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EEG-fMRI findings in late seizure recurrence following temporal lobectomy: A possible contribution of area tempestas.

Garganis K, Kokkinos V, Zountsas B - Epilepsy Behav Case Rep (2013)

Bottom Line: Late seizure relapses following temporal lobectomy for drug-resistant temporal lobe epilepsy occur in 18-30% of operated-on cases, and recent evidence suggests that a significant proportion of them are due to maturation and activation of proepileptic tissue having defied initial resection and located at the vicinity of or at a short distance from its borders, usually over the posterior medial, basal temporal-occipital, and lateral temporal regions.This case report of a patient with late seizure relapse, three years following an initially successful right temporal lobectomy for ipsilateral medial temporal sclerosis, is the first one in the literature to demonstrate interictal EEG-fMRI evidence of significant BOLD signal changes over the inferior, basal and lateral temporal and temporooccipital cortices posterior to the resection margin, plus a significant BOLD signal change over the ipsilateral basal frontal region, closely corresponding to the piriform cortex/area tempestas.Our case study provides further functional imaging evidence in support of maturation/activation of proepileptic tissue located at the vicinity of the initial temporal lobe resection in cases of late seizure relapses and suggests, in addition, a possible role for the piriform cortex/area tempestas in the relapsing process.

View Article: PubMed Central - PubMed

Affiliation: Epilepsy Center of Thessaloniki, "St. Luke's" Hospital, Panorama, Thessaloniki, Greece.

ABSTRACT
Late seizure relapses following temporal lobectomy for drug-resistant temporal lobe epilepsy occur in 18-30% of operated-on cases, and recent evidence suggests that a significant proportion of them are due to maturation and activation of proepileptic tissue having defied initial resection and located at the vicinity of or at a short distance from its borders, usually over the posterior medial, basal temporal-occipital, and lateral temporal regions. Experimental studies in animals and functional imaging studies in humans suggest that the area tempestas, a particular region of the basal-frontal piriform cortex, is critical for kindling and initiation and propagation of seizure activity arising from different cortical foci, especially limbic ones. This case report of a patient with late seizure relapse, three years following an initially successful right temporal lobectomy for ipsilateral medial temporal sclerosis, is the first one in the literature to demonstrate interictal EEG-fMRI evidence of significant BOLD signal changes over the inferior, basal and lateral temporal and temporooccipital cortices posterior to the resection margin, plus a significant BOLD signal change over the ipsilateral basal frontal region, closely corresponding to the piriform cortex/area tempestas. Our case study provides further functional imaging evidence in support of maturation/activation of proepileptic tissue located at the vicinity of the initial temporal lobe resection in cases of late seizure relapses and suggests, in addition, a possible role for the piriform cortex/area tempestas in the relapsing process.

No MeSH data available.


Related in: MedlinePlus

A) Interictal EEG of our patient showing a typical discharge of right frontal/frontotemporal distribution. B) Ictal EEG with right frontal/frontotemporal onset.
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f0005: A) Interictal EEG of our patient showing a typical discharge of right frontal/frontotemporal distribution. B) Ictal EEG with right frontal/frontotemporal onset.

Mentions: At 3, 12, and 24 months postoperation, the patient was continuously seizure-free and had had normal routine EEGs. Until the 24th month, the patient has been constantly on his preoperative antiepileptic regime, consisting of levetiracetam 2000 mg/day and oxcarbazepine 1200 mg/day. By that time, gradual oxcarbazepine withdrawal was undertaken, removing 300 mg from the total daily dosage every 3 months. About one month following complete oxcarbazepine withdrawal and under conditions of intense emotional stress, the patient relapsed. He would report again the same aura of rising epigastric sensation and fearful feeling, along with the same preoperative semiology of oral and manual automatisms, albeit with less clouding of awareness, shorter seizure duration, and rapid recovery. He experienced about 10 isolated events within the next 3 months until he was subjected to a new video-EEG study. The study revealed strictly unilateral, right-sided interictal sharp wave activity localized over the frontotemporal region (Fp2/F4/F8) (Fig. 1A). Several typical seizures were recorded with semiology similar to his preoperative ones and an ictal EEG correlate consisting of semirhythmic 2- to 3-Hz repetitive sharp waves evolving to 3- to 4-Hz sharply contoured waves, with a broad right anterior quadrant distribution closely resembling the preoperative ictal EEG (Fig. 1B). A new MRI scan demonstrated the cavity of the initial anteromedial temporal lobectomy and no evidence of new pathology.


