Ictal SPECT reveals different epileptogenic zones in frontal lobe epilepsy.

We report a patient with frontal lobe epilepsy due to a right frontal astrocytoma (WHO Grade III) in whom two ictal SPECTs (single photon emission tomography) were performed during two seizures with different semiology and different EEG seizure patterns. Subtraction of ictal and interictal SPECT showed right lateral frontal hyperperfusion during a left face clonic seizure, and right mesial fronto-polar hyperperfusion during a subclinical seizure. This report demonstrates that ictal SPECT may reflect different seizure semiology from the frontal lobe of the same individual and that simultaneous EEG is indispensable for the correct interpretation of SPECT in epilepsy.

Frontal Lobe Epilepsy: A Primer for Psychiatrists and a Systematic Review of Psychiatric Manifestations.

BACKGROUND: Frontal lobe epilepsy (FLE) can masquerade as a primary psychiatric condition, be misdiagnosed in-lieu of a true psychiatric disorder, or may be comorbid with psychiatric illness. OBJECTIVES: To (1) qualitatively review psychiatric manifestations of FLE and (2) to systematically review the cases/case series of psychiatric manifestations of FLE presented in the literature to date. METHODS: A systematic review of the literature was performed following the PRISMA guidelines and using PubMed/Medline, PsychInfo, and Cochrane database of systematic reviews to identify cases and case series of psychiatric manifestations of FLE. RESULTS: A total of 35 separate articles were identified. Further, 17 patients primarily presented with psychosis, 33 with affective symptoms, and 16 with personality changes. Also, 62% of cases were males and 38% were females. Ages ranged from 2-83 years with the average age of 32.7. Prior psychiatric history was reported in 27.3% of cases. Causes of seizure were known in 53%, with the most common causes being dysplasia and tumor. Only 6 cases (<10%) did not have electroencephalographic correlations. Psychiatric manifestations were primarily ictal in 74.3% of the cases. Associated manifestations included motor (63.6%), cognitive (34.8%), and medical (9.0%) findings. Surgery was required in 31.8% of the cases, whereas others were treated with medications alone. All, but 3, patients were seizure free and saw an improvement in symptoms with treatment. CONCLUSIONS: Given the complexity and multifunctionality of the frontal lobes, FLE can present with complex, psychiatric manifestations, with associated motor, cognitive, and medical changes; thus, psychiatrists should keep FLE on the differential diagnosis of complex neuropsychiatric cases.

Multimodal Assessment Reveals Late-Onset Hemispheric Shift of Language in a Child with Meningocerebral Dysplasia.

We report on a girl with progressive left frontal tissue destruction starting at the age of almost 8 years. She manifested acutely with epileptic seizures accompanied by Broca aphasia as well as transient right hemiparesis. Due to refractory epilepsy developing over the next years, which originated from the left frontal lobe, the decision was made to proceed to epilepsy surgery. By then, her language functions had recovered despite progressive left frontal tissue-destruction, raising the possibility of a hemispheric shift of language. Clinical functional magnetic resonance imaging (fMRI) was conducted to localize brain regions involved in language production. A complex pattern of clear right-hemispheric dominance, but with some left-sided contribution was found. However, a Wada test suggested the left hemisphere to be critical, seemingly contradicting fMRI. Invasive electroencephalogram recordings could reconcile these results by identifying the fMRI-detected, residual left-sided activation as being relevant for speech production. Only by combining the localizing information from fMRI with the information obtained by two invasive procedures could the unusual pattern of late-onset language reorganization be uncovered. This allowed for extensive left frontal resection, with histology confirming meningocerebral angiodysplasia. Postoperatively, language functions were preserved and seizure outcome was excellent. The implications of our findings for presurgical assessments in children are discussed.

[Clinicopathologic study of intractable epilepsy-related encephalitis].

