Diagnostic accuracy of large and medium vessel occlusions in acute stroke imaging by neurology residents and stroke fellows: A comparison of CT angiography alone and CT angiography with CT perfusion.

INTRODUCTION: Neurology senior residents and stroke fellows are first to clinically assess and interpret imaging studies of patients presenting to the emergency department with acute stroke. The aim of this study was to compare the diagnostic accuracy of brain CT angiography (CTA) with and without CT perfusion (CTP) between neurology senior residents and stroke fellows. METHODS: In this neuroimaging study, nine practitioners (four senior neurology residents (SNRs) and five stroke fellows (SFs)) clinically assessed and interpreted the imaging data of 50 cases (15 normal images, 21 large vessel occlusions (LVOs) and 14 medium vessel occlusions (MeVOs) in two sessions, 1 week apart in comparison to final diagnosis of experienced neuroradiologist and experienced stroke neurologist consensus. Interrater agreement of CTA alone and CTA with CTP was quantified using kappa statistics, sensitivity, specificity and overall accuracy. RESULTS: Overall, arterial occlusions were correctly identified in 221/315 (70.1%) with CTA alone and in 266/315 (84.4%) with CTA and CTP (p < 0.001). The sensitivity of overall arterial occlusions detection with CTA alone was 94.2% (95% CI: 90.8%-96.6%) while with addition of CTP was 98% (95% CI: 95.6%-99.3%), The specificity of CTA alone was 74.7% (95% CI: 67.2%-81.3%) which increased with CTP to 84.4% (95% CI: 77.7%-89.8%). The likelihood of correct identification with CTA alone was 156/189 (82.54%) for LVOs and 65/126 (51.59%) for MeVOs. This increased to 169/189 (89.42%; p = 0.054) for LVOs and 97/126 (76.98%; p < 0.001) for MeVOs when the CTA images with CTP were viewed. There was good overall interrater agreement between readers when using CTA alone (k 0.71, 95% CI, 0.62-0.80) and almost perfect (k 0.85, 95% CI, 0.76-0.94) when CTP was added to the image for interpretation. CTA and CTP had a significantly lower median interquartile range (IQR) interpretation time than CTA alone (114 [IQR, 103-120] s vs 156 [IQR, 133-160] s, p < 0.001). DISCUSSION: In cerebral arterial occlusions, the rate of LVO and MeVOs detections increases when adding CTP to CTA. The accuracy and time for diagnosing arterial occlusion can be significantly improved if CTP is added to CTA. As MeVOs are commonly missed by front-line neurology senior residents or stroke fellows, cases with significant deficits and no apparent arterial occlusions need to be reviewed with neuroradiological expertise.

The Significance of LRDA With Bilateral Involvement Compared With GRDA on EEG in Critically Ill Patients.

PURPOSE: Lateralized rhythmic delta activity (LRDA) is highly associated with seizures but generalized rhythmic delta activity (GRDA; symmetric by definition) has no known seizure association. A subset of LRDA includes patterns that are "bilateral asymmetric LRDA" (LRDA-ba), falling between purely unilateral LRDA and GRDA. The significance of this finding has not been previously addressed. METHODS: Clinical, EEG, and imaging findings were reviewed in all patients with >6 hours of continuous EEG and LRDA-ba between 2014 and 2019. They were compared with a control group of patients with GRDA, matched 1:1 for prevalence, duration, and frequency of the predominant rhythmic pattern. RESULTS: Two hundred fifty-eight patients with LRDA-ba and 258 matched controls with GRDA were identified. Statistically significant findings included that patients with LRDA-ba were more likely to have presented with an ischemic stroke (LRDA-ba 12.4% vs. GRDA 3.9%) or subdural hemorrhage (8.9% vs. 4.3%); those with GRDA were more likely to have a metabolic encephalopathy (GRDA 10.5% vs. LRDA-ba 3.5%) or "altered mental state" without clear etiology (12.5% vs. 4.3%). Patients with LRDA-ba were significantly more likely to have a background EEG asymmetry (LRDA-ba 62.0% vs. GRDA 25.6%) or focal (arrhythmic) slowing (40.3% vs. 15.5%), and acute (65.5% vs. 46.1%) or focal (49.6% vs. 28.3%) abnormalities on computed tomography scan. Patients with LRDA-ba were more likely to have focal sporadic epileptiform discharges (95.4% vs. 37.9%), lateralized periodic discharges (32.2% vs. 5.0%), and focal electrographic seizures (33.3% vs. 11.2%); however, patients with LRDA-ba alone (i.e., without sporadic epileptiform discharges or PDs) showed only a trend toward increased seizures (17.3%) compared with a matched group of patients with GRDA alone (9.9%, P = 0.08). CONCLUSIONS: Patients with LRDA-ba had a higher proportion of acute focal abnormalities compared with a matched group of patients with GRDA. The LRDA-ba was associated with additional evidence of focal cortical excitability on EEG (sporadic epileptiform discharges and lateralized periodic discharges) and seizures but with only a trend toward increased seizures when other signs of focal excitability were absent.

