Seizure-alerting behavior in dogs owned by people experiencing seizures.

INTRODUCTION: The unpredictability of epileptic seizures is considered an important threat to the quality of life of a person with epilepsy. Currently, however, there are no tools for seizure prediction that can be applied to the domestic setting. Although the information about seizure-alert dogs - dogs that display changes in behavior before a seizure that are interpreted by the owner as an alert - is mostly anecdotal; living with an alerting dog (AD) has been reported to improve quality of life of the owner by reducing the stress originating from the unpredictability of epileptic seizures and, sometimes, diminishing the seizure frequency. AIM OF THE STUDY: The aim of the study was to investigate, at an international level, the behaviors displayed by trained and untrained dogs that are able to anticipate seizures and to identify patient- and dog-related factors associated with the presence or absence of alerting behavior. METHODOLOGY: An online questionnaire for dog owners with seizures was designed. Information about the participants (demographics, seizure type, presence of preictal symptoms) and their dogs (demographics, behavior around the time of seizures) was collected. In addition, two validated scales were included to measure the human-dog relationship (Monash Dog-Owner Relationship scale (MDORS)) and five different traits of the dogs' personality (Monash Canine Personality Questionnaire refined (MCPQ-R)). RESULTS: Two hundred and twenty-seven responses of people experiencing seizures were received from six participant countries: 132 from people with dogs that had started alerting spontaneously, 10 from owners of trained AD, and the rest from owners of dogs that did not display any alerting behavior (nonalerting dog (NAD)). Individuals' gender, age, or seizure type did not predict the presence of alerting behavior in their dogs. People who indicated that they experience preictal symptoms were more likely to have a spontaneously AD. The owner-dog bond was significantly higher with ADs compared with NADs, and ADs scored significantly higher than NADs in the personality traits "Amicability", "Motivation", and "Training focus". CONCLUSION: This study collected a large group of dog owners with seizures reporting behavioral changes in their dogs before their seizures occurred. This was associated with the presence of preictal symptoms. The seizure-alerting behavior of the dog may have a positive influence on the bond between the owner and the dog.

Efficacy and safety of corpus callosotomy after vagal nerve stimulation in patients with drug-resistant epilepsy.

OBJECTIVE Vagal nerve stimulation (VNS) and corpus callosotomy (CC) have both been shown to be of benefit in the treatment of medically refractory epilepsy. Recent case series have reviewed the efficacy of VNS in patients who have undergone CC, with encouraging results. There are few data, however, on the use of CC following VNS therapy. METHODS The records of all patients at the authors' center who underwent CC following VNS between 1998 and 2015 were reviewed. Patient baseline characteristics, operative details, and postoperative outcomes were analyzed. RESULTS Ten patients met inclusion criteria. The median follow-up was 72 months, with a minimum follow-up of 12 months (range 12-109 months). The mean time between VNS and CC was 53.7 months. The most common reason for CC was progression of seizures after VNS. Seven patients had anterior CC, and 3 patients returned to the operating room for a completion of the procedure. All patients had a decrease in the rate of falls and drop seizures; 7 patients experienced elimination of drop seizures. Nine patients had an Engel Class III outcome, and 1 patient had a Class IV outcome. There were 3 immediate postoperative complications and 1 delayed complication. One patient developed pneumonia, 1 developed transient mutism, and 1 had persistent weakness in the nondominant foot. One patient presented with a wound infection. CONCLUSIONS The authors demonstrate that CC can help reduce seizures in patients with medically refractory epilepsy following VNS, particularly with respect to drop attacks.

Investigating social cognition in epilepsy using a naturalistic task.

