Clinical Mimics: An Emergency Medicine-Focused Review of Stroke Mimics

A case of spinal epidural lipomatosis presenting as a stroke mimic

Here we present the case of a patient with right upper extremity and right lower extremity weakness of a three-day duration, which triggered a stroke evaluation. Ultimately, the diagnosis of spinal epidural lipomatosis (SEL) was made. Non-stroke diagnoses that present with stroke-like symptoms are referred to in the medical literature as stroke mimics. Such cases present with neurological deficits that imitate acute ischemic stroke. The frequency of such presentations occurs in up to 30% of initially suspected stroke. This case illustrates that SEL can present as a stroke mimic. To our knowledge, this is the first description of a presentation in the medical literature of SEL as a stroke mimic.

Diagnostic value of whole-brain computed tomographic perfusion imaging for suspected large artery occlusion stroke patients in emergency department

PURPOSE

To evaluate the diagnostic value of whole-brain computed tomographic perfusion (WB-CTP) in emergency department for suspected large artery occlusion stroke.

METHODS

Suspected large artery occlusion (LAO) stroke patients had initial WB-CTP in the neurological emergency department from August 2016 to August 2018 were retrospectively reviewed for analysis. The sensitivity and specificity of non-contrast computed tomographic scan (NCCT) or WB-CTP for diagnosis of cerebral infarction was compared between the anterior circulation and posterior circulation. The imaging characteristics of WB-CTP in patients with stroke-mimics were described.

RESULTS

Among the 300 included patients, 259 patients (86.3%) were finally diagnosed as cerebral infarction, 16 (5.3%) were transient ischemic attack, 10 (3.3%) were epileptic seizure and 3 (1%) were cerebral venous sinus thrombosis (CVST). For patients with final diagnosis of cerebral infarction, WB-CTP found abnormality in 206 cases (79.5%). NCCT had poor sensitivity (4.6%) but high specificity (100%) for cerebral infarction. The CTP imaging had a sensitivity of 81.2% in anterior circulation and 59.6% in posterior circulation stroke, both with good specificity (57.1% and 92.6%, respectively). 60% (6/10) of epileptic patients showed abnormal perfusion in CTP maps, which was inconsistent with cerebral arterial supply territories. Hypoperfusion manifestations were discovered in areas adjacent to occlusion sinus of all 3 CVST cases.

CONCLUSION

This retrospective study indicates WB-CTP can be useful in identifying acute ischemic stroke in emergency department, especially for patients with acute LAO stroke. Moreover, WB-CTP may have a value in differentiating stroke mimics such as epilepsy and CVST.

Clinical Differences Between Stroke and Stroke Mimics in Code Stroke Patients

BACKGROUND

The code stroke system is designed to identify stroke patients who may benefit from reperfusion therapy. It is essential for emergency physicians to rapidly distinguish true strokes from stroke mimics to activate code stroke. This study aimed to investigate the clinical and neurological characteristics that can be used to differentiate between stroke and stroke mimics in the emergency department (ED).

METHODS

We conducted a retrospective observational study of code stroke patients in the ED from January to December 2019. The baseline characteristics and the clinical and neurological features of stroke mimics were compared with those of strokes.

RESULTS

A total of 409 code stroke patients presented to the ED, and 125 (31%) were diagnosed with stroke mimics. The common stroke mimics were seizures (21.7%), drug toxicity (12.0%), metabolic disorders (11.2%), brain tumors (8.8%), and peripheral vertigo (7.2%). The independent predictors of stroke mimics were psychiatric disorders, dizziness, altered mental status, and seizure-like movements, while current smoking, elevated systolic blood pressure, atrial fibrillation on the initial electrocardiogram, hemiparesis as a symptom, and facial palsy as a sign suggested a stroke. In addition, the likelihood of a stroke in code stroke patients tended to increase as the number of accompanying deficits increased from the following set of seven focal neurological deficits: hemiparesis (or upper limb monoparesis), unilateral limb sensory change, facial palsy, dysarthria, aphasia (or neglect), visual field defect, and oculomotor disorder (P < 0.001).

CONCLUSION

Some clinical and neurological characteristics have been identified to help differentiate stroke mimics from true stroke. In particular, the likelihood of stroke tended to increase as the number of accompanying focal neurological deficits increased.

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.