Neuroimaging Correlates of Lateralized Rhythmic Delta Activity, Lateralized Periodic Discharges, and Generalized Rhythmic Delta Activity on EEG in Critically Ill Patients.

PURPOSE: The neuroimaging correlates of lateralized rhythmic delta activity (LRDA) are not well defined, and imaging findings between different epileptiform patterns have seldom been compared directly. METHODS: Patients were retrospectively selected from a critical care EEG database between December 2014 and December 2017. Patients were included if they had greater than 6 hours of continuous EEG that contained LRDA, lateralized periodic discharges LPDs), or generalized rhythmic delta activity (GRDA) and had an MRI within 48 hours of the EEG. Clinical, EEG, and MRI characteristics were collected and compared. RESULTS: All the following results showed statistical significance between the groups: Patients with GRDA were more likely to have a normal MRI (LRDA, 0%; LPDs, 0.8%; GRDA, 17.3%), although the majority were abnormal. In patients with LRDA and LPDs, the MRI abnormalities were much more likely lateralized to one side, whereas in those with GRDA, they were more likely to have bilateral or multifocal abnormalities. Across all groups most abnormalities were acute, although this proportion was higher in patients with LRDA and LPDs compared with that in those with GRDA (LRDA, 91.3%; LPDs, 86.0%; GRDA, 70.4%). An MRI abnormality that was concordant with the side of LRDA was present in 66.3%, with 17.3% having discordant findings. These were similar in patients with LPDs (concordant 67.4%; discordant 11.6%). CONCLUSIONS: Patients with LRDA had a similarly high rate of acute focal abnormalities ipsilateral to the EEG pattern compared with those with LPDs. Patients with GRDA were more likely to have a normal MRI, but the majority of patients with GRDA still had acute focal findings.

Neuromyelitis optica spectrum disorders in Arabian Gulf (NMOAG); establishment and initial characterization of a patient registry.

OBJECTIVE: To describe the clinical and radiological characteristics of neuromyelitis optica spectrum disorders (NMOSD) patients from the Arabian Gulf relative to anti-aquaporin 4 antibody serostatus. METHODS: Retrospective multicentre study of hospital records of patients diagnosed with NMOSD based on 2015 International Panel on NMOSD Diagnosis (IPND) consensus criteria. RESULTS: One hundred forty four patients were evaluated, 64.3% were anti-AQP4 antibody positive. Mean age at onset and disease duration were 31±12 and 7 ±â€¯6 years respectively. Patients were predominantly female (4.7:1). Overall; relapsing course (80%) was more common than monophasic (20%). Optic neuritis was the most frequent presentation (48.6%), regardless of serostatus. The proportion of patients (54.3%) with visual acuity of ≤ 0.1 was higher in the seropositive group (p = 0.018). Primary presenting symptoms of transverse myelitis (TM) were observed in 29% of patients, and were the most significant correlate of hospitalization (p<0.001). Relative to anti-APQ4 serostatus, there were no significant differences in terms of age of onset, course, relapse rates or efficacy outcomes except for oligoclonal bands (OCB), which were more often present in seronegative patients (40% vs.22.5%; p = 0.054). Irrespective of serostatus, several disease modifying therapies were instituted including steroids or immunosuppressives, mostly, rituximab and azathioprine in the cohort irrespective of serostatus. The use of rituximab resulted in reduction in disease activity. CONCLUSION: This is the first descriptive NMOSD cohort in the Arabian Gulf region. Seropositive patients were more prevalent with female predominance. Relapsing course was more common than monophasic. However, anti-AQP4 serostatus did not impact disease duration, relapse rate or therapeutic effectiveness. These findings offer new insights into natural history of NMOSD in patients of the Arabian Gulf and allow comparison with patient populations in different World regions.