OBJECTIVE: The primary objective for this study was to assess social cognition in patients with focal epilepsy using a naturalistic task, which accurately models complex real-world social interaction. METHODS: We conducted an observational study of social cognition in 43 patients with focal epilepsy and in 22 controls. Patients and controls completed The Awareness of Social Inference Test, which measures both basic and advanced social cognition in a realistic video-based format. Patient and controls also completed standard measures of cognitive functioning and measures of depression. RESULTS: Compared to controls, we found that patients with epilepsy (PWEs) had no difficulty identifying positively valenced emotional states (happiness) yet had difficulty identifying most negatively valenced emotional states (anger, fear, and disgust). In addition, PWEs were able to identify sincere exchanges correctly but could not identify sarcastic and insincere exchanges. We found that basic social cognition significantly correlated with standard generalized cognitive measures, whereas advanced social cognition did not. Finally, age at onset had significant impact on social cognition, whereas other epilepsy characteristics did not. SIGNIFICANCE: PWEs have deficits in social cognition when measured using a naturalistic video-based task. Advanced social cognition may be an independent cognitive domain in PWEs that is not adequately measured using standard psychometric instruments. Problems with social cognition may arise as a consequence of epilepsy during the periods of robust social development in childhood and adolescence.

Migraine and epilepsy: review of the literature.

Migraine and epilepsy are disorders that are common, paroxysmal, and chronic. In many ways they are clearly different diseases, yet there are some pathophysiological overlaps, and overlaps in clinical symptomatology, particularly with regard to visual and other sensory disturbances, pain, and alterations of consciousness. Epidemiological studies have revealed that the two diseases are comorbid in a number of individuals. Both are now recognized as originating from electrical disturbances in the brain, although their wider manifestations involve the recruitment of multiple pathogenic mechanisms. An initial excess of neuronal activity in migraine leads to cortical spreading depression and aura, with the subsequent recruitment of the trigeminal nucleus leading to central sensitization and pain. In epilepsy, neuronal overactivity leads to the recruitment of larger populations of neurons firing in a rhythmic manner that constitutes an epileptic seizure. Migraine aura and headaches may act as a trigger for epileptic seizures. Epilepsy is not infrequently accompanied by preictal, ictal, and postictal headaches that often have migrainous features. Genetic links are also apparent between the two disorders, and are particularly evident in the familial hemiplegic migraine syndromes where different mutations can produce either migraine, epilepsy, or both. Also, various medications are found to be effective for both migraine and epilepsy, again pointing to a commonality and overlap between the two disorders.

A comparison of continuous video-EEG monitoring and 30-minute EEG in an ICU.

AIM: To determine whether there is added benefit in detecting electrographic abnormalities from 16-24 hours of continuous video-EEG in adult medical/surgical ICU patients, compared to a 30-minute EEG. METHODS: This was a prospectively enroled non-randomized study of 130 consecutive ICU patients for whom EEG was requested. For 117 patients, a 30-minute EEG was requested for altered mental state and/or suspected seizures; 83 patients continued with continuous video-EEG for 16-24 hours and 34 patients had only the 30-minute EEG. For 13 patients with prior seizures, continuous video-EEG was requested and was carried out for 16-24 hours. We gathered EEG data prospectively, and reviewed the medical records retrospectively to assess the impact of continuous video-EEG. RESULTS: A total of 83 continuous video-EEG recordings were performed for 16-24 hours beyond 30 minutes of routine EEG. All were slow, and 34% showed epileptiform findings in the first 30 minutes, including 2% with seizures. Over 16-24 hours, 14% developed new or additional epileptiform abnormalities, including 6% with seizures. In 8%, treatment was changed based on continuous video-EEG. Among the 34 EEGs limited to 30 minutes, almost all were slow and 18% showed epileptiform activity, including 3% with seizures. Among the 13 patients with known seizures, continuous video-EEG was slow in all and 69% had epileptiform abnormalities in the first 30 minutes, including 31% with seizures. An additional 8% developed epileptiform abnormalities over 16-24 hours. In 46%, treatment was changed based on continuous video-EEG. CONCLUSION: This study indicates that if continuous video-EEG is not available, a 30-minute EEG in the ICU has a substantial diagnostic yield and will lead to the detection of the majority of epileptiform abnormalities. In a small percentage of patients, continuous video-EEG will lead to the detection of additional epileptiform abnormalities. In a sub-population, with a history of seizures prior to the initiation of EEG recording, the benefits of continuous video-EEG in monitoring seizure activity and influencing treatment may be greater.

