaemic attack, mimic) was determined by the hospital investigator. This pre-specified subgroup analysis assessed the safety and efficacy of transdermal GTN (5 mg daily for 4 days) versus sham patch among stroke mimic patients. The primary outcome was the 7-level modified Rankin Scale (mRS) at 90 days.

RESULTS

Among 1149 participants in RIGHT-2, 297 (26%) had a final diagnosis of mimic (GTN 134, sham 163). The mimic group were younger, mean age 67 (SD: 18) vs 75 (SD: 13) years, had a longer interval from symptom onset to randomisation, median 75 [95% CI: 47,126] vs 70 [95% CI:45,108] minutes, less atrial fibrillation and a lower systolic blood pressure and Face-Arm-Speech-Time tool score than the stroke group. The three most common mimic diagnoses were seizure (17%), migraine or primary headache disorder (17%) and functional disorders (14%). At 90 days, the GTN group had a better mRS score as compared to the sham group (adjusted common odds ratio 0.54; 95% confidence intervals 0.34, 0.85; p = 0.008), a difference that persisted at 365 days. There was no difference in the proportion of patients who died in hospital, were discharged to a residential care facility, or suffered a serious adverse event.

CONCLUSIONS

One-quarter of patients suspected by paramedics to have an ultra-acute stroke were subsequently diagnosed with a non-stroke condition. GTN was associated with unexplained improved functional outcome observed at 90 days and one year, a finding that may represent an undetected baseline imbalance, chance, or real efficacy. GTN was not associated with harm.

TRIAL REGISTRATION

This trial is registered with International Standard Randomised Controlled Trials Number ISRCTN 26986053 .

Evaluation of Transient Ischemic Attack and Minor Stroke: A Rapid Outpatient Model for the COVID-19 Pandemic and Beyond

The grim circumstances of the COVID-19 pandemic have highlighted the need to refine and adapt stroke systems of care. Patients' care-seeking behaviors have changed due to perceived risks of in-hospital treatment during the pandemic. In response to these challenges, we optimized a recently implemented, novel outpatient approach for the evaluation and management of minor stroke and transient ischemic attack, entitled RESCUE-TIA. This modified approach incorporated telemedicine visits and remote testing, and proved valuable during the pandemic. In this review article, we provide the evidence-based rationale for our approach, describe its operationalization, and provide data from our initial experience.

Telestroke Assessment With Perfusion CT Improves the Diagnostic Accuracy of Stroke vs. Mimic

Background and Purpose: CT perfusion (CTP) has been implemented widely in regional areas of Australia for telestroke assessment. The aim of this study was to determine if, as part of telestroke assessment, CTP provided added benefit to clinical features in distinguishing between strokes and mimic and between transient ischaemic attack (TIA) and mimic.

Methods: We retrospectively analysed 1,513 consecutively recruited patients referred to the Northern New South Wales Telestroke service, where CTP is performed as a part of telestroke assessment. Patients were classified based on the final diagnosis of stroke, TIA, or mimic. Multivariate regression models were used to determine factors that could be used to differentiate between stroke and mimic and between TIA and mimic.

Results: There were 693 strokes, 97 TIA, and 259 mimics included in the multivariate regression models. For the stroke vs. mimic model using symptoms only, the area under the curve (AUC) on the receiver operator curve (ROC) was 0.71 (95% CI 0.67–0.75). For the stroke vs. mimic model using the absence of ischaemic lesion on CTP in addition to clinical features, the AUC was 0.90 (95% CI 0.88–0.92). The multivariate regression model for predicting mimic from TIA using symptoms produced an AUC of 0.71 (95% CI 0.65–0.76). The addition of absence of an ischaemic lesion on CTP to clinical features for the TIA vs. mimic model had an AUC of 0.78 (95% CI 0.73–0.83)

Conclusions: In the telehealth setting, the absence of an ischaemic lesion on CTP adds to the diagnostic accuracy in distinguishing mimic from stroke, above that from clinical features.

