SUMMARYObjective: Focal cortical dysplasia (FCD) is currently recognized as the most common cause of neocortical pharmacoresistant epilepsy. Epilepsy surgery has become an increasingly successful treatment option. Herein, the largest patient cohort reported to date is analyzed regarding long-term outcome and factors relevant for long-term seizure control. Methods: Two hundred eleven children and adults undergoing epilepsy surgery for histologically proven FCD and a follow-up period of 2-12 years were analyzed regarding the longitudinal course of seizure control, effects of FCD type, localization, magnetic resonance imaging (MRI), timing of surgery, and postoperative antiepileptic treatment. Results: After 1 year, Engel class I outcome was achieved in 65% of patients and the percentage of seizure-free patients remained stable over the following (up to 12) years. Complete resection of the assumed epileptogenic area, lower age at surgery, and unilobar localization were positive prognostic indicators of long-term seizure freedom. Seizure recurrence was 12% after the first year, whereas 8% achieved late seizure freedom either following additional introduction of antiepileptic drugs (AEDs) (4%), a reoperation (2%), or a running down phenomenon (2%). Thirty-nine percent of patients had a reduction of AED from polytherapy to monotherapy or a complete cessation of AED treatment. Late seizure relapse was seen in nine patients during reduction of AEDs (i.e., in 12% of all patients with AED tapering); in four of them seizures persisted after reestablishment of antiepileptic medication. Significance: Postoperative long-term seizure outcome was favorable in patients with FCD and remained stable in 80% of patients after the first postoperative year. Several preoperative factors revealed to be predictive for the postoperative outcome and may help in the preoperative counseling of patients with FCD and in the selection of ideal candidates for epilepsy surgery.

SUMMARYPurpose: To evaluate the potential diagnostic value of a novel magnetic resonance image (MRI) postprocessing technique in subtle forms of subcortical band heterotopia (SBH). The method was introduced to improve the visualization of blurred graywhite matter junctions associated with focal cortical dysplasia but was found to be applicable also to SBH. We have recently proposed a new voxel-based method for postprocessing of magnetic resonance images (MRIs) in order to improve the recognition and delineation of focal cortical dysplasia (FCD) . The method is based on algorithms of SPM (statistical parametric mapping software, Wellcome Department of Imaging Neuroscience Group, London, U.K., http://www.fil.ion.ucl.ac.uk/spm) and was developed to highlight brain regions with blurring, that is, disturbed dif-

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The reliability of frontal and temporal fMRI activations for the determination of hemisphere language dominance was evaluated in comparison with intracarotid amytal testing (IAT). Twenty-two patients were studied by IAT (bilateral in 13, unilateral in 9 patients) and fMRI using a paradigm requiring semantic decisions. Global and regional (frontal and temporoparietal) lateralisation indices (LI) were calculated from the number of activated (r>0.4) voxels in both hemispheres. Frontolateral activations associated with the language task were seen in all patients, temporoparietal activations in 20 of 22. Regional LI corresponded better with IAT results than global LI. Frontolateral LI were consistent with IAT in all patients with bilateral IAT (including three patients with right dominant and one patient with bilateral language representation) and were not conflicting in any of the patients with unilateral IAT. Temporoparietal LI were discordant with IAT in two patients with atypical language representation. In the determination of hemisphere dominance for language, regional analysis of fMRI activation is superior to global analysis. In cases with clear-cut fMRI lateralisation, i.e. consistent lateralised activation of frontal and temporoparietal language zones, IAT may be unnecessary. FMRI should be performed prior to IAT in all patients going to be operated in brain regions potentially involved in language.