Quality improvement opportunities in caring for patients with nonepileptic seizures.

Background. Patients with nonepileptic seizures (NES) are challenging to treat for myriad reasons. Often patients may be misdiagnosed with having epilepsy and then may suffer unintended consequences of treatment side effects with antiepileptic medication. In addition, patients may be maligned by health care providers due to a lack of ownership by both psychiatrists and neurologists and a dearth of dedicated professionals who are able to effectively treat and reduce severity and frequency of symptoms. Aims of Case Report. Many psychiatrists and neurologists are unaware of the extent of the barriers to care faced by patients with NES (PWNES) and the degree of perception of maltreatment or lack of therapeutic alliance at various stages of their care, including medical workup, video-EEG monitoring, and follow-up plans. We present the case of a patient with NES who experienced numerous barriers as well as incoordination to her care despite being offered a breadth of resources and discuss the quality improvement opportunities that may exist to improve care of patients with NES. Conclusion. No known literature has documented the extensive barriers to care of PWNES in parallel to quality improvement opportunities for improving their care. We endeavor to contribute to the overall formulation and development of a clinical care pathway for PWNES.

Reducing severity of comorbid psychiatric symptoms in an epilepsy clinic using a colocation model: results of a pilot intervention.

RATIONALE: Patients with epilepsy (PWEs) and patients with nonepileptic seizures (PWNESs) constitute particularly vulnerable patient populations and have high rates of psychiatric comorbidities. This potentially decreases quality of life and increases health-care utilization and expenditures. However, lack of access to care or concern of stigma may preclude referral to outpatient psychiatric clinics. Furthermore, the optimal treatment for NESs includes longitudinal psychiatric management. No published literature has assessed the impact of colocated psychiatric services within outpatient epilepsy clinics. We, therefore, evaluated the colocation of psychiatric services within a level 4 epilepsy center. METHODS: From July 2013 to June 2014, we piloted an intervention to colocate a psychiatrist in the Dartmouth-Hitchcock Epilepsy Center outpatient clinic one afternoon a week (0.1 FTE) to provide medication management and time-limited structural psychotherapeutic interventions to all patients who scored greater than 15 on the Neurological Disorders Depression Inventory for Epilepsy (NDDI-E) and who agreed to referral. Psychiatric symptom severity was assessed at baseline and follow-up visits using validated scales including NDDI-E, Patient Health Questionnaire-9 (PHQ-9), Generalized Anxiety Disorder-7 (GAD-7), and cognitive subscale items from Quality of Life in Epilepsy-31 (QOLIE-31) scores. RESULTS: Forty-three patients (18 males; 25 females) were referred to the clinic over a one-year interval; 27 (64.3%) were seen in follow-up with a median of 3 follow-up visits (range: 1 to 7). Thirty-seven percent of the patients had NESs exclusive of epilepsy, and 11% of the patients had dual diagnosis of epilepsy and NESs. Psychiatric symptom severity decreased in 84% of the patients, with PHQ-9 and GAD-7 scores improving significantly from baseline (4.6±0.4 SD improvement in PHQ-9 and 4.0±0.4 SD improvement in GAD-7, p-values<0.001). Cognitive subitem scores for NDDI-E and QOLIE-31 at their most recent visit were significantly improved compared with nadir scores (3.3±0.6 SD improvement in NDDI-E and 1.5±0.2 SD improvement in QOLIE-31, p-values<0.001). These results are, moreover, clinically significant-defined as improvement by 4-5 points on PHQ-9 and GAD-7 instruments-and are correlated with overall improvement as measured by NDDI-E and cognitive subscale QOLIE-31 items. CONCLUSION: A colocated psychiatrist demonstrated reduction in psychiatric symptoms of PWEs and PWNESs, improving psychiatric access and streamlining their care. Epileptologists were able to dedicate more time to managing epilepsy as opposed to psychiatric comorbidities. As integrated models of collaborative and colocated care are becoming more widespread, mental health-care providers located in outpatient neurology clinics may benefit both patients and providers.