Stroke mimics: incidence, aetiology, clinical features and treatment

Mimics account for almost half of hospital admissions for suspected stroke. Stroke mimics may present as a functional (conversion) disorder or may be part of the symptomatology of a neurological or medical disorder. While many underlying conditions can be recognized rapidly by careful assessment, a significant proportion of patients unfortunately still receive thrombolysis and admission to a high-intensity stroke unit with inherent risks and unnecessary costs. Accurate diagnosis is important as recurrent presentations may be common in many disorders. A non-contrast CT is not sufficient to make a diagnosis of acute stroke as the test may be normal very early following an acute stroke. Multi-modal CT or magnetic resonance imaging (MRI) may be helpful to confirm an acute ischaemic stroke and are necessary if stroke mimics are suspected. Treatment in neurological and medical mimics results in prompt resolution of the symptoms. Treatment of functional disorders can be challenging and is often incomplete and requires early psychiatric intervention.

Ischemic stroke mimics: A comprehensive review

BACKGROUND

Ischemic stroke is the leading cause of disability and one of the leading causes of death. Ischemic stroke mimics (SMs) can account for a noteble number of diagnosed acute strokes and even can be thrombolyzed.

METHODS

The aim of our comprehensive review was to summarize the findings of different studies focusing on the prevalence, type, risk factors, presenting symptoms, and outcome of SMs in stroke/thrombolysis situations.

RESULTS

Overall, 61 studies were selected with 62.664 participants. Ischemic stroke mimic rate was 24.8% (15044/60703). Most common types included peripheral vestibular dysfunction in 23.2%, toxic/metabolic in 13.2%, seizure in 13%, functional disorder in 9.7% and migraine in 7.76%. Ischemic stroke mimic have less vascular risk factors, younger age, female predominance, lower (nearly normal) blood pressure, no or less severe symptoms compared to ischemic stroke patients (p < 0.05 in all cases). 61.7% of ischemic stroke patients were thrombolysed vs. 26.3% among SMs (p < 0.001). (p < 0.001). Overall intracranial hemorrhage was reported in 9.4% of stroke vs. 0.7% in SM patients (p < 0.001). Death occurred in 11.3% of stroke vs 1.9% of SM patients (p < 0.001). Excellent outcome was (mRS 0-1) was reported in 41.8% ischemic stroke patients vs. 68.9% SMs (p < 0.001). Apart from HINTS manouvre or Hoover sign there is no specific method in the identification of mimics. MRI DWI or perfusion imaging have a role in the setup of differential diagnosis, but merit further investigation.

CONCLUSION

Our article is among the first complex reviews focusing on ischemic stroke mimics. Although it underscores the safety of thrombolysis in this situation, but also draws attention to the need of patient evaluation by physicians experienced in the diagnosis of both ischemic stroke and SMs, especially in vertigo, headache, seizure and conversional disorders.

Overview of Acute Ischemic Stroke Evaluation and Management

Stroke is a major contributor to death and disability worldwide. Prior to modern therapy, post-stroke mortality was approximately 10% in the acute period, with nearly one-half of the patients developing moderate-to-severe disability. The most fundamental aspect of acute stroke management is "time is brain". In acute ischemic stroke, the primary therapeutic goal of reperfusion therapy, including intravenous recombinant tissue plasminogen activator (IV TPA) and/or endovascular thrombectomy, is the rapid restoration of cerebral blood flow to the salvageable ischemic brain tissue at risk for cerebral infarction. Several landmark endovascular thrombectomy trials were found to be of benefit in select patients with acute stroke caused by occlusion of the proximal anterior circulation, which has led to a paradigm shift in the management of acute ischemic strokes. In this modern era of acute stroke care, more patients will survive with varying degrees of disability post-stroke. A comprehensive stroke rehabilitation program is critical to optimize post-stroke outcomes. Understanding the natural history of stroke recovery, and adapting a multidisciplinary approach, will lead to improved chances for successful rehabilitation. In this article, we provide an overview on the evaluation and the current advances in the management of acute ischemic stroke, starting in the prehospital setting and in the emergency department, followed by post-acute stroke hospital management and rehabilitation.

