Temporal lobe surgery in Germany from 1988 to 2008: diverse trends in etiological subgroups.

BACKGROUND AND PURPOSE: In the epilepsy community, there is talk that the number of classical patients with early onset temporal lobe epilepsy (TLE) and Ammon's horn sclerosis (AHS) is decreasing. This is counterintuitive, considering the success story of epilepsy surgery, improved diagnostic methods and the current recommendation of early admission to surgery. In order to recognize trends, the development of temporal lobe surgery over 20 years in three major German epilepsy centers was reviewed. METHODS: Age at surgery and duration of epilepsy, which was differentiated according to histopathology (AHS, developmental, tumor, vascular), year of surgery and center, were evaluated in a cohort of 2812 patients from three German epilepsy centers who underwent temporal lobe surgery between 1988 and 2008. The analysis was carried out for the pooled cohort as well as for each center separately. RESULTS: Of all patients, 52% showed AHS. Compared with other pathologies, the AHS group had the earliest epilepsy onset and the longest duration of epilepsy. Across five time epochs, the diagnosis of AHS increased in the first epoch, remaining constant thereafter. Contrary to the trends in other pathologies, in the AHS group the mean age of patients at surgery increased by 7 years and the duration of epilepsy until surgery increased by 5 years. This trend could be replicated in all three centers. As initially hypothesized for all groups, age and duration of epilepsy in other pathology groups remained constant or indicated earlier submission to surgery. CONCLUSIONS: During the first few years studied, most probably due to progress in brain imaging, the proportion of patients with AHS increased. However, despite stable numbers over time, and contrary to the trends in other pathology groups, age and duration of epilepsy in mesial TLE with AHS (mTLE + AHS) increased over time. This supports the hypothesis of a decreasing incidence of AHS. This trend is discussed with respect to disease-modifying factors which have changed the incidence of classical mTLE + AHS or, alternatively, to recent developments in antiepileptic drug treatment, the appraisal of surgery and economic incentives for treatment options other than surgery.

A comprehensive analysis of early outcomes and complication rates after 769 craniotomies in pediatric patients.

PURPOSE: Perioperative complications following craniotomy in pediatric neurosurgery have received little attention. We analyzed perioperative complications and early outcomes following craniotomy in a large cohort of pediatric patients. METHODS: A retrospective chart review identified 769 operations (27 % epilepsy surgery, 26 % trauma, 21 % tumor, 7 % vascular, 4 % infections, 14 % other, and 88 % supratentorial) in 641 patients <16 years (mean age 8.5 years). We recorded all perioperative complications and functional outcomes 30 days after surgery. RESULTS: Excluding epilepsy surgery cases, 17.5 % patients had emergency surgery. There were 38 new major neurological deficits (5.0 %; excluding deficits incurred as part of the surgical strategy). New neurological deficits occurred more frequently following operations for brain tumors, when compared to other surgeries (P < 0.001), and after surgery for infratentorial lesions (P < 0.001). Local complications occurred in 3.9 %, systemic complications in 2.5 % of patients. Ventricular shunting or endoscopic ventriculostomy was necessary in 87 patients (11.3 %). Surgical mortality was 2.0 % (including moribund patients after trauma or vascular incidence). Preoperative Karnofsky Performance Index (KPI) and the incurrence of new neurological deficits proved the most powerful predictors of functional outcome. Emergency surgery or repeat craniotomies were not correlated with increased rates of local complications. CONCLUSIONS: Craniotomies for pediatric patients carry a low morbidity and mortality. Systemic complications seem to occur less often in the pediatric than in the adult population. Good surgical outcomes require a proper balance between local pediatric neurosurgical care for emergency cases and centralized treatment of more difficult cases.

Seizure outcome, functional outcome, and quality of life after hemispherectomy in adults.

