Swedish consensus reached on recording, interpretation and reporting of neonatal continuous simplified electroencephalography that is supported by amplitude-integrated trend analysis.

Continuous monitoring of electroencephalography (EEG), with a focus on amplitude-integrated EEG (aEEG), has been used in neonatal intensive care for decades. A number of systems have been suggested for describing and quantifying aEEG patterns. Extensive full-montage EEG monitoring is used in specialised intensive care units. The American Clinical Neurophysiology Society published recommendations for defining and reporting EEG findings in critically ill adults and infants. Swedish neonatologists and clinical neurophysiologists collaborated to optimise simplified neonatal continuous aEEG and EEG recordings based on these American documents. CONCLUSION: This paper describes the Swedish consensus document produced by those meetings.

Outcomes of multilobar resections for epilepsy in Sweden 1990-2013: a national population-based study.

BACKGROUND: Reports on outcome after multilobar resection (MLR) are scarce and most are retrospective single-centre studies or case studies with few patients. The aim of this study is to present seizure and complication outcomes 2 years after MLR in a prospective population-based series. METHOD: The Swedish National Epilepsy Surgery Registry (SNESUR) provides prospective population-based data on outcome and complications after epilepsy surgery. For this study, we have analysed data on seizure outcome and complications after MLR from the SNESUR between 1990 and 2013. RESULTS: Fifty-seven patients underwent MLR; 40/57 surgeries were performed between 1990 and 2000. Sixteen operations were classified as partial hemispherotomy. Resections were right-sided in 33 (58 %) patients. Mean age was 17.3 years (range, 0.3-63.4 years) and mean duration of epilepsy before surgery was 11.0 years (range, 0.2-37 years). Preoperative neurological deficits were seen in 19 patients (33.3 %). Learning disability (LD) was seen in 18 patients (31.6 %), six had severe LD (IQ <50). Seizure outcome after 2 years was available for 53 patients. Thirteen (24.5 %) were seizure-free and 12 (22.6 %) had >75 % seizure frequency reduction. Three (5.3 %) patients suffered major complications: infarction of the middle cerebral artery, epidural abscess and hemiparesis. Minor complications were seen in ten patients. There was no mortality. CONCLUSIONS: This prospective, population-based study provides data on seizure outcome and complications after MLR. In selected patients MLR can be considered, but expectations for seizure freedom should not be too high and patients and parents should be counselled appropriately.

Complications to invasive epilepsy surgery workup with subdural and depth electrodes: a prospective population-based observational study.

OBJECTIVE: In some patients who undergo presurgical workup for drug-resistant epilepsy invasive seizure monitoring is needed to define the seizure onset zone and delineate eloquent cortex. Such procedures carry risks for complications causing permanent morbidity and even mortality. In this study, prospective data on complications in a national population-based sample were analysed. DESIGN: Complication data from the prospective Swedish National Epilepsy Surgery Register were analysed for 271 patients in whom therapeutic surgery was preceded by invasive monitoring 1996-2010. RESULTS: Complications occurred in 13/271 patients (4.8%). Subdural grids carried the highest risk of complications (7.4%). There was no surgical mortality or permanent morbidity. Subdural haematomas were most common (n=7) followed by epidural haematomas (n=3). Valproate treatment and having a haematoma was associated with an OR of 1.53 (CI 0.38 to 6.12) compared to having a haematoma without valproate treatment. Having a complication during invasive monitoring was associated with a significant OR of 6.27 (CI 1.32 to 29.9) of also having a complication at therapeutic surgery compared to the risk of having a complication only at surgery. CONCLUSIONS: In this prospective population-based epilepsy surgery series, the most common complications were haematomas, and subdural grids carried the highest risk. Close supervision and rapid interventions led to avoidance of permanent morbidity. The clinical implications of the slightly increased risk of haematomas with valproate treatment needs further investigation as does the finding of an increased risk for complications at epilepsy surgery for patients who had a complication during invasive monitoring.

