Ictal and interictal brain SPECT imaging in epilepsy using technetium-99m-ECD.
The aim of this study was to evaluate the use of 99mTc-ethyl cysteinate dimer (ECD), also known as 99mTc-bicisate, in the presurgical evaluation of patients suffering from medically intractable epilepsy.


METHODS
Twenty-three brain SPECT studies (8 ictally and 15 interictally) were performed on 16 patients with a high-resolution annular SPECT system (CERASPECT). For the ictal studies, the tracer was injected in the very early phase of the seizure. The delay between seizure onset and 99mTc-ECD injection was 2-20 sec.


RESULTS
Interictally, all patients showed circumscribed hypoperfusions. In four patients, the SPECT lesion represented only structural defects. Circumscribed increased tracer uptake was observed in all ictal studies. For all patients with temporal lobe epilepsy without significant mass lesion, in whom an interictal and ictal 99mTc-ECD-SPECT study could be obtained, the asymmetry index was 0.88 +/- 0.03 for the interictal and 1.23 +/- 0.08 for the ictal studies.


CONCLUSIONS
The data suggest that 99mTc-ECD is an effective marker of cerebral perfusion imaging in epilepsy. In comparison to other tracers, it has a high in vitro stability and is therefore particularly useful for ictal studies in the very early phase after seizure onset.
Grünwald
F
F
Department of Nuclear Medicine, University of Bonn, Germany.
Menzel
C
C
Pavics
L
L
Bauer
J
J
Hufnagel
A
A
Reichmann
K
K
Sakowski
R
R
Elger
C E
CE
Biersack
H J
HJ
D000293:Adolescent; D000328:Adult; D001921:Brain / Q000000981:diagnostic imaging*; D003545:Cysteine / Q000031:analogs & derivatives*; D004569:Electroencephalography; D004827:Epilepsy / Q000000981:diagnostic imaging*; D005260:Female; D006801:Humans; D008297:Male; D015609:Organotechnetium Compounds; D012640:Seizures / Q000000981:diagnostic imaging; D013997:Time Factors; D015899:Tomography, Emission-Computed, Single-Photon
D015609:Organotechnetium Compounds; C059659:technetium Tc 99m bicisate; D003545:Cysteine