The use of 2-deoxy-2-[18F]fluoro-D-glucose (FDG-PET) positron emission tomography in the routine diagnosis of epilepsy.
OBJECTIVE
Positron emission tomography with 2-deoxy fluoroglucose positron emission tomography (18-FDG-PET) is widely used in the pre-surgical evaluation of subjects with epilepsy, but little is known of its usefulness in a non-surgical population.


METHODS
We analyzed the sensitivity of PET as a diagnostic tool in a large unselected population of epilepsy subjects. Pre-surgical and non-surgical portions of this population were individually assessed as well. The relationship of PET abnormalities to other neurodiagnostic tests was examined. Statistical assessment relied primarily on contingency tables (chi-square tests), with ANOVA or non-parametric assessment used as necessary.


RESULTS
While PET was more likely to identify areas of decreased metabolism in the surgical population than in the non-surgical populations, it nevertheless found a significant number of abnormalities in the total population and in the non-surgical group alone. Even in groups in which the clinical diagnosis was unknown, abnormalities were found 40% of the time. PET was useful as an exclusionary diagnostic tool for non-epileptic seizures (NES) and primary generalized epilepsies (PGE) with sensitivity, specificity, and accuracy > 90%. The PET was somewhat more sensitive than magnetic resonance imaging (MRI) in finding abnormalities in the total population, but was less sensitive than electroencephalography (EEG).


CONCLUSIONS
PET may be a useful diagnostic tool in the general epilepsy population even when a definitive clinical diagnosis is not suggested by other modalities.
Swartz
Barbara E
BE
Department of Neurology, VAMC West Los Angeles, Los Angeles, CA, USA. barbara.swartz@uhhs.com
Brown
Charles
C
Mandelkern
Mark A
MA
Khonsari
Ali
A
Patell
Ashok
A
Thomas
Ken
K
Torgersen
Denise
D
Delgado-Escueta
A V
AV
Walsh
Gregory O
GO