Thrombolytic Refusal Over Telestroke

Background

Tissue plasminogen activator (tPA) refusal is 4%-6% for acute ischemic stroke (AIS) in the emergency department. Telestroke (TS) has increased the use of tPA for AIS but is accompanied by barriers in communication that can affect tPA consent. We characterized the incidence of tPA refusal in our TS network and its associated reasons.

Methods

Patients with AIS who were offered tPA within 4.5 hours from symptom onset according to American Heart Association guidelines were identified within our Lone Star Stroke Consortium Telestroke Registry from September 2015 to December 2018. We compared baseline characteristics and clinical outcomes between patients who refused tPA and patients who accepted tPA.

Results

Among the 1,242 patients who qualified for tPA and were offered treatment, 8% refused tPA. Female and non-Hispanic Black patients and patients with a prior history of stroke were more likely to decline tPA. Patients who refused tPA presented with a lower NIHSS and were associated with a final diagnosis of stroke mimic (odds ratio [OR] 0.23; 95% confidence interval [CI] 0.15-0.36). Good outcome (90-day modified Rankin Scale 0-2) was the same among patients who received tPA and those who refused (OR 0.80; 95% CI 0.42-1.54). The most common reasons for refusal were rapidly improving and mild/nondisabling symptoms and concern for potential side effects.

Conclusion

tPA refusal over TS is comparable to previously reported rates; there was no difference in outcomes among patients who received tPA compared with those who refused. Sex and racial differences associated with an increased tPA refusal warrant further investigation in efforts to achieve equity/parity in tPA decisions.

Validation of the Telestroke Mimic Score in Mayo Clinic population

OBJECTIVES

Telestroke consultations enable hospital providers to administer intravenous (IV) alteplase to patients who would otherwise not receive it due to lack of an in-hospital stroke team. However, up to 30% of acute stroke patient evaluations are deemed to be stroke mimics. Mimics present a challenge with the limitations of a virtual neurological exam. The administration of IV alteplase in these patients is not without risk. With the cost and risk associated with IV alteplase, there are both ethical and practical incentives to avoid administering alteplase to a patient manifesting a stroke-mimic. Recently a retrospective analysis validated a TeleStroke Mimic Score (TM-Score) to help detect stroke mimics. We retrospectively applied this tool to Mayo Clinic Stroke Telemedicine for Arizona Rural Residents (STARR) telestroke database to provide external validation in an independent study population.

MATERIALS AND METHODS

We analyzed 339 patients in the STARR database for validation of the TM-Score, which was applied retrospectively to determine whether it predicted stroke-mimic, using data available during each patient's telestroke consult. We assessed the TM-Score's performance with a receiver-operating characteristic (ROC) curve. A scatter plot of the data was assembled to demonstrate the relationship between the TM-Score and the likelihood of having a stroke mimic, and was compared to the nomogram in the original TM-Score study.

RESULTS

When the TM-Score was applied to Mayo Clinic STARR validation cohort, the area under the ROC curve was 0.78, larger than that of the derivation cohort in the original study (0.75). Further analysis suggested that a TM-Score > 25 or < 10 provided a greater degree of confidence that the patient had presented with stroke or stroke mimic, respectively.  In STARR cohort, additional variables were significantly different between stroke and stroke mimic populations, including a history of sleep apnea and diabetes.

CONCLUSIONS

We determined that the original TM-Score was valid when applied to Mayo Clinic STARR telestroke population.

[Telemedicine in stroke-pertinent to stroke care in Germany]

BACKGROUND AND OBJECTIVE

Telemedical stroke networks improve stroke care and provide access to time-dependent acute stroke treatment in predominantly rural regions. The aim is a presentation of data on its utility and regional distribution.

METHODS

The working group on telemedical stroke care of the German Stroke Society performed a survey study among all telestroke networks.

RESULTS

Currently, 22 telemedical stroke networks including 43 centers (per network: median 1.5, interquartile range, IQR, 1-3) as well as 225 cooperating hospitals (per network: median 9, IQR 4-17) operate in Germany and contribute to acute stroke care delivery to 48 million people. In 2018, 38,211 teleconsultations (per network: median 1340, IQR 319-2758) were performed. The thrombolysis rate was 14.1% (95% confidence interval 13.6-14.7%) and transfer for thrombectomy was initiated in 7.9% (95% confidence interval 7.5-8.4%) of ischemic stroke patients. Financial reimbursement differs regionally with compensation for telemedical stroke care in only three federal states.