EEG-fMRI findings in late seizure recurrence following temporal lobectomy: A possible contribution of area tempestas.

Garganis K, Kokkinos V, Zountsas B - Epilepsy Behav Case Rep (2013)

A) Interictal EEG of our patient showing a typical discharge of right frontal/frontotemporal distribution. B) Ictal EEG with right frontal/frontotemporal onset.
© Copyright Policy - CC BY-NC-ND
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4150631&req=5

f0005: A) Interictal EEG of our patient showing a typical discharge of right frontal/frontotemporal distribution. B) Ictal EEG with right frontal/frontotemporal onset.
Mentions: At 3, 12, and 24 months postoperation, the patient was continuously seizure-free and had had normal routine EEGs. Until the 24th month, the patient has been constantly on his preoperative antiepileptic regime, consisting of levetiracetam 2000 mg/day and oxcarbazepine 1200 mg/day. By that time, gradual oxcarbazepine withdrawal was undertaken, removing 300 mg from the total daily dosage every 3 months. About one month following complete oxcarbazepine withdrawal and under conditions of intense emotional stress, the patient relapsed. He would report again the same aura of rising epigastric sensation and fearful feeling, along with the same preoperative semiology of oral and manual automatisms, albeit with less clouding of awareness, shorter seizure duration, and rapid recovery. He experienced about 10 isolated events within the next 3 months until he was subjected to a new video-EEG study. The study revealed strictly unilateral, right-sided interictal sharp wave activity localized over the frontotemporal region (Fp2/F4/F8) (Fig. 1A). Several typical seizures were recorded with semiology similar to his preoperative ones and an ictal EEG correlate consisting of semirhythmic 2- to 3-Hz repetitive sharp waves evolving to 3- to 4-Hz sharply contoured waves, with a broad right anterior quadrant distribution closely resembling the preoperative ictal EEG (Fig. 1B). A new MRI scan demonstrated the cavity of the initial anteromedial temporal lobectomy and no evidence of new pathology.

Bottom Line: Late seizure relapses following temporal lobectomy for drug-resistant temporal lobe epilepsy occur in 18-30% of operated-on cases, and recent evidence suggests that a significant proportion of them are due to maturation and activation of proepileptic tissue having defied initial resection and located at the vicinity of or at a short distance from its borders, usually over the posterior medial, basal temporal-occipital, and lateral temporal regions.This case report of a patient with late seizure relapse, three years following an initially successful right temporal lobectomy for ipsilateral medial temporal sclerosis, is the first one in the literature to demonstrate interictal EEG-fMRI evidence of significant BOLD signal changes over the inferior, basal and lateral temporal and temporooccipital cortices posterior to the resection margin, plus a significant BOLD signal change over the ipsilateral basal frontal region, closely corresponding to the piriform cortex/area tempestas.Our case study provides further functional imaging evidence in support of maturation/activation of proepileptic tissue located at the vicinity of the initial temporal lobe resection in cases of late seizure relapses and suggests, in addition, a possible role for the piriform cortex/area tempestas in the relapsing process.

View Article: PubMed Central - PubMed

Affiliation: Epilepsy Center of Thessaloniki, "St. Luke's" Hospital, Panorama, Thessaloniki, Greece.

ABSTRACT
Late seizure relapses following temporal lobectomy for drug-resistant temporal lobe epilepsy occur in 18-30% of operated-on cases, and recent evidence suggests that a significant proportion of them are due to maturation and activation of proepileptic tissue having defied initial resection and located at the vicinity of or at a short distance from its borders, usually over the posterior medial, basal temporal-occipital, and lateral temporal regions. Experimental studies in animals and functional imaging studies in humans suggest that the area tempestas, a particular region of the basal-frontal piriform cortex, is critical for kindling and initiation and propagation of seizure activity arising from different cortical foci, especially limbic ones. This case report of a patient with late seizure relapse, three years following an initially successful right temporal lobectomy for ipsilateral medial temporal sclerosis, is the first one in the literature to demonstrate interictal EEG-fMRI evidence of significant BOLD signal changes over the inferior, basal and lateral temporal and temporooccipital cortices posterior to the resection margin, plus a significant BOLD signal change over the ipsilateral basal frontal region, closely corresponding to the piriform cortex/area tempestas. Our case study provides further functional imaging evidence in support of maturation/activation of proepileptic tissue located at the vicinity of the initial temporal lobe resection in cases of late seizure relapses and suggests, in addition, a possible role for the piriform cortex/area tempestas in the relapsing process.

No MeSH data available.


Related in: MedlinePlus