Table 1.
Patient demographics
| No. | Age (years) | Onset of epilepsy (years) | Hemispheric language dominance (fMRI) | Semiology | Scalp EEG (contact names based on EEG 33 system) | Neuroimaging findings | Primary hypothesis of EZ |
|---|---|---|---|---|---|---|---|
| 1 | 42 | 3 | Left |
1. Psychic aura 2. Automotor seizure 3. Dystonic posturing of the left arm 4. Post-ictal nose wiping with the right hand |
Interictal: Intermittent right temporal slowing and right temporal sharp waves Ictal: Fast activity in posterior parietal region |
1. Right mesial temporal sclerosis Hippocampal volumes: Right 2.34 cm3 Left 2.94 cm3 Ratio 79% 2. FDG PET inconclusive |
Neocortical posterior quadrant onset with early temporal involvement |
| 2 | 43 | 14 | Left |
1. Psychic aura 2. Complex motor/hyperkinetic seizure 3. Loss of awareness 4. Post-ictal speech difficulties |
Interictal: Intermittent slow left and right temporal regions. Sharp waves left anterior temporal (F7 > LSPh > F11 > F3, ~ 50%) and right fronto-temporal (F8 > RSPh > F12 > T4, ~ 50%) Ictal: Left temporal discharges at onset of seizure |
1. Normal structural imaging 2. FDG PET left frontal and temporal hypometabolism 3. Ictal SPECT inconclusive |
Left frontal (neuropsychological testing implicates the dominant fronto-temporal region) |
| 3 | 26 | 6 | Left |
1. Autonomic aura 2. Automotor seizure—vomiting followed by outstretched arms and clenched fists 3. Dialeptic—behavioral arrest with loss of awareness followed by oral automatisms 4. Secondary generalized tonic/clonic seizure |
Interical: Polyspikes and sharp waves (F8 > FC6 > F4) in runs without clinical change Ictal: Right inferior frontal > right fronto-central onset with prominent ictal tachycardia |
1. Normal structural imaging 2. FDG PET—mildly reduced tracer activity in both temporal lobes |
Right hemispheric / insula (neuropsychological testing implicates the nondominant temporal region) |
| 4 | 34 | 1 | Left |
1. Psychic/autonomic aura 2. Hyperkinetic seizure (bicycling movements in both legs) |
Interictal: No abnormalities Ictal: Left temporal lobe onset |
1. Left temporal hippocampal sclerosis 2. FDG PET—reduced metabolic activity in the left temporal lobe |
Left fronto-temporal (neuropsychological testing unable to distinguish left frontal from temporal dysfunction due to language barrier) Possible nonepileptic attacks |
| 5 | 25 | 9 | Not performed |
1. Unspecified aura 2. Dialeptic seizure 3. Left arm and leg tonic seizure 4. Axial tonic seizure |
Interictal: Intermittent slow over vertex (Cz) and right fronto-central (F4 and C4) Ictal: Right fronto-central onset |
1. Hemosiderin staining in the left superior frontal gyrus suggestive of cavernoma 2. FDG PET—minimal hypometabolism in left superior frontal region 3. Ictal SPECT—hyperperfusion in the left superior frontal and right frontal regions |
Right mesial frontal lobe (neuropsychological testing suggests frontal lobe dysfunction) |
| 6 | 37 | 7 | Bilateral |
1. Unspecified aura 2. Asymmetric tonic seizure (left arm extended) 3. Dialeptic seizure |
Interictal: Very rare sharp waves anterior frontal region Ictal: Rhythmic activity (3–5 Hz) fronto-central region |
1. Normal structural imaging 2. FDG PET—subtle reduction in metabolic activity in right frontal lobe 3. Ictal SPECT—hyperperfusion in the right frontal lobe |
Right fronto-central (neuropsychological testing suggests dominant hemisphere dysfunction) |
| 7 | 31 | 3 | Right |
1. Right arm somatosensory aura 2. Asymmetric tonic seizure (right arm) 3. Post-ictal right arm weakness 4. Dialeptic/automotor seizure |
Interictal: Sharp waves left fronto-temporal (max F7/T7) with polyspikes and left posterior temporo-parietal (max P7) Ictal: Attenuation and low amplitude fast in left temporo-parietal region. Repetitive left temporo-parietal sharp waves |