Depth recordings in patients with Parkinson's disease on dopaminergic therapy have revealed a tendency for oscillatory activity in the basal ganglia that is sharply tuned to frequencies of approximately 70 Hz and increases with voluntary movement. It is unclear whether this activity is essentially physiological and whether it might be involved in arousal processes. Here we demonstrate an oscillatory activity with similar spectral characteristics and motor reactivity in the human thalamus. Depth signals were recorded in 29 patients in whom the ventral intermediate or centromedian nucleus were surgically targeted for deep brain stimulation. Thirteen patients with four different pathologies showed sharply tuned activity centred at approximately 70 Hz in spectra of thalamic local field potential (LFP) recordings. This activity was modulated by movement and, critically, varied over the sleep-wake cycle, being suppressed during slow wave sleep and re-emergent during rapid eye movement sleep, which physiologically bears strong similarities with the waking state. It was enhanced by startle-eliciting stimuli, also consistent with modulation by arousal state. The link between this pattern of thalamic activity and that of similar frequency in the basal ganglia was strengthened by the finding that fast thalamic oscillations were lost in untreated parkinsonian patients, paralleling the behaviour of this activity in the basal ganglia. Furthermore, there was sharply tuned coherence between thalamic and pallidal LFP activity at approximately 70 Hz in eight out of the 11 patients in whom globus pallidus and thalamus were simultaneously implanted. Subcortical oscillatory activity at approximately 70 Hz may be involved in movement and arousal.

Roughly a third of patients with temporal lobe epilepsy due to antero-inferior meningoencephaloceles is obese and has MRI signs of idiopathic intracranial hypertension.

SUMMARYPurpose: To assess the efficacy and tolerability of chronic high-frequency deep brain stimulation (DBS) in adult patients with progressive myoclonic epilepsy (PME) syndromes. Methods: Five adult patients (four male, 28-39 years) with PME underwent chronic high-frequency DBS according to a study protocol that had been approved by the local ethics committee. Electrodes were implanted in the substantia nigra pars reticulata (SNr)/subthalamic nucleus (STN) region in the first patient and additionally in the ventral intermediate nucleus (VIM) bilaterally in the following four cases. Follow-up took place in intervals of 3 months and DBS effects were compared with baseline frequency of passive and activation-induced myoclonic jerks and daily life performance 8 weeks prior to implantation. Key Findings: Follow-up periods ranged from 12-42 months (median 24 months). The best clinical effects were seen with SNr/STN DBS in all patients. VIM stimulation failed to achieve acute therapeutic effects and revealed low side-effect thresholds and even triggering of myoclonia. In all patients the reduction of myoclonic seizures was observed and ranged between 30% and 100% as quantified by a standardized video protocol. All patients reported clinically relevant improvements of various capabilities such as free standing and walking or improved fine motor skills. In one patient with an excellent initial response generalized tonic-clonic seizures increased after 3 months of stimulation following extensive traumarelated surgery. The best effect was seen in the least impaired patient. Significance: DBS of the SNr/STN may be an effective treatment option for patients with PME. Less impaired patients may benefit more markedly. KEY WORDS: Myoclonic epilepsy, Surgery, Deep brain stimulation, Stereotaxy.According to the Proposal of the International League Against Epilepsy (ILAE) (Commission on Classification and Terminology of the International League Against Epilepsy, 1989), progressive myoclonic epilepsy (PME) syndromes are classified as relatively well-defined entities such as Unverricht-Lundborg disease or Lafora's disease. In many instances though, a more specified classification is lacking, although recent developments in molecular genetics have helped to achieve a better understanding of PME (Shahwan et al., 2005). Patients with PME usually develop highly drug-resistant and often trigger-dependent myoclonic jerks and generalized tonic-clonic seizures. The stimulus sensitivity, the severity, the frequent association with additional ataxia and fine motor skills impairment and the correlation with sleeplessness regularly lead to dramatic impairment of personal quality of life with the necessity to use helmets or wheelchairs. In addition, the course of the diseases usually progresses, so that some disorders like Lafora's disease are characterized by a very rapid deterioration with fatal prognosis, whereas other forms such as UnverrichtLundborg disease often show a slow progression with severe impairment of the patients over decades...

A total of 120 patients with histologically proven focal cortical dysplasias (FCD) were retrospectively analysed for prognostic factors for successful epilepsy surgery. Multivariate data analyses showed that older age at epilepsy surgery, occurrence of secondarily generalised seizures and a multilobar extent of the dysplasia were significant negative predictors. In univariate analyses, longer duration of epilepsy, need for intracranial EEG recordings and incomplete resection of the FCD were factors which significantly reduced the chance of becoming seizure free. Histological subtype of the FCD and age at epilepsy onset had no significant predictive value. These findings strongly suggest early consideration of epilepsy surgery in FCD patients.