The prognostic value of [F]FDG-PET in nonrefractory partial epilepsy.
OBJECTIVE
Regional abnormalities of cerebral glucose metabolism, as identified by 18-fluorodeoxyglucose positron emission tomography (FDG-PET) have prognostic value regarding the outcome of epilepsy surgery in patients with refractory partial epilepsy. The value of FDG-PET abnormalities in nonrefractory patients has not been investigated systematically. This study examines whether FDG-PET could be used for early identification of nonrefractory epilepsy in patients who will become pharmacoresistant later during the course of their disease.


METHODS
We investigated interictal abnormalities of cerebral glucose metabolism by using FDG-PET in 125 consecutive patients with nonrefractory cryptogenic partial epilepsy and normal cranial magnetic resonance imaging (MRI), and we compared relative changes in seizure frequency in 90 patients after > or =2 years of follow-up.


RESULTS
Regional asymmetry of tracer distribution was seen in 43 of the 90 patients. Forty-one patients had regional glucose hypometabolism in the temporal and two patients in an extratemporal region. No difference between patients with and without a hypometabolic focus was found regarding seizure freedom after follow-up. This held true also for the subgroup of patients with epilepsy onset within 1 year before admission. Only patients with regional glucose metabolism showed an increase in seizure frequency. Multivariate analysis showed that only anticonvulsive treatment before index admission and the possibility of localizing the epileptogenic focus by using all available clinical and EEG data were independently associated with continuing seizures after a median follow-up period of 43 months.


CONCLUSIONS
Regional hypometabolism in FDG-PET is not significantly associated with a lower likelihood of successful anticonvulsant drug therapy in patients with nonrefractory partial epilepsy. Careful analysis of all routinely available clinical and neurophysiologic data has a much better predictive power to identify patients with medically refractory epilepsy early in the course of the disease. However, if PET data are available, they could help in identifying patients with a less benign course.
Weitemeyer
Lars
L
Department of Neurology, University of Münster, Münster, Germany.
Kellinghaus
Christoph
C
Weckesser
Matthias
M
Matheja
Peter
P
Loddenkemper
Tobias
T
Schuierer
Gerhard
G
Schober
Otmar
O
Ringelstein
E Bernd
EB
Lüdemann
Peter
P
D000293:Adolescent; D000328:Adult; D000368:Aged; D000927:Anticonvulsants / Q000627:therapeutic use; D001921:Brain / Q000000981:diagnostic imaging* / Q000378:metabolism; D004351:Drug Resistance; D004569:Electroencephalography / Q000706:statistics & numerical data; D004828:Epilepsies, Partial / Q000175:diagnosis / Q000000981:diagnostic imaging* / Q000188:drug therapy*; D005260:Female; D019788:Fluorodeoxyglucose F18 / Q000378:metabolism; D005500:Follow-Up Studies; D005947:Glucose / Q000378:metabolism; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D015999:Multivariate Analysis; D009483:Neuropsychological Tests; D049268:Positron-Emission Tomography / Q000706:statistics & numerical data*; D011237:Predictive Value of Tests; D011379:Prognosis; D013702:Temporal Lobe / Q000000981:diagnostic imaging / Q000378:metabolism; D014018:Tissue Distribution; D016896:Treatment Outcome
D000927:Anticonvulsants; D019788:Fluorodeoxyglucose F18; D005947:Glucose