Biopsy negative giant cell arteritis-Revised diagnostic criteria: Giant cell arteritis diagnostic criteria.

BACKGROUND: Diagnosis of giant cell arteritis has traditionally relied on demonstration of pathologic changes on temporal artery biopsy. METHOD: To highlight recent advances in large vessel imaging resulting in revised diagnostic criteria for giant cell arteritis. CONCLUSION: We call attention to the revised diagnostic criteria imaging evidence of extracranial large vessel thickening as an alternative to temporal artery biopsy in diagnosis of giant cell arteritis in a patient with heralding anterior fornix infarct.

Early Magnetic Resonance Imaging Decreases Hospital Length of Stay in Patients with Ischemic Stroke.

BACKGROUND: Imaging modalities are important part of stroke evaluation. Noncontrast head computed tomography (CT) is the initial imaging modality in acute stroke and although important to rule out acute hemorrhage and making a decision on thrombolytic treatment, ischemic changes may not be visible on CT for up to 24 hours. Magnetic resonance imaging (MRI) brain is an invaluable tool to confirm an ischemic stroke and facilitates stroke evaluation. Objective of this study was to investigate the correlation between time to MRI and length of hospital stay. METHODS: A total of 432 patients admitted to Hartford Hospital (Comprehensive Stroke Center) with a focal neurological deficit in the year 2014 and got a CT head and MRI brain were enrolled in the study. Data collection was done via stroke database and retrospective chart review. Patients with any hemorrhage or age <18 years were excluded from the study. Patients were categorized as having had an early (within 12 hours) or a late (more than 12 hours) MRI. We used chi-square and Wilcoxon ranked sum test to compare time from arrival to MRI and length of stay in the hospital. RESULTS: There was a statistically significant difference in hospital length of stay between patients who obtained MRI within 12 hours, as compared with patients who had MRI greater than 12 hours after admission, early MRI group 3 days (1.8, 4.9) versus 4 days (2.6, 7.0), P < .001. CONCLUSIONS: Our study suggests that brain MRI performed within 12 hours of admission facilitates stroke evaluation and decreases hospital length of stay. It provides evidence for cost effectiveness of MRI in ischemic stroke.

Optic Nerve Enhancement and Restricted Diffusion in Postoperative Visual Loss.

Postoperative visual loss is rare and most often due to posterior ischemic optic neuropathy. We describe optic nerve MR imaging of a 37-year-old man with postoperative visual loss due to posterior ischemic optic neuropathy after complicated aortic aneurysm surgery. MR demonstrated restricted diffusion and focal enhancement of both optic nerves. Combined restricted diffusion and focal enhancement is a unique MR imaging feature with postoperative vision loss.

A syndrome of bilateral symmetrical basal ganglia lesions in diabetic dialysis patients.

A rare syndrome of acute symmetrical bilateral basal ganglia lesions in diabetic dialysis patients that manifests clinically with headache, dysarthria, and gait and movement disorder has been described almost exclusively in patients of Asian descent. The pathophysiology of this condition has not been established. Of the 28 cases reported, 3 patients have been from North America. In the context of magnetic resonance imaging showing dramatic resolution of lesions of the basal ganglia, this report describes a fourth case from North America of a 47-year-old Hispanic woman with diabetes on dialysis therapy who presented with headache, unsteady gait, and slurred speech. We also consider presymptomatic metabolic abnormalities in the pathogenesis of this disease.

MR Imaging Patterns and Prognosis in Powassan Virus Encephalitis.

BACKGROUND: Powassan virus (POWV) encephalitis is an arbovirus infection and the only tick-borne encephalitis serogroup which is present in mainland North America. The magnetic resonance (MR) imaging described with POWV encephalitis is varied, nonspecific, and limited in number, and as such, imaging patterns and outcomes with this arbovirus infection are not well appreciated. METHODS: A case report and literature review of the MR imaging associated with POWV encephalitis and correlate of the MR pattern with outcome is considered. RESULTS: The cerebellar dominant MR imaging pattern was identified in 50% of POWV encephalitis cases and was associated with a 60% fatality rate. POWV encephalitis with prominent cerebellar involvement on MR imaging responded to intravenous steroid. CONCLUSIONS: A cerebellar dominant MR pattern in POWV encephalitis was common, associated with a poor prognosis, and recognition could change management from supportive to life-saving.

Neurological Diagnosis: Artificial Intelligence Compared With Diagnostic Generator.

