Small temporal pole encephaloceles: A treatable cause of “lesion negative” temporal lobe epilepsy

Abou-Hamden, Amal; Lau, Mandy; Fabinyi, Gavin; Berkovic, Samuel F.; Jackson, Graeme D.; Mitchell, L. Anne; Kalnins, Renate M; Fitt, Gregory J; Archer, John S.

doi:10.1111/j.1528-1167.2010.02572.x

Cited by 66 publications

(74 citation statements)

References 6 publications

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“…In light of these findings, there are major arguments to think that STPE in patients with TLE are not coincidental. The fact that several patients in our series, as well as in others, [5][6][7][8][9]13,14 were rendered seizure-free after a small resection that included the herniated parenchyma, suggests a significant participation of this type of lesion in the epileptogenic zone. Moreover, in patients with RFE, ictal EEG showed a pattern congruent with the localization of the lesion.…”

Section: Discussionmentioning

confidence: 99%

“…In this setting, evaluation of ictal nonverbal reaction to sensory stimuli and assessment of the patient's ability to recall ictal events postictally (such us the inability to speak and comprehend during the seizure) would be more appropriate to determine ictal awareness and avoid classifying an aphasic seizure as a CPS. 32,35 Although several of our cases show that medically refractory epilepsy associated with STPE may be remediable by surgery, the optimal surgical strategy is still controversial, [5][6][7][8][9]13 since the epileptogenic zone in these cases may not necessarily overlap perfectly with the radiologic alteration depicted on MRI. Moreover, we and others 13 have shown that STPE can be clearly bilateral in some patients, raising the concern that there could be patients with bilateral pathology despite just having a unilateral lesion on the MRI.…”

Section: Discussionmentioning

confidence: 99%

“…Accordingly, 12 RFE patients with STPE were identified through a systematic search of our MRI database of patients with focal epilepsy evaluated for surgery. These patients were identified retrospectively from January 2007 to November 2010, since we were not aware of the relevance of STPEs in patients with epilepsy, 5 and prospectively from then on. Classification of the type of epilepsy in this subgroup of patients was done based on seizure semiology, and ictal electroencephalography (EEG) findings.…”

Section: Patient Selectionmentioning

confidence: 99%

“…1 However, 20-30% patients evaluated for surgery have normal MRI studies [2][3][4] or subtle structural lesions that are easily overlooked if not guided by semiology. In this regard, small case-series [5][6][7][8][9][10][11][12] have previously emphasized that small temporal encephalocele could be an unrecognized cause of epilepsy. Two recent articles, 13,14 studying larger groups of patients, have provided further evidence about this pathology as a significant cause of temporal lobe epilepsy in patients in whom the MRI was read as normal or noninformative.…”

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confidence: 99%

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Small temporal pole encephalocele: A hidden cause of “normal” MRI temporal lobe epilepsy

et al. 2016

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SUMMARYObjective: Small temporal pole encephalocele (STPE) can be the pathologic substrate of epilepsy in a subgroup of patients with noninformative magnetic resonance imaging (MRI). Herein, we analyzed the clinical, neurophysiologic, and radiologic features of the epilepsy found in 22 patients with STPE, and the frequency of STPE in patients with refractory focal epilepsy (RFE). Methods: We performed an observational study of all patients with STPE identified at our epilepsy unit from January 2007 to December 2014. Cases were detected through a systematic search of our database of RFE patients evaluated for surgery, and a prospective collection of patients identified at the outpatient clinic. The RFE database was also employed to analyze the frequency of STPE among the different clinical subgroups. Results: We identified 22 patients with STPE (11 women), including 12 (4.0%) of 303 patients from the RFE database, and 10 from the outpatient clinic. The median age was 51.5 years (range 29-75) and the median age at seizure onset was 38.5 years (range 15-73). Typically, 12 (80%) of 15 patients with left STPE reported seizures with impairment of language. Among the RFE cases, STPE were found in 9.6% of patients with temporal lobe epilepsy (TLE), and in 0.5% of those with extra-TLE (p = 0.0001). STPEs were more frequent in TLE patients with an initial MRI study reported as normal (23.3%) than in those with MRI-visible lesions (1.4%; p = 0.0002). Stereo-electroencephalography was performed in four patients, confirming the localization of the epileptogenic zone at the temporal pole with late participation of the hippocampus. Long-term seizure control was achieved in four of five operated patients. Significance: STPE can be a hidden cause of TLE in a subgroup of patients with an initial report of "normal" MRI. Early identification of this lesion may help to select patients for presurgical evaluation and tailored resection.