Long-term seizure, cognitive, and psychiatric outcome following trans-middle temporal gyrus amygdalohippocampectomy and standard temporal lobectomy.

OBJECT: Previous comparisons of standard temporal lobectomy (STL) and selective amygdalohippocampectomy (SelAH) have been limited by inadequate long-term follow-up, variable definitions of favorable outcome, and inadequate consideration of psychiatric comorbidities. METHODS: The authors performed a retrospective analysis of seizure, cognitive, and psychiatric outcomes in a noncontemporaneous cohort of 69 patients with unilateral refractory temporal lobe epilepsy and MRI evidence of mesial temporal sclerosis after either an STL or an SelAH and examined seizure, cognitive, and psychiatric outcomes. RESULTS: The mean duration of follow-up for STL was 9.7 years (range 1-18 years), and for trans-middle temporal gyrus SelAH (mtg-SelAH) it was 6.85 years (range 1-15 years). There was no significant difference in seizure outcome when "favorable" was defined as time to loss of Engel Class I or II status; better seizure outcome was seen in the STL group when "favorable" was defined as time to loss of Engel Class IA status (p=0.034). Further analysis revealed a higher occurrence of seizures solely during attempted medication withdrawal in the mtg-SelAH group than in the STL group (p=0.016). The authors found no significant difference in the effect of surgery type on any cognitive and most psychiatric variables. Standard temporal lobectomy was associated with significantly higher scores on assessment of postsurgical paranoia (p=0.048). CONCLUSIONS: Overall, few differences in seizure, cognitive, and psychiatric outcome were found between STL and mtg-SelAH on long-term follow-up. Longer exposure to medication side effects after mtg-SelAH may adversely affect quality of life but is unlikely to cause additional functional impairment. In patients with high levels of presurgical psychiatric disease, mtg-SelAH may be the preferred surgery type.

Occipitotemporal hippocampal depth electrodes in intracranial epilepsy monitoring: safety and utility.

OBJECT: Intracranial monitoring for epilepsy has been proven to enhance diagnostic accuracy and provide localizing information for surgical treatment of intractable seizures. The authors investigated the usefulness of hippocampal depth electrodes in the era of more advanced imaging techniques. METHODS: Between 1988 and 2010, 100 patients underwent occipitotemporal hippocampal depth electrode (OHDE) implantation as part of invasive seizure monitoring, and their charts were retrospectively reviewed. The authors' technique involved the stereotactically guided (using the Leksell model G frame) implantation of a 12-contact depth electrode directed along the long axis of the hippocampus, through an occipital twist drill hole. RESULTS: Of the 100 patients (mean age 35.0 years [range 13-58 years], 51% male) who underwent intracranial investigation, 84 underwent resection of the seizure focus. Magnetic resonance imaging revealed mesial temporal sclerosis (MTS) in 27% of patients, showed abnormal findings without MTS in 55% of patients, and showed normal findings in 18% of patients. One patient developed a small asymptomatic occipital hemorrhage around the electrode tract. The use of OHDEs enabled epilepsy resection in 45.7% of patients who eventually underwent standard or selective temporal lobe resection. The hippocampal formation was spared during surgery because data obtained from the depth electrodes showed no or only secondary involvement in 14% of patients with preoperative temporal localization. The use of OHDEs prevented resections in 12% of patients with radiographic evidence of MTS. Eighty-three percent of patients who underwent resection had Engel Class I (68%) or II (15%) outcome at 2 years of follow-up. CONCLUSIONS: The use of OHDEs for intracranial epilepsy monitoring has a favorable risk profile, and in the authors' experience it proved to be a valuable component of intracranial investigation. The use of OHDEs can provide the sole evidence for resection of some epileptogenic foci and can also result in hippocampal sparing or prevent likely unsuccessful resection in other patients.