CONCLUSION

Telemedical stroke care is utilized in about 1 out of 10 stroke patients in Germany. Telemedical stroke networks achieve similar rates of thrombolysis and transfer for thrombectomy compared with neurological stroke units and contribute to stroke care in rural regions. Standardization of network structures, financial assurance and uniform quality measurements may further strengthen the importance of telestroke networks in the future.

Diagnostic Accuracy in Teleneurological Stroke Consultations

Background: The accuracy of diagnosing acute cerebrovascular disease via a teleneurology service and the characteristics of misdiagnosed patients are insufficiently known. Methods: A random sample (n = 1500) of all teleneurological consultations conducted between July 2015 and December 2017 was screened. Teleneurological diagnosis and hospital discharge diagnosis were compared. Diagnoses were then grouped into two main categories: cerebrovascular disease (CVD) and noncerebrovascular disease. Test characteristics were calculated. Results: Out of 1078 consultations, 52% (n = 561) had a final diagnosis of CVD. Patients with CVD could be accurately identified via teleneurological consultation (sensitivity 95.2%, 95% CI 93.2–96.8), but we observed a tendency towards false-positive diagnosis (specificity 77.4%, 95% CI 73.6–80.8). Characteristics of patients with a false-negative CVD diagnosis were similar to those of patients with a true-positive diagnosis, but patients with a false-negative CVD diagnosis had ischemic heart disease less frequently. In retrospect, one patient would have been considered a candidate for intravenous thrombolysis (0.2%). Conclusions: Teleneurological consultations are accurate for identifying patients with CVD, and there is a very low rate of missed candidates for thrombolysis. Apart from a lower prevalence of ischemic heart disease, characteristics of “stroke chameleons” were similar to those of correctly identified CVD patients.

Telestroke consultation can accurately diagnose ischemic stroke mimics

INTRODUCTION

Telestroke (TS) networks are standard in many areas of the US. Despite TS systems having approximately 33% mimic rates, it is unknown if TS can accurately diagnose patients with acute ischemic stroke (AIS) versus stroke mimics.

METHODS

We performed a retrospective review of consecutive TS consults to 27 TS sites in six states during 2018. Clinical information and diagnosis were extracted from discharge records and compared to those from the TS consult. Discharge diagnoses were verified and coded into 12 categories. Cases without a clear discharge diagnosis and intracerebral haemorrhage were excluded. We report agreement and a Cohen's kappa between TS and discharge diagnoses for the category of AIS/transient ischemic attack (TIA) versus stroke mimic.

RESULTS

We included 404 cases in the analysis (mean age 66 years; 54% women). Of these, 225 had a TS diagnosis of AIS/TIA; 102 (45%) received intravenous tissue plasminogen activator. Our study demonstrated a high diagnostic agreement for AIS/TIA (88%) with a kappa of 0.75 for stroke and mimics. Of the 179 patients diagnosed with a stroke mimic on TS, 27 (15%) were diagnosed with AIS/TA by discharge. TS mimic diagnosis had a positive predictive value (PPV) of 85% and a negative predictive value (NPV) of 90%; TS diagnosis of stroke/TIA had PPV 90%, NPV 85%.

DISCUSSION

We found excellent correlation between TS and discharge diagnoses for patients with both stroke and stroke mimics. This suggests that TS systems can accurately assess a wider variety of patients with acute neurologic syndromes other than AIS.

External validation of stroke mimic prediction scales in the emergency department

BACKGROUND

Acute ischemic stroke is a time-sensitive emergency where accurate diagnosis is required promptly. Due to time pressures, stroke mimics who present with similar signs and symptoms as acute ischemic stroke, pose a diagnostic challenge to the emergency physician. With limited access to investigative tools, clinical prediction, tools based only on clinical features, may be useful to identify stroke mimics. We aim to externally validate the performance of 4 stroke mimic prediction scales, and derive a novel decision tree, to improve identification of stroke mimics.

