Objective
Nonconvulsive status epilepticus (NCSE) is misdiagnosed in >50% of cases in the emergency department. Computed tomographic perfusion (CTP) has been implemented in the hyperacute setting to ...detect seizure‐induced hyperperfusion. However, the diagnostic value of CTP is limited by the lack of thresholds for hyperperfusion and high interrater variability. This pilot case–control study aims at identifying the diagnostic value of reverse Tmax (rTmax) in differentiating NCSE from acute ischemic stroke in the hyperacute setting.
Methods
We enrolled patients with NCSE (Salzburg criteria‐based diagnosis) and stroke cases 1:1 matched for clinical features and time of presentation. CTP standard maps (mean transit time MTT–cerebral blood volume–cerebral blood flow CBF) and rTmax maps were elaborated and rated by two experts in CTP blinded to the final diagnosis. Hyperperfusion was adjudicated for standard CTP maps as an increase in CBF and a decrease in MTT, and for rTmax as the presence of a black area on 3‐, 2‐, and 1‐s threshold maps. Cronbach alpha was used for interrater agreement; receiver operating curve analysis was run to measure accuracy with area under the curve.
Results
Overall, 34 patients were included (17 NCSE, 17 stroke; time from onset to imaging = 2 h for both groups). People with NCSE were older and more frequently had a history of epilepsy. NCSE patients had hyperperfusion on rTmax maps in 11 of 17 cases versus zero of 17 in stroke. Intra‐ and interrater reliability was higher for rTmax than for standard CTP maps (κ = 1 vs. κ = .6). rTmax was 82% (95%CI = 67–97%) accurate in predicting NCSE versus stroke in the hyperacute setting. Agreement between neuroimaging and electroencephalography (EEG) was limited at a hemispheric level for standard CTP maps, whereas rTMax had agreement with EEG largely reaching the sublobar level.
Significance
rTmax mapping might represent a reliable tool to spot NCSE‐induced hyperperfusion with a threshold‐based reproducible approach. Further studies are needed for validation and implementation in the differential diagnosis of focal neurological deficit in the hyperacute setting.
Studies on post-stroke seizures have produced conflicting results. Our study aim was to further elucidate the incidence and predictive factors of early post-stroke seizures (ES) and their ...relationship with outcome.
relevant clinical data were prospectively collected in 2,053 patients with acute stroke admitted to the Stroke Unit from 2004 to 2008.
Sixty-six patients (8 hemorrhagic and 58 ischemic strokes) aged 73-88 years (mean age 82 years) presented seizures in the first week after stroke onset. The type of ischemic stroke was atherothrombotic in 10 patients, cardioembolic in 21, lacunar in 4, undetermined in 19, and of other etiology in 4. Twenty-seven patients had generalized convulsive, 6 had complex partial, and 33 had simple partial seizures. Status epilepticus was observed in 13 patients. The severity of strokes in patients with ES was greater than in those without (National Institutes of Health Stroke Scale >14 in 50 vs. 25%), so mortality (30 days) was higher (29 vs. 14%). Independent seizure predictors were: total anterior circulation infarct, hemorrhagic transformation, hyperglycemia, and the interaction term diabetes × hyperglycemia.
ES may be considered a marker of stroke severity. Cortical location of the lesion, hemorrhagic transformation, and hyperglycemia in patients without diabetes are important predictors of ES.
