"Generalized-to-focal" epilepsy: stereotactic EEG and high-frequency oscillation patterns
Epileptic Disord
; 24(6): 1087-1094, 2022 12 01.
Article
em En
| MEDLINE
| ID: mdl-36190316
ABSTRACT
Objective:
We aimed to clarify the pathophysiology of epilepsy involving seizures with apparently generalized onset, progressing to focal ictal rhythm through stereotactic EEG (SEEG) implantation, recording, stimulation and high-frequency oscillation (HFO) analysis.Methods:
We identified two patients with seizures with bilateral electrographic onset evolving to focal ictal rhythm, who underwent SEEG implantation. Patients had pre-surgical epilepsy work-up, including prolonged video scalp EEG, brain MRI, PET, ictal/interictal SPECT, MEG, and EEG-fMRI prior to SEEG implantation.Results:
Both patients had childhood-onset seizures involving behavioural arrest and left versive head and eye deviation, evolving to bilateral tonic-clonic convulsions. Seizures were electrographically preceded by diffuse, bilateral 3-Hz activity resembling absence seizures. Both had suspected focal lesions based on neuroimaging, including 3T MRI and voxel-based post-processing in one patient. Electrode stimulation did not elicit any habitual electroclinical seizures. HFO analysis showed bilateral focal regions with high fast-ripple rates.Significance:
"Generalized-to-focal" seizures may occur due to a diffuse, bilateral epileptic network, however, both patients showed ictal evolution from a generalized pattern to a single dominant focus which may explain why the focal aspect of their seizures had a consistent clinical semiology. Patients such as these may have a unique form of generalized epilepsy, but focal/multifocal cerebral abnormalities are also a possibility.Palavras-chave
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Base de dados:
MEDLINE
Assunto principal:
Epilepsias Parciais
/
Epilepsia Generalizada
/
Epilepsia Tipo Ausência
Idioma:
En
Ano de publicação:
2022
Tipo de documento:
Article