METHODS

We performed a retrospective cross-sectional study at a primary stroke centre, served by a telestroke hub. We included consecutive patients who were administered intravenous thrombolysis for suspected acute ischemic stroke from January 2015 to October 2017. Four stroke mimic prediction tools (FABS, simplified FABS, Telestroke Mimic Score and Khan Score) were rated simultaneously, using only clinical information prior to administration of thrombolysis. The final diagnosis was ascertained by an independent stroke neurologist. Area under receiver operating curve (AUROC) analysis was performed. A classification tree analysis was also conducted using variables which were found to be significant in the univariate analysis.

RESULTS

Telestroke Mimic Score had the highest discrimination for stroke mimics among the 4 scores tested (AUROC = 0.75, 95% CI = 0.63-0.87). However, all 4 scores performed similarly (DeLong p > 0.05). Telestroke Mimic Score had the highest sensitivity (91.3%), while Khan score had the highest specificity (88.2%). All 4 scores had high positive predictive value (88.1 to 97.5%) and low negative predictive values (4.7 to 32.3%). A novel decision tree, using only age, presence of migraine and psychiatric history, had a higher prediction performance (AUROC = 0.80).

CONCLUSION

Four tested stroke mimic prediction scales performed similarly to identify stroke mimics in the emergency setting. A novel decision tree may improve the identification of stroke mimics.

Telemedicine in neurology

Purpose

While there is strong evidence supporting the importance of telemedicine in stroke, its role in other areas of neurology is not as clear. The goal of this review is to provide an overview of evidence-based data on the role of teleneurology in the care of patients with neurologic disorders other than stroke.

Recent findings

Studies across multiple specialties report noninferiority of evaluations by telemedicine compared with traditional, in-person evaluations in terms of patient and caregiver satisfaction. Evidence reports benefits in expediting care, increasing access, reducing cost, and improving diagnostic accuracy and health outcomes. However, many studies are limited, and gaps in knowledge remain.

Summary

Telemedicine use is expanding across the vast array of neurologic disorders. More studies are needed to validate and support its use.

Impact of Statewide Telestroke Network on Acute Stroke Treatment in Hawai'i

Hawai'i faces unique challenges in providing access to subspecialty care, particularly on the islands outside of O'ahu. Telemedicine allows remote treatment of patients with acute ischemic stroke by a neurologist with stroke expertise. The Hawai'i Telestroke Program was implemented in 2012 to connect hospitals with limited neurology coverage to a tertiary stroke center on O'ahu with 24/7 stroke neurology coverage. By 2017, seven hospitals were included in the program. The clinical data and revascularization therapy rate for all telestroke cases between January 2012 and July 2017 were analyzed. Annual telestroke consultations increased from 11 in 2012 to 203 in 2016. Among a total of 490 telestroke consultations, 318 patients (64.9%) were diagnosed with ischemic stroke while the remaining 172 patients had other diagnoses. Revascularization therapies, including intravenous tissue plasminogen activator and mechanical thrombectomy, were provided in 190 patients (38.8%). Using the discharge modified Rankin Scale, 141 (44.3%) patients were functionally independent at the time of hospital discharge, while 162 (50.9%) were disabled or dependent, and 15 (4.7%) died while in the hospital. Of the 490 telestroke consultations, 151 patients (30.8%) were transferred to the hub hospital while 69.2% of patients were able to remain in their local hospital. In summary, development of the Hawai'i Telestroke Program resulted in an increasing number of acute telestroke consultations and revascularization therapies at seven hospitals with limited neurological subspecialty coverage. Utilization of telemedicine in acute stroke treatment is feasible and may help address existing disparities of subspecialty care in Hawai'i.

Migraine as a Stroke Mimic and as a Stroke Chameleon

PURPOSE OF REVIEW

This review details the frequency of and ways in which migraine can be both an ischemic stroke/transient ischemic attack mimic (false positive) and chameleon (false negative). We additionally seek to clarify the complex relationships between migraine and cerebrovascular diseases with regard to diagnostic error.