BACKGROUND: Functional hemispherectomy is a well-established method in childhood epilepsy surgery with only a few reports on its application in adults. METHODS: We report on 27 patients (median age 30 years, range 19-55) with a follow-up of more than 1 year (median 124 months, range 13-234). Etiology was developmental in two (one schizencephaly, one hemimegalencephaly), acquired in 21 (two hemiatrophy, 17 porencephaly, two postencephalitic), and progressive in four (Rasmussen's encephalitis). RESULTS: At last available follow-up, 22 patients were seizure free (81 % ILAE class 1), one had auras (4 % ILAE class 2), one had no more than three seizures per year (4 % ILAE class 3). Thirty-seven percent were without antiepileptic drugs. Seventeen patients of 20 responding patients stated improved quality of life after surgery, one patient reported deterioration, and two patients reported no difference. Additionally, a self-rated postoperative functional status and changes compared to the pre-operative status was assessed. Six patients improved in gait, ten remained unchanged, and four deteriorated. Three patients improved in speech, none deteriorated. Hand function got worse five times, and in 15 cases remained unchanged. There was no mortality, one bone flap infection, and one subdural hematoma. Hydrocephalus was seen in three cases (12 %). CONCLUSIONS: It is possible to achieve good seizure outcome results despite long-standing epilepsy across a variety of etiologies, comparable to epilepsy surgery in pediatric patients. Adult patients do not have to expect more problems with new deficits, appear to cope quite well, and mostly profit from surgery in several quality of life domains.

Pediatric functional hemispherectomy: outcome in 92 patients.

BACKGROUND: The revival of epilepsy surgery after the introduction of modern presurgical evaluation procedures has led to an increase in hemispherectomy or hemispherotomy procedures. Since a large part of our pediatric series was done using a newer hemispherotomy technique, we focus mainly on the outcomes after a recently developed hemispherotomy technique (transsylvian keyhole). METHODS: Ninety-six pediatric patients (aged 4 months to 18 years, mean 7.3) were operated on between 1990 and 2009; 92 were available with follow-up. RESULTS: The most frequent diagnosis was porencephaly in 46 % of all patients. Progressive etiologies were present in 20 % and developmental etiologies in 22 %. At last available outcome (LAO), 85 % of the patients were seizure free (ILAE class 1). Year-to-year outcome was rather stable; usually over 80 % were class 1 for up to 13 years (n = 24). Of 92 assessable patients, 71 were treated with the transsylvian keyhole technique, with 89 % being seizure free. The overall shunt rate was 5.3 % for the whole series and 3 % for the keyhole technique subgroup. Mortality was 1 of 96 patients. Excluding patients with hemimegalencephaly (HME), patients with the shortest duration of epilepsy and the lowest age at seizure onset had the highest rates of seizure freedom. The etiology does influence outcome, with HME patients having the poorest seizure outcome and patients with Sturge-Weber syndrome and porencephaly having excellent seizure control. CONCLUSION: Hemispherotomies/functional hemispherectomies are very effective and safe procedures for treating drug-resistant epilepsy with extensive unihemispheric pathology. Etiology and surgery type clearly influence seizure outcome.

Insular lesionectomy for refractory epilepsy: management and outcome.

Surgical treatment of deep-seated insular lesions causing refractory epilepsy is thought to be difficult due to the complicated accessibility and close proximity of eloquent areas. Here we report our experience with insular lesionectomies. Twenty-four patients (range 1-62 years, mean 27) who underwent epilepsy-surgery for a lesion involving the insular region, were identified from the epilepsy surgery data bank. We analysed pre-surgical diagnostics, surgical strategy and postoperative follow up concerning functional morbidity and seizure outcome (range 12-168 months, mean 37.5). Eight patients had pure insular lesions, in 16 cases the lesion extended either to the frontal (n = 3) or temporal lobe (n = 8) or was multilobar (n = 5). Sixteen resections (66.7%) were done on the right side. Six patients required invasive EEG-recording, three patients received intra-operative electrocorticography. In seven patients only subtotal resection of the insular lesion was possible due to involvement of eloquent areas. Thirteen patients suffered from glial/glioneural tumours (WHO grades I-III), 11 from non-neoplastic lesions. Postoperatively, one patient had a hemihypesthesia and one patient had a deterioration of a pre-existing hemiparesis; two patients had a hemianopia as calculated deficit (mild permanent morbidity 16.6%). According to the ILAE-classification, 15 patients were completely seizure free (62.5%, ILAE 1). Around 79.2% had satisfactory seizure outcome (ILAE 1-3). In selected patients an individually tailored lesionectomy of insular lesions can be performed, which is acceptably safe and provides a high rate of satisfactory seizure relief. Even subtotal resection can result in good seizure control.

Epilepsy surgery for insular lesions.