Interictal PET and ictal subtraction SPECT: sensitivity in the detection of seizure foci in patients with medically intractable epilepsy.

PURPOSE: Interictal positron emission tomography (PET) and ictal subtraction single photon emission computed tomography (SPECT) of the brain have been shown to be valuable tests in the presurgical evaluation of epilepsy. To determine the relative utility of these methods in the localization of seizure foci, we compared interictal PET and ictal subtraction SPECT to subdural and depth electrode recordings in patients with medically intractable epilepsy. METHODS: Between 2003 and 2009, clinical information on all patients at our institution undergoing intracranial electroencephalography (EEG) monitoring was charted in a prospectively recorded database. Patients who underwent preoperative interictal PET and ictal subtraction SPECT were selected from this database. Patient characteristics and the findings on preoperative interictal PET and ictal subtraction SPECT were analyzed. Sensitivity of detection of seizure foci for each modality, as compared to intracranial EEG monitoring, was calculated. KEY FINDINGS: Fifty-three patients underwent intracranial EEG monitoring with preoperative interictal PET and ictal subtraction SPECT scans. The average patient age was 32.7 years (median 32 years, range 1-60 years). Twenty-seven patients had findings of reduced metabolism on interictal PET scan, whereas all 53 patients studied demonstrated a region of relative hyperperfusion on ictal subtraction SPECT suggestive of an epileptogenic zone. Intracranial EEG monitoring identified a single seizure focus in 45 patients, with 39 eventually undergoing resective surgery. Of the 45 patients in whom a seizure focus was localized, PET scan identified the same region in 25 cases (56% sensitivity) and SPECT in 39 cases (87% sensitivity). Intracranial EEG was concordant with at least one study in 41 cases (91%) and both studies in 23 cases (51%). In 16 (80%) of 20 cases where PET did not correlate with intracranial EEG, the SPECT study was concordant. Conversely, PET and intracranial EEG were concordant in two (33%) of the six cases where the SPECT did not demonstrate the seizure focus outlined by intracranial EEG. Thirty-three patients had surgical resection and >2 years of follow-up, and 21 of these (64%) had Engel class 1 outcome. No significant effect of imaging concordance on seizure outcome was seen. SIGNIFICANCE: Interictal PET and ictal subtraction SPECT studies can provide important information in the preoperative evaluation of medically intractable epilepsy. Of the two studies, ictal subtraction SPECT appears to be the more sensitive. When both studies are used together, however, they can provide complementary information.

Subdural interhemispheric grid electrodes for intracranial epilepsy monitoring: feasibility, safety, and utility: clinical article.

OBJECT: Intracranial monitoring for epilepsy has been proven to enhance diagnostic accuracy and provide localizing information for surgical treatment of intractable seizures. The authors investigated their experience with interhemispheric grid electrodes (IHGEs) to assess the hypothesis that they are feasible, safe, and useful. METHODS: Between 1992 and 2010, 50 patients underwent IHGE implantation (curvilinear double-sided 2 × 8 or 3 × 8 grids) as part of arrays for invasive seizure monitoring, and their charts were retrospectively reviewed. RESULTS: Of the 50 patients who underwent intracranial investigation with IHGEs, 38 eventually underwent resection of the seizure focus. These 38 patients had a mean age of 30.7 years (range 11-58 years), and 63% were males. Complications as a result of IHGE implantation consisted of transient leg weakness in 1 patient. Of all the patients who underwent resective surgery, 21 (55.3%) had medial frontal resections, 9 of whom (43%) had normal MRI results. Localization in all of these cases was possible only because of data from IHGEs, and the extent of resection was tailored based on these data. Of the 17 patients (44.7%) who underwent other cortical resections, IHGEs were helpful in excluding medial seizure onset. Twelve patients did not undergo resection because of nonlocalizable or multifocal disease; in 2 patients localization to the motor cortex precluded resection. Seventy-one percent of patients who underwent resection had Engel Class I outcome at the 2-year follow-up. CONCLUSIONS: The use of IHGEs in intracranial epilepsy monitoring has a favorable risk profile and in the authors' experience proved to be a valuable component of intracranial investigation, providing the sole evidence for resection of some epileptogenic foci.

