[Show abstract][Hide abstract] ABSTRACT: Objective
Selective serotonin reuptake inhibitors (SSRIs) are often used in the treatment of depressive disorders in patients with epilepsy. Pro- and anti-convulsive effects of SSRIs are discussed controversially. The aim of this study was to investigate a possible impact of SSRIs-treatment on duration of EEG and clinical features in epilepsy patients.
We studied video-EEG data from 162 patients with focal epilepsies between January 2006 and March 2008 using a case-control study design. Eleven patients with 19 complex focal seizures (CFSs) and 16 secondary generalised tonic-clonic seizures (sGTCSs) treated with SSRIs (SSRIs+) were matched to 13 patients without SSRIs-treatment (SSRIs-). We compared duration of ictal EEG in CFSs and sGTCSs, duration of convulsions in sGTCSs and duration of postictal EEG suppression after sGTCSs in SSRIs+ and SSRIs- patients.
Ictal EEG duration of both, CFSs and sGTCSs, was significantly longer in SSRIs+ patients than in SSRIs- patients (p = 0.004 and p = 0.015, respectively). No significant difference was found between convulsive phase duration of sGTCSs as well as duration of postictal EEG suppression after sGTCSs in both groups.
Seizures last significantly longer in patients with epilepsy and SSRIs as co-medication. A causative role of SSRIs in ictal activity has to be explored in prospective studies.
Clinical neurology and neurosurgery 01/2014; · 1.30 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Midbrain-hindbrain malformations (MHM) may coexist with malformations of cortical development (MCD). This study represents a first attempt to investigate the spectrum of MHM in a large series of patients with MCD and epilepsy. We aimed to explore specific associations between MCD and MHM and to compare two groups of patients: MCD with MHM (wMHM) and MCD without MHM (w/oMHM) with regard to clinical and imaging features. Two hundred and twenty patients (116 women/104 men, median age 28 years, interquartile range 20-44 years at the time of assessment) with MCD and epilepsy were identified at the Departments of Neurology and Pediatrics, Innsbruck Medical University, Austria. All underwent high-resolution MRIs (1.5-T) between 01.01.2002 and 31.12.2011. Midbrain-hindbrain structures were visually assessed by three independent raters. MHM were seen in 17% (38/220) of patients. The rate of patients wMHM and w/oMHM differed significantly (p=0.004) in three categories of MCD (category I - to abnormal neuronal proliferation; category II - to abnormal neuronal migration; and category III - due to abnormal neuronal late migration/organization): MCD due to abnormal neuronal migration (31%) and organization (23%) were more commonly associated with MHM compared to those with MCD due to abnormal neuronal proliferation (9%). Extensive bilateral MCD were seen more often in patients wMHM compared to those w/oMHM (63% vs. 36%; p=0.004). In wMHM group compared to w/oMHM group there were higher rates of callosal dysgenesis (26% vs. 4%; p<0.001) and hippocampal abnormalities (52% vs. 27%; p<0.001). Patients wMHM were younger (median 25 years vs. 30 years; p=0.010) at the time of assessment and had seizure onset at an earlier age (median 5 years vs. 12 years; p=0.043) compared to those w/oMHM. Patients wMHM had higher rates of learning disability (71% vs. 38%; p<0.001), delayed developmental milestones (68% vs. 35%; p<0.001) and neurological deficits (66% vs. 47%; p=0.049) compared to those w/oMHM. The groups (wMHM and w/oMHM) did not differ in their response to antiepileptic treatment, seizure outcome, seizure types, EEG abnormalities and rate of status epilepticus. Presence of MHM in patients with MCD and epilepsy is associated with severe morphological and clinical phenotypes.