Added Value of MRI over CT of the Brain in Intensive Care Unit Patients.

BACKGROUND: Intensive care unit (ICU) patients with neurological impairments often require neuroimaging. However, the relative sensitivity of various imaging modalities of the brain has not yet been explored in this population. METHODS: In this study, we compare the findings of CT and MRI scans in ICU patients to (1) identify the number and rate of clinically relevant lesion detected by MRI while missed by CT and vice versa and (2) determine specific lesion types for which CT versus MRI discrepancies exist. A review of medical records included CT and MRI reports of patients who underwent these procedures while they were patients in our ICUs between July 2004 and July 2009. MRI and CT were compared regarding their ability to detect clinically relevant abnormalities. Odds ratios with 95% confidence limits were calculated to compare diagnostic categories regarding the rate of discrepant MRI versus CT findings, followed by power analyses to estimate sample sizes necessary to allow for further testing in a larger trial. RESULTS: MRI revealed clinically relevant additional abnormalities over CT in 129 of 136 patients (95%) that included the detection of additional finding for 15/27 hemorrhagic lesions (55.6%), 33/36 (92%) ischemic strokes, 19/27 (70%) traumatic lesions, 8/14 (57%) infections, 15/24 (62.5%) metabolic abnormalities, and all seven neoplasms. Odds ratio analysis revealed the added sensitivity of MRI to be greater for ischemic and neoplastic lesions than for trauma, metabolic-related abnormalities, infection, or hemorrhage. CONCLUSIONS: MRI is more sensitive than CT in identifying clinically meaningful lesions in at least a subset of ICU patients, regardless of pathology.

Quantomo: validation of a computer-assisted methodology for the volumetric analysis of intracerebral haemorrhage.

BACKGROUND: Volume measurements of intracerebral haemorrhage are prognostically important and are increasingly used in clinical trials to measure the effects of potential interventions. The purpose of this work is to establish the reliability of haematoma volume measurements obtained using a computer-assisted method called Quantomo (for quantitative tomography) and the ABC/2 method. Hypothesis Quantomo reliably detects smaller changes in intracerebral haemorrhage volume as compared with the ABC/2 method because computer-assisted volume measurements are tailored to measure the geometry of individual haematoma volumes whereas the ABC/2 method approximates all haematoma volumes as ellipsoids. METHODS: Thirty randomly selected computed tomography scans with intracerebral haemorrhage were measured by four raters a total of four times each (two sessions using Quantomo and two using the ABC/2 method). Interrater and intrarater reliability for both techniques were calculated simultaneously using a two-way random-effects analysis of variance model. The precision of intracerebral haemorrhage volume measurement was quantified as the minimum detectable difference with 95% confidence intervals. RESULTS: The median (first quartile and third quartile) intracerebral haemorrhage volume measurements of all rater and sessions for Quantomo were 32.7 ml (6.2 and 54.4 ml) and for ABC/2 40.7 ml (8.6 and 76.0 ml). Quantomo intracerebral haemorrhage volume measurements were more precise, having an inter- and intrarater minimum detectable difference of 8.1 and 5.3 ml, while the inter- and intrarater minimum detectable difference for ABC/2 were 37.0 and 15.7 ml. CONCLUSIONS: Quantomo is a computer-assisted methodology that is more reliable for quantifying intracerebral haemorrhage volume as compared with the ABC/2 method.