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Section: Discussionmentioning

confidence: 99%

Section: Discussionmentioning

confidence: 99%

Section: Patient Selectionmentioning

confidence: 99%

mentioning

confidence: 99%

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Small temporal pole encephalocele: A hidden cause of “normal” MRI temporal lobe epilepsy

et al. 2016

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“…Chassoux et al [12] and Abou-Hamden et al [13] found that histopathologically MRI- TLE resulted from microencephalocele or focal cortical dysplasia in the temporal lobe. Carne et al [2] demonstrated that the extent of hypometabolism of MRI- TLE is broader than HS + TLE, suggesting that they are distinct from each other.…”

Section: Discussionmentioning

confidence: 99%

Surgical Treatment of MRI-Negative Temporal Lobe Epilepsy Based on PET: A Retrospective Cohort Study

Feng

Hu²,

Pan³

et al. 2014

Stereotact Funct Neurosurg

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Introduction: Using retrospective and comparative methods, we aim to discuss the surgical treatment of magnetic resonance imaging (MRI)-negative temporal lobe epilepsy (TLE) presented with positive positron emission tomography (PET) results. Methods: From the viewpoint of semiology, demography, surgical treatment and prognosis evaluation, we compared 19 MRI-negative, PET-positive TLE patients to 41 TLE with hippocampal sclerosis patients, and then statistically analyzed the differences between these 2 cohorts. Results: Under intraoperative electrocorticography monitoring, all patients underwent successful standard anterior temporal lobectomy. It appears that there is no significant difference between the surgical outcome of MRI-negative/PET-positive TLE (Engle class I: 68.4%, Engle class I + II: 84.2%) and TLE with hippocampal sclerosis (Engle class I: 68.3%, Engle class I + II: 80.5%). The analysis also shows that to some extent MRI-negative, PET-positive TLE might be distinct from TLE with hippocampal sclerosis as a clinical entity, i.e. the former is not a subtype of the latter. History of febrile convulsion and occurrence of secondary generalized tonic-clonic seizure may possibly differentiate them from each other. Conclusion: Successful resective surgery of MRI-negative TLE based on PET can yield similar favorable results to TLE with hippocampal sclerosis. This study demonstrates that with reasonable presurgical workup, such TLE subtypes can be surgically treated without invasive intracranial electrode implantation.

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Gyratory seizures as a presentation of temporal encephalocele

et al. 2019

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Gyratory seizures ( GS ) are rare and have been reported in focal (frontal and temporal) as well as generalized epilepsies. The exact neuroanatomical substrate of gyration during a seizure is not clearly understood, but is thought to be due to the involvement of the basal ganglia. The direction of gyration occurring without head version is thought to have ipsilateral cerebral origins, while gyrational seizures preceded by forced head version are suggestive of seizure onset contralateral to the direction of gyration or the presence or absence of forced head version is thought to have important implications for lateralization of seizure origins from the direction of gyration. This case describes gyratory seizures in a young boy with a temporal encephalocele. Report of MRI brain initially indicated no abnormalities, but careful review revealed a left temporal encephalocele. PET scan showed left temporal hypometabolism. The patient underwent a left anterior temporal resection with amygdalohippocampectomy ( ATL + AH ) and is seizure‐free for 18 months. Temporal encephalocele is the most commonly iatrogenic but may also be spontaneous, post‐traumatic, or in relation to chronic otitis media. This case suggests that gyratory seizures may be a unique presentation of temporal encephalocele and this possibility warrants investigation in patients with medically refractory epilepsy.

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Small temporal pole encephaloceles: A treatable cause of “lesion negative” temporal lobe epilepsy

Cited by 66 publications

References 6 publications

Small temporal pole encephalocele: A hidden cause of “normal” MRI temporal lobe epilepsy

Small temporal pole encephalocele: A hidden cause of “normal” MRI temporal lobe epilepsy

Surgical Treatment of MRI-Negative Temporal Lobe Epilepsy Based on PET: A Retrospective Cohort Study

Gyratory seizures as a presentation of temporal encephalocele

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