Abstract:
OBJECTIVE--To examine patterns of temporal and extratemporal
regional interictal glucose hypometabolism in individual patients with
unilateral mesial temporal lobe epilepsy (TLE). Previous reports
disagree on which extratemporal areas can be hypometabolic in TLE.
DESIGN--Case series of patients with TLE who underwent interictal
fludeoxyglucose F 18 positron emission tomography, compared
quantitatively with normal positron emission tomography. SETTING--
Patients referred for surgical treatment of medically refractory complex
partial seizures. PATIENTS AND OTHER PARTICIPANTS--Ten normal
volunteers; 27 patients with TLE selected to exclude seizures of
bilateral temporal or extratemporal onset. RESULTS--Regional
hypometabolism occurred in 25 patients. Hypometabolic regions were
ipsilateral to seizure onset and included lateral temporal (in 78% of
patients), mesial temporal (70%), thalamic (63%), basal ganglial (41%),
frontal (30%), parietal (26%), and occipital (4%). Specific patterns of
temporal and extratemporal hypometabolism varied considerably across the
TLE group. CONCLUSIONS--Any of the previously reported anatomic areas of
hypometabolism can occur in individual patients with TLE. The prevalence
of thalamic hypometabolism suggests a pathophysiologic role for the
thalamus in initiation or propagation of temporal lobe seizures or in
the interictal cognitive dysfunction of TLE