Figura. Esquema de los tipos de patrones de propagación en el electroencefalograma de superficie, hallados en pacientes con epilepsia refractaria asociada a esclerosis temporal mesial unilateral.
Tabla. Distribución de las principales características clínicas en los pacientes con epilepsia refractaria asociada a esclerosis temporal mesial, en función del tipo de patrón ictal en el EEG. |
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Crisis |
Casos |
Tiempo de inicio clínico |
Ritmo del |
Duración media |
Aura |
Semiología ictal registrada |
Crisis febriles |
EPI |
Crisis reflejas |
Tipo de |
Evolución (clase Engel IA / total) |
|||
A a |
C b |
D c |
||||||||||||
Patrón 1 |
19 |
11 |
3-10 s |
Theta, alfa/beta |
45 s |
Epigástrica |
5 |
2 |
4 |
8 |
2 |
0 |
10 LTA, 1 AH |
8 / 11 |
Patrón 2A |
10 |
7 |
2-47 s |
Theta |
22 s |
Epigástrica gustativa, miedo |
2 |
3 |
2 |
2 |
2 |
2 |
6 LTA, 1 AH |
4 / 7 |
Patrón 2B |
15 |
5 |
2-9 s |
Theta |
84 s |
No |
1 |
4 |
0 |
1 |
2 |
1 |
4 LTA, 1 AH |
4 / 5 |
Patrón 3 |
6 |
2 |
4-10 s |
Theta, delta |
35 s |
Epigástrica, vértigo |
0 |
0 |
0 |
0 |
0 |
0 |
1 LTA, 1 AH |
2 / 2 |
Patrón 4 |
11 |
4 |
3-15 s |
Theta, theta/delta, puntas |
30 s |
No |
1 |
3 |
0 |
0 |
2 |
0 |
3 LTA, |
2 / 3 d |
Patrón 5 |
1 |
1 |
2 s |
Theta/delta |
20 s |
No |
1 |
0 |
0 |
0 |
1 |
1 |
1 AH |
0 / 1 |
AH: amigdalohipocampectomía; EEG: electroencefalograma; EPI: evento precipitante inicial; LTA: lobectomía temporal anterior; tto.: tratamiento. a Ausencia de fenómenos motores, o son bilaterales; b Secuencia clásica de automatismos orales precoces seguidos de distonía contralateral o automatismos ipsilaterales; c Distonía unilateral precoz; d Evolución de los tres casos quirúrgicos en el grupo de cuatro pacientes con patrón EEG de tipo 4. |
Clinico-electroencephalographic variants in pharmacoresistant mesial temporal lobe epilepsy Introduction. Focal epilepsy secondary to mesial temporal sclerosis (MTS) is one of the main causes of refractory epilepsy. It is typically associated with frontotemporal discharges in the electroencephalogram (EEG), a characteristic image in the magnetic resonance scan and a probability of post-operative remission above 70%. Aims. To identify different patterns of ictal propagation in surface EEG recordings in patients with refractory epilepsy and MTS, and to analyse their relation with the post-operative outcome. Patients and methods. We conducted a retrospective review of the medical records of patients with refractory epilepsy secondary to MTS evaluated in the Epilepsy Surgery Programme of the Hospital de Clínicas, Montevideo (n = 30). The propagation of ictal rhythms was analysed in time windows of three seconds, and propagation maps were produced for each seizure. Results. Six patterns were identified: ipsilateral temporal (type 1; 37%), bilateral frontotemporal with (type 2A; 22%) or without (type 2B; 17%) extension to suprasylvian regions, alternating temporal (type 3; 13%), unilateral suprasylvian (type 4; 7%) and bilateral at onset (type 5; 3%). The type 1 pattern was associated with classic clinical features and a favourable post-operative outcome. The clinical variants were associated with extratemporal EEG propagation. Patients with reflex seizures continued with post-operative seizures. Overall, no unambiguous relation was found between the ictal EEG pattern and the post-operative outcome. Conclusions. The ictal EEG pattern does not allow for a surgical prognosis in patients with epilepsy secondary to MTS. The history of reflex seizures in these patients may be a red flag suggesting a less favourable surgical outcome. Key words. Electroencephalography. Epilepsy. Hippocampal sclerosis. Ictal pattern. Mesial temporal sclerosis. Seizure. |