Ictal Magnetic Resonance Imaging Research Articles

Association of ictal imaging changes in status epilepticus and neurological deterioration.

In patients with status epilepticus (SE), the clinical significance of ictal changes on magnetic resonance imaging (MRI) is insufficiently understood. We here studied whether the presence of ictal MRI changes was associated with neurological deterioration at discharge. The retrospective cohort comprised all identifiable patients treated at Odense University Hospital in the period 2008-2017. All amenable MRIs were systemically screened for ictal changes. Patient demographics, electroencephalography, seizure characteristics, treatment, and SE duration were assessed. Neurological status was estimated before and after SE. The predefined endpoint was the association of neurological deterioration and ictal MRI changes. Of 261 eligible patients, 101 received at least one MRI during SE or within 7 days after cessation; 43.6% (44/101) had SE due to non- or less brain-damaging etiologies. Patients who received MRI had a longer duration of SE, less frequently had a history of epilepsy, and were more likely to have SE due to unknown causes. Basic characteristics (including electroencephalographic features defined by the Salzburg criteria) did not differ between patients with (n= 20) and without (n= 81) ictal MRI changes. Timing of MRI was important; postictal changes were rare within the first 24 h and hardly seen >5 days after cessation of SE. Ictal MRI changes were associated with a higher risk of neurological deterioration at discharge irrespective of etiology. Furthermore, they were associated with a longer duration of SE and higher long-term mortality that reached statistical significance in patients with non- or less brain-damaging etiologies. In this retrospective cohort, ictal changes on MRI were associated with a higher risk of neurological deterioration at discharge and, possibly, with a longer duration of SE and poorer survival.

Various pathophysiological states of acute symptomatic seizures immediately after ischemic stroke, namely “onset seizures,” shown by complementary use of peri‐ictal magnetic resonance imaging and electroencephalography

AbstractBackground“Onset seizures” are acute symptomatic seizures occurring within 24 h after the onset of ischemic stroke, and their pathophysiological states are unknown. Electroencephalography is commonly used to diagnose epileptic activities; however, it is limited for use with acute stroke. Magnetic resonance imaging, including diffusion‐weighted imaging and perfusion imaging with arterial spin labeling, are applied mainly in an emergency. Ictal hyperperfusion on arterial spin labeling and cortical hyperintensity of cytotoxic edema on diffusion‐weighted imaging, peri‐ictally, can be obtained from an epileptically activated cortex.AimWe aimed to show pathophysiological states of onset seizures by complementary use of peri‐ictal magnetic resonance imaging and electroencephalography.MethodsFour patients diagnosed as onset seizures underwent an initial magnetic resonance imaging and subsequent electroencephalography.ResultsIn case 1, having persistent non‐convulsive status epilepticus after control of onset seizures, ictal magnetic resonance imaging and electroencephalography findings clearly showed the topographical relationship between the acute atherothrombotic infarction and the peri‐infarction activated cortex. In case 2, with multiple embolic strokes in the bifrontal lobes, prolonged arterial spin labeling hyper signals were observed in the perirolandic area of the right leg; cortical hyperintensity on diffusion‐weighted imaging and paroxysmal activities on electroencephalography were not shown. In cases 3 and 4, postictal hypoperfusion was shown in the large extent involving the multiple embolic infarctions. Because the epileptic cortex was located in the convexity, electroencephalography clearly showed inter‐ictal paroxysms in case 3, and localized slow wave in case 4.ConclusionThe present study shows that the complementary use of peri‐ictal arterial spin labeling/diffusion‐weighted imaging and electroencephalography potentially offers the ability to document the various pathophysiological states of onset seizure.

The initial use of arterial spin labeling perfusion and diffusion-weighted magnetic resonance images in the diagnosis of nonconvulsive partial status epileptics

BackgroundIn the diagnosis of nonconvulsive status epilepticus (NCSE), capture of ongoing ictal electroencephalographic (EEG) findings is the gold standard; however, this is practically difficult without continuous EEG monitoring facilities. Magnetic resonance imaging (MRI), including diffusion-weighted imaging (DWI) and perfusion MRI with arterial spin labeling (ASL), have been applied mainly in emergency situations. Recent reports have described that ictal MRI findings, including ictal hyperperfusion on ASL and cortical hyperintensity of cytotoxic edema on DWI, can be obtained from epileptically activated cortex. We demonstrate the characteristics and clinical value of ictal MRI findings. MethodsFifteen patients diagnosed as having NCSE (eight had complex partial status epilepticus (SE) and seven subtle SE) who underwent an initial MRI and subsequent EEG confrmation, participated in this study. Follow-up MRI and repeated routine EEG were performed. ResultsIn 11 patients (73%), ictal MRI findings were obtained on both DWI and ASL, while in four (27%) patients, ictal hyperperfusion was found on ASL without any DWI findings being obtained. In all 10 patients with an epileptogenic lesion, there was a tight topographical relationship between the lesion and the localization of ictal MRI findings. In the other five patients, ictal MRI findings were useful to demonstrate the pathophysiological mechanism of NCSE of non-lesional elderly epilepsy, or ‘de novo’ NCSE of frontal origin as situation-related NCSE. Ictal MRI findings are generally transient; however, in three cases they still persisted, even though ictal EEG findings had completely improved. ConclusionThe present study clearly demonstrates that the initial use of ASL and DWI could help to diagnose partial NCSE and also combined use of the MRI and EEG allows documentation of the pathophysiological mechanism in each patient.

Magnetic resonance imaging in occipital lobe epilepsy with frequent seizures

Magnetic resonance imaging and single-photon emission computed tomography provide useful information in the evaluation of the pathophysiology of epileptic foci. Ictal magnetic resonance imaging in a 7-year-old male with occipital lobe epilepsy revealed mild swelling of the left temporo-occipital region, with hyperintensity on T 2-weighted and fluid attenuated inversion recovery images. This lesion, however, was not detected on diffusion-weighted imaging. An ictal single-photon emission computed tomography study using 99mTc-ECD demonstrated left temporo-occipital hyperperfusion. T 2-weighted and fluid attenuated inversion recovery images revealed hyperintensity without atrophy 4 months after control of his seizures. The focus in nonconvulsive status epilepticus has been reported as showing hyperintensity on T 2-weighted, fluid attenuated inversion recovery and diffusion-weighted images. Since hyperintensity on diffusion-weighted imaging reflects cytotoxic intracellular edema due to excitotoxicity, and his ictal diffusion-weighted image exhibited no remarkable change, the lesions in the left temporo-occipital region resulted from vasogenic edema. Cytotoxic edema resulting from excitotoxicity leads to neuronal death, causing cortical atrophy. Thus, diffusion-weighted imaging is a useful tool to predict the prognosis of frequent seizures.