RECENT FINDINGS

Nearly 2% of all patients evaluated emergently for possible stroke have an ultimate diagnosis of migraine; approximately 18% of all stroke mimic patients treated with intravenous thrombolysis have a final diagnosis of migraine. Though the treatment of a patient with migraine with thrombolytics confers a low risk of complication, symptomatic intracerebral hemorrhage may occur. Three clinical prediction scores with high sensitivity and specificity exist that can aid in the diagnosis of acute cerebral ischemia. Differentiating between migraine aura and transient ischemic attacks remains challenging. On the other hand, migraine is a common incorrect diagnosis initially given to patients with stroke. Among patients discharged from an emergency visit to home with a diagnosis of a non-specific headache disorder, 0.5% were misdiagnosed. Further development of tools to quantify and understand sources of stroke misdiagnosis among patients who present with headache is warranted. Both failure to identify cerebral ischemia among patients with headache and overdiagnosis of ischemia can lead to patient harms. While some tools exist to help with acute diagnostic decision-making, additional strategies to improve diagnostic safety among patients with migraine and/or cerebral ischemia are needed.

Enhancement of Intravenous Thrombolysis by Nationwide Telestroke Care in Slovenia: A Model of Care for Middle-Income Countries

Background: Stroke expertise is critical for timely and appropriate intravenous thrombolysis (IVT) and affects IVT use. Introduction: In Slovenia, IVT is administered in general hospitals, which often lack on-site neurologic expertise. To overcome this obstacle, a national telestroke network, TeleKap, has been implemented. The aim of the study was to determine whether TeleKap is associated with enhanced IVT use. Materials and Methods: This investigation was a retrospective observational study comparing the number of acute ischemic stroke (AIS) patients and the use of IVT during the first 3 consecutive years. TeleKap, a decentralized hub-and-spoke telestroke model covering the entire nation, consists of one comprehensive stroke center and 12 spokes classified according to the availability of on-site neurologic expertise. Results: During the observation period, we treated a total of 1,316 patients with AIS, of which 508 (38.6%) received IVT. We found statistically significant positive trends in the number of IVT patients (142 in 2015, 158 in 2016, and 208 in 2017; B = 4.39, standard error (SE) = 1.59, p = 0.01) and the number of AIS patients (326 in 2015, 424 in 2016, and 566 in 2017; B = 14.42, SE = 5.19, p = 0.01) for all spokes. The trend in the IVT rate was numerically negative but did not reach statistical significance (43.5% in 2015, 37.3% in 2016, and 36.7% in 2017; p = 0.30). Discussion: TeleKap enhanced IVT use regardless of on-site neurologic expertise. Conclusions: TeleKap proved to be efficient. It could serve as a model of telestroke care for other similar countries.

The Accuracy of Large Vessel Occlusion Recognition Scales in Telestroke Setting

Introduction: A significant proportion of acute ischemic stroke (AIS) patients who are evaluated through telestroke consultation are transferred to thrombectomy-capable stroke centers (TSCs) for concern of large vessel occlusion (LVO). Patient triage selection is commonly based on the clinical suspicion of LVO, which lacks specificity and could result in unnecessary transfers. In this study, we aimed to assess the accuracy of the most commonly used LVO recognition scales in telestroke setting. Methods: AIS patients transferred to TSCs for suspicion of an LVO were included in this retrospective study. Patients were evaluated by a stroke neurologist through a telestroke consult before transfer. The National Institute of Health Stroke Scale (NIHSS) score documented by the stroke neurologist was retrieved from medical records and used to calculate five other LVO recognition scales (Rapid Arterial Occlusion Evaluation Scale [RACE], Field Assessment Stroke Triage for Emergency Destination [FAST-ED], Cincinnati Prehospital Stroke Severity Scale [CPSSS], 3-item stroke scale [3I-SS], and Prehospital Acute Stroke Severity Scale [PASS]). We calculated the sensitivity, specificity, accuracy, positive and negative predictive values, false positive rate (FPR), and false negative rate (FNR) of each score using published cutoffs and then examined all possible cutoff values for each of these scales in addition to the NIHSS. Results: A total of 439 patients were included in the final analysis. A total of 48.5% of patients had an LVO confirmed on computed tomography angiogram. RACE score had the highest accuracy (78%). Overall, the five derived LVO recognition scores have at least 10% FNR. When examining all possible cutoff values, the NIHSS (cutoff of 6) had a 3% FNR but 73% FPR (false transfer). Conclusion: The use of the NIHSS and other LVO recognition scores over telestroke may result in unnecessary transfers. Better diagnostic tools that could maximize sensitivity with acceptable specificity are urgently needed.