[Show abstract][Hide abstract] ABSTRACT: The objective of this study was to further explore proper name (PN) retrieval and conceptual knowledge in patients with left and right temporal lobe epilepsy (69 patients with LTLE and 62 patients with RTLE) using a refined assessment procedure. Based on the performance of a large group of age- and education-matched normals, a new test of famous faces and famous landmarks was designed. Recognition, naming, and semantic knowledge were assessed consecutively, allowing for a better characterization of deficient levels in the naming system. Impairment in PN retrieval was common in the cohort with TLE. Furthermore, side of seizure onset impaired stages of name retrieval differently: LTLE impaired the lexico-phonological processing, whereas RTLE mainly impaired the perceptual-semantic stage of object recognition. In addition to deficient PN retrieval, patients with TLE had reduced conceptual knowledge regarding famous persons and landmarks.
[Show abstract][Hide abstract] ABSTRACT: Valproic acid (VPA), as one of the most widely prescribed antiepileptic drugs (AED) for many types of epilepsy in adults and children, is associated with weight gain, alteration of adipocytokine homeostasis, insulin resistance and Non-Alcoholic Fatty Liver Disease (NAFLD). Retinol-binding protein 4 (RBP4) and Glucagon-like peptide-1 (GLP-1) are considered as important new targets in modern type 2 diabetes mellitus therapy linked to insulin resistance, NAFLD and visceral obesity acting via peripheral or central mechanisms. We herein demonstrate the lack of an influence of VPA treatment on RBP4 and GLP-1 in otherwise healthy patients. In summary, the absence of any relationship with RBP4 and GLP-1 concentrations does not suggest a role of these novel insulin resistance parameters as potential regulators of glucose and fat metabolism during VPA-therapy.
[Show abstract][Hide abstract] ABSTRACT: This study investigates the impact of generalized tonic-clonic seizures (GTCS) and antiepileptic drugs (AED) during pregnancy on gestational age (GA) and anthropometric data of newborns. One hundred twenty-nine singleton pregnancies resulting in live births from September 1999 to October 2010 in 106 women with epilepsy on AED therapy, recorded within the framework of the EURAP (International Registry of Antiepileptic Drugs and Pregnancy) program at the Department of Neurology, Medical University Innsbruck, Austria, were studied. Occurrence of ≥1 GTCS during pregnancy was associated with a shorter GA [median (range) 37.5 [35.1-41.6] vs. 39.7 [29.1-46.3] weeks; p ≤ 0.001], an overall five times higher preterm risk (p = 0.042) and a reduced birth weight in boys (2,900 [2,050-3,870] vs. 3,205 [1,575-4,355] g; p = 0.040). In primipara, when compared to multipara, GTCS ≥1 significantly reduced the GA (37.9 [35.1-41.6] vs. 39.7 [29.4-44.9] weeks; p = 0.020) and raised the incidence of low birth weight (LBW) (p = 0.022) in neonates. Antiepileptic drug polytherapy significantly increased the risk for small-for-gestational-age regarding weight (SGA(W); p = 0.035) and regarding weight and/or length (SGA(W/L); p = 0.046) when compared to monotherapy. GTCS during pregnancy was associated with diverse negative effects comprising shorter GA, an increased incidence of prematurity and LBW in primiparous women. Furthermore, AED polytherapy was correlated with an enhanced risk for SGA delivery. Re-evaluating the need for drug therapy (in particular polytherapy), maintaining seizure control for a given period before pregnancy and counseling about the importance of preventing GTCS might improve pregnancy outcome in women with epilepsy.
Journal of Neurology 09/2012; · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Selective amygdalohippocampectomy (AHE) has been associated with postoperative cerebral vasospasm (CVS) in patients with medically intractable temporal lobe epilepsy. The incidence in temporal lobe resection (TLR) is unknown. This retrospective cohort study evaluates the incidence of and risk factors for the development of CVS in patients with TLR and AHE.
A total of 119 patients were included between 1998 and 2009. All patients were evaluated by standardized preoperative and postoperative transcranial Doppler sonography (TCD) evaluations and neurologic examinations. Postoperative CT scans were evaluated by an independent radiologist and the volume of bleeding within the resection cavity was quantified.