OBJECTIVE: Due to the proximity of eloquent areas of the brain, the surgical treatment of insular lesions causing refractory epilepsy is considered difficult. We report here on our experience in this field. METHODS: We identified 24 patients (age: 1-62 years, mean 27) who underwent epilepsy surgery for an insular lesion from the epilepsy surgery data bank. We analyzed the preoperative diagnostics, surgical strategy and postoperative follow-up (duration: 12-168 months, mean 37.5) for functional morbidity and seizure outcome. RESULTS: Eight patients had strictly insular lesions while, in 16 cases, the lesion extended into the frontal (n=3) or temporal (n=8) lobe, or was multilobar (n=5). Sixteen resections (66.7%) were right-sided. Six patients required invasive EEG with implanted electrodes, while three had the aid of intraoperative electrocorticography. In 12 patients, continuous electrophysiological monitoring was used intraoperatively (phase reversal, motor evoked potentials) and, in seven, neuronavigation. In seven patients, only subtotal resection of the insular lesion was possible due to involvement of eloquent areas, and two patients required repeat surgery to complete the resection. Thirteen patients had glial/glioneural tumours (WHO grades I-III), 11 from non-neoplastic lesions. Postoperatively, two patients (8.3%) had a transient neurological deficit (hemiparesis and dysphasia, respectively). One patient had permanent hemihypaesthesia, another had permanent deterioration of preexistent hemiparesis and two had hemianopia as calculated deficit (16.6% rate of mild permanent morbidity). According to the International League against Epilepsy (ILAE) classification, 15 patients were totally seizure-free (62.5%, ILAE 1) and 79.2% had a satisfactory seizure outcome (ILAE 1-3). CONCLUSION: In selected patients, an individually tailored lesionectomy of insular lesions can be performed, with acceptable safety, to provide a high rate of satisfactory seizure relief. Indeed, even subtotal resection can result in effective seizure control.

Focal cortical dysplasia: long term seizure outcome after surgical treatment.

BACKGROUND: Studies of long term outcome after epilepsy surgery for cortical malformations are rare. In this study, we report our experience with surgical treatment and year to year long term outcome for a subgroup of patients with focal cortical dysplasia (FCD). METHODS: We retrospectively analysed the records of 49 patients (females n = 26; males n = 23; mean age 25 (11) years) with a mean duration of epilepsy of 18 years (range 1-45). Preoperative MRI, histological results based on the Palmini classification and clinical year to year follow-up according to the International League Against Epilepsy (ILAE) classification were available in all patients. RESULTS: 98% of patients had a lesion on preoperative MRI. In addition to lobectomy (n = 9) or lesionectomy (n = 40), 14 patients had multiple subpial transections of the eloquent cortex. The resected tissue was classified as FCD type II b in 41 cases with an extratemporal (88%) and FCD type II a in 8 cases with a temporal localisation (100%). After a mean follow-up of 8.1 (4.5) years, 37 patients (76%) were seizure free, a subgroup of 23 patients (47%) had been completely seizure free since surgery (ILAE class 1a) and 4 patients (8%) had only auras (ILAE class 2). Over a 10 year follow-up, the proportion of satisfactory outcomes decreased, mainly within the first 3 years. During long term follow-up, 48% stopped antiepileptic drug treatment, 34% received a driver's license and 57% found a job or training. CONCLUSION: Surgical treatment of epilepsy with FCD is not only successful in the short term but also has a satisfying long term outcome which remains constant after 3 years of follow-up but is not associated with better employment status or improvement in daily living.

Angiocentric neuroepithelial tumor mimicking Ammon's horn sclerosis--case report.

CASE REPORT: We report on a 46-year-old male patient with pharmacoresistant temporal lobe epilepsy (TLE). Based on ictal EEG patterns and MRI scans, Ammon's horn sclerosis (AHS) or an epilepsy-associated tumor was included in the differential diagnosis. RESULTS: Histopathological examination of the surgical specimen revealed the unusual finding of a monomorphous angiocentric neuroepithelial tumor composed of small round cells and bipolar processes with perivascular aggregation. Immunohistochemistry detected perivascular-oriented expression of GFAP and cytoplasmic immunoreactivity of EMA and vimentin. Mitotic or other signs of proliferative activity were lacking. During a 2-year follow-up, the patient was seizure-free. CONCLUSIONS: Albeit AHS is the most frequent finding in TLE specimens, uncommon neuroepithelial tumors with hippocampal growth pattern have to be considered in the differential diagnosis of mesial TLE. The present case meets the criteria of an angiocentric neuroepithelial tumor recently proposed as a new clinicopathological entity. These tumors may be compatible with a maldevelopmental origin during early brain development.

