LangzeitEEG

LangzeitEEG, or long-term electroencephalography, refers to extended recording of brain electrical activity beyond a standard EEG session. These recordings, often performed over several days to weeks, aim to capture spontaneous events such as seizures and to study interictal abnormalities in a naturalistic setting.

Two main approaches are used: ambulatory EEG (aEEG), where portable scalp electrodes are worn at home or in an outpatient setting for multiple days, and inpatient long-term video-EEG monitoring (vEEG) in a hospital, which combines continuous EEG with synchronized video for duration typically ranging from several days to weeks. In selected cases, invasive monitoring with subdural grids or depth electrodes is employed to localize epileptogenic tissue when noninvasive methods are inconclusive. Electrode placement generally follows the international 10-20 system for scalp recordings.

LangzeitEEG is primarily used to characterize seizure frequency and semiology, determine the onset zone for potential epilepsy surgery, differentiate epileptic seizures from psychogenic non-epileptic seizures (PNES), and evaluate response to antiepileptic therapy or changes in medication. It can also document events of uncertain etiology and assess circadian patterns of spreading or clustering.

Interpretation relies on the correlation of EEG data with clinical events recorded on video, with attention to interictal spikes, sharp waves, and ictal onset patterns. Longer recordings increase the likelihood of capturing infrequent seizures and provide information about seizure burden and diurnal variation that can influence treatment decisions.

Advantages include higher diagnostic yield and more precise seizure localization than short EEG, particularly for surgical planning. Limitations involve seizure infrequency, patient discomfort or noncompliance, artifacts and cost. Risks are generally low for noninvasive monitoring, but invasive procedures carry typical surgical risks.

Typical durations vary: ambulatory monitoring may last several days, while inpatient vEEG often spans 3–7 days or longer. Findings from LangzeitEEG guide diagnosis, treatment planning, and, when appropriate, surgical candidacy, contributing to individualized epilepsy management.