MRI as a first-line imaging modality in acute ischemic stroke: a sustainable concept

Background:

Computed tomography (CT) scans are the first-line imaging technique in acute stroke patients based on the argument of rapid feasibility. Using magnetic resonance imaging (MRI) as the first-line imaging technique is the exception to the rule, although it provides much more diagnostic information and avoids exposure to radiation. We evaluated whether an MRI-based acute stroke concept is fast, suitable, and useful to improve recanalization rates and patient outcomes.

Methods:

We performed a retrospective observational cohort study comparing patients treated at a comprehensive stroke center (Ulm/Germany) applying an MRI-based acute stroke concept with patients recorded in a large comprehensive stroke registry in Baden-Württemberg (Germany). We analyzed the quality indicators of acute stroke treatment, patient’s outcome, and the rate of transient ischemic attack (TIA) at discharge.

Results:

A total of 2182 patients from Ulm and 82,760 patients from the Baden-Württemberg (BW) stroke registry (including 29,575 patients of comprehensive stroke centers (BWc)) were included. Intravenous thrombolysis rate was higher in Ulm than in BW or the BWc stroke centers (Ulm 27.4% versus BW 20.9% versus BWc 26.1; p < 0.01), while a door-to-needle time <30 min could be achieved more frequently (Ulm 73.6% versus BW 44.1% versus BWc 47.1%; p < 0.01). Thrombectomy rate in patients with a proximal vascular occlusion was higher (Ulm 69.2% versus BW 50.7% versus BWc 59.3; p < 0.01). The number of TIA diagnoses was lower (Ulm 16.2% versus BW 24.6% versus BWc 19.9%; p < 0.01). More patients showed a shift to a favorable outcome (Ulm 21.1% versus BW 16.9% versus BWc 15.3; p < 0.01). Complication rates were similar.

Conclusions:

The MRI-based acute stroke concept is suitable, fast and seems to be beneficial. The time-dependent quality indicators were better both in comparison to all stroke units and to the comprehensive stroke units in the area. Based on the MRI concept, high rates of recanalization procedures and fewer TIA diagnoses could be observed. In addition, there was a clear trend towards an improved clinical outcome. A clinical trial comparing the effects of CT and MRI as the primary imaging technique in otherwise identical stroke unit settings is warranted.

Multimodality Imaging in Acute Ischemic Stroke

Stroke is the most common cause of mortality and morbidity worldwide. The prognosis of stroke depends upon the area affected and its early treatment. Time is of the essence in the care of stroke patients as it is estimated that approximately 1.9 million neurons, 14 billion synapses, and 12 km myelinated nerve fibers are lost per minute. Therefore, early diagnosis and prompt treatment are necessary. The primary goal of imaging in acute stroke is to diagnose the underlying cause, estimate the area affected, predict response towards thrombolytic therapy and to exclude the conditions mimicking stroke. With advancements in radiology, multiple imaging modalities are available for diagnosis and predicting prognosis. None of them is considered alone to be perfect. In this era of multimodality imaging, the decision of choosing appropriate techniques depends upon purpose and availability. Non-Contrast Computed Tomography is time effective, and helps in excluding other causes, Trans Cranial Doppler is time-effective and cost-effective with wide availability, however, is operator dependent and less sensitive. It holds a great future in sonothrombolysis. Magnetic Resonance Imaging is so far considered to be the most superior one in terms of early diagnosis, planning for interventional treatment and predicting the response of treatment. However, it is limited due to high cost and lack of availability. The current review gives a detailed account of all imaging modalities available for imaging stroke and their associated pros and cons.

[Effects of the prehospital care with and without suspecting acute stroke: a single stroke center study]

We retrospectively examined the differences between paramedic triage and final diagnosis in the cases that were transported to our hospital between May 2016 and March 2019. About 30% of the patients with suspected stroke were diagnosed other than stroke. Some of the patients without suspected stroke were diagnosed with large vessel occlusion and were treated with mechanical thrombectomy. The time from arrival at the hospital to treatment was significantly longer in the patients without suspected stroke than with suspected stroke. To achieve a better prehospital care, we need to accept a wide range of stroke mimics, and to continuously feedback the paramedics about the importance of paralysis, cortical symptoms in stroke.

Types of occult cancer in stroke and the relation to smoking

OBJECTIVES

Stroke is associated with a higher risk of occult cancer. We studied the types of occult cancer most often associated with stroke.

