Abstract
Objective
Epilepsy, a prevalent neurological disorder in children, manifests through recurrent
seizures due to abnormal neuronal activity. Drug-resistant epilepsy (DRE) is a significant
clinical challenge, often necessitating advanced diagnostic approaches to optimize
treatment strategies. Single photon emission computed tomography (SPECT) imaging,
particularly using the radiopharmaceutical 99mTc-ethyl cysteinate dimer (99mTc-ECD),
offers potential in localizing epileptogenic zones, especially when conventional magnetic
resonance imaging (MRI) and electroencephalography (EEG) findings are inconclusive.
This study was performed to evaluate patterns of brain perfusion using 99mTc-ECD SPECT
in children aged < 18 years diagnosed with DRE, and to correlate these findings with
clinical evaluations, MRI, and video EEG reports.
Materials and Methods
A descriptive observational study was conducted over 18 months on 60 children with
DRE. Each participant underwent a detailed clinical history, video EEG, MRI, and a
99mTc-ECD brain perfusion SPECT scan. The SPECT images were analyzed visually and
semiquantitatively for hypoperfusion and hyperperfusion patterns. Data were cross-referenced
with clinical lateralization, MRI findings, and EEG results to assess concordance.
Results
A total of 60 children with DRE and mean age of 11.02 + 3.8 years (1–< 18 years) including
16 (26.7%) female and 44 (73.3%) male patients were prospectively analyzed. Forty
of 60 (66.7%) patients had normal MRI brain study and 23/60 (38.3%) patients had normal
EEG records. Medial temporal lobe hypoperfusion was seen in all patients, while 16/60
(26.67%) patients had additional foci of hyperperfusion in left frontal lobe and 14/60
(23.3%) patients in right frontal lobe. Thirty-six of 60 (60%) patients had involvement
of one hemisphere, 24/60 (40%) showed perfusion abnormalities in both hemispheres.
Moderate to severe hypoperfusion was seen in left temporal lobe in 39/60 (65%) patients
whereas 30/60 (50%) patients showed moderate to severe hypoperfusion in right temporal
lobe. SPECT findings were concordant with EEG in 16/60 (26.67%) of cases and concordant
MRI, EEG, and 99mTc-ECD was seen in 5/60 (8.3%) cases.
Conclusion
99mTc-ECD brain perfusion SPECT is a valuable diagnostic tool in the comprehensive
evaluation of pediatric DRE. It enhances lateralization and localization of epileptogenic
zones, especially when conventional imaging is nondiagnostic. Interictal brain SPECT,
is easily available, indispensable, and complementary in diagnosis. Combining it with
clinical and electrophysiological evaluation can significantly improve clinical outcome
and management of patients with DRE.
Keywords
seizure onset zone - temporal lobe epilepsy - 99mTc-ECD brain perfusion SPECT - drug-resistant
epilepsy - interictal-ictal SPECT