Of 107 patients with longitudinal TCD data, 35 (32.7%) developed postoperative CVS. The incidence of CVS did not differ between patients with TLR and AHE. CVS was associated with female gender and a higher bleeding volume in the postoperative CT scan (p = 0.035 and 0.046). Patients with CVS showed a significantly higher incidence of postoperative neurologic signs and symptoms (48.6%) compared to patients without CVS (25%, p = 0.015). The mean length of stay was significantly prolonged in patients with diffuse CVS compared to patients with localized CVS or no CVS (28.8 ± 10.9, 24.2 ± 6.6, and 18.2 ± 6.1 days, p < 0.001).
CVS is a frequent complication of surgery for temporal lobe epilepsy irrespective of the resection method. Important risk factors for the development of postoperative CVS are female gender and a higher amount of bleeding in the postoperative CT. Patients with CVS more frequently have neurologic signs and symptoms resulting in prolonged hospital stay.
[Show abstract][Hide abstract] ABSTRACT: Status epilepticus (SE) and seizure clusters (SC) represent neurologic emergencies with a case fatality rate up to 34%, depending on cause and comorbidity. As SE becomes more refractory to treatment over time, appropriate medication is important. This study aimed to investigate efficacy and tolerability of intravenous (IV) lacosamide (LCM) in treatment of SC and SE. Data of patients with SE or SC who were treated with IV LCM between December 2009 and February 2011 in two Austrian centers were analyzed retrospectively. Clinical information was extracted from patients' charts. Forty-eight patients (26f/22m) aged median 62 years (range 17-95 years) were identified. Thirty-five percent of patients (17 of 48) had SC and 65% (31 of 48) had SE. SE was nonconvulsive in 10 (32%), convulsive in 11 (36%), and focal in 10 (32%) patients. SE was acute symptomatic in six (20%) and remote symptomatic in 11 (35%) patients. Fourteen (45%) had preexisting epilepsy. Median initial bolus dose was 200 mg (range 200-400 mg) in patients with SE and 200 mg in patients with SC. Maximum infusion rate was 60 mg/min. Cessation was observed in 42 patients (88%). Success rate in patients with SE receiving LCM as first or second drug was 100% (8 of 8), as third drug 81% (11 of 15), and as fourth or later drug 75% (6 of 8). There were no side effects observed except for pruritus and skin rash in two patients. These data support use of IV LCM as a potential alternative to standard antiepileptic drugs for acute treatment of seizure emergency situations, although randomized controlled studies are needed.
[Show abstract][Hide abstract] ABSTRACT: Cranial nerves (CNs) crossing between the brainstem and skull base at the level of the tentorial hiatus may be at risk in temporomesial surgery involving subpial dissection and/or tumorous growth leading to distorted anatomy. We aimed to identify the surgical steps most likely to result in CN damage in this type of surgery.
Electromyographic responses obtained with standard neuromonitoring techniques and a continuous free-running EMG were graded as either contact activity or pathological spontaneous activity (PSA) during subpial resection of temporomesial structures in 16 selective amygdalohippocampectomy cases. Integrity of peripheral motor axons was tested by transpial/transarachnoidal electrical stimulation while recording compound muscle action potentials from distal muscle(s).
Continuous EMG showed pathological activity in five (31.2%) patients. Nine events with PSA (slight activity, n = 8; strong temporary activity, n = 1) were recorded. The oculomotor nerve was involved three times, the trochlear nerve twice, the facial nerve once, and all monitored nerves on three occasions. Surgical maneuvers associated with PSA were the resection of deep parts of the hippocampus and parahippocampal gyrus (CN IV, twice; CN III, once), lining with or removing cotton patties from the resection cavity (III, twice; all channels, once) and indirect exertion of tension on the intact pia/arachnoid of the uncal region while mobilizing the hippocampus and parahippocampal gyrus en bloc (all channels, once; III, once). CMAPs were observed at 0.3 mA in two patients and at 0.6 mA in one patient, and without registering the exact amount of intensity in three patients.