Long-term follow-up after callosotomy--a prospective, population based, observational study.

OBJECTIVE: Analyze the long-term outcome of callosotomies with regard to seizure types and frequencies and antiepileptic drug treatment. METHODS: This longitudinal observational study is based on data from the prospective Swedish National Epilepsy Surgery Register. Thirty-one patients had undergone callosotomy in Sweden 1995-2007 and had been followed for 2 and 5 or 10 years after surgery. Data on their seizure types and frequencies, associated impairments, and use of antiepileptic drugs have been analyzed. RESULTS: The median total number of seizures per patient and month was reduced from 195 before surgery to 110 two years after surgery and 90 at the long-term follow-up (5 or 10 years). The corresponding figures for drop attacks (tonic or atonic) were 190 before surgery, 100 2 years after surgery, and 20 at the long-term follow-up. Ten (56%) of the 18 patients with drop attacks were free from drop attacks at long-term follow-up. Three of the remaining eight patients had a reduction of >75%. At long-term follow-up, four were off medication. Only one of the 31 patients had no neurologic impairment. SIGNIFICANCE: The present population-based, prospective observational study shows that the corpus callosotomy reduces seizure frequency effectively and sustainably over the years. Most improvement was seen in drop attacks. The improvement in seizure frequency over time shown in this study suggests that callosotomy should be considered at an early age in children with intractable epilepsy and traumatizing drop attacks.

Surgical outcomes in patients with epileptogenic tumours and cavernomas in Sweden: good seizure control but late referrals.

PURPOSE: Seizure outcome after epilepsy surgery is to an important extent related to underlying aetiology. In this study of patients who underwent epilepsy surgery with a lesional aetiology in Sweden 1990-2004, the aim was to investigate seizure outcome and prognostic factors. METHODS: All patients operated on during the time period with a histopathological diagnosis of an epileptogenic tumour (ganglioglioma (GGL), dysembryoblastic neuroepithelial tumour (DNET) and low grade astrocytoma (AST)) or a cavernous haemangioma (CAH) were identified in the population based Swedish National Epilepsy Surgery Register. Univariate and multivariate analyses were performed to determine the independent contribution of the following variables to seizure outcome: age at surgery; epilepsy duration; preoperative seizure frequency; localisation of the resection; and histopathology. RESULTS: Of the 156 identified patients who had a 2 year follow-up (103 adults and 53 children), 71% had temporal, 16% frontal and 13% parietal and occipital lobe resections. Mean presurgical epilepsy duration was 13 years in adults and 5 years in children. Main histopathological diagnosis was GGL or DNET in 67, CAH in 42 and AST in 47 patients. 77% of patients had sustained seizure freedom (with or without aura) 2 years after surgery. In the multivariate analysis, only diagnosis other than AST was independently associated with becoming seizure free. CONCLUSION: In this population based series, 120/156 patients (77%) with epileptogenic tumours and cavernomas were seizure free 2 years after surgery. Many had a very long epilepsy history. Seizure outcome can be improved if epilepsy surgery is considered earlier in patients with epileptogenic lesions.

Seizure outcome after resective epilepsy surgery in patients with low IQ.