OBJECTIVE: To investigate the clinicopathologic features of intractable epilepsy related encephalitis. METHODS: The clinical and pathologic findings of 15 cases of intractable epilepsy after functional neurosurgical treatment were reviewed and analyzed retrospectively. RESULTS: All patients, including four male and 11 female, had medically intractable epilepsy. The mean age of onset for seizure was 5.3 years (1-15 years) and the disease duration was 4.7 years (0.5-15 years). A definite past history was identified in 11 patients, including viral encephalitis in nine patients, anoxia in utero and head trauma in one patient respectively. The extent and sites of involvement were different, including single cerebral hemisphere diffusely in five cases, multiple lobes in seven cases, and single lobe in three cases. Temporal lobe was involved in 13 cases, frontal lobe in eight, parietal lobe in eight, occipital lobe in seven, and insular lobe in four. Microscopically, all cases were characterized by perivascular inflammatory cells infiltration in the subarachnoid space. The focal cerebral cortex showed obvious atrophy with various degrees of the neuronal loss and glial proliferation, eventually leading to glial scar formation. In addition, microglia nodules, lymphatic cuff and neuronophagia were also observed. Seven cases of focal cortical dysplasia were identified among the 11 cases with adequate perilesional cerebral cortex. Hippocampus sclerosis was found in two cases. Intranuclear inclusions were seen in six cases, and these were immunopositive of cytomegalovirus-late antigen, and three cases also showed multinucleated giant cells and calcifications. CONCLUSION: Encephalitis is one of the common causes of refractory epilepsy, and may result in refractory epilepsy as a sequel.

Novel pathological abnormalities of deep brain structures including dysplastic neurons in anterior striatum associated with focal cortical dysplasia in epilepsy.

OBJECT: Some patients are not seizure free even after epileptogenic cortical resection. The authors recently described a case of frontal lobe epilepsy cured after the resection of periventricular white matter and striatum, in which dysplastic neurons were revealed. The authors attempted to confirm similar cases. METHODS: They reviewed the records of 8 children with frontal lobe epilepsy who had daily (7) or monthly (1) seizures and underwent resections including deep brain structures. RESULTS: Five patients underwent multiple resections. Neuroimaging of the deep structures showed the transmantle sign in 3 patients, ictal hyperperfusion in 6, reduced iomazenil uptake in 2, and spike dipole clustering in 6. All patients became seizure free postoperatively. Focal cortical dysplasia of various types was diagnosed in all patients. Dysmorphic neurons were found in the cortex and subcortical white matter of 5 patients. The striatum was verified in 3 patients in whom dysmorphic neurons were scattered. In the periventricular white matter, prominent astrocytosis was evident in all cases. CONCLUSIONS: Pathological abnormalities such as dysmorphic neurons and astrocytosis in deep brain structures would play a key role in epileptogenesis.

Rates and predictors of long-term seizure freedom after frontal lobe epilepsy surgery: a systematic review and meta-analysis.

OBJECT: Frontal lobe epilepsy (FLE) is the second-most common focal epilepsy syndrome, and seizures are medically refractory in many patients. Although various studies have examined rates and predictors of seizure freedom after resection for FLE, there is significant variability in their results due to patient diversity, and inadequate follow-up may lead to an overestimation of long-term seizure freedom. METHODS: In this paper the authors report a systematic review and meta-analysis of long-term seizure outcomes and predictors of response after resection for intractable FLE. Only studies of at least 10 patients examining seizure freedom after FLE surgery with postoperative follow-up duration of at least 48 months were included. RESULTS: Across 1199 patients in 21 studies, the overall rate of postoperative seizure freedom (Engel Class I outcome) was 45.1%. No trend in seizure outcomes across all studies was observed over time. Significant predictors of long-term seizure freedom included lesional epilepsy origin (relative risk [RR] 1.67, 95% CI 1.36-28.6), abnormal preoperative MRI (RR 1.64, 95% CI 1.32-2.08), and localized frontal resection versus more extensive lobectomy with or without an extrafrontal component (RR 1.71, 95% CI 1.26-2.43). Within lesional FLE cases, gross-total resection led to significantly improved outcome versus subtotal lesionectomy (RR 1.99, 95% CI 1.47-2.84). CONCLUSIONS: These findings suggest that FLE patients with a focal and identifiable lesion are more likely to achieve seizure freedom than those with a more poorly defined epileptic focus. While seizure freedom can be achieved in the surgical treatment of medically refractory FLE, these findings illustrate the compelling need for improved noninvasive and invasive localization techniques in FLE.

