Magnetoencephalographic Recordings in Infants Using a Standard-Sized Array: Technical Adequacy and Diagnostic Yield
Sumiya Shibata1, John C Mosher, Prakash Kotagal
1Epilepsy Center, Neurological Institute, The Cleveland Clinic Foundation, Cleveland, Ohio, U.S.A.
Summary
Magnetoencephalography (MEG) effectively detects epilepsy in infants using standard adult equipment. Advanced processing techniques and head position monitoring ensure accurate results without specialized infant-sized machines.
Area of Science:
- Neurology
- Medical Imaging
Background:
- Most magnetoencephalography (MEG) systems are designed for adults, posing challenges for infant examinations.
- Few MEG systems are specifically built for infants, making adult-sized systems the routine choice for pediatric epilepsy evaluations.
Purpose of the Study:
- To assess the clinical utility of conventional adult-sized MEG devices for diagnosing epilepsy in infants.
- To determine if MEG can successfully detect epileptiform discharges in infants with smaller head sizes relative to the sensor helmet.
Main Methods:
- A retrospective review of 964 MEG epilepsy examinations from January 2008 to May 2015.
- Reanalysis of data from infant patients (age <2 years) to identify epileptiform discharges.
- Application of temporally extended signal space separation and movement compensation with head position monitoring.
Main Results:
- Nine infants (approximately 1%) underwent MEG examinations using adult-sized equipment.
- Epileptic abnormalities were detected in all nine infants, with interictal abnormalities in all and ictal abnormalities in five.
- Source amplitudes of interictal dipoles ranged from 46.0 to 437.2 nA-m (mean: 180.1 nA-m).
Conclusions:
- Conventional adult MEG systems are effective for detecting epileptic abnormalities in infants.
- Head position monitoring and advanced postprocessing techniques enhance the reliability of MEG in infants.
- MEG is a valuable tool for managing infant epilepsy without requiring specialized equipment for small heads.