The most dangerous steps leading to cranial nerve damage during mesial temporal lobe surgery are the final stages of the intervention while the resection is being completed in the deep posterior part and the resection cavity is being lined with patties. Distant traction may act on nerves crossing the tentorial hiatus via the intact arachnoid.
[Show abstract][Hide abstract] ABSTRACT: Video-electroencephalography (EEG) monitoring plays a central role in the presurgical evaluation of medically refractory epilepsies and the diagnosis of nonepileptic attack disorders (NEADs). The aim of this study was to analyze safety and adverse events (AEs) during video-EEG monitoring.
We retrospectively evaluated 596 video-EEG sessions in 507 patients (233 men, mean age 36 years, standard deviation = 14, range 9-80 years) within a 6-year period. AEs were examined in detail and their risk factors were assessed using multiple logistic regression analysis. Key
Forty-four patients (9%) experienced 53 AEs: 20 had psychiatric events (17 postictal psychosis, 2 panic attacks, 1 interictal psychosis), 15 had injuries (14 falls with minor injuries, 2 falls with fractures, 2 fractures without fall, 1 fall with epidural hematoma), 10 patients had 13 episodes of status epilepticus (SE), and one AE was treatment-related (valproic acid--induced encephalopathy). Patients with AEs were older (p = 0.036) and had a longer duration of epilepsy (p = 0.019). All AEs resulted in a prolonged hospital stay (p < 0.001). Ninety-one percent of the AEs occurred within the first 4 days of monitoring. Independent risk factors were duration of epilepsy >17 years [odds ratio (OR) 3.096; 95% confidence interval (CI) 1.548-6.189], a previous history of psychiatric illness (OR 16.882; 95% CI 5.469-52.110), a history of seizure-related injuries (OR 3.542; 95% CI 1.069-11.739), or a history of SE (OR 3.334; 95% CI 1.297-8.565). Significance: The most common AEs were postictal psychosis, falls, and SE. Patients with an older age, long disease duration, psychiatric comorbidity, history of injuries, and SE have a higher risk.
[Show abstract][Hide abstract] ABSTRACT: Hippocampal abnormalities may coexist with malformations of cortical development (MCD). This cross-sectional MRI study aimed at categorizing hippocampal abnormalities in a large group of MCD and comparing MCD patients with (group W) and without (group W/O) hippocampal abnormalities.
Hippocampal anatomy, rotation, size, internal structure, and MRI signal alterations were assessed visually by 3 independent raters in patients with MCD and epilepsy. Four types of hippocampal abnormalities were examined in 220 patients (116 women, mean age 31 +/- 16.6, range 2-76 years): partially infolded/hypoplastic hippocampus (HH), hippocampal sclerosis (HS), malrotated hippocampus (MH), and enlarged hippocampus (EH). The commonest MCD in the cohort were focal cortical dysplasia (27%), polymicrogyria (PMG) (21%), developmental tumors (15%), and periventricular nodular heterotopia (PNH) (14%).
Hippocampal abnormalities were seen in 69/220 (31%) patients: HH in 34/69 (49%); HS in 18/69 (26%); MH in 15/69 (22%); and EH in 2/69 (3%). PNH (21/30 [70%]) and PMG (22/47 [47%]) were most commonly associated with hippocampal abnormalities. Compared to the W/O group, patients in the W group had a higher rate of learning disability (W 41/69 [59%] vs W/O 56/151 [37%]; p = 0.003) and delayed developmental milestones (W 36/69 [52%] vs W/O 53/151 [35%]; p = 0.025); groups did not differ otherwise with regard to clinical presentation. HH was associated with symptomatic generalized epilepsies (11/34 [32%]) and high rate of learning disability (27/34 [79%]), neurologic deficits (25/34 [73%]), and delayed developmental milestones (23/34 [68%]).
About a third of patients with malformations of cortical development had hippocampal abnormalities. Patients with hypoplastic hippocampus had the most severe clinical phenotype.