Angiocentric glioma and surrounding cortical dysplasia manifesting as intractable frontal lobe epilepsy--case report.

A 26-year-old man presented with a case of angiocentric glioma manifesting as medically refractory epilepsy. Magnetic resonance imaging revealed a hyperintense lesion in the right superior frontal gyrus on T(2)-weighted imaging, with cortical hyperintense rim on T(1)-weighted images and minimum contrast enhancement. Video-electroencephalography (EEG) monitoring characterized his seizures as originating from the right frontal lobe. Long-term EEG recording from implanted subdural electrodes disclosed epileptic activities extending beyond the margin of the radiological lesion. Extended cortical resection of the superior frontal gyrus including the tumor and the surrounding epileptic cortices was performed. Postoperatively, he became seizure-free with antiepileptic medication during a 12-month follow-up period. Histological examination of the surgical specimen showed the characteristic findings of angiocentric glioma. Associated cortical dyslamination consistent with cortical dysplasia was found in the surrounding cortex. Angiocentric glioma is a slow-growing or stable tumor frequently presenting with intractable epilepsy. Surgical treatment would be aimed primarily at control of epilepsy. Complete lesionectomy usually results in postoperative seizure freedom, but the present case shows evidence for associated cortical dysplasia with this tumor entity. Careful pre-surgical evaluation for epilepsy is necessary to achieve better seizure outcome.

Cingulate epileptogenesis in hypothalamic hamartoma.

Hypothalamic hamartoma (HH) is a relatively rare cause of epilepsy, mainly affecting children. Nearly all patients develop gelastic seizures, often followed by other focal seizure types. Our case illustrates the mechanisms of epileptogenesis in HH. The patient developed gelastic attacks as a baby, and secondarily generalized seizures and drop attacks at 9 years of age. Magnetic resonance imaging (MRI) confirmed the presence of a HH. Presurgical assessment with intracranial electroencephalography (EEG) monitoring recorded gelastic seizures with generalized epileptiform activity. Functional stimulation of the hamartoma provoked gelastic attacks. Single pulse electrical stimulation (SPES) was used to identify epileptogenic cortex. SPES of the left cingular cortex provoked generalized responses similar to the spontaneous generalized discharges. Our results suggest that long-standing history of epilepsy in patients with HH may be related to additional sources of epileptogenic activity. Electrical stimulation performed in this patient provided additional data to favor the hypothesis of secondarily epileptogenesis in the cingulate gyrus independently from the primary origin in the HH.

[Case of frontal lobe epilepsy with gelastic seizures induced by emotion].

Gelastic seizures without hypothalamic hamartoma is a rare forms of epilepsy. Here, we report the case of 4-year-old girl with gelastic seizures. There was no delay in mental or motor development of the patient. The patient exhibited a peculiar seizure pattern that suddenly clung to her mother stiffening her body and an outburst of laughter with no apparent cause. The frequency of the seizures increased over a period of 1 month. Although the brain MRI and interictal EEG showed no abnormality, ictal EEG showed a 14 Hz wave discharge and subsequent slow-wave activity and suppression in bilateral frontal areas. The seizures responded favorably to oral administration of carbamazepine. The induction of the seizures could be related to theophylline administration and emotional excitation.

Interictal rhythmical midline theta differentiates frontal from temporal lobe epilepsies.

PURPOSE: We evaluated the role of interictal rhythmical midline theta (RMT) in the identification of frontal lobe epilepsy (FLE) and its differentiation from temporal lobe epilepsy (TLE) and nonepileptic controls. METHODS: We included 162 individuals in the study: 54 FLE patients, 54 TLE patients, and 54 nonepileptic controls. Continuous electroencephalographic (EEG)-video monitoring was performed in all individuals. Interictal RMT was included only if it occurred during definite awake states. RMT associated with drowsiness or mental activation and ictal RMT was excluded. RESULTS: We identified RMT significantly more frequently in FLE patients (48.1%, 26 of 54) than in TLE patients (3.7%, 2 of 54) (p < 0.01), and not in the control group. The average frequency was 6 Hz (range 5-7 Hz), and the average RMT bursts lasted 8 s (3-12 s). Interestingly, all mesial FLE patients (n = 4) (as established by invasive EEG recordings) showed RMT, whereas this was less frequently the case in the other FLE patients (44%, 22 of 50) (p = 0.03). Thirteen of our 54 patients with FLE (24%) did not have any interictal epileptiform discharges (IEDs), but RMT was observed in the majority of these patients (62%, 8 of 13). CONCLUSION: Interictal RMT is common and has a localizing value in patients with FLE, provided that conditions such as drowsiness and mental activation as confounding factors for RMT are excluded. RMT should be included in the evaluation of patients considered for resective epilepsy surgery.