1. Extensive damage to left hemisphere lined by gliotic rim involving temporal, parietal, and insula lobes | Left centro-parietal (neuropsychological testing suggests widespread cerebral dysfunction maximally implicating the nondominant fronto-parietal region) |
| 8 | 36 | 4 | Left |
1. Dialeptic seizure 2. Automotor seizure 3. Secondary generalized tonic/clonic seizure |
Interictal: Sharp waves right temporal (max T4) 80% and sharp waves left anterior temporal (max F7) 20% Ictal: Onset nonlocalizable. Evolution more prominent over right hemisphere |
1. Normal structural imaging 2. FDG PET—reduced metabolic activity in temporal lobes bilaterally, right more than left |
Right fronto-temporal (neuropsychological testing did not provide any consistent lateralizing or localizing signs) |
| 9 | 33 | 7 | Left |
1. Left arm and leg somatosensory aura 2. Autonomic aura 3. Automotor seizure 4. Secondary generalized tonic/clonic seizure |
Interictal: Intermittent right temporal slowing Ictal: Right temporal onset with wider right hemispheric onset recorded in some seizures |
1. Right hippocampal sclerosis Hippocampal volumes: Right 2.08 cm3 Left 2.53 cm3 Ratio 82% |
Right temporal plus (neuropsychological testing suggests dominant fronto-temporal dysfunction) |
| 10 | 19 | 15 | Left |
1. Bilateral visual/auditory aura 2. Automotor seizure 3. Secondary generalized tonic/clonic seizure |
Interictal: Sharp wave left temporal (LSph and T7) and left frontal (Fp1 > F3 > Fz) Ictal: Spike and slow waves left hemisphere, maximal fronto-centro-temporal region with spread to the right |
1. Normal structural imaging 2. FDG PET—mild reduction in metabolic activity in the left temporal lobe |
Left fronto-temporal (neuropsychological testing suggests left temporal lobe dysfunction) |
| 11 | 29 | 22 | Left |
1. Psychic aura 2. Automotor seizure—left hand and oral automatisms 3. Secondary generalized tonic/clonic seizure |
Interictal: Sharp waves right temporal maximal (F12 and T8). Rare left temporal sharp waves (F11) Ictal: Regional right inferior temporal onset which evolves to rhythmic theta and propagation to the right parasagittal and left temporal regions |
1. Right hippocampal sclerosis Hippocampal volumes: Right 2.14 cm3 Left 2.76 cm3 Ratio 77.6% 2. FDG PET – Reduced metabolic activity in the right temporal lobe |
Right fronto-temporal (neuropsychological testing suggests right frontal lobe dysfunction) |
| 12 | 32 | 22 | Right |
1. Bilateral somatosensory aura 2. Asymmetric tonic seizure—head turn to left with bilateral arm extension 3. Secondary generalized tonic/clonic seizure |
Interictal: Sharp waves left fronto-central region (F3/FC1 > FC5) Ictal: Left fronto-central onset |
1. Subtle left hippocampal sclerosis Hippocampal volumes: Right 3.02 cm3 Left 2.93 cm3 Ratio 97% 2. FDG PET—reduced hypometabolism over the left hemisphere most prominent in the left inferior frontal region |
Left fronto-central (neuropsychological testing suggests dominant temporal lobe dysfunction) |
| 13 | 36 | 27 | Left |
1. Dialeptic seizure 2. Automotor seizure 3. Secondary generalized tonic/clonic seizure |
Interictal: Sharp waves right anterior temporal (50%), left anterior temporal (30%), right frontopolar (10%), and left frontopolar (5%) Right fronto-central paroxysmal fast activity Ictal: Right hemispheric activity at onset, maximal centro-parietal regions followed by temporal spread |
1. Widening of the sulci over the right cerebral hemisphere suggestive of a perinatal right hemispheric insult 2. FDG PET—Reduced metabolic activity in right frontal and temporal lobes |
Right fronto-temporal (neuropsychological testing did not provide any consistent lateralizing or localizing signs) |