OBJECTIVE: Artificial intelligence has recently become available for widespread use in medicine, including the interpretation of digitized information, big data for tracking disease trends and patterns, and clinical diagnosis. Comparative studies and expert opinion support the validity of imaging and data analysis, yet similar validation is lacking in clinical diagnosis. Artificial intelligence programs are here compared with a diagnostic generator program in clinical neurology. METHODS: Using 4 nonrandomly selected case records from New England Journal of Medicine clinicopathologic conferences from 2017 to 2022, 2 artificial intelligence programs (ChatGPT-4 and GLASS AI) were compared with a neurological diagnostic generator program (NeurologicDx.com) for diagnostic capability and accuracy and source authentication. RESULTS: Compared with NeurologicDx.com, the 2 AI programs showed results varying with order of key term entry and with repeat querying. The diagnostic generator yielded more differential diagnostic entities, with correct diagnoses in 4 of 4 test cases versus 0 of 4 for ChatGPT-4 and 1 of 4 for GLASS AI, respectively, and with authentication of diagnostic entities compared with the AI programs. CONCLUSIONS: The diagnostic generator NeurologicDx yielded a more robust and reproducible differential diagnostic list with higher diagnostic accuracy and associated authentication compared with artificial intelligence programs.

When a brain lesion necessitates chest CT.

Brain lesions as heralding manifestations of systemic disease can pose a diagnostic problem, particularly when other organ system involvement is not apparent and neuroimaging is nonspecific. Computerized tomography (CT) may identify additional lesion sites. However, when chest roentgenogram is negative chest CT is not routinely considered. A patient is presented in whom chest CT led to lung biopsy and diagnosis of cerebral cryptococcoma when clinical and neuroimaging features were nonspecific, and chest x-ray and serology were negative. We suggest that chest CT is warranted in patients with abnormal brain imaging not typical of a primary brain process, even in the presence of a negative chest x-ray.

MR Three-Territory Sign in Cancer-Associated Hypercoagulation Stroke (Trousseau Syndrome): An Overlooked Diagnostic Feature: MR Three-Territory Sign.

BACKGROUND: Stroke in the setting of three-territory lesion pattern on magnetic resonance-diffusion-weighted imaging "three-territory sign" (TTS) is predominately due to cancer-associated hypercoagulation (CAH). Our goal is to determine the frequency with which "TTS" is overlooked as a diagnostic feature of cancer-associated hypercoagulation stroke. METHODS: Over a 4-year period (October 2016 to October 2020), stroke admissions with magnetic resonance imaging defined three-territory diffusion-weighted imaging lesions were identified. Patients were prospectively accrued in an observational study from the neurology service at Hartford Hospital, a 938 bed facility with a comprehensive stroke center with 2792 stroke admissions during the study period. RESULTS: Twenty-two patients met selection criteria, 4 due to infectious endocarditis, 16 due to stroke from CAH and 2 with no identifiable etiology. Of the 16 CAH patients, 5 were male and 11 female, mean age=72 (range: 47 to 91). Cancer type (biopsy proven unless noted) was cholangiocarcinoma=3, adenocarcinoma of lung=3, adenocarcinoma of breast=1, pancreatic carcinoma=3 (2 biopsy, 1 ultrasound), adenocarcinoma, origin unknown=1, non-small cell carcinoma of lung=2, carcinoid=1, ovarian carcinoma=1, lung mass (not biopsied)=1. Malignancy was known in 7 and occult in 9 at stroke presentation. Consideration of malignancy-related hypercoagulation as the cause of stroke was appreciated in 1 of 16 radiology reports and in 4 of 16 neurology admission notes. CONCLUSION: TTS is a frequently missed diagnostic magnetic resonance feature in cancer-associated hypercoagulation stroke and often heralds occult malignancy.

MR Target Sign in Cerebral Aspergillosis.

Magnetic resonance (MR) is an effective imaging modality in the evaluation of infectious brain disease, yet findings are often nonspecific. The presence of a diagnostic feature can facilitate early treatment, particularly where mortality is high. We highlight MR apparent diffusion coefficient/T2-weighted target sign in the diagnosis of cerebral aspergillosis.

Positron emission tomography in diagnosis of visual variant Alzheimer disease.