Outcome of frontal lobe epilepsy surgery.

PURPOSE: There is still controversy in deciding which patients with frontal lobe epilepsy (FLE) should undergo resective surgery, even though it is a well-established therapy. The aim of this study is to define multiple outcome measures and determine whether there are certain subpopulations of preferred surgical candidates that have a more favorable seizure prognosis. METHODS: Fifty-eight patients underwent resective FLE surgery with a mean follow-up period of 79.3 months (range 12-208 months). Patient demographics, clinical seizure characteristics, seizure-onset zone within the frontal lobes, and diagnostic tests were tabulated. Engel class, International League Against Epilepsy (ILAE) class, postoperative seizure patterns, time to first recurrent seizure, and seizures and employment during the last year of follow-up were used as outcome measures. Neuropsychological performance and Beck Depression Inventory (BDI) scores were used to define neuropsychological outcome and examined as predictors of seizure outcome. KEY FINDINGS: Thirty-three (57%) patients with resective surgery had an Engel class I outcome and 29 (50%) had an ILAE class I outcome. Mean time to first seizure after surgery was 33.3 months (range 0-208). Only 14 patients (24%) were completely seizure-free without auras (Engel IA) throughout the entire follow-up period. The most common pattern of seizure recurrence was mixed, with prolonged periods of seizure freedom intermixed with recurrences. In addition, 32% of patients made gains in employment and 52% were able to reduce use of antiepileptic drugs (AEDs), although only 9% discontinued AEDs. No significant association was found between class I or class IA outcome and the presence of a focal magnetic resonance imaging (MRI) abnormality, any specific localization of seizure focus within the frontal lobe, or neuropsychological change. SIGNIFICANCE: Findings indicate that that long-term outcome is generally favorable in FLE resective surgery, and support the need for considering multiple outcome measures to more fully characterize clinically relevant postsurgical changes. Outcome can be favorable even in MRI-negative patients.

Seizure prognosis of patients with low-grade tumors.

PURPOSE: Seizures frequently impact the quality of life of patients with low grade tumors. Management is often based on best clinical judgment. We examined factors that correlate with seizure outcome to optimize seizure management. METHODS: Patients with supratentorial low-grade tumors evaluated at a single institution were retrospectively reviewed. Using multiple regression analysis the patient characteristics and treatments were correlated with seizure outcome using Engel's classification. RESULTS: Of the 73 patients with low grade tumors and median follow up of 3.8 years (range 1-20 years), 54 (74%) patients had a seizure ever and 46 (63%) had at least one seizure before tumor surgery. The only factor significantly associated with pre-surgical seizures was tumor histology. Of the 54 patients with seizures ever, 25 (46.3%) had a class I outcome at last follow up. There was no difference in seizure outcome between grade II gliomas (astrocytoma grade II, oligodendroglioma grade II, mixed oligo-astrocytoma grade II) and other pathologies (pilocytic astrocytoma, ependymomas, DNET, gangliocytoma and ganglioglioma). Once seizures were established seizure prognosis was similar between different pathologies. Chemotherapy (p=0.03) and radiation therapy (p=0.02) had a positive effect on seizure outcome. No other parameter including significant tumor growth during the follow up period predicted seizure outcome. Only three patients developed new-onset seizures after tumor surgery that were non-perioperative. Anticonvulsant medication was tapered in 14 patients with seizures and 10 had no further seizures. Five patients underwent additional epilepsy surgery with a class I outcome in four. Two patients received a vagal nerve stimulator with >50% seizure reduction. DISCUSSION: Seizures at presentation are the most important factor associated with continued seizures after tumor surgery. Pathology does not influence seizure outcome. Use of long term prophylactic anticonvulsants is unwarranted. Chemotherapy and radiation therapy have a favorable impact on seizure outcome. Additional epilepsy surgery is effective.

