Lesions masquerading as acute stroke

Radiologic Findings in a Patient With Mitochondrial Encephalomyopathy With Lactic Acidosis and Stroke-Like Episodes Syndrome: A Case Report

Mitochondrial encephalomyopathy with lactic acidosis and stroke-like episodes (MELAS) syndrome is a rare, genetically inherited mitochondrial disorder that typically manifests in childhood. The most common radiologic features include basal ganglia calcification, atrophy, and stroke-like cortical lesions. We present the case of an 18-year-old female patient with no known medical history who arrived at the emergency department with altered mental status following a suicide attempt. The patient's initial workup, including a computed tomography (CT) scan of the brain, revealed abnormal findings, prompting further investigation into the patient's medical history. It was later discovered that the patient had a previous diagnosis of MELAS syndrome. This diagnosis helped explain both the radiologic abnormalities and her psychiatric symptoms. This case underscores the importance of recognizing radiologic presentations of rare conditions such as MELAS syndrome, which may contribute to the broader spectrum of clinical manifestations associated with the disease.

Beyond the Stroke: A Case Report of Multiple Sclerosis

Multiple sclerosis is an inflammatory, autoimmune demyelinating condition and poses diagnostic challenges due to varied presentations. This case report presents a divergence from typical clinical presentations of multiple sclerosis (MS), as the initial presentation resembled symptoms of a brain stem stroke. Conventionally, MS suspicion arises in the presence of previous neurological deficits or signs of optic neuritis. This case emphasises the need for high suspicion of MS in a suspected stroke or transient ischaemic attack (TIA). A 29-year-old woman presented with symptoms characterised by crossed hemiparesis, reduced coarse touch sensation, and paraesthesia of face and upper limb, which initially mimicked symptoms of a brain stem stroke with a normal CT head. MRI revealed multiple hyperintense lesions indicative of demyelinating disease, likely MS. MRI contrast did not identify active lesions. Further investigations included a vasculitis screen, MOG antibodies, and serum angiotensin-converting enzyme (ACE) levels. Treatment with intravenous methylprednisolone for working diagnosis of clinically isolated syndrome (CIS), a classification subset of MS, resulted in symptomatic improvement. The patient responded well and had a lumbar puncture in neurology follow-up, confirming relapsing and remitting multiple sclerosis (RRMS) and was started on disease-modifying treatment (DMT). Diagnosis of MS relies on McDonald criteria, emphasising dissemination in time and space. Early intervention and familiarity with diagnostic criteria are crucial when dealing with MS. This case highlights the diagnostic complexities of MS and the importance of a comprehensive approach to clinical evaluation. A young patient presenting with progressive symptoms affecting activities of daily living should prompt urgent investigations for early initiation of treatment. Familiarity with diagnostic criteria and treatment options optimises patient care in MS management.

MRI vs CT for Baseline Imaging Evaluation in Acute Large Artery Ischemic Stroke: A Subanalysis of the SWIFT-DIRECT Trial

BACKGROUND AND OBJECTIVES

Whether MRI or CT is preferable for the evaluation of patients with suspected stroke remains a matter of debate, given that the imaging modality acquired at baseline may be a relevant determinant of workflow delays and outcomes with it, in patients with stroke undergoing acute reperfusion therapies.

METHODS

In this post hoc analysis of the SWIFT-DIRECT trial that investigated noninferiority of thrombectomy alone vs IV thrombolysis (IVT) + thrombectomy in patients with an acute ischemic anterior circulation large vessel occlusive stroke eligible to receive IVT within 4.5 hours after last seen well, we tested for a potential interaction between baseline imaging modality (MRI/MR-angiography [MRA] vs CT/CT-angiography [CTA]) and the effect of acute treatment (thrombectomy vs IVT + thrombectomy) on clinical and safety outcomes and procedural metrics (primary analysis). Moreover, we examined the association between baseline imaging modality and these outcomes using regression models adjusted for age, sex, baseline NIH Stroke Scale (NIHSS), occlusion location, and Alberta Stroke Program Early CT Score (ASPECTS) (secondary analysis). Endpoints included workflow times, the modified Rankin scale (mRS) score at 90 days, the rate of successful reperfusion, the odds for early neurologic deterioration within 24 hours, and the risk of symptomatic intracranial hemorrhage. The imaging modality acquired was chosen at the discretion of the treating physicians and commonly reflects center-specific standard procedures.