[Show abstract][Hide abstract] ABSTRACT: To review the experience with a new system (VBH system) for minimally invasive frameless stereotactic guidance, acting as a common platform to provide multimodal image integration and surgical navigation in a consecutive series of 25 patients who underwent surgery for drug-resistant seizures.
The usefulness of the VBH system for integrating all images to produce one dataset and for intraoperative instrument guidance and navigation was judged semiquantitatively in a three-tiered scale (+, ++, +++). Seizure outcome was classified according to Engel.
The presurgical evaluation extended over 21.2 months (mean). A total of 141 registrations of images were performed (mean 5.6 per patient, range: 2 to 16). In 19 (76%) of 25 patients structural data fused with functional data were used for the presurgical workup. Six patients proceeded directly to navigated resection. Nineteen patients (76%) underwent invasive recording, of whom 13 underwent resective surgery. In seven patients (28%) the combination of multimodal image fusion and intra-operative stereotactic guidance was judged "essential" (+++) to remove the epileptogenic zone. Integration of all images to form one dataset was "essential" (+++) for decision making in 15 and "helpful" (++) in 4 patients (overall 76% of patients). Intraoperative use of frameless neuronavigation was "essential" (+++) in ten and "helpful" (++) in all remaining patients. Eighty percent of the patients achieved satisfactory seizure outcome after 1 year.
The VBH system is a safe and effective non-invasive tool for repetitive imaging, multimodal image fusion and frameless stereotactic surgical navigation in candidates for epilepsy surgery.
[Show abstract][Hide abstract] ABSTRACT: Patients undergoing long-term treatment with valproic acid (VPA) are prone to develop different features of the metabolic syndrome (MS). The aim of the present study was to evaluate the occurrence of non-alcoholic fatty liver disease (NAFLD), insulin resistance (IR) and a pro-atherogenic lipid profile in patients undergoing VPA, carbamazepine (CBZ) and lamotrigine (LTG) monotherapy compared to healthy controls.
Abdominal ultrasound as well as measurement of serum fasting insulin and glucose, serum lipids and liver function parameters were performed in VPA (n=23), CBZ (n=22) and LTG (n=23) treated non-diabetic and non-obese epileptic patients compared to healthy controls (n=16).
Ultrasound measurement demonstrated characteristics of fatty liver disease in 60.9% of VPA, in 22.7% of CBZ, in 8.7% of LTG treated patients and in 12.5% of the healthy controls, with highest level of steatosis seen in VPA treated patients. In addition, patients on VPA monotherapy showed a higher body-mass index (BMI) when compared to LTG treated patients and controls (p<or=0.049). Total cholesterol (TC), low-density lipoprotein cholesterol (LDL-C), high-density lipoprotein cholesterol (HDL-C) and gamma-glutamyltransferase (gammaGT) were greatest in the CBZ group (p<or=0.043). Interestingly, serum fasting glucose, serum fasting insulin as well as the HOMA-IR did not differ significantly between groups.
In conclusion, VPA (and moderately CBZ) therapy is related to increased risk for ultrasonographic signs of fatty liver disease, emphasizing the importance of regular ultrasound measurements as well as monitoring of serum lipids and BMI during enzyme-modulating AED treatment.
Epilepsy research 05/2009; 86(1):42-7. · 2.48 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: [Case records of Epileptic Disorders. Anatomo-electro clinical correlations. Case 01-2009]. Tuberous sclerosis complex (TSC) is a multisystem genetic disorder with variable phenotypic expression, caused by mutations in one of the two tumor suppressor genes, TSC1 or TSC2. Epilepsy is the most common neurological presentation and seizures are often medically intractable. Definition of the epileptogenic zone during presurgical evaluation is challenging given the multiple potentially epileptogenic lesions visible on MRI. However, TSC patients may nevertheless achieve seizure freedom, when preoperative evaluation yields concordant results. The strategies used in these patients vary substantially among different epilepsy surgery centres. We present a 21-year-old right-handed, intellectually not impaired woman with TSC and medically intractable seizures since the age of 15 years. Careful multi-stage presurgical evaluation, including prolonged video-EEG-monitoring, cerebral high resolution MRI, ictal and interictal [99m Tc]HMPAO-SPECT, [18 F]FDG-PET and further invasive recordings with subdural and depth electrodes led to the identification of an epileptogenic tuber with concordant seizure onset zone in the right neocortical temporal lobe. A tailored resection was performed leading to excellent surgical outcome (follow-up 12 months, Engel class I).