MATERIALS AND METHODS

All patients with incident stroke in Denmark 2003-2015 were identified through the Danish Stroke Registry (n = 85 893) and matched 1:10 on age and sex to the Danish background population without history of stroke (n = 858 740). Linking data to the Danish Cancer Registry, we determined the prevalence of occult cancer in stroke defined as the event of previously unknown cancer during a one-year follow-up in the stroke and the background population. We stratified cancers into the 15 most common cancers and into cancers related to and not related to smoking.

RESULTS

Prevalence (per 1000 person-years; stroke/background population) of smoking-related occult cancers (lung, colon, bladder rectum, pancreas, kidney, stomach, and head and neck) was 13.3/8.1 (P < .01) and of cancers not related to smoking (prostate, breast, melanoma, non-Hodgkin lymphoma, ovary, endometrial) it was 6.6/6.2 (P > .05). Among men with stroke prostate (5.8), lung (5.7), and colon cancers (2.9) were most frequent; among women, it was lung (4.7), breast(3.5), and colon cancer(2.8). Among men in the background population, prostate(5.4), lung (3.0), and colon cancers (2.1) were most frequent. Among women, it was breast (3.7), lung(2.1), and colon cancers (1.9).

CONCLUSION

Stroke patients' increased risk of occult cancer was predominantly for smoking-related cancers while there was no higher risk for the most frequent cancers unrelated to smoking, that is, prostate and breast cancers. Lung cancer is the dominant type of occult cancer in stroke.

Occult primary brain cancers manifesting in the aftermath of ischaemic and haemorrhagic stroke

Introduction

Symptoms of occult brain cancer may mimic stroke. Misdiagnosis may lead to improper treatment and delayed diagnosis. We characterised strokes associated with occult primary brain cancer and determined risk that ischaemic and haemorrhagic strokes are associated with occult primary brain cancer.

Patients and methods

All patients with incident stroke in Denmark 2003-2015 were identified through the Danish Stroke Registry (n = 85,893) and matched 1:10 on age and sex to the Danish background population without a stroke history (n = 858,740). This cohort was linked to the Danish Cancer Registry and prevalence of occult primary brain cancer defined as the event of previously unknown primary brain cancer during a one-year follow-up was estimated. We used Cox regression models to study risk of occult primary brain cancer in comparison to the background population.

Results

Of 77,484 patients with ischaemic strokes, 39 (1 in 2000) were associated with primary brain cancer; of 8409 with haemorrhagic strokes, it was 126 (1 in 66). In the background cohort, 205 (1 in 4000) had occult primary brain cancer. The multivariate stroke risk factor analysis showed that patients with occult primary brain cancer differed significantly from those without occult primary brain cancer indicating they might have stroke mimics rather than true strokes.Discussion and conclusions: Strokes associated with occult primary brain cancer tend to be stroke mimics rather than true strokes. Primary brain cancer is rare in patients with ischaemic stroke (1 in 2000); risk that misdiagnosis results in maltreatment is, therefore, very low. Occult primary brain cancers are mainly found among patients with haemorrhagic stroke; they are not uncommon (1 in 66) and should always be kept in mind.

A Helpful Tool in Diagnosing Stroke Mimics: Arterial Spin Labeled Perfusion Magnetic Resonance Imaging

BACKGROUND

Prompt and effective management of acute ischemic stroke in the emergency setting requires a high level of suspicion and accurate diagnosis. Conversely, identifying stroke mimics can be challenging, given the similarity of their clinical symptomatology, the necessary rapid assessment and triage, and the overall frenetic pace inherent in the goal of rapid thrombolysis ("time is brain").

CASE REPORT

We describe a case that involves an elderly patient with acute hemiplegia and dysarthria. Given these concerning symptoms, and multiple preexisting cerebrovascular risk factors (including paroxysmal atrial fibrillation), a "stroke alert" was issued. Imaging was negative for infarct and she was ultimately diagnosed with hemiplegic migraine based on her symptoms and impressive findings on a novel magnetic resonance sequence called arterial spin labeled (ASL) perfusion. WHY SHOULD AN EMERGENCY PHYSICIAN BE AWARE OF THIS?: Identifying a nonischemic etiology in a presumed stroke patient, while often difficult, can obviate unnecessary treatment, improve patient care, and promote appropriate resource allocation. As imaging and treatment of cerebrovascular disease advances, the optimization of multidisciplinary care should incorporate neuroradiologists informing and availing their clinical colleagues of applications of an ever-expanding imaging armamentarium. This case is an excellent example of both a common challenging stroke mimic and the potential benefits of ASL perfusion imaging in refining and expediting accurate diagnosis. In addition, it serves as a more general introduction to the particular strengths of this noninvasive, noncontrast magnetic resonance technique, which can be employed to assess varied emergent neuropathology.

