Functional imaging: I. Relative predictive value of intracranial electroencephalography

Authors

  • Robert C. Knowlton MD, MSPH,

    Corresponding author
    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    • UAB Epilepsy Center, 312 Civitan International Research Center, 1719 6th Avenue South, Birmingham, AL 35294-0001
    Search for more papers by this author
  • Rotem A. Elgavish MD, PhD,

    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    Search for more papers by this author
  • Nita Limdi PharmD, PhD, MSPH,

    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    Search for more papers by this author
  • Al Bartolucci PhD,

    1. Division of Biostatistics, University of Alabama at Birmingham School of Public Health, University of Alabama at Birmingham, Birmingham, AL
    Search for more papers by this author
  • Buddhiwardhan Ojha MD, MPH,

    1. Veterans Administration Medical Center Imaging Service, West Palm Beach, FL
    Search for more papers by this author
  • Jeffrey Blount MD,

    1. Department of Surgery, Division of Neurosurgery, University of Alabama at Birmingham School of Medicine; Birmingham, AL
    Search for more papers by this author
  • Jorge G. Burneo MD, MSPH,

    1. Epilepsy Programme, Department of Clinical Neurological Sciences, University of Western Ontario, London, Ontario, Canada
    Search for more papers by this author
  • Lawrence Ver Hoef MD,

    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    Search for more papers by this author
  • Lebron Paige MD,

    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    Search for more papers by this author
  • Edward Faught MD,

    1. Department of Neurology, University of Alabama at Birmingham Epilepsy Center, University of Alabama at Birmingham School of Medicine, Birmingham, AL
    Search for more papers by this author
  • Pongkiat Kankirawatana MD,

    1. Department of Pediatrics, Division of Pediatric Neurology, University of Alabama at Birmingham School of Medicine; Birmingham, AL
    Search for more papers by this author
  • Kristen Riley MD,

    1. Department of Surgery, Division of Neurosurgery, University of Alabama at Birmingham School of Medicine; Birmingham, AL
    Search for more papers by this author
  • Ruben Kuzniecky MD

    1. New York University Comprehensive Epilepsy Center, New York University Medical School, New York, NY
    Search for more papers by this author

Abstract

Objective

To gain information on the predictive and prognostic value of magnetic source imaging (MSI), 2-[18F]fluoro-2-deoxy-D-glucose positron emission tomography (18FDG-PET), and ictal single-photon emission computed tomography (SPECT) as compared with intracranial electroencephalography (ICEEG) localization in epilepsy surgery.

Methods

This work was part of a cohort study of epilepsy surgery candidates not sufficiently localized with noninvasive studies. Of 160 patients enrolled over 4 years, 77 completed ICEEG seizure monitoring. Sensitivity, specificity, and predictive values relative to ICEEG were computed for each modality.

Results

Seizures were not captured in five patients. Of the 72 diagnostic ICEEG studies, seizure localization results were 74% localized, 10% multifocal, and 17% nonlocalized. Sixty-one percent were localized to neocortical regions. Depending on patient subgroup pairs, sensitivity ranged from 58 to 64% (MSI), 22 to 40% (PET), and 39 to 48% (SPECT); specificity ranges were 79 to 88% (MSI), 53 to 63% (PET), and 44 to 50% (SPECT). Gains in diagnostic yield were seen only with the combination of MSI and PET or MSI and ictal SPECT. Localization concordance with ICEEG was greatest with MSI, but a significant difference was demonstrated only between MSI and PET. Moderate redundancy was seen between PET and ictal SPECT (κ = 0.452; p = 0.011).

Interpretation

Conclusively positive MSI has a high predictive value for seizures localized with ICEEG. Diagnostic gain may be achieved with addition of either PET or ictal SPECT to MSI. Diagnostic values for imaging tests are lower than “true values” because of the limitations of ICEEG as a gold standard. Ann Neurol 2008

Ancillary