Differential Diagnosis of Cerebral Hemispheric Pathology: Multimodal Approach

Can Presurgical Interhemispheric EEG Connectivity Predict Outcome in Hemispheric Surgery? A Brain Machine Learning Approach

OBJECTIVES

Hemispherotomy (HT) is a surgical option for treatment of drug-resistant seizures due to hemispheric structural lesions. Factors affecting seizure outcome have not been fully clarified. In our study, we used a brain Machine Learning (ML) approach to evaluate the possible role of Inter-hemispheric EEG Connectivity (IC) in predicting post-surgical seizure outcome.

METHODS

We collected 21 pediatric patients with drug-resistant epilepsy; who underwent HT in our center from 2009 to 2020; with a follow-up of at least two years. We selected 5-s windows of wakefulness and sleep pre-surgical EEG and we trained Artificial Neuronal Network (ANN) to estimate epilepsy outcome. We extracted EEG features as input data and selected the ANN with best accuracy.

RESULTS

Among 21 patients, 15 (71%) were seizure and drug-free at last follow-up. ANN showed 73.3% of accuracy, with 85% of seizure free and 40% of non-seizure free patients appropriately classified.

CONCLUSIONS

The accuracy level that we reached supports the hypothesis that pre-surgical EEG features may have the potential to predict epilepsy outcome after HT.

SIGNIFICANCE

The role of pre-surgical EEG data in influencing seizure outcome after HT is still debated. We proposed a computational predictive model, with an ML approach, with a high accuracy level.

A DWI study of the contralateral hemisphere in cerebral hemiatrophy

BACKGROUND AND AIM

Cerebral hemiatrophy (CHA) is a congenital or acquired loss of volume in one hemisphere of the brain. The MR findings of the affected hemisphere have been a subject of many studies, however, the contralateral hemisphere has not been investigated. There is, in fact, an integrity between two hemispheres of the brain through transverse connection fibers. The aim of this study is to investigate the changes in the contralateral hemisphere in CHA.

MATERIALS AND METHODS

Apparent diffusion coefficient (ADC) values were measured in deep gray and white matter areas in the normal-appearing contralateral hemisphere in 23 patients with CHA, in order to get in vivo information about a possible Wallerian degeneration or microstructural changes. Results were compared with the control group.

RESULTS

Normal ADC values were encountered in the contralateral hemisphere in all (100%) CHA patients. The difference between the ADC values of gray and white matter in CHA patients and the control group was not statistically significant.

CONCLUSION

Normal ADC values in the contralateral hemisphere in CHA patients suggests a compensatory mechanism restricting Wallerian degeneration or diffusion alteration.

Hemiconvulsion-hemiplegia-epilepsy syndrome. Magnetic resonance findings in a 3-year-old boy

The term 'hemiconvulsion-hemiplegia-epilepsy syndrome' (HHE) was first used by Gastaut et al. to describe the se-quential combination of unilateral or predominantly unilateral clonic seizures (hemiconvulsion), occurring during the first 2 years of life, immediately followed by an ipsilateral flaccid hemiplegia lasting 7 or more days. In the following phase partial epileptic seizures occur. We report a case of HHE syndrome in a 3-year-old boy with partial seizures (hemiconvulsion lasting 15-30 minutes) followed by left hemiplegia and hyporeflexia. Magnetic resonance imaging showed diffuse and high signal hyperintensity of the whole right cerebral hemisphere. Diffusion-weighted images showed a reduction of the apparent diffusion coefficient in the subcortical region. Magnetic resonance arterio-graphy showed a narrow flow signal in the distal territory of the right middle cerebral artery. The authors emphasize the importance of neuroradiological findings in early diagnosis and in the follow-up of HHE syndrome.

Pediatric intensive care treatment of uncontrolled status epilepticus

The critically ill mechanically ventilated child with ongoing seizures that are refractory to any treatment presents a distinct challenge in pediatric neurocritical care. The evidence base from randomized controlled trials on which anti-epileptic drug (AED) strategy should be used is inadequate. This review of refractory and super-refractory status epilepticus summarizes recent pediatric case series regarding definitions, the second-tier AED therapies once initial anticonvulsants have failed, and the experience of high-dose midazolam, barbiturate anesthesia, and volatile anesthetics for uncontrolled status epilepticus.