Epilepsy surgery has been questioned for patients with low IQ, since a low cognitive level is taken to indicate a widespread disturbance of cerebral function with unsatisfactory prognosis following resective surgery. The prevalence of epilepsy in patients with cognitive dysfunction is, however, higher than in the general population and the epilepsy is often more severe and difficult to treat. It is therefore important to try to clarify whether IQ predicts seizure outcome after resective epilepsy surgery. The Swedish National Epilepsy Surgery Register, which includes data on all epilepsy surgery procedures in Sweden since 1990, was analysed for all resective procedures performed 1990-99. Sustained seizure freedom with or without aura at the 2-year follow-up was analysed as a function of pre-operative IQ level categorized as IQ <50, IQ 50-69 and IQ >or=70 and was also adjusted for the following variables: age at epilepsy onset, age at surgery, pre-operative seizure frequency, pre-operative neurological impairment, resection type and histopathological diagnosis. Four hundred and forty-eight patients underwent resective epilepsy surgery in Sweden from 1990 to 1999 and completed the 2-year follow-up: 72 (16%) had IQ <70, (18 with IQ <50 and 54 with IQ 50-69) and 376 IQ >or=70. There were 313 adults and 135 children or=70 group. There was a significant relation between IQ category and seizure freedom [odds ratio (OR) 0.41, 95% confidence interval (CI) 0.27-0.62] and this held also when adjusting for clinical variables [OR 0.58 (95% CI 0.35-0.95)]. In this population-based epilepsy surgery series, IQ level was shown to be an independent predictor of seizure freedom at the 2-year follow-up. However, many of the low-IQ patients benefit from surgery, especially patients with lesions. Low IQ should not exclude patients from resective epilepsy surgery, but is an important prognostic factor to consider in the counselling process.

Successful localization of the Broca area with short-train pulses instead of 'Penfield' stimulation.

Direct electrical stimulation of functional cortical areas is a standard procedure in epilepsy and glioma surgery. Many previous studies support that stimulation of the motor cortex with short-train pulses is a less epileptogenic alternative to the 50-60Hz 'Penfield' technique. However, whether the short-train stimulation is useful also in mapping of speech areas is unclear. In this case report we present a patient with oligodendroglioma near the Broca area. Extraoperative electrical stimulation via a subdural grid electrode was primarily performed to locate the speech area. The cortex was stimulated with short-train pulses (5 pulses, 0.5 pulse duration and 3ms interpulse interval) in addition to 1-3s 50Hz stimulation. The patient had speech arrest from both types of stimulation techniques during a naming task. It was however critical that the short (14.5ms) train stimulation was synchronized with the presentation of the naming objects. If not, there was no speech arrest. Despite this possible pitfall, this case has encouraged us to further try short-train stimulation in attempts to reduce stimulus-triggered seizures during mapping of eloquent areas.

[Status epilepticus in children and adults]. / Status epilepticus hos barn och vuxna - Orsaken är ofta akut sjukdom ­ utredning och behandling bör ske parallellt.

Status epilepticus, a condition with prolonged or repeated seizures, is a common neurological emergency with significant morbidity and mortality. This text outlines the treatment and initial work-up for convulsive and non-convulsive status epilepticus in adults and children. The most serious form is convulsive (tonic-clonic) status epilepticus, which requires rapid treatment and work-up. Bensodiazepines are the preferred initial treatment, while antiepileptic drugs and anesthetics are added if seizures continue. For other forms of status epilepticus, the treatment depends on the type of seizures and the patient's general condition. Etiological work-up is essential in any case of status epilepticus. Effective treatment and work-up in status epilepticus requires a defined treatment protocol and multidisciplinary cooperation.

Cranial Nerve Coactivation and Implication for Nerve Transfers to the Facial Nerve.

In reanimation surgery, effortless smile can be achieved by a nonfacial donor nerve. The underlying mechanisms for this smile development, and which is the best nonfacial neurotizer, need further clarification. The aim of the present study was therefore to further explore the natural coactivation between facial mimic muscles and muscles innervated by the most common donor nerves used in smile reanimation. The study was conducted in 10 healthy adults. Correlation between voluntary facial muscle movements and simultaneous electromyographic activity in muscles innervated by the masseter, hypoglossal, and spinal accessory nerves was assessed. The association between voluntary movements in the latter muscles and simultaneous electromyographic activity in facial muscles was also studied. Smile coactivated the masseter and tongue muscles equally. During the seven mimic movements, the masseter muscle had fewer electromyographically measured coactivations compared with the tongue (two of seven versus five of seven). The trapezius muscle demonstrated no coactivation during mimic movements. Movements of the masseter, tongue, and trapezius muscles induced electromyographically recorded coactivation in the facial muscles. Bite resulted in the strongest coactivation of the zygomaticus major muscle. The authors demonstrated coactivation between voluntary smile and the masseter and tongue muscles. During voluntary bite, strong coactivation of the zygomaticus major muscle was noted. The narrower coactivation pattern in the masseter muscle may be advantageous for central relearning and the development of a spontaneous smile. The strong coactivation between the masseter muscle and the zygomaticus major indicates that the masseter nerve may be preferred in smile reanimation.