RESULTS

Four hundred five of 408 patients enrolled in the SWIFT-DIRECT trial were included in this substudy. Two hundred (49.4%) patients underwent MRI/MRA, and 205 (50.6%) underwent CT/CTA. Patients with MRI/MRA had lower NIHSS scores (16 [interquartile range (IQR) 12-20] vs 18 [IQR 14-20], p = 0.012) and lower ASPECTS (8 [IQR 6-9] vs 8 [IQR 7-9], p = 0.021) compared with those with CT/CTA. In terms of the primary analysis, we found no evidence for an interaction between baseline imaging modality and the effect of IVT + thrombectomy vs thrombectomy alone. Regarding the secondary analysis, MRI/MRA acquisition was associated with workflow delays of approximately 20 minutes, higher odds of functional independence at 90 days (adjusted odds ratio [aOR] 1.65, 95% CI 1.07-2.56), and similar mortality rates (aOR 0.73, 95% CI 0.36-1.47) compared with CT/CTA.

DISCUSSION

This post hoc analysis does not suggest treatment effect heterogeneity of IVT + thrombectomy vs thrombectomy alone in large artery stroke patients with different imaging modalities. There was no evidence that functional outcome at 90 days was less favorable following MRI/MRA at baseline compared with CT/CTA, despite significant workflow delays.

TRIAL REGISTRATION INFORMATION

ClinicalTrials.gov Identifier: NCT03192332.

Breaking Stereotypes: A Unique Presentation of New-Onset Multiple Sclerosis

Multiple sclerosis (MS) is a chronic demyelinating disorder resulting in demyelination, neuroaxonal degeneration, and sclerosis. This often-debilitating disease affects young females mainly. Literature describing the pathology and phenotypic features is vast. Although there are extensive descriptions of new-onset MS presentations, few document the initial presentation as a transient ischemic attack or ischemic stroke. The case we present highlights the rarity of such presentation. In the literature, we found scarce reports about MS as presenting as a stroke mimicker with some studies quoting from 2.2% to 4.4% of the cases having MS. Our case serves as a reminder that MS can mimic acute ischemic strokes and the importance of maintaining MS apart of the differential in a young female with no significant history present with acute neurological deficits to reduce the complications of MS and the healthcare-associated costs.

Neuroimaging for differential diagnosis of transient neurological attacks

BACKGROUND

Rapid yet comprehensive neuroimaging protocols are required for patients with suspected acute stroke. However, stroke mimics can account for approximately one in five clinically diagnosed acute ischemic strokes and the rate of thrombolyzed mimics can be as high as 17%. Therefore, to accurately determine the diagnosis and differentiate mimics from true transient ischemic attacks, acute ischemic stroke is a challenge to every clinician.

DISCUSSION

Medical history and neurological examination, noncontract head computed tomography, and routine magnetic resonance imaging play important roles in the assessment and management of patients with transient neurological attacks in the emergency department. This review attempts to summarize how neuroimaging can be utilized to help differentiate the most common mimics from transient ischemic attack and acute ischemic stroke.

CONCLUSION

Although imaging can help direct critical triage decisions for intravenous thrombolysis or endovascular therapy, more detailed medical history and neurological examination are crucial for making a prompt and accurate diagnosis for transient neurological attack patients.

MRI or CT for Suspected Acute Stroke: Association of Admission Image Modality with Acute Recanalization Therapies, Workflow Metrics and Outcomes

Objective

To examine rates of intravenous thrombolysis (IVT), mechanical thrombectomy (MT), door‐to‐needle (DTN) time, door‐to‐puncture (DTP) time, and functional outcome between patients with admission magnetic resonance imaging (MRI) versus computed tomography (CT).

Methods

An observational cohort study of consecutive patients using a target trial design within the nationwide Swiss‐Stroke‐Registry from January 2014 to August 2020 was carried out. Exclusion criteria included MRI contraindications, transferred patients, and unstable or frail patients. Multilevel mixed‐effects logistic regression with multiple imputation was used to calculate adjusted odds ratios with 95% confidence intervals for IVT, MT, DTN, DTP, and good functional outcome (mRS 0–2) at 90 days.

Results

Of the 11,049 patients included (mean [SD] age, 71 [15] years; 4,811 [44%] women; 69% ischemic stroke, 16% transient ischemic attack, 8% stroke mimics, 6% intracranial hemorrhage), 3,741 (34%) received MRI and 7,308 (66%) CT. Patients undergoing MRI had lower National Institutes of Health Stroke Scale (median [interquartile range] 2 [0–6] vs 4 [1–11]), and presented later after symptom onset (150 vs 123 min, p < 0.001). Admission MRI was associated with: lower adjusted odds of IVT (aOR 0.83, 0.73–0.96), but not with MT (aOR 1.11, 0.93–1.34); longer adjusted DTN (+22 min [13–30]), but not with longer DTP times; and higher adjusted odds of favorable outcome (aOR 1.54, 1.30–1.81).