Epileptic disorders: international epilepsy journal with videotape 04/2009; 11(1):75-9. · 1.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: In temporal lobe epilepsies an asymmetric termination (AST) of the clonic phase of secondary generalized tonic-clonic seizures (sGTCS) reliably lateralizes the side of seizure onset. The last clonic activity occurs ipsilateral to the side of the seizure onset zone. We compared the prevalence and lateralizing value of AST in sGTCS of frontal and temporal lobe origin as well as in primary generalized tonic-clonic seizures (pGTCS).
We analyzed 177 seizures in 84 consecutive patients. Forty-one patients had temporal lobe epilepsy (TLE), 24 frontal lobe epilepsy (FLE), and 19 had nonfocal (primary) generalized epilepsies (GE). All patients underwent intensive video-EEG (electroencephalography) monitoring, high-resolution magnetic resonance imaging (MRI), neuropsychological testing, and single photon emission computed tomography/positron emission tomography (SPECT/PET) when feasible. Two investigators blinded for diagnosis, EEG, and imaging data assessed frequency and side of the last clonic jerk.
AST occurred in 63% of patients with TLE (47% of seizures), in 71% with FLE (60% of seizures), and in 42% with GE (21% of seizures). These results were not significant for patients, but significant for seizures in TLE versus GE and in FLE versus GE (p < 0.001). The positive predictive value (PPV) for the side of seizure onset was 74% (p = 0.003) in TLE and 75% (p = 0.008) in FLE.
AST in sGTCS lateralizes the side of seizure onset in TLE and in FLE to the ipsilateral hemisphere with a high PPV. However, AST was also observed in GE. Therefore, asymmetric clinical signs should not inevitably lead to the assumption of focal epilepsy syndromes.
[Show abstract][Hide abstract] ABSTRACT: Antiepileptic drugs (AEDs) like phenytoin (PHE), carbamazepine (CBZ), barbiturates and valproic acid (VPA) interfere with folic acid absorption and metabolism, which in turn can be the cause of adverse pregnancy outcome.
To study the prophylactic effect of folic acid supplementation with regard to spontaneous abortion and preterm delivery (fetal demise after week 20 of gestational age) in pregnant women receiving AED therapy, as well as benefits of most common dosage and preconceptional commencement.
Prospective examination of 104 patients, registered in EURAP from 1999-2004 at a single center and a retrospective analysis of data from our epilepsy databank completed with medical records and patients interviews of the Department of Neurology of Innsbruck University Hospital from 1971 to 1999.
388 pregnancies in 244 patients were analyzed. Pregnancies with folic acid supplementation showed significant reduction of spontaneous abortion. With regard to monotherapies, in the group of women taking VPA, supplementation of folic acid had significant benefit. Other examined monotherapies (CBZ, PHE, and PB) known to interfere with folic acid showed no significant results.
This study confirms the prophylactic effect of folic acid supplementation on spontaneous abortion. For AED therapy, folic acid supplementation should be part of the therapy of every pregnant epileptic woman, especially for those treated with VPA.
Journal of Neurology 08/2008; 255(12):1926-31. · 3.58 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Head and eye turning is frequently observed during seizures. Versions with tonic and/or clonic symptoms can be differentiated from smooth head deviations. Head turning as a prominent symptom of status epilepticus has not previously been reported. We present eight case reports, (7 women/1 man, mean age 41 years, median 41.5, range 10 to 74), of status epilepticus (SE), with head turning as a prominent motor symptom. Six were accompanied by continuous frontal, occipital and temporal ictal epileptiform discharges. Furthermore, two patients had absence status with rhythmic and clonic head versions. While the localizing significance of head turnings in SE is low, in our cases, the direction was away from the discharging hemisphere in all cases of focal SE regardless of whether the turning was classified as version (three cases) or deviation (three cases). In this small series of SE, the classical observation of a patient looking away from the discharging hemisphere is still valid.