[On the best strategies on the best results for surgery of frontal epilepsy]. / Quelles stratégies pour quels résultats dans la chirurgie des épilepsies partielles frontales?

Frontal lobe epilepsy surgery is the second most common surgery performed for drug-resistant partial epilepsy. We investigated the longitudinal outcome in a cohort of patients investigated since 1990 with SEEG and modern diagnostic techniques. We reviewed 105 patients who underwent surgery between 1990 and 2005 (mean follow-up, six years; range: one to 17 years) and analyzed the year-per-year follow-up according to Engel's classification. Favorable outcome (Class I) was observed for 70% and this result was stable at least five years after surgery. More than 90% of patients with lesion-related epilepsies (focal cortical dysplasia and dysembryoplastic neuroepithelial tumors) became seizure-free. Less than 50% of patients classified as having cryptogenic epilepsy (defined as normal imaging and neuropathology on surgical specimen) had a favorable outcome. Permanent neurological sequelae were subtle and rare, especially after surgery for dysplasia in eloquent cortex (primary motor cortex). Our data indicate that frontal surgery is a successful treatment in patients when electrophysiological and morphological investigations demonstrate a well-defined epileptogenic zone or lesion to be surgically resected. Progress in electrophysiological and brain-imaging techniques will further improve the selection of frontal lobe epilepsy surgery candidates.

Intractable cryptogenic frontal lobe epilepsy in a patient with MURCS association.

The MURCS association is a rare, nonrandom association of müllerian duct aplasia, renal aplasia and cervicothoracic somite dysplasia. The etiology is unknown. Although it is usually a sporadic disorder, familial cases with uterovaginal anomalies have been reported. Occasionally, it may be accompanied by abnormalities involving various other organs or systems. Malformations related to the central nervous system are very rare and the presence of seizures has not been reported previously. We present a 26-year-old female with MURCS association who had late onset, drug resistant partial seizures presumably originating in the frontal lobe.

[A case of coexistence with cavernous angioma and focal cortical dysplasia].

There have recently been a number of new pathological findings of specimens from epileptic foci that have become widespread of surgical treatment. We reported a case with seizures resulting from brain lesions which pathologically demonstrated a coexistence with a cavernous angioma and a focal cortical dysplasia. A 24-year-old man was admitted to our hospital because of generalized convulsion from 1 year ago. Brain MRI revealed an enhanced mass lesion, in diameter 1.5 cm, with hemosiderin rim in the left temporal tip. Ictal EEG showed the initiation of the spike from the lateral side of the left temporal lobe. Because the epileptogenic focus was thought to be the lateral side in the left temporal lobe, anterolateral temporal resection was performed and subsequently total removal of the tumor was performed. He had no seizure after surgery. A light microscopic examination was performed on specimens stained with hematoxilin and eosin. We verified to be pathologically coexistent with a cavernous angioma and a focal cortical dysplasia. We also found unusual neurons that were accompanied by perineuronal glial satellitosis in the subcortical white matter, those were occasionally observed in epileptic foci and were thought to be a form of neuronal migration disorders.

Uncommon, exceptional and atypical: a case of frontal lobe epilepsy due to cortical dysplasia.

We report a case of frontal lobe epilepsy due to focal cortical dysplasia that included three independent unusual features. The patient, a 45-year-old, right-handed woman, had her first seizure at age 29, well into adulthood. Seizures had been easily controlled with medication for 15 years, then without provocation they became medically intractable during a single, identifiable day. Resection of the dysplastic tissue in the posterior dorsolateral right frontal cortex rendered the patient seizure-free, but produced a significant, non-fluent, Broca type, crossed aphasia. In addition, the seizure semiology was striking and remarkable, a common finding in frontal lobe epilepsy. [Published with video sequences].