Treatment results in patients with intracranial ependymomas.

OBJECTIVE: To evaluate the treatment outcomes of patients with intracranial ependymomas. METHODS: Between 1988-2007, 27 consecutive patients, with 9 patients (33%) aged under 16 years, were treated at our institution for an intracranial ependymoma. Pertinent clinical data were retrieved from the patients' charts. The histopathological findings in 25 cases were reviewed using the 2007 World Health Organization (WHO) classification system. Median follow-up was 84 months. RESULTS: Infratentorial tumors were diagnosed in 22, and supratentorial tumors in 5 patients. Histopathological findings were ependymoma WHO grade II (E II) in 14 patients, and anaplastic ependymoma WHO grade III (AE III) in 13 patients. A complete tumor resection was achieved with the first operation in 20 cases (74%). Primary adjuvant therapy consisted of chemotherapy alone in a 17-month-old child with an incompletely resected posterior fossa AE III, radiation therapy alone in 4 cases, and combined radiation therapy and chemotherapy in 7 cases. Tumor recurrence was seen in 10 cases (37%), including 5 patients with an E II and 5 patients with an AE III. The 5-year progression-free survival (PFS) was 74% and 67% for E II and AE III, respectively. The 5-year PFS was 80% following a complete resection, and 56% in patients with a residual tumor. CONCLUSIONS: Surgery alone, as the primary treatment, achieves a good outcome in most patients with E II. Good results can be achieved with surgery and adjuvant local radiotherapy in patients with AE III.

The validity of the Child Behavior Checklist for children with epilepsy.

The validity of the Child Behavior Checklist (CBCL) for patients with epilepsy has been questioned, because several items may reflect seizure semiology rather than habitual behavior. This study compared a standard version of the CBCL with an adjusted version that excluded those ambiguous items. Participants were 58 pediatric patients with epilepsy who were assessed preoperatively and 1 year after successful surgical treatment. Before surgery, the adjusted version indicated significantly lower values for the scales Attention Problems, Thought Problems, and Total Problems than the standard version. After surgery, the difference between the standard and adjusted versions and the scores for the ambiguous items were unchanged, although all patients were completely seizure free at that time. Elevated scores on the ambiguous items thus probably reflect real behavioral problems and are not due to confusion with seizure semiology. The results support the CBCL as a valid assessment tool in children with epilepsy.

Correlation of health-related quality of life after surgery for mesial temporal lobe epilepsy with two seizure outcome scales.

PURPOSE: The objective of this study was to correlate health-related quality of life (HRQOL) after surgery for mesial temporal lobe epilepsy, as revealed by a postoperative screening tool, to different modalities of seizure outcome classification (Engel, International League Against Epilepsy (ILAE)). METHOD: One hundred twenty-eight of one hundred forty consecutive patients returned a HRQOL questionnaire at a mean of 36 months after selective amygdalohippocampectomy. Patients answered in two ways: with an absolute estimation (values 1-4) and with a self-rated relative change (-1, 0, +1) after surgery. RESULTS: Eighty patients were seizure- and aura-free (63.3% ILAE 1), 16 continued to have auras (12.5% ILAE 2), and 13 experienced 1-3 seizure days per year after surgery (10.2% ILAE 3). Ninety-two patients were classified seizure-free (71.9% Engel I), and 17 had two or fewer seizures per year (13.3% Engel II). Of 110 patients in ILAE 1-3, 100 (91%) stated good or even very good postoperative HRQOL, and 99 (90.0%) reported improvements in HRQOL. Only 9 of the remaining 18 (50%) reported good or very good HRQOL after surgery (P=0.01). Corresponding results were obtained with Engel classes I and II, suggesting a trend toward ILAE 1-3 and Engel I and II as overall satisfactory outcomes. A more detailed HRQOL assessment yielded lowest scores in the cognitive domain, and a significant correlation of self-rated changes in cognitive functioning with seizure control (P=0.01). Changes in physical capabilities and mood were significantly better with satisfactory seizure outcome (P=0.006 and P<0.001, respectively), whereas the social aspects were not significantly dependent on seizure outcome (P=0.06). CONCLUSION: Correlation of HRQOL and seizure control suggested that ILAE 1-3 and Engel I and II most likely represent overall satisfactory outcome. Subdomain analyses revealed cognitive abilities as the most critical feature associated with seizure control, whereas social aspects remained mainly stable.