Epileptic disorders: international epilepsy journal with videotape 07/2008; 10(2):119-29. · 1.17 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Medial temporal (MTL) structures have crucial functions in episodic (EM), but also in semantic memory (SM) processing. Preoperative functional magnetic resonance imaging (fMRI) activity within the MTL is increasingly used to predict post-surgical memory capacities. Based on the hypothesis that EM and SM memory functions are both hosted by the MTL the present study wanted to explore the relationship between SM related activations in the MTL as assessed before and the capacity of EM functions after surgery. Patients with chronic unilateral left (n=14) and right (n=12) temporal lobe epilepsy (TLE) performed a standard word list learning test pre- and postoperatively, and a fMRI procedure before the operation using a semantic decision task. SM processing caused significant bilateral MTL activations in both patient groups. While right TLE patients showed asymmetry of fMRI activation with more activation in the left MTL, left TLE patients had almost equal activation in both MTL regions. Contrasting left TLE versus right TLE patients revealed greater activity within the right MTL, whereas no significant difference was observed for the reverse contrast. Greater effect size in the MTL region ipsilateral to the seizure focus was significantly and positively correlated with preoperative EM abilities. Greater effect size in the contralateral MTL was correlated with better postoperative verbal EM, especially in left TLE patients. These results suggest that functional imaging of SM tasks may be useful to predict postoperative verbal memory in TLE. They also advocate a common neuroanatomical basis for SM and EM processes in the MTL.
Brain Research 07/2008; 1223:73-81. · 2.88 Impact Factor
[Show abstract][Hide abstract] ABSTRACT: Semi-invasive foramen ovale electrodes (FOEs) are used as an alternative to invasive recording techniques in the presurgical evaluation of patients with temporal lobe epilepsy. To maximize patient safety and interventional success, frameless stereotactic FOE placement by use of a variation of an upper jaw fixation device with an external fiducial frame, in combination with an aiming device and standard navigation software, was evaluated by the Innsbruck Epilepsy Surgery Program.
Patients were immobilized noninvasively with the Vogele-Bale-Hohner headholder (Medical Intelligence GmbH, Schwabmünchen, Germany) to plan computed tomography and surgery. Frameless stereotactic cannulation of the foramen and intracranial electrode placement were achieved with the help of an aiming device mounted to the base plate of the headholder. Ease of applicability, safety, and results obtained with foramen ovale recording were investigated.
Twenty-six FOEs were placed in 13 patients under general anesthesia. The foramen ovale was successfully cannulated in all patients. One patient reported transient painful mastication after the procedure as a complication attributable to use of the Vogele-Bale-Hohner mouthpiece. In one patient, a persistent slight buccal hypesthesia was present 3 months after the procedure. To pass the foramen, slight adjustments in the needle position had to be made in 10 sides (38.4%). To place the intracranial electrodes, adjustments were necessary six times (23.7%). An entirely new path had to be planned once (3.8%). Seizure recording provided conclusive information in all patients (100%). Outcome in operated patients was Engel Class Ia in six patients, Class IId in one patient, Class IIb in one patient, and Class IVa in one patient (minimum follow-up, 6 mo).
The Vogele-Bale-Hohner headholder combined with an external registration frame eliminates the need for invasive head clamp fixation. FOE placement can be planned "offline" and performed under general anesthesia later. This can be valuable in patients with distorted anatomy and/or small foramina or in patients not able to undergo the procedure under sedation. Results are satisfactory with regard to patient safety, patient comfort, predictability, and reproducibility. FOEs supported further treatment decisions in all patients.