The electroclinical-imagiological spectrum and long-term outcome of transient periictal MRI abnormalities

Canas, Nuno; Breia, Paula; Soares, Pedro; Saraiva, Paulo; Calado, Sofia; Jordão, Constança; Vale, José

doi:10.1016/j.eplepsyres.2010.07.019

Cited by 49 publications

(87 citation statements)

References 34 publications

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“…Regarding the differential diagnosis, type I and IIa can mimic encephalitis, type IIb an intracerebral neoplasm and type V, due to the leptomeningeal involvement, meningoencephalitis; type IV can mimic several pathologies and in type V the ictal onset may have a poor localizing value (Raghavendra et al, 2007). Our classification has several similarities to the classification proposed by Raghavendra and colleagues (Raghavendra et al, 2007), although we did not find any TPMA restricted to the subcortical white matter (Canas et al, 2010b Topographically, the great majority of type 1, type 2A and 2B TPMA are focal and unilateral, while most type 2C are larger (hemispheric, lobar, multilobar) and/ or bilateral. Tumor-like TPMA are frequently disclosed in patients with presenting seizures without a known etiology and generally are associated with a good outcome (Canas et al, 2010a); conversely, type 2C generally occur in patients with a previous history of epilepsy, and are associated with a high percentage of clinical and MRI sequelae (Canas et al, 2010b).…”

Section: Classificationsupporting

confidence: 46%

“…After that, two comprehensive classification systems to cover the broad spectrum of changes that comprise TPMA were proposed by us (Canas et al, 2010b) and other authors (Raghavendra et al, 2007). These two classifications are based mostly on TPMA patterns and signal abnormalities, facilitating their recognition by Neurologist and Neuroradiologists, and helping in their differential diagnosis.…”

Section: Classificationmentioning

confidence: 99%

“…Although they can arise anywhere in the cerebral neocortex, they are commonly disclosed in the posterior and perirolandic regions or in the periphery of old encephaloclastic lesions (Silverstein & Alexander, 1998;Canas et al, 2010b). Less frequently they have a marked subcortical component, with mass effect and gyral effacement, mimicking an intracerebral neoplasm (Canas et al, 2010a;Cohen-Gadol et al, 2004;Hicdonmez et al, 2003); are more diffuse or bilateral; or are associated with remote signal abnormalities, affecting structures anatomically distant from the neocortical seizure focus, including the contralateral cerebellar hemisphere (cerebellar diaschisis), thalamus (more frequently the pulvinar), splenium of the corpus callosum, caudate and globus pallidus (Cole, 2004).…”

Section: Topography and Patternsmentioning

confidence: 99%

“…DWI is the most sensitive MRI-sequence in detecting TPMA (restriction to water diffusion present in more than 90% of the cases), being frequently the only reliable signal abnormality in small TPMAs restricted to the cerebral cortex or in TPMAs bordering old encephaloclastic lesions (Canas et al, 2010b). In the cases in which attenuation diffusion coefficient (ADC) studies were obtained, some authors reported an increased DWI signal with decreased diffusivity, compatible with cytotoxic edema (Chu et al, 2001;Parmar et al, 2006;Szabo et al, 2005), and others a decreased DWI signal with increased diffusivity, disclosing vasogenic edema (Hong et al, 2004;Wieshmann et al, 1997); other authors, including ourselves, described diverse findings in the TPMA ADC studies, with some patients showing a predominantly cytotoxic or vasogenic edema, while others having intermixed areas of both types of edema, mainly cortical cytotoxic edema and subcortical vasogenic edema (Canas et al, 2010a(Canas et al, , 2010bKim et al, 2001). The timing of MRI acquisition has been proposed by some authors as one of the factors that could contribute to these apparently non-congruent findings regarding the TPMA ADC signal abnormalities (Briellmann et al, 2005;Hong et al, 2004).…”

Section: Signal Abnormalitiesmentioning

confidence: 99%

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MRI Abnormalities Induced by Seizures

Canas¹,

Soares²

2012

Neuroimaging - Clinical Applications

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Section: Classificationsupporting

confidence: 46%

Section: Classificationmentioning

confidence: 99%

Section: Topography and Patternsmentioning

confidence: 99%

Section: Signal Abnormalitiesmentioning

confidence: 99%

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MRI Abnormalities Induced by Seizures

Canas¹,

Soares²

2012

Neuroimaging - Clinical Applications

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“…Could MRI changes be attributed to other factors than tumor progression ? Transient MRI signal changes are reported in the context of intense seizure activity, both in children (Yang, Kim et al 2002) and adults, even mimicking tumor (Finn, Blumenthal et al 2007; (Canas, Breia et al 2010). Changes in tumor volume appearance has been occasionnaly associated with the use of vigabatrin in a 5-year-old female after resection of an anaplastic oligodendroglioma, with a reversal of MRI changes observed after discontinuation of the drug (Yang, Pruthi et al).…”

