The Value of PET Scan (and MRI and Wada Test) in Patients With Bitemporal Epileptiform Abnormalities

Benbadis, Selim R.; So, Norman K.; Antar, Mohamed A.; Barnett, Gene H.; Morris, Harold H.

doi:10.1001/archneur.1995.00540350048016

Cited by 50 publications

(31 citation statements)

References 28 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…The degree of lateralization is defined as the number of IEDs originating from one hemisphere as compared with the total number of IEDs originating from both hemispheres. Epileptiform activity has often been considered "lateralized" in TLE by many investigators if >80-90% of the discharges originated from one temporal lobe (4,6,10,17,19). Our study showed that 13 (76%) of 17 patients with bilateral independent IEDs (see Table 1) would be considered not to have lateralized discharges by using the 90% criterion, although all the patients had only unilateral IEDs in routine short-term EEGs.…”

Section: Discussionmentioning

confidence: 65%

Frequency of Bitemporal Independent Interictal Epileptiform Discharges in Temporal Lobe Epilepsy

et al. 2000

View full text Add to dashboard Cite

Summary:Purpose: Bitemporal interictal epileptiform discharges (IEDs) occur in 542% of scalp EEGs in patients with temporal lobe epilepsy (TLE) studied with routine EEGs or partial analysis of long-term recordings.Methods: Twenty-eight patients with TLE demonstrating exclusively unilateral temporal IEDs on routine EEGs underwent 24-h continuous recording. The entire record was visually inspected for epileptiform discharges. We used continuous EEG to assess the significance of long-term recording in detecting bilateral IEDs.Results: Twenty-two patients had left temporal IEDs; 21 had right temporal IEDs. Seventeen (61%) patients had IEDs originating from both the right and left temporal lobes. The probability of detecting bilateral independent IEDs was correlated with the duration of continuous EEG recording. There was no correlation between the number of IEDs originating from one side and the probability of detecting independent IEDs on the other side. The frequencies of IEDs were not correlated with the length of time since onset of epilepsy.Conclusions: The findings suggest that when long-term recordings are performed, the incidence of bilateral discharges in TLE is higher than previously reported in the literature and supports the view that TLE is commonly a bilateral disease.

show abstract

Section: Discussionmentioning

confidence: 65%

Frequency of Bitemporal Independent Interictal Epileptiform Discharges in Temporal Lobe Epilepsy

et al. 2000

View full text Add to dashboard Cite

show abstract

“…Some of Group I patients might prove not to have TLE despite clinical and neurophysiological clues suggestive of a temporal lobe onset. Earlier series dealing with heterogeneous populations have not emphasized imaging findings [15][16][17][18] . The majority of Group I patients had no demonstrable pathology within the surgical specimen.…”

Section: Discussion Discussionmentioning

confidence: 99%

Results of surgery in patients with bilateral independent temporal lobe spiking (BITLS) with normal MRI or bilateral mesial temporal sclerosis (MTS) investigated with bilateral subdural grids

Cukiert¹,

Sousa²,

Machado³

et al. 2000

Arq. Neuro-Psiquiatr.

View full text Add to dashboard Cite

-Purpose: The introduction of new technologies in the clinical practice have greatly decreased the number of patients submitted to invasive recordings. On the other hand, some patients with refractory temporal lobe epilepsy have normal MR scans or bilateral potentially epileptogenic lesions. This paper reports the results of invasive neurophysiology and surgical outcome in such patients. Method: Sixteen patients were studied. Eleven had normal MRI (Group I) and five had bilateral mesial temporal sclerosis (Group II). All patients had BITLS and non-localizatory seizures on video-EEG monitoring. All patients were implanted bilaterally with 32-contacts subdural grids. They were submitted to a cortico-amygdalo-total hippocampectomy at the side defined by chronic electrocorticography (ECoG). Results: In Group I, seizures came from a single side in nine patients. In nine patients, seizures started at one side, spread to the ipsolateral contacts and contralaterally afterwards. On the other hand, in two Group I patients seizures started in one mesial region and spread to the contralateral parahippocampus and neocortex before spreading to ipsolateral contacts. All patients in Group II had seizures starting unilaterally with focal EcoG onset in the mesial regions. Eight Group I patients are seizure-free and three are in Engel's class II. Eighty percent of Group II patients are seizure-free after surgery and one patient is in Engel's class II. Conclusion: Good surgical results can be obtained in patients with BITLS. Patients with normal MRI seem to have a worse prognosis when compared to patients with unilateral or even bilateral MTS. Extensive subdural coverage is essential in patients with normal MRI.KEY WORDS: bitemporal epilepsy, surgery, subdural grids, outcome, MRI. Resultados cirúrgicos em pacientes com descargas bilaterais independentes do lobo temporal (DBILT) e ressonância magnética normal ou com esclerose mesial bilateral investigados com implante bilateral de grades subdurais.RESUMO -Introdução: A introdução de novas tecnologias na prática clínica tem diminuído em muito a necessidade do estudo com eletrodos invasivos em pacientes epilépticos refratários. Por outro lado, alguns pacientes com epilepsia do lobo temporal ainda possuem exames de imagem normais ou com lesões potencialmente epileptogênicas bilaterais. Este estudo relata os resultados da neurofisiologia invasiva e da cirurgia neste grupo de pacientes. Métodos: Dezesseis pacientes foram estudados. Onze possuíam RM normal (grupo I) e 5 esclerose mesial bilateral (grupo II). Todos possuíam DBILT e crises não-localizatórias após vídeo-monitorização. Todos foram implantados bilateralmente com placas subdurais de 32 contatos cada. Eles foram submetidos a córtico-amigdalo-hipocampectomia do lado definido pela neurofisiologia invasiva. Resultado: No grupo I, as crises originaram-se em somente um lado em 9 pacientes. Em 9 pacientes, as crises iniciavam-se em um lado, espraiandose para os contatos ipsilaterais e a seguir contralateralmente. Por outro la...