Neuromuscular block and the electroencephalogram during sevoflurane anaesthesia.

The effect of neuromuscular block on the anaesthetic depth of hypnosis is an elusive question. We simultaneously investigated the influence of neuromuscular block on the bispectral index, a measure of hypnosis during general anaesthesia, and on the electroencephalogram. Patients were anaesthetized with sevoflurane. Noxious tetanic electrical stimulation was applied on two occasions: before and after profound neuromuscular block achieved with rocuronium. Neuromuscular block significantly attenuated the effect from noxious stimulation on electroencephalogram power and synchrony in the gamma band (P<0.05), and the corresponding effect on bispectral index (P<0.02). These findings are probably due to the reduced arousing afferent input from paralysed muscles, and not to changes in the frontal electromyogram.

Prospective and longitudinal long-term employment outcomes after resective epilepsy surgery.

OBJECTIVE: To investigate long-term employment outcomes after resective epilepsy surgery in a national population-based cohort of adults. METHODS: In the Swedish National Epilepsy Surgery Register, all adults who were operated with resective epilepsy surgery from 1995 to 2010 were identified. Two-year follow-up was available for 473/496, 5-year follow-up for 220/240, 10-year follow-up for 240/278, and 15-year follow-up for 85/109 patients. RESULTS: There were no significant changes in employment outcome over time at group level, but for those with full-time employment at baseline, 79%, 79%, 57%, and 47% of seizure-free patients were in full-time work at 2-, 5-, 10-, and 15-year follow-up, compared to patients with benefits at baseline, where 16%, 27%, 31%, and 33% of seizure-free patients worked full time at these time points (p = 0.018 at 10 years). More patients with full-time work had ability to drive, a family of their own, and higher educational status than patients in part-time work or on benefits. Univariate predictors for employment at long term were having employment preoperatively, higher education, favorable seizure outcome, male sex, and younger age at surgery. Multivariate predictors were having employment preoperatively, favorable seizure outcome, and younger age. CONCLUSIONS: The best vocational outcomes occurred in seizure-free patients who were employed or students at baseline, which may reflect a higher general psychosocial level of function. Younger age also predicted better employment outcomes and it therefore seems plausible that early referral for surgery could contribute to better vocational outcomes.

Complications of epilepsy surgery in Sweden 1996-2010: a prospective, population-based study.

OBJECT: Detailed risk information is essential for presurgical patient counseling and surgical quality assessments in epilepsy surgery. This study was conducted to investigate major and minor complications related to epilepsy surgery in a large, prospective series. METHODS: The Swedish National Epilepsy Surgery Register provides extensive population-based data on all patients who were surgically treated in Sweden since 1990. The authors have analyzed complication data for therapeutic epilepsy surgery procedures performed between 1996 and 2010. Complications are classified as major (affecting daily life and lasting longer than 3 months) or minor (resolving within 3 months). RESULTS: A total of 865 therapeutic epilepsy surgery procedures were performed between 1996 and 2010, of which 158 were reoperations. There were no postoperative deaths. Major complications occurred in 26 procedures (3%), and minor complications in 65 (7.5%). In temporal lobe resections (n = 523), there were 15 major (2.9%) and 41 minor complications (7.8%); in extratemporal resections (n = 275) there were 9 major (3.3%) and 22 minor complications (8%); and in nonresective procedures (n = 67) there were 2 major (3%) and 2 minor complications (3%). The risk for any complication increased significantly with age (OR 1.26 per 10-year interval, 95% CI 1.09-1.45). Compared with previously published results from the same register, there is a trend toward lower complication rates, especially in patients older than 50 years. CONCLUSIONS: This is the largest reported prospective series of complication data in epilepsy surgery. The complication rates comply well with published results from larger single centers, confirming that epilepsy surgery performed in the 6 Swedish centers is safe. Patient age should be taken into account when counseling patients before surgery.