The 2CAN Score

Background and Purpose—

A quarter of acute strokes occur in patients hospitalized for another reason. A stroke recognition instrument may be useful for non-neurologists to discern strokes from mimics such as seizures or delirium. We aimed to derive and validate a clinical score to distinguish stroke from mimics among inhospital suspected strokes.

Methods—

We reviewed consecutive inpatient stroke alerts in a single academic center from January 9, 2014, to December 7, 2016. Data points, including demographics, stroke risk factors, stroke alert reason, postoperative status, neurological examination, vital signs and laboratory values, and final diagnosis, were collected. Using multivariate logistic regression, we derived a weighted scoring system in the first half of patients (derivation cohort) and validated it in the remaining half of patients (validation cohort) using receiver operating characteristics testing.

Results—

Among 330 subjects, 116 (35.2%) had confirmed stroke, 43 (13.0%) had a neurological mimic (eg, seizure), and 171 (51.8%) had a non-neurological mimic (eg, encephalopathy). Four risk factors independently predicted stroke: clinical deficit score (clinical deficit score 1: 1 point; clinical deficit score ≥2: 3 points), recent cardiac procedure (1 point), history of atrial fibrillation (1 point), and being a new patient (<24 hours from admission: 1 point). The score showed excellent discrimination in the first 165 patients (derivation cohort, area under the curve=0.93) and remaining 165 patients (validation cohort, area under the curve=0.88). A score of ≥2 had 92.2% sensitivity, 69.6% specificity, 62.2% positive predictive value, and 94.3% negative predictive value for identifying stroke.

Conclusions—

The 2CAN score for recognizing inpatient stroke performs well in a single-center study. A future prospective multicenter study would help validate this score.

Evaluation of a score for the prehospital distinction between cerebrovascular disease and stroke mimic patients

Background

Patients with a sudden onset of focal neurological deficits consistent with stroke, who turn out to have alternative conditions, have been labeled stroke mimics.

Aims

We assessed a recently validated telemedicine-based stroke mimic score (TeleStroke mimic score; TM-score) and individual patient characteristics with regard to its discriminative value between cerebrovascular disease and stroke mimic patients in the in-person, pre-hospital setting.

Methods

We evaluated patients cared for in a mobile stroke unit in Berlin, Germany. We investigated whether the TM-score (comprising six parameters), Face Arm Speech Time test, and individual patient characteristics were able to differentiate cerebrovascular disease from stroke mimic patients.

Results

We included 423 patients (299 (70.7%) cerebrovascular disease and 124 (29.3%) stroke mimic) in the final analysis. A TM-score > 30 indicated a high probability of a cerebrovascular disease and a score ≤15 of a stroke mimic. The TM-score performed well to identify stroke mimics (area under the curve of 0.74 under receiver-operating characteristic curve analysis). The cerebrovascular disease patients were older (74.8 vs. 69.8 years, p = 0.001), had more often severe strokes (NIHSS > 14 25.8% vs. 11.3%, p = 0.001), presented more often with weakness of the face (70.9% vs. 42.7%, p = 0.001) or arm (60.9% vs. 33.9%, p = 0.001), dysarthria (59.5% vs. 40.3%, p < 0.001), history of atrial fibrillation (38.1% vs. 21.0%, p = 0.001), arterial hypertension (78.9% vs. 53.2%, p < 0.001), and less often with seizure (0.7% vs. 21.0%, p < 0.001).

Conclusions

The TM-score and certain patient characteristics can help paramedics and emergency physicians in the field to identify stroke mimic patients and select the most appropriate hospital destination.