title: Multimodal diagnosis of epilepsy using conditional dependence and multiple imputation.
abstract: The definitive diagnosis of the type of epilepsy, if it exists, in medication-resistant seizure disorder is based on the efficient combination of clinical information, long-term video-electroencephalography (EEG) and neuroimaging. Diagnoses are reached by a consensus panel that combines these diverse modalities using clinical wisdom and experience. Here we compare two methods of multimodal computer-aided diagnosis, vector concatenation (VC) and conditional dependence (CD), using clinical archive data from 645 patients with medication-resistant seizure disorder, confirmed by video-EEG. CD models the clinical decision process, whereas VC allows for statistical modeling of cross-modality interactions. Due to the nature of clinical data, not all information was available in all patients. To overcome this, we multiply-imputed the missing data. Using a C4.5 decision tree, single modality classifiers achieved 53.1%, 51.5% and 51.1% average accuracy for MRI, clinical information and FDG-PET, respectively, for the discrimination between non-epileptic seizures, temporal lobe epilepsy, other focal epilepsies and generalized-onset epilepsy (vs. chance, p<0.01). Using VC, the average accuracy was significantly lower (39.2%). In contrast, the CD classifier that classified with MRI then clinical information achieved an average accuracy of 58.7% (vs. VC, p<0.01). The decrease in accuracy of VC compared to the MRI classifier illustrates how the addition of more informative features does not improve performance monotonically. The superiority of conditional dependence over vector concatenation suggests that the structure imposed by conditional dependence improved our ability to model the underlying diagnostic trends in the multimodality data.
authors.affiliation: Dept. of Biomathematics, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095, Telephone: (310) 986-3307 ; Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Wesley T
authors.initials: WT
authors.lastname: Kerr
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Eric S
authors.initials: ES
authors.lastname: Hwang
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Kaavya R
authors.initials: KR
authors.lastname: Raman
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Sarah E
authors.initials: SE
authors.lastname: Barritt
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Akash B
authors.initials: AB
authors.lastname: Patel
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Justine M
authors.initials: JM
authors.lastname: Le
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Jessica M
authors.initials: JM
authors.lastname: Hori
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Emily C
authors.initials: EC
authors.lastname: Davis
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Chelsea T
authors.initials: CT
authors.lastname: Braesch
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Emily A
authors.initials: EA
authors.lastname: Janio
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Edward P
authors.initials: EP
authors.lastname: Lau
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Andrew Y
authors.initials: AY
authors.lastname: Cho
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Ariana
authors.initials: A
authors.lastname: Anderson
authors.affiliation: Dept. of Molecular & Medical Pharmacology, Ahmanson Translational Imaging Division, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Daniel H S
authors.initials: DH
authors.lastname: Silverman
authors.affiliation: Dept. of Radiology, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Noriko
authors.initials: N
authors.lastname: Salamon
authors.affiliation: Dept. of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Jerome
authors.initials: J
authors.lastname: Engel
authors.affiliation: Dept. of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: John M
authors.initials: JM
authors.lastname: Stern
authors.affiliation: Dept. of Psychiatry, Neuropsychiatric Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095 ; Dept. of Radiology, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095 ; Dept. of Neurology, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095 ; Dept. of Psychology, Biomedical Physics, Biomedical Engineering, California Nanosystems Institute, David Geffen School of Medicine at the University of California, Los Angeles, Semel Institute, 760 Westwood Plaza, Suite 17-369, Los Angeles, California 90095.
authors.forename: Mark S
authors.initials: MS
authors.lastname: Cohen