Intraoperative electrocorticography in epilepsy surgery: useful or not?

Intraoperative electrocorticography (ECoG) has been traditionally used in the surgical management of medically refractory partial epilepsies to identify the location and limits of the epileptogenic area, to guide the extent of resection, and to assess its completeness. Although in clinical use for many years, the basic questions regarding indications and limitations of this method has remained unanswered. ECoG plays a major role in tailored temporal lobectomies, whereas, it serves no practical purpose in standard resection of medial temporal lobe epilepsy (TLE) with magnetic resonance imaging (MRI) evidence of mesial temporal sclerosis (MTS). Residual hippocampal spikes, unaltered by resection, correlate with a greater proportion of seizure recurrence. Intraoperative hippocampal ECoG can allow sparing of functionally important hippocampus, thus minimising postoperative memory decline. ECoG eminently aids removal of developmental malformations of brain, and most importantly, the excision of highly epileptogenic cortical dysplasias (CDs) for deciding the extent of resection for best seizure control. The ECoG can be a valuable tool during multiple subpial transections (MST).

Focal fast rhythmic epileptiform discharges on scalp EEG in a patient with cortical dysplasia.

A distinctive scalp electroencephalographic (EEG) pattern of focal fast rhythmic epileptiform discharges (FREDs) in a 23-year-old man with symptomatic localization related epilepsy is presented. Magnetic resonance imaging (MRI) of the brain revealed cortical dysplasia over the right temporal region where the peculiar EEG abnormality was detected. We suggest that this characteristic EEG pattern may be predictive of focal cortical dysplasia (FCD). A brief review of the rhythmic EEG abnormalities in FCDs is also presented.

Outcomes after resective epilepsy surgery in patients over 50 years of age in Sweden 1990-2009--a prospective longitudinal study.

PURPOSE: Most epilepsy surgery candidates are young adults. Outcome reports after epilepsy surgery in patients ≥50 years are few and varying. The aim of this study was to describe patient characteristics of older compared to younger adults and analyse seizure, complication and vocational outcomes in a large population-based series. METHODS: We analysed data from the Swedish National Epilepsy Surgery Register for 1990-2009 for patients ≥19 years at resective surgery who had completed two-year follow-up. Variables studied were seizure outcome, histo-pathological diagnoses, complications and vocational outcome. Data from patients ≥50 years and 19-49 years at surgery were compared. RESULTS: 558 Adults underwent resective epilepsy surgery 1990-2009 and had two-year follow-up. 12% of the adults (67 patients) were ≥50 years at surgery. Patients ≥50 had longer epilepsy duration, more often had mesial sclerosis and less often had neurodevelopmental tumours and cortical malformations. The proportion of seizure-free patients at two-year follow-up did not differ between those ≥50 and 19-49 years (61% versus 61% seizure-free last year, 48% versus 43% completely seizure-free since surgery), neither did the occurrence of major complications (3% in both groups). The vocational situation was mainly stable between baseline and two-year follow-up in both groups, although older patients were less often employed than younger. CONCLUSION: 12% of adults in the Swedish series were ≥50 years at epilepsy surgery. Seizure outcome was as good for older as for younger adults, and there was no difference in the occurrence of major complications. This constitutes important information in the presurgical counselling process.

Trigeminal nerve stimulation does not acutely affect cortical excitability in healthy subjects.