A 65-year-old man with a 3-year history of difficulty seeing had normal ophthalmologic and neurologic examinations except for impaired visual spatial and perceptual function. Brain MRI failed to disclose any structural abnormalities, but positron emission tomography (PET) performed 2 weeks later showed prominent hypometabolism in the parieto-occipital regions bilaterally. These findings were considered consistent with the visual variant of Alzheimer disease (VVAD). Although the dissociation between normal structural and abnormal functional imaging has been reported before in VVAD, this patient is a reminder that PET may be useful to confirm the diagnosis before the disease becomes advanced.

Three Territory Sign: An MRI marker of malignancy-related ischemic stroke (Trousseau syndrome).

BACKGROUND: Multiple acute cerebral territory infarcts of undetermined origin are typically attributed to cardioembolism, most frequently atrial fibrillation. However, the importance of 3-territory involvement in association with malignancy is under-recognized. We sought to highlight the "Three Territory Sign" (TTS) (bilateral anterior and posterior circulation acute ischemic diffusion-weighted imaging [DWI] lesions), as a radiographic marker of stroke due to malignancy. METHODS: We conducted a single-center retrospective analysis of patients from January 2014 to January 2016, who suffered an acute ischemic stroke with MRI-DWI at our institution, yielding 64 patients with a known malignancy and 167 patients with atrial fibrillation, excluding patients with both to eliminate bias. All DWI images were reviewed for 3-, 2-, and 1-territory lesions. Chi-square test of proportion was used to test significance between the 2 groups. RESULTS: We found an association between the groups (malignancy vs atrial fibrillation) and the number of territory infarcts (p < 0.0001). Pairwise comparisons using the Holm p value adjustment showed no difference between 1- and 2-territory patterns (p = 0.465). However, the TTS was 6 times more likely observed within the malignancy cohort as compared to patients with atrial fibrillation (23.4% [n = 15] vs 3.5% [n = 6]) and was different from both 1-territory (p < 0.0001) and 2-territory patterns (p = 0.0032). CONCLUSION: The TTS is a highly specific marker and 6 times more frequently observed in malignancy-related ischemic stroke than atrial fibrillation-related ischemic stroke. Evaluation for underlying malignancy in patients with the TTS is reasonable in patients with undetermined etiology.

Neuroimaging in acute posterior cerebral artery infarction.

BACKGROUND: The role of neuroimaging in acute posterior cerebral artery (PCA) territory infarction is less well appreciated compared with the anterior cerebral circulation because PCA infarction occurs less frequently and more often is associated with limited neurologic deficit not qualifying for thrombolytic therapy. On occasion, however, hemiparesis and/or visual field defect accompanies PCA infarction that would warrant thrombolytic therapy. REVIEW SUMMARY: As neuroimaging plays a central role in the diagnosis and treatment of acute stroke in the thrombolytic era, a series of case studies is presented to illustrate the role of computed tomography and magnetic resonance imaging in the setting of acute PCA infarction. CONCLUSION: Familiarity with the neuroimaging features of acute PCA infarction can facilitate management in those select patients that qualify for thrombolytic therapy.

Magnetic resonance correlate of hemiparesis in posterior cerebral artery infarction.

BACKGROUND: Magnetic resonance (MR) imaging of posterior cerebral artery infarction with hemiparesis (PCAH) is limited to case reports with T2-weighted lesions involving the cerebral peduncle. OBJECTIVE: We sought to extend the MR imaging correlate of PCAH. METHODS: The case histories and MR/MR angiography findings of 4 patients with PCAH were examined. RESULTS: Distinct from previously described MR imaging findings with PCAH, diffusion-weighted imaging and/or FLAIR changes were noted in the thalamogeniculate artery (TGA) territory in one patient; in the distribution of the TGA and lateral posterior choroidal artery (PChA) in two patients; and in the TGA and lateral PChA combined with the peduncular perforating arteries of the cerebral peduncle in one patient. CONCLUSION: Diffusion-weighted imaging changes of infarction in the distribution of the TGA alone or combined with lateral PChA involvement with or without cerebral peduncle infarction correlate with PCAH.

A Fatal Case of Undiagnosed Candida Meningitis: Role of Computer-assisted Diagnosis.

Diagnostic error is an increasing health care concern. An intravenous drug abuser with chronic meningitis died after a prolonged hospitalization from fungal meningitis diagnosed at autopsy. We examine the diagnostic pitfalls and consider how a computer-assisted diagnostic system may influence the outcome of an otherwise fatal condition.