Wavelet transform has emerged over recent years as a favoured tool for the investigation of biomedical signals, which are highly non-stationary by their nature. A relevant wavelet-based approach in ...the analysis of biomedical signals exploits the capability of wavelet transform to separate the signal energy among different frequency bands (i.e., different scales), realizing a good compromise between temporal and frequency resolution. The rationale of this paper is twofold: (i) to present a mathematical formalization of energy calculation from wavelet coefficients, in order to obtain uniformly time distributed atoms of energy across all the scales; (ii) to show two different applications of the wavelet-based energetic approach to biomedical signals. One application concerns the study of epileptic brain electrical activity, with the aim of identifying typical patterns of energy redistribution during the seizure. Results obtained from this method provide interesting indications on the complex spatio-temporal dynamics of the seizure. The other application concerns the electro-oculographic tracings, with the purpose of realizing an automatic detector of a particular type of eye movements (slow eye movements), important to identify sleep phases. The algorithm is able to identify this eye movement pattern efficiently, characterizing it in rigorous energetic terms. The energetic approach built within the framework of the multiresolution decomposition appears as a powerful and versatile tool for the investigation and characterization of transient events in biomedical signals.
Vitamin K antagonists, such as warfarin, used in oral anticoagulation therapy currently represent the standard drugs for the primary and secondary prevention of stroke in non-valvular atrial ...fibrillation (AF), with a relative risk reduction close to 70%. Newer oral anticoagulants, such as direct thrombin inhibitors (i.e., dabigatran) and direct factor Xa inhibitors (i.e., apixaban and rivaroxaban) have been recently compared with warfarin in large randomized trials for stroke prevention in AF. The new oral anticoagulants showed, compared with warfarin, no statistically significant difference in the rate of stroke or systemic embolism in secondary prevention (patients with previous transient ischemic attack or stroke) subgroups. With regard to safety, the risk of intracranial bleeding was reduced with new anticoagulants compared with warfarin. Indirect treatment comparisons of clinical trials on secondary prevention cohorts showed no significant difference in efficacy among apixaban, rivaroxaban, and dabigatran; but dabigatran 110 mg was associated with less intracranial bleedings than rivaroxaban.
BackgroundNon-convulsive status epilepticus (NCSE) is a time-dependent neurological disorder often misdiagnosed in the emergency setting. Electroencephalography (EEG) is often not available on a 24/7 ...basis, and Salzburg criteria may at times miss the diagnosis. Here, we tested the accuracy of hyperperfusion on CT perfusion imaging (CTP) in the identification of NCSE against Salzburg criteria, to define its potential role in a pragmatic diagnostic workflow.MethodsWe enrolled consecutive patients with suspected acute seizure or seizure disorder undergoing brain imaging with CTP and EEG from January 2021 to March 2023. EEG recordings, Salzburg criteria and CTP hyperperfusion were rated and adjudicated by two independent experts blinded to patient status. A reference standard including all clinical, lab, imaging, EEG and therapeutic data was used to adjudicate NCSE diagnosis. Sensitivity, specificity, diagnostic accuracy, positive and negative predictive values (NPV) were calculated for CTP hyperperfusion and Salzburg criteria versus NCSE adjudicated according to reference standard.ResultsSeventy-seven patients were enrolled. Among 21 NCSE cases, 17 were adjudicated according to Salzburg criteria (81%) and 4 received NCSE diagnosis according to reference standard. Agreement between EEG and CTP emerged in 16/21 NCSE cases, reaching sublobar level in 37.5% of cases. Receiver operator curve analysis suggested good accuracy for CTP hyperperfusion for the diagnosis of NCSE (AUROC 0.79, 95% CI 0.69 to 0.89). CTP hyperperfusion had a high NPV for NCSE (NPV 0.97, 95% CI 0.86 to 1).ConclusionCTP hyperperfusion may be implemented in the emergency fast-track to rule out NCSE, given very high NPV. Further validation studies are needed to evaluate CTP application in real-world setting for NCSE codes.
The effect of water activity on the stability of carotenoids in dehydrated carrots was studied.
Freeze-dried carrots from blanched and unblanched batches were placed in air-tight glass jars ...containing saturated salt solutions with water activity ranging from 0.052 to 0.75, at 40
°C. The equilibrium moisture, water activity, α- and β-carotene, and lutein contents were analysed at different storage times.