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.

Crossed cerebellar hyperperfusion in patients with seizure-related cerebral cortical lesions: an evaluation with arterial spin labelling perfusion MR imaging

PURPOSE

Crossed cerebellar (CC) diaschisis refers to a decrease in cerebellar perfusion in the presence of contralateral supratentorial lesions. Most of the previous studies have examined stroke patients. In contrast to strokes, seizure-related cerebral cortical lesions (SCCLs) usually show hyperperfusion, and therefore, cerebellar perfusion patterns are expected to be different from those of strokes. With arterial spin labelling (ASL), we evaluated the cerebellar perfusion status in patients with SCCLs.

MATERIALS AND METHODS

Using a search of the recent database over the last 31 months, 26 patients were enrolled in this study. The inclusion criteria were as follows: (1) a history of seizures, (2) MR examination taken within 24 h from the last seizure, (3) the presence of SCCLs on T2/FLAIR or DWI, (4) hyperperfusion in the corresponding areas of SCCLs on ASL, and (5) no structural abnormality in the cerebellum. The perfusion status in the contralateral cerebellum was evaluated and categorized as hyper-, iso- and hypoperfusion. The asymmetric index (AI) of cerebellar perfusion was calculated by ROI measurement of the signal intensity on ASL.

RESULTS

The mean time between the last seizure and MR examinations was 5 h 30 min. CC hyperperfusion was observed in 17 patients (65.4%), hypoperfusion in 7 (26.9%) and isoperfusion in 2 (7.7%). Regarding the location of SCCLs, CC hyperperfusion was more frequent (71.4 vs. 58.3%), and the mean AI was higher (42.0 vs. 11.5) when the lesion involved the frontal lobe.

CONCLUSIONS

In patients with SCCLs, CC hyperperfusion occurred more often than hypo- and isoperfusion, especially when the lesions involved the frontal lobe.

When migraine mimics stroke: A systematic review

BACKGROUND

Migraine with aura may mimic an acute ischemic stroke, so that an improper administration of thrombolytic treatment can expose migrainous patients to severe adverse effects.

METHODS

This systematic review quantifies the relevance of migraine with aura among stroke mimics, checking for thrombolysis' safety in these patients. We reviewed the literature after 1995, distinguishing from studies dealing with stroke mimics treated with systemic thrombolysis and those who were not treated with systemic thrombolysis.

RESULTS

Migraine with aura is responsible for 1.79% (CI 95% 0.82-3.79%) of all the emergency Stroke Unit evaluations and it represents 12.24% (CI 95% 6.34-22.31%) of stroke mimics in the group not treated with systemic thrombolysis. 6.65% (CI 95% 4.32-9.78%) of systemic thrombolysis administrations are performed in patients without an acute ischemic stroke. Migraine with aura is responsible for 17.91% of these (CI 95% 13.29-23.71%). The reported rate of adverse events seems extremely low (0.01%).

CONCLUSION

Migraine with aura is the third most common stroke mimic, following seizures and psychiatric disorders; it is responsible for about 18% of all improper thrombolytic treatments. Despite the absence of strong supporting data, thrombolysis in migraine with aura seems to be a procedure with an extremely low risk of adverse events.

Interdisciplinary approach to compensation of hypoglycemia in diabetic patients with chronic heart failure

