Focal EEG abnormalities and focal ictal semiology in generalized epilepsy

Abstract

In clinical practice, the diagnosis of focal vs generalized epilepsy dictates the management of the patient. The distinction between generalized and focal epilepsy is at times imperfect and some epilepsies have features that fall in between these two extremes. An example is the occurrence of focal interictal and focal ictal abnormalities in generalized epilepsies. As a part of the special issue on "The epileptogenic zone in pediatric epilepsy surgery", this focused narrative review will discuss different focal abnormalities seen in generalized epilepsy. An overlap of focal and generalized epileptiform abnormalities may support a continuum between focal and generalized epilepsy. When evaluating patients in the "gray zone", other factors such as ictal semiology, neuroimaging, genetic testing and functional deficits may need to be considered to reach an accurate diagnosis. Being aware of possible occurrence of focal clinical and EEG features in generalized epilepsy will help clinicians select more preferred AED (s), avoiding potential iatrogenic side effects and inappropriate consideration for epilepsy surgery.

Loss of glutamate transportereaat2aleads to aberrant neuronal excitability, recurrent epileptic seizures and hypoactivity

“…Our findings in eaat2a -/mutant zebrafish may also have a broader relevance for epilepsy research. The current clinical dichotomy between focal and generalized seizures is operational and may not reflect mechanistic distinctions [63][64][65] . Recent research in human patients using advanced neurophysiological methods and functional imaging is transforming our understanding on ictogenesis.…”

Advanced Bioelectrical Signal Processing Methods: Past, Present and Future Approach—Part II: Brain Signals

“…The EEG recording is frequently applied to diagnose epilepsy, which causes abnormalities in the EEG readings [ 33 , 34 ]. It can be also used to diagnose sleep disorders, coma, depth of anesthesia, encephalopathies, and brain death [ 35 , 36 , 37 ].…”

Nanotheranostics in epilepsy: A perspective for multimodal diagnosis and strategic management

“…The major conventional and primary strategies for diagnosis of any type epilepsy include diagnostic instruments such as electroencephalogram (EEG) to record pattern of brain waves, computed tomography (CT), magnetic resonance imaging (MRI) and positron emission tomography (PET), whereas genetic testing offers secondary tools to diagnose the epilepsy. [ 1,2,4,6,11,13 ] The confirmation of disorder is tested by analyzing the biomarkers (specific proteins, enzymes, lesions) present in the brain or from the biofluids like blood, cerebrospinal fluid, DNA, biopsy, saliva, and so on. Similarly, the conventional treatment strategies include monotherapy or adjunctive therapy of various AEDs such as carbamazepine, gabapentin, phenytoin, oxcarbazepine, and so on in divided doses according to the type of epilepsy.…”