Interpretation

We found an association of MRI with lower rates of IVT and a significant delay in DTN, but not in DTP and rates of MT. Given the delays in workflow metrics, prospective trials are required to show that tissue‐based benefits of baseline MRI compensate for the temporal benefits of CT. ANN NEUROL 2022;92:184–194

Metabolically Active Subacute Infarct Masquerading as Metastasis: A Finding not to be overlooked in Asymptomatic Oncology Patients

A 50-year-old man with carcinoma of the right buccal mucosa underwent staging whole-body 18F-fluorodeoxyglucose positron emission tomography–computed tomography, which revealed a hypermetabolic heterogeneously enhancing lobulated primary lesion in the right buccal region and an incidental finding of subacute stroke. The case highlights the importance of discriminating brain neoplasms mimicking stroke from true ischemic stroke, which is crucial for appropriate management of patients in an oncology setting.

Errors in the Diagnosis of Stroke-Tales of Common Stroke Mimics and Strokes in Hiding

Introduction:

Stroke mimics are some of the common causes of misdiagnosis of stroke, with an attendant surfeit of finances and resources.

Aim:

We attempt to discuss some of the common neurological conditions mimicking stroke in the emergency.

Methods:

We reviewed the articles in English discussing stroke mimics in the last 5 years of publication.

Purpose of the Review:

We discuss the most common causes of stroke mimics encountered in neurological practice. In this short communication, we shall focus on the discussion of the diagnostic pitfalls and clinical clues that will help distinguish mimics from a true stroke.

Clinical presentation, risk factors and outcome of central nervous system metastasis vs stroke in cancer patients

BACKGROUND AND PURPOSE

Cancer and stroke are the second and third causes of death worldwide; brain metastases (BM) occur in one third of patients with cancer, any neurologic deficit in these population always prompts the clinician to discard metastases for their presence carries a bad outcome. Both might share clinical presentation and differences in their outcome are not entirely known. The aim was to compare risk factors, clinical presentation, and outcome of cancer patients with BM vs stroke.

METHODS

A descriptive study with prospectively acquired data from a cancer referral center included patients seen at the neuro-oncologic unit from March 2011 to February 2018 with confirmed cancer who had BM or stroke.

RESULTS

Six hundred and thirteen BM patients were compared with 268 with stroke and cancer. Demographic factors, cancer type, risk factors, clinical presentation, and outcome are presented. Median overall survival in months for those with any stroke was 15 (95%confidence interval [CI] 8.6-21.4)-5 (95%CI 0.12.4) for hemorrhagic stroke and 22 (95%CI 13.4-30.6) in the ischemic group-and for those with BM 12 (95%CI 10.4-13.6). Hemorrhagic stroke commonly found in stroke patients as well as focal motor weakness, aphasia, and altered mental status. BM was more common in breast and lung cancer with headache, visual complaint, and/or vertigo.

CONCLUSION

Survival in cancer patients with BM is not that different than those with stroke, but clinical presentation and risk factors were found different.

Diffuse low-grade glioma mimicking ischaemic infarct: a case report

Diffuse Low-Grade Gliomas (LGGs) include World Health Organization (WHO) grade II diffuse astrocytoma, oligodendroglioma and oligoastrocytoma. Since the neurological symptoms of LGGs are often subtle and deceptive, LGGs are easily overlooked at their early stage. Here, we report a case of a 49-year-old female with symptoms and imaging manifestations mimicking ischaemic infarct. After treatments for ischaemic stroke, the symptoms initially fluctuated and then aggravated. In addition, we found that the locations of the lesions did not match the vascular distribution and no obvious abnormalities were observed by Computed Tomography (CT) angiography and transcranial Doppler. The results from the Magnetic Resonance Spectroscopy (MRS) and from the stereotactic biopsy directed to the final diagnosis of WHO grade II, isocitrate dehydrogenase (IDH)-wild-type diffuse astrocytoma. This is the first reported LGG case with a stroke-like onset. This case illustrates how easy it is to misdiagnose an LGG as a stroke if just using cerebral CT and magnetic resonance imaging. MRS and biopsy can assist with the differential diagnosis process thereby avoiding inappropriate or delayed treatments.