Temporal lobe epilepsy in childhood: review article

The authors present a review article on temporal lobe epilepsy in childhood. We performed a search in the literature. The main etiologies of temporal lobe epilepsy in childhood are developental tumors and focal cortical displasia, besides temporal medial sclerosis. The clinical features may be variable particularly in children younger than six years of age. Epilepsy may present with generalized seizures. Electroencephalographic findings are also variable and show a functional dysfunction of several brain areas besides temporal lobes, especially frontal lobes. Recent advances demonstrate that temporal lobe epilepsy in childhood present with great etiologic, clinical and electroencephalographic diversity

Ictal SPECT analyzed by three-dimensional stereotactic surface projection in frontal lobe epilepsy patients.

We analyzed preoperative ictal SPECT results from 18 frontal lobe epilepsy patients who underwent epilepsy surgery (mean age 22.9 years). Seizure onset at implanted subdural electrodes was defined as the epileptic focus in 16 of 18 patients. In two additional patients, the resected area on postoperative magnetic resonance images was defined as the epileptic focus. The radioisotope 99mTc-ECD was injected in all patients within 5 s after seizure onset. SPECT images were analyzed by three-dimensional stereotactic surface projection (3-D SSP). Areas of hyperperfusion identified by ictal SPECT were concordant with the site of epileptic focus in 11 patients (61.1%, concordant group) and were non-concordant in 7 patients (38.9%, non-concordant group). The non-concordant group had a higher number of patients with a history of acquired brain damages, such as encephalitis or brain surgery (p < 0.05). Only 3 of 11 patients in the concordant group showed areas of localized hyperperfusion within epileptic foci, whereas 8 patients showed areas of hyperperfusion extending to other regions. Ictal SPECT analyzed by 3-D SSP is useful as a mode of presurgical evaluation in frontal lobe epilepsy patients without a history of encephalitis or surgical treatment. We caution that rapid seizure spread may result occasionally in areas of hyperperfusion extending to adjacent or remote regions.

Spatio-temporal analysis by voltage topography of ictal electroencephalogram on MR surface anatomy scan for the localization of epileptogenic areas.

A 15-year-old girl developed intractable epilepsy following a right transcallosal resection of the intraventricular teratoma. Magnetic resonance (MR) imaging showed a T (2)-prolonged subcortical lesion in the right frontal lobe as well as a residual intraventricular tumor. The integration of the voltage topography of ictal onset activities of the scalp-recorded electroencephalogram (EEG) and a surface anatomy scan of MR images clearly revealed the epileptogenic area on the cortex above the subcortical lesion, with the propagation pattern towards the frontopolar area. Excision of the epileptogenic cortex and underlying gliosis resulted in a successful cessation of the epilepsy. This non-invasive EEG technique provided useful information that accurately localized the epileptogenic area on a large structural abnormality without invasive intracranial electrocorticographic monitoring.

Epilepsy and variation in the frontal lobe artery.

A patient with a rare variation of fronto-orbital artery (FOA) that developed generalized tonic and clonic seizures is reported. The epilepsy focus was in her left frontal region, where blood was supplied by the contralateral fronto-orbital artery. The region was vulnerable to ischemic changes due to a decrease in blood CO2 gas caused by an increase in endogenous progesterone in the luteal period. The anomaly illustrates an important mechanism of ischemia in epilepsy.

[Opercular syndrome after bilateral cerebral surgery: presentation of a case report]. / Síndrome opercular tras cirugía cerebral bilateral: presentacion de un caso.

AIM: To present a case of bilateral opercular syndrome after surgery on both cerebral hemispheres. CASE REPORT: A girl was studied at 3 years of age because of a benign intracranial tumor in the middle region of the brain. At the age of 5 years, the tumor was partially removed through the right hemisphere. Three years latter, the patient was operated through the left hemisphere because of growth in the tumor to the left side of the brain. After the second operation, the patient showed the complete symptomatology of the bilateral opercular syndrome, which did not change during this year. CONCLUSION: This is a case which the presence of a bilateral opercular syndrome seems to be caused by the surgical lesions of both opercular zones.