Section: -3 Could Time Of Surgery Influence Epilepsy Outcome ?mentioning

confidence: 99%

Brain tumor epilepsy: A reappraisal and six remaining issues to be debated

Vercueil

2011

Revue Neurologique

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Epilepsy associated with brain tumors presents with specific features deserving medical attention : 1) although commonly reported in patients with brain tumor, either as revealing mode or as a remote complication, limited knowledge is available regarding their epidemiology, clinical evolution, surgical outcome, physiopathology and treatment, providing only clues for clinical management. 2) seizures appear even more threatening for patients and care-givers, providing seizures could meant tumor progression and recurrence. This factor adds to the negative impact epilepsy carry on quality of life measures. 3) pharmacotherapy is complicated by the use of chemotherapy and interaction between antiepileptic drugs and antineoplastic agents are frequent and potentially harmful. 4) the high incidence of epilepsy enlights the question of prophylaxy with antiepileptic drugs, in patients without seizures, or during the perioperative period, and after surgery, when gross total resection has been achieved. This article attempts to provide the reader with an overview of brain tumor epilepsy in its specific aspects and to comment on some remaining issues.

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Electroencephalographic Periodic Discharges and Frequency-Dependent Brain Tissue Hypoxia in Acute Brain Injury

et al. 2017

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IMPORTANCE Periodic discharges (PDs) that do not meet seizure criteria, also termed the ictal interictal continuum, are pervasive on electroencephalographic (EEG) recordings after acute brain injury. However, their association with brain homeostasis and the need for clinical intervention remain unknown.OBJECTIVE To determine whether distinct PD patterns can be identified that, similar to electrographic seizures, cause brain tissue hypoxia, a measure of ongoing brain injury. DESIGN, SETTING, AND PARTICIPANTSThis prospective cohort study included 90 comatose patients with high-grade spontaneous subarachnoid hemorrhage who underwent continuous surface (scalp) EEG (sEEG) recording and multimodality monitoring, including invasive measurements of intracortical (depth) EEG (dEEG), partial pressure of oxygen in interstitial brain tissue (PbtO 2 ), and regional cerebral blood flow (CBF). Patient data were collected from June 1, 2006, to September 1, 2014, at a single tertiary care center. The retrospective analysis was performed from September 1, 2014, to May 1, 2016, with a hypothesis that the effect on brain tissue oxygenation was primarily dependent on the discharge frequency.MAIN OUTCOMES AND MEASURES Electroencephalographic recordings were visually classified based on PD frequency and spatial distribution of discharges. Correlations between mean multimodality monitoring data and change-point analyses were performed to characterize electrophysiological changes by applying bootstrapping. RESULTSOf the 90 patients included in the study (26 men and 64 women; mean [SD] age, 55 [15] years), 32 (36%) had PDs on sEEG and dEEG recordings and 21 (23%) on dEEG recordings only. Frequencies of PDs ranged from 0.5 to 2.5 Hz. Median PbtO 2 was 23 mm Hg without PDs compared with 16 mm Hg at 2.0 Hz and 14 mm Hg at 2.5 Hz (differences were significant for 0 vs 2.5 Hz based on bootstrapping). Change-point analysis confirmed a temporal association of high-frequency PD onset (Ն2.0 Hz) and PbtO 2 reduction (median normalized PbtO 2 decreased by 25% 5-10 minutes after onset). Increased regional CBF of 21.0 mL/100 g/min for 0 Hz, 25.9 mL/100 g/min for 1.0 Hz, 27.5 mL/100 g/min for 1.5 Hz, and 34.7 mL/100 g/min for 2.0 Hz and increased global cerebral perfusion pressure of 91 mm Hg for 0 Hz, 100.5 mm Hg for 0.5 Hz, 95.5 mm Hg for 1.0 Hz, 97.0 mm Hg for 2.0 Hz, 98.0 mm Hg for 2.5 Hz, 95.0 mm Hg for 2.5 Hz, and 67.8 mm Hg for 3.0 Hz were seen for higher PD frequencies.CONCLUSIONS AND RELEVANCE These data give some support to consider redefining the continuum between seizures and PDs, suggesting that additional damage after acute brain injury may be reflected by frequency changes in electrocerebral recordings. Similar to seizures, cerebral blood flow increases in patients with PDs to compensate for the increased metabolic demand but higher-frequency PDs (>2 per second) may be inadequately compensated without an additional rise in CBF and associated with brain tissue hypoxia, or higher-frequency PDs may reflect inadequacies in brain compensatory...

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The electroclinical-imagiological spectrum and long-term outcome of transient periictal MRI abnormalities

Cited by 49 publications

References 34 publications

MRI Abnormalities Induced by Seizures

MRI Abnormalities Induced by Seizures

Brain tumor epilepsy: A reappraisal and six remaining issues to be debated

Electroencephalographic Periodic Discharges and Frequency-Dependent Brain Tissue Hypoxia in Acute Brain Injury

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