show abstract

“…Hypometabolism in the extratemporal cortex (including the temporal cortex contralateral to the seizure focus) on FDG PET is not an uncommon finding in TLE [3,5,6,7]. Extratemporal hypometabolism seems to be associated with a poor seizure outcome after surgery in TLE [3,5,6,7].…”

Section: Introductionmentioning

confidence: 99%

Extratemporal hypometabolism on FDG PET in temporal lobe epilepsy as a predictor of seizure outcome after temporal lobectomy

Choi

Kim

Hong

et al. 2003

Eur J Nucl Med Mol Imaging

108

View full text Add to dashboard Cite

We investigated the relationship between the presence of extratemporal hypometabolism on fluorine-18 fluorodeoxyglucose positron emission tomography (FDG PET) and seizure outcome after temporal lobectomy in patients with medically intractable temporal lobe epilepsy (TLE). In 47 patients with intractable unilateral mesial TLE, regional metabolic changes on FDG PET images obtained during the 2 months preceding anterior temporal lobectomy were compared with postoperative seizure outcome. Postoperative seizure outcome was evaluated with a mean follow-up period of 6.1+/-0.6 years (range 5.2-7.2 years). Forty-two (89%) of the 47 patients achieved a good postoperative seizure outcome (Engel class I or II). All patients had hypometabolism in the temporal cortex ipsilateral to the epileptogenic region on FDG PET scans. Fourteen (78%) of the 18 patients with hypometabolism only in the ipsilateral temporal cortex were completely seizure free (Engel class Ia) after surgery. In contrast, five (45%) of the 11 patients with extratemporal cortical hypometabolism confined to the ipsilateral cerebral hemisphere and only four (22%) of the 18 patients with hypometabolism in the contralateral cerebral cortex were completely seizure free after surgery. The postoperative seizure-free rates were significantly different across the three groups of patients with different cortical metabolic patterns ( P<0.005). Furthermore, all of the nine patients with a non-class I outcome (Engel class II-IV) had extratemporal (including contralateral temporal) cortical hypometabolism. Thalamic hypometabolism was noted in 20 (43%) of the 47 patients (ipsilateral in 12, bilateral in 8). Sixteen (59%) of the 27 patients with normal thalamic metabolism were completely seizure free after surgery, while only seven (35%) of the 20 patients with thalamic hypometabolism became completely seizure free ( P<0.05). Multivariate analysis revealed that among variables including clinical, EEG, magnetic resonance imaging, pathological and FDG PET metabolic findings, only cortical metabolic pattern was an independent factor for the prediction of postoperative seizure outcome ( P<0.005). It is concluded that extratemporal cortical hypometabolism outside the seizure focus, in particular hypometabolism in the contralateral cerebral cortex, may be associated with a poorer postoperative seizure outcome in TLE and may represent underlying pathology that is potentially epileptogenic. Thalamic hypometabolism, which was associated, but not independently, with a higher likelihood of postoperative seizures, may be secondary to extratemporal or temporal pathology.

show abstract

The Value of PET Scan (and MRI and Wada Test) in Patients With Bitemporal Epileptiform Abnormalities

Cited by 50 publications

References 28 publications

Frequency of Bitemporal Independent Interictal Epileptiform Discharges in Temporal Lobe Epilepsy

Frequency of Bitemporal Independent Interictal Epileptiform Discharges in Temporal Lobe Epilepsy

Results of surgery in patients with bilateral independent temporal lobe spiking (BITLS) with normal MRI or bilateral mesial temporal sclerosis (MTS) investigated with bilateral subdural grids

Extratemporal hypometabolism on FDG PET in temporal lobe epilepsy as a predictor of seizure outcome after temporal lobectomy

Contact Info

Product

Resources

About