Transient increase of fractional anisotropy in reversible vasogenic edema

Brain vasogenic edema, involving disruption of the blood-brain barrier, is a common pathological condition in several neurological diseases, with a heterogeneous prognosis. It is sometimes reversible, as in posterior reversible encephalopathy syndrome, but often irreversible and our current clinical tools are insufficient to reveal its reversibility. Here, we show that increased fractional anisotropy in magnetic resonance imaging is associated with the reversibility of vasogenic edema. Spontaneously, hypertensive rats-stroke prone demonstrated posterior reversible encephalopathy syndrome-like acute encephalopathy in response to high-dose cyclosporine A treatment; the deteriorating neurological symptoms and worsening scores in behavioral tests, which were seen in acute phase, dissappered after recovery by cessation of cyclosporine A. In the acute phase of encephalopathy, the fractional anisotropy and apparent diffusion coefficient increased in areas with IgG leakage. This increase of fractional anisotropy occurred in the absence of demyelination: fluid leakage into the myelinated space increased the axial, but not the radial, diffusivity, resulting in the increased fractional anisotropy. This increased fractional anisotropy returned to pre-encephalopathy values in the recovery phase. Our results highlight the importance of the fractional anisotropy increase as a marker for the reversibility of brain edema, which can delineate the brain areas for which recovery is possible.

Advanced Neuroimaging in the Evaluation of Spinal Cord Tumors and Tumor Mimics: Diffusion Tensor and Perfusion-Weighted Imaging

Spinal cord tumors are an important component of pathologic diseases involving the spinal cord. Conventional magnetic resonance (MR) imaging only provides anatomical information. MR diffusion tensor imaging (DTI) and MR perfusion-weighted imaging (PWI) may detect microstructure diffusion and hemodynamic changes in these tumors. We review recent application studies of MR DTI and PWI in spinal cord tumors. Overall, MR DTI and MR PWI are promising imaging tools that are especially useful in improving differential diagnosis between spinal cord tumors and tumor mimics, preoperative evaluation of resectability, and providing assistance in surgical navigation.

Magnetic Resonance Imaging in Acute Ischemic Stroke Patients with Mild Symptoms: An Opportunity to Standardize Intravenous Thrombolysis

BACKGROUND

Patients presenting with mild stroke symptoms are excluded inconsistently from intravenous (IV) thrombolysis. We aimed to compare acute magnetic resonance imaging findings in patients with mild symptoms to those with more severe deficits to identify clinically mild patients who might benefit from IV thrombolysis.

METHODS

We retrospectively studied consecutive stroke patients presenting with perfusion deficit who underwent time-of-flight magnetic resonance angiography within 24 hours of time last seen normal. Two raters measured the lesion volumes on diffusion-weighted imaging (DWI) and perfusion-weighted imaging (PWI) with mismatch (MM) calculated as PWI minus DWI. Occlusion site was categorized as "proximal," "distal," or "magnetic resonance angiography-negative" by consensus review. Stroke with mild symptoms was defined as admit National Institutes of Health Stroke Scale score of 4 or less. Values were reported as n (%).

RESULTS

Ninety-one patients were included; 56 (61.5%) with nonmild and 35 (38.5%) with mild symptoms. After stratifying for occlusion site, there were no differences in PWI and MM lesion volumes for the nonmild versus mild patients (P = .34-.98 and P = .54-1, respectively). Furthermore, there was a trend for thrombolyzed mild stroke patients (88%, n = 7 of 8) to more likely have a favorable clinical outcome (discharge modified Rankin score ≤ 2) versus untreated patients (70%, n = 16 of 23).

CONCLUSIONS

When present, conspicuous vessel occlusions in clinically mild stroke patients are concomitant with similar perfusion deficit and MM volumes in more clinically severe stroke patients. Coupled with a trend toward better outcomes in mild stroke patients who were treated with IV tissue plasminogen activator (t-PA), this could indicate that advanced imaging may be used in standardizing the way these patients are selected for IV t-PA therapy.

Imaging Patterns and Management Algorithms in Acute Stroke: An Update for the Emergency Radiologist

Neuroimaging plays a key role in the initial work-up of patients with symptoms of acute stroke. Understanding the advantages and limitations of available CT and MR imaging techniques and how to use them optimally in the emergency setting is crucial for accurately making the diagnosis of acute stroke and for rapidly determining appropriate treatment.

MR screening of candidates for thrombolysis: How to identify stroke mimics?

Stroke mimics account for up to a third of suspected strokes. The main causes are epileptic deficit, migraine aura, hypoglycemia, and functional disorders. Accurate recognition of stroke mimics is important for adequate identification of candidates for thrombolysis. This decreases the number of unnecessary treatments and invasive vascular investigations. Correctly identifying the cause of symptoms also avoids delaying proper care. Therefore, this pictorial review focuses on what the radiologist should know about the most common MRI patterns of stroke mimics in the first hours after onset of symptoms. The issues linked to the accurate diagnosis of stroke mimics in the management of candidates for thrombolysis will be discussed.