Efficacy of vagus nerve stimulation for refractory epilepsy among patient subgroups: a re-analysis using the Engel classification.

Optimal candidates for VNS as a treatment for refractory epilepsy have not been identified. In this retrospective two-center study, we used the Engel classification for evaluating seizure outcome, and tried to identify predictive factors for outcome by means of subgroup analysis. The medical records of patients who have been treated with VNS for at least one year at Dartmouth-Hitchcock Medical Center and Ghent University Hospital were evaluated. Seizure frequency outcome was assessed using the Engel classification for the study population as a whole, and for patient subgroups with regard to mental functioning, seizure type, predisposing factors for developing epilepsy, age at time of VNS implantation and epilepsy duration. 189 patients (102M/87F) were included in the study (mean FU: 41 months). 6% had a class I outcome (seizure-free), 13% a class II outcome (almost seizure-free), 49% a class III outcome (worthwhile improvement) and 32% had a class IV outcome (no improvement). When patients were divided into specific subgroups, a statistically significant better outcome was found patients with normal mental functioning (p=0.029). In our series, results for VNS are clearly inferior to resective surgery, but comparable to other treatment modalities for refractory epilepsy. With combined class I and II outcomes around 20%, and another 50% of patients having worthwhile improvement, VNS is a viable alternative when resective surgery is not feasible.

Stereotactic depth electrode investigation of the insula in the evaluation of medically intractable epilepsy.

OBJECT: The authors describe their experience with stereotactic implantation of insular depth electrodes in patients with medically intractable epilepsy. METHODS: Between 2001 and 2009, 20 patients with epilepsy and suspected insular involvement during seizures underwent intracranial electrode array implantation at the authors' institution. All patients had either 1 or 2 insular depth electrodes placed as part of an intracranial array. RESULTS: A total of 29 insular depth electrodes were placed using a frontal oblique trajectory. Eleven patients had a single insular electrode placed and 8 patients had 2 insular electrodes placed unilaterally. One patient had bilateral insular electrodes implanted. Postoperative imaging demonstrated satisfactory placement in all but 1 instance, and there was no associated morbidity or mortality. Fourteen patients underwent a subsequent resection, involving the frontal lobe (9 patients), temporal lobe (4), or frontotemporal lobes (1), and of these, 11 currently have Engel Class I outcome. Two patients (10%) had seizures originating within the insula and another 5 patients (25%) demonstrated early specific insular involvement. Neither patient with an insular seizure focus went on to resection. All 5 of the patients with early specific insular involvement underwent an insula-sparing resective procedure with Engel Class I outcome in all cases. CONCLUSIONS: Stereotactic placement of insular electrodes via a frontal oblique approach is a safe and efficient technique for investigating insular involvement in medically intractable epilepsy. The information obtained from insular recording can be valuable for appreciating the degree of insular contribution to seizures, allowing localization to the insula or clearer implication of other sites.

Intractable occipital lobe epilepsy: clinical characteristics and surgical treatment.

Intractable occipital lobe epilepsy remains a surgical challenge. Clinical characteristics of 14 patients were analyzed. Twelve patients had surgery, seven patients had visual auras (50%) and only eight patients (57%) had posterior scalp EEG changes. Ictal single-proton emission computed tomography (SPECT) incorrectly localized in 7 of 10 patients. Six patients (50%) had Engel's class I outcome. Patients with inferior occipital seizure onset appeared to fare better (three of four class I) than patients with lateral or medial occipital seizure onset (three of eight class I). Patients who had all three occipital surfaces covered with electrodes had a better outcome (four of five class I) than patients who had limited electroencephalography (EEG) coverage (two of seven class I). Magnetic resonance imaging (MRI) lesions did not guarantee a seizure free outcome. In conclusion, visual auras, scalp EEG, and imaging findings are not reliable for correct identification of occipital onset. Occipital seizure onset can be easily missed in nonlesional epilepsy. Comprehensive intracranial EEG coverage of all three occipital surfaces leads to better outcomes.