The Guggenheim–Anderson–de Boer (GAB) equation was applied to model experimental data for moisture content as a function of water activity, and to calculate the monolayer water activity, where the oxidative reactions are expected to be at minimum. Estimated monolayer water activity was 0.33 (confidential limits at 95%: 0.26 and 0.38). α- and β-carotene, and lutein degradation followed pseudo-first-order kinetics in all dehydrated carrots, with rate constants ranging from 0.031 to 0.374 days
−1. Similar rate constants were found between α- and β-carotene, whereas lutein degraded faster.
In both blanched and unblanched batches the rate of carotenoid degradation was at a minimum over the water activity range 0.31–0.54. Blanching resulted in a higher initial carotenoid content, but it accelerated carotenoid decrease during storage of dehydrated carrots.
Watershed infarcts can involve the brainstem, with lesions distributed across the terminal supply from the vertebral and cerebellar arteries. Brain imaging can highlight a comma-shaped lesion at the ...edge of vertebral and posteroinferior cerebellar artery vascularization territory. Such peculiar MRI lesion shape might suggest a watershed hypoperfusion etiology and direct workup towards causes of hemodynamic impairment, including postural hypotension, cardiac failure, or vertebral artery origin occlusion.
BACKGROUND AND PURPOSE—As a reliable scoring system to detect the risk of symptomatic intracerebral hemorrhage after thrombectomy for ischemic stroke is not yet available, we developed a nomogram for ...predicting symptomatic intracerebral hemorrhage in patients with large vessel occlusion in the anterior circulation who received bridging of thrombectomy with intravenous thrombolysis (training set), and to validate the model by using a cohort of patients treated with direct thrombectomy (test set).
METHODS—We conducted a cohort study on prospectively collected data from 3714 patients enrolled in the IER (Italian Registry of Endovascular Stroke Treatment in Acute Stroke). Symptomatic intracerebral hemorrhage was defined as any type of intracerebral hemorrhage with increase of ≥4 National Institutes of Health Stroke Scale score points from baseline ≤24 hours or death. Based on multivariate logistic models, the nomogram was generated. We assessed the discriminative performance by using the area under the receiver operating characteristic curve.
RESULTS—National Institutes of Health Stroke Scale score, onset-to-end procedure time, age, unsuccessful recanalization, and Careggi collateral score composed the IER-SICH nomogram. After removing Careggi collateral score from the first model, a second model including Alberta Stroke Program Early CT Score was developed. The area under the receiver operating characteristic curve of the IER-SICH nomogram was 0.778 in the training set (n=492) and 0.709 in the test set (n=399). The area under the receiver operating characteristic curve of the second model was 0.733 in the training set (n=988) and 0.685 in the test set (n=779).
CONCLUSIONS—The IER-SICH nomogram is the first model developed and validated for predicting symptomatic intracerebral hemorrhage after thrombectomy. It may provide indications on early identification of patients for more or less postprocedural intensive management.
Purpose: To report a new form of reflex epilepsy in which the seizures are repeatedly and exclusively triggered by answering the telephone.
Methods: Three patients with a history of telephone‐induced ...seizures were studied in detail by means of clinical, EEG, and neuroradiologic investigations. Intensive video‐EEG monitoring to record the reflex seizures also was performed in all cases.
Results: The patients (two men, one woman, aged 21 to 30 years) had the onset during early adulthood of complex partial and secondarily generalized seizures exclusively triggered by answering the telephone. The seizures were stereotyped, with subjective auditory or vertiginous auras and inability to speak or understand the spoken voices. In one patient, a telephone‐induced seizure arising from the dominant temporal lobe was recorded by means of video‐EEG technique. In the interictal EEGs, temporal abnormalities were detected in all cases. The patients had a normal neurologic examination and normal magnetic resonance imaging or computed tomography scans.
Conclusions: We suggest that telephone epilepsy is a previously unrecognized form of reflex epilepsy induced by a complex auditory stimulus involving the lateral temporal areas.
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