New 7T MRI scanners enable life-changing surgery for hard-to-treat epilepsy patients

Good news!

"A breakthrough imaging technique is transforming the treatment of drug-resistant epilepsy by enabling doctors to pinpoint elusive brain lesions. ...

ultra-powerful MRI scanners are now identifying subtle differences in brain tissue that were previously undetectable, prompting a reassessment of treatment plans for 58% of patients in a recent study. ..."

From the abstract:

"Objective

To implement parallel transmit (pTx) 7T magnetic resonance imaging (MRI) in the pre-surgical evaluation of 3T-negative patients with drug-resistant focal epilepsy, and to compare quality to conventional single transmit (specifically, circularly polarized [CP]) 7T MRI.

Methods

We implemented a comparative protocol comprising both pTx and CP 7T MRI in consecutive adult candidates for epilepsy surgery who had negative or equivocal 3T MRI imaging. Here we report the outcomes from the first 31 patients. We acquired pTx and CP T1, T2, fluid-attenuated inversion recovery (FLAIR) and edge-enhancing gradient echo (EDGE) images, all in the same three-dimensional (3D) 0.8 mm isotropic space. Two-dimensional (2D) high-resolution T2 and T2*-weighted sequences were acquired only in CP mode due to current technological limitations. Two neuroradiologists, a neurologist, and a neurosurgeon made independent, blinded quality and preference ratings of pTx vs CP images. Quantitative methods were used to assess signal dropout.

Results

7T revealed previously-unseen structural lesions in nine patients (29%), confirmed 3T-equivocal lesions in four patients (13%), and disproved 3T-equivocal lesions in four patients (13%).

Lesions were better visualized on pTx than CP in 57% of cases, and never better visualized on CP.

Clinical management was altered by 7T in 18 cases (58%).

Nine cases were offered surgical resection and one laser interstitial thermal therapy (LITT).

Three cases were removed from the surgical pathway because of bilateral or extensive lesions.

Five cases were offered stereo-electroencephalography (sEEG) with better targeting (in three because the 7T lesion was deemed equivocal by the multi-disciplinary team (MDT), and in two because the lesion was extensive).

Blinded comparison confirmed significantly better overall quality of pTx FLAIR images (F(2, 184) = 13.7, p = 2.88 × 10−6), whereas pTx MP2RAGE images were subjectively non-inferior and had improved temporal lobe coverage with quantitatively less signal drop-out.

Significance

pTx-7T is implementable in a clinical pathway, changed management in 58% of patients where 3T + FDG-PET had not enabled resection, and is superior to single transmit 7T MRI."

New scans enable life-changing surgery for epilepsy patients

Powerful new MRI scans enable life-changing surgery in first for adults with epilepsy (original news release 1) "Scientists have used a new technique that has enabled ultra-powerful magnetic resonance imaging (MRI) scanners to identify tiny differences in patients’ brains that cause treatment-resistant epilepsy. The first study to use this approach, it has allowed doctors at Addenbrooke’s Hospital, Cambridge, to offer the patients surgery to cure their condition."

Ultra-powerful MRI study offers hope for people with hard-to-treat epilepsy (original news release 2)

Parallel transmit 7T MRI for adult epilepsy pre-surgical evaluation (open access)

Comparison of images produced using existing 3T MRI imaging (left) and parallel transmit 7T MRI (right). Both images show a side view of the brain with close ups shown in the inset frames.

Researchers can now detect epilepsy without waiting for seizures

Good news!

"... The group made giant strides toward a different way of detecting seizures. New research found that changes in large-scale neuronal activations can be detected in the brains of epileptic patients during periods when no seizure is taking place. The study ... compared the high-density EEGs of 37 patients with temporal lobe epilepsy to those of 37 healthy controls. ...
“We found that the alteration of the spreading of neuronal avalanches in temporal lobe epilepsy is clustered around those brain areas which are fundamental for seizure initiation and diffusion” ... “This opens up the possibility to a new preliminary diagnostic method, especially important for the difficult cases where scalp EEG fails to detect seizures and additional investigations are necessary.” ..."

From the abstract and key points:

"Abstract

Objective

Large aperiodic bursts of activations named neuronal avalanches have been used to characterize whole-brain activity, as their presence typically relates to optimal dynamics. Epilepsy is characterized by alterations in large-scale brain network dynamics. Here we exploited neuronal avalanches to characterize differences in electroencephalography (EEG) basal activity, free from seizures and/or interictal spikes, between patients with temporal lobe epilepsy (TLE) and matched controls.

Method

We defined neuronal avalanches as starting when the z-scored source-reconstructed EEG signals crossed a specific threshold in any region and ending when all regions returned to baseline. This technique avoids data manipulation or assumptions of signal stationarity, focusing on the aperiodic, scale-free components of the signals. We computed individual avalanche transition matrices to track the probability of avalanche spreading across any two regions, compared them between patients and controls, and related them to memory performance in patients.

Results

We observed a robust topography of significant edges clustering in regions functionally and structurally relevant for the TLE, such as the entorhinal cortex, the inferior parietal and fusiform area, the inferior temporal gyrus, and the anterior cingulate cortex. We detected a significant correlation between the centrality of the entorhinal cortex in the transition matrix and the long-term memory performance (delay recall Rey–Osterrieth Complex Figure Test).

Significance

Our results show that the propagation patterns of large-scale neuronal avalanches are altered in TLE during the resting state, suggesting a potential diagnostic application in epilepsy. Furthermore, the relationship between specific patterns of propagation and memory performance support the neurophysiological relevance of neuronal avalanches.

Key Points

1. Investigation of the brain dynamics during resting-state activity in patients with temporal lobe epilepsy (TLE) using neuronal avalanches (i.e., large-scale patterns of activation)
2. We found higher transition probabilities in patients with TLE in the entorhinal cortex, inferior temporal and fusiform gyri, and anterior cingulate cortex
3. We found higher eigenvector centrality of the left entorhinal cortex in the avalanche transition matrix, which was related to reduced long-term memory performance
4. Discussion of the potential application of the avalanche transition matrix as a diagnostic tool in presurgical evaluations and epilepsy type differentiation"

Researchers can now detect epilepsy without waiting for seizures

Altered spreading of neuronal avalanches in temporal lobe epilepsy relates to cognitive performance: A resting-state hdEEG study (open access)

FIGURE 1 Graphical representation of analysis pipeline.

New AI System Predicts Seizures With Near-Perfect Accuracy

Good news (but dated from Nov. 2019)!

"... the researchers incorporated another classification approach whereby a deep learning algorithm extracts and analyzes the spatial-temporal features of the patient’s brain activity from different electrode locations, boosting the accuracy of their model. And finally, EEG readings can involve multiple “channels” of electrical activity, ... applied an additional algorithm to identify the most appropriate predictive channels of electrical activity; this also speeds up the prediction process. ... With the software component complete, ... the next step is to develop a customized computer chip to process the algorithm"

New AI System Predicts Seizures With Near-Perfect Accuracy - IEEE Spectrum A novel AI design can accurately predict seizures up to one hour before they occur, with 99.6 accuracy