Diabetes mellitus is a chronic disease requiring lifelong control with hypoglycemic agents that must demonstrate excellent efficacy and safety profiles. In patients taking glucose-lowering drugs, hypoglycemia is a common cause of death associated with arrhythmias, increased thrombus formation, and specific effects of catecholamines due to sympathoadrenal activation. Focus is now shifting from merely glycemic control to multifactorial approach. In the context of individual drugs and classes, this article reviews interdisciplinary strategies evaluating metabolic effects of drugs for treatment of chronic heart failure (CHF) which can mask characteristic hypoglycemia symptoms. Hypoglycemia unawareness and cardiac autonomic neuropathy are discussed. Data suggesting that hypoglycemia modulates immune response are reviewed. The potential role of gut microbiota in improving health of patients with diabetes and CHF is emphasized. Reports stating that nondiabetic CHF patients can have life-threatening hypoglycemia associated with imbalance of thyroid hormones are discussed. Regular glycemic control based on HbA1c measurements and adequate pharmacotherapy remain the priorities in diabetes management. New antihyperglycemic drugs with safer profiles should be preferred in vulnerable CHF patients. Multidrug interactions must be considered. Emerging therapies with reduced hypoglycemia risk, telemedicine, sensor technologies, and genetic testing predicting hypoglycemia risk may help solving the challenges of hypoglycemia in CHF patients with diabetes. Interdisciplinary work may involve cardiologists, diabetologists/endocrinologists, immunologists, gastroenterologists, microbiologists, nutritionists, imaging specialists, geneticists, telemedicine experts, and other relevant specialists. This review emphasizes that systematic knowledge on pathophysiology of hypoglycemia in diabetic patients with CHF is largely lacking and the gaps in our understanding require further discoveries.

Stroke Chameleons and Stroke Mimics in the Emergency Department

PURPOSE OF REVIEW

We discuss the frequency of stroke misdiagnosis in the emergency department (ED), identify common diagnostic pitfalls, describe strategies to reduce diagnostic error, and detail ongoing research.

RECENT FINDINGS

The National Academy of Medicine has re-defined and highlighted the importance of diagnostic errors for patient safety. Recent rates of stroke under-diagnosis (false-negative cases, "stroke chameleons") range from 2-26% and 30-43% for stroke over-diagnosis (false-positive cases, "stroke mimics"). Failure to diagnosis stroke can preclude time-sensitive treatments and has been associated with poor outcomes. Strategies have been developed to improve detection of posterior circulation stroke syndromes, but ongoing work is needed to reduce under-diagnosis in other atypical stroke presentations. The published rates of harm associated with stroke over-diagnosis, particularly thrombolysis of stroke mimics, remain low. Additional strategies to improve the accuracy of stroke diagnosis should focus on rapid clinical reasoning in the time-sensitive setting of acute ischemic stroke and identifying imperfections in the healthcare system which may contribute to diagnostic error.

PreHospital Ambulance Stroke Test - pilot study of a novel stroke test

Background

There is a need for a prehospital stroke test that in addition to high sensitivity for stroke, also is able to communicate stroke severity similar to the National Institute of Health Stroke Scale (NIHSS).

Methods

The PreHospital Ambulance Stroke Test (PreHAST), an eight item test based on NIHSS, which scores stroke severity from 0–19 points, was designed and adapted for the ambulance services. In the pilot study the ambulance nurses used PreHAST to assess patients with suspected stroke in the prehospital setting. Regardless of the results after PreHAST testing the patients were triaged with a provisional stroke diagnosis. The PreHAST scores were compared with the final diagnosis and the ability to differentiate stroke and transient ischemic attacks (TIA) with ongoing symptoms at evaluation from non-stroke patients was analysed.

Results

69 patients were included in the study, 26 had stroke/TIA and 43 other diagnoses. All stroke/TIA patients were identified by PreHAST (sensitivity 100% (95% CI; 87-100%)). The specificity increased with higher PreHAST scores and the discriminative capacity for PreHAST for different cut off values showed an area under the curve of 0.77 (95%CI; 0.66-0.88) in the receiver operating characteristic (ROC) analysis.

Discussion

PreHAST is designed for high sensitivity, screening for a broad range of stroke symptoms including most key components of NIHSS. The promising sensitivity between 87 and 100% in our study has to be confirmed in a larger study also including multiple centres. Higher PreHAST scores implied more typical patterns of stroke and accordingly the proportion of stroke mimics decrease with higher scores. However, also stroke mimics with epilepsy/seizure and patients with deficit after prior stroke could show higher PreHAST scores. Other prehospital stroke tests that evaluate stroke severity have been designed with the main purpose to screen for large vessel occlusion. The advantage of PreHAST is the dual purpose not only to evaluate stroke severity but also to screen for stroke in general.

Conclusions

PreHAST is a new screening test of stroke adapted for ambulance services that in addition to high sensitivity for stroke, provides a grading system with increasing specificity with higher scores.