BACKGROUND: Trigeminal nerve stimulation (TNS) has recently emerged as a new therapeutic option for patients with drug-resistant epilepsy but its potential mechanisms of action are not known. Since other antiepileptic treatments have been shown to alter cortical excitability, thereby reducing the liability to seizures, it has been suggested that cranial nerve stimulation such as TNS may act in the same way. OBJECTIVE: To study whether TNS has the potential to alter cortical excitability in healthy subjects. METHODS: An adaptive paired-pulse transcranial magnetic stimulation protocol stimulating the dominant hand motor area was used to measure resting motor threshold (rMT), short-interval intracortical inhibition (SICI), intracortical facilitation (ICF) and long-interval intracortical inhibition (LICI) before, during, and after 40 min of 120 Hz bilateral external continuous trigeminal nerve stimulation. Neuronavigation was used for guidance. RESULTS: TNS was well tolerated by all subjects. No significant changes were seen in the parameters studied. CONCLUSION: Unlike for example anti-epileptic drugs and the ketogenic diet, trigeminal nerve stimulation does not seem to alter cortical excitability in healthy subjects. This is the first study on cortical excitability in relation to continuous trigeminal nerve stimulation. It still remains to be proven that TNS has the prerequisites to effectively counteract epileptic events in humans.

Long-term outcomes of epilepsy surgery in Sweden: a national prospective and longitudinal study.

OBJECTIVE: To investigate prospective, population-based long-term outcomes concerning seizures and antiepileptic drug (AED) treatment after resective epilepsy surgery in Sweden. METHODS: Ten- and 5-year follow-ups were performed in 2005 to 2007 for 278/327 patients after resective epilepsy surgery from 1995 to 1997 and 2000 to 2002, respectively. All patients had been prospectively followed in the Swedish National Epilepsy Surgery Register. Ninety-three patients, who were presurgically evaluated but not operated, served as controls. RESULTS: In the long term (mean 7.6 years), 62% of operated adults and 50% of operated children were seizure-free, compared to 14% of nonoperated adults (p < 0.001) and 38% of nonoperated children (not significant). Forty-one percent of operated adults and 44% of operated children had sustained seizure freedom since surgery, compared to none of the controls (p < 0.0005). Multivariate analysis identified ≥30 seizures/month at baseline and long epilepsy duration as negative predictors and positive MRI to be a positive predictor of long-term seizure-free outcome. Ten years after surgery, 86% of seizure-free children and 43% of seizure-free adults had stopped AEDs in the surgery groups compared to none of the controls (p < 0.0005). CONCLUSIONS: This population-based, prospective study shows good long-term seizure outcomes after resective epilepsy surgery. The majority of the patients who are seizure-free after 5 and 10 years have sustained seizure freedom since surgery. Many patients who gain seizure freedom can successfully discontinue AEDs, more often children than adults. CLASSIFICATION OF EVIDENCE: This study provides Class III evidence that more patients are seizure-free and have stopped AED treatment in the long term after resective epilepsy surgery than nonoperated epilepsy patients.

Cholinergic neuromuscular hyperactivity in patients with myasthenia gravis seropositive for MuSK antibody.

A 75-year-old man with severe oculobulbar myasthenia gravis (MG) treated with acetylcholine esterase inhibitors (AChEIs) was found to have muscle-specific tyrosine kinase (MuSK) antibodies. Neurophysiological examination displayed extra repetitive discharges after the compound motor action potential (CMAP) at low-frequency stimulation, possibly triggered by AChEI. This indicates an abnormal sensitivity to acetylcholine in patients with MuSK antibodies and may be a useful indicator of the adverse effect of AChEI treatment in these patients.

Clinical neurophysiology in Uppsala, 1967-2001.

This is a review of the activities at the Department and Institution of Clinical Neurophysiology at Uppsala University Hospital from 1967 to 2001. The most important routine clinical methods are briefly described, and a summary of some of the research projects is given.