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- Amandusson, Åsa
(author)
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Comparison between adaptive and fixed stimulus paired-pulsetranscranial magnetic stimulation (ppTMS) in normal subjects
- 2017
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In: Clinical Neurophysiology Practice. - : Elsevier BV. - 2467-981X. ; , s. 91-97
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Journal article (peer-reviewed)abstract
- ObjectivesPaired-pulse TMS (ppTMS) examines cortical excitability but may require lengthy test procedures and fine tuning of stimulus parameters due to the inherent variability of the elicited motor evoked potentials (MEPs) and their tendency to exhibit a ‘ceiling/floor effects’ in inhibition trials. Aiming to overcome some of these limitations, we implemented an ‘adaptive’ ppTMS protocol and compared the obtained excitability indices with those from ‘conventional’ fixed-stimulus ppTMS.MethodsShort- and long interval intracortical inhibition (SICI and LICI) as well as intracortical facilitation (ICF) were examined in 20 healthy subjects by adaptive ppTMS and fixed-stimulus ppTMS. The test stimulus intensity was either adapted to produce 500 μV MEPs (by a maximum likelihood strategy in combination with parameter estimation by sequential testing) or fixed to 120% of resting motor threshold (rMT). The conditioning stimulus was 80% rMT for SICI and ICF and 120% MT for LICI in both tests.ResultsThere were significant (p < 0.05) intraindividual correlations between the two methods for all excitability measures. There was a clustering of SICI and LICI indices near maximal inhibition (‘ceiling effect’) in fixed-stimulus ppTMS which was not observed for adaptive SICI and LICI.ConclusionsAdaptive ppTMS excitability data correlates to those acquired from fixed-stimulus ppTMS.SignificanceAdaptive ppTMS is easy to implement and may serve as a more sensitive method to detect changes in cortical inhibition than fixed stimulus ppTMS. Whether equally confident data are produced by less stimuli with our adaptive approach (as already confirmed for motor threshold estimation) remains to be explored.
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- Axelson, Hans W., et al.
(author)
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Successful localization of the Broca area with short-train pulses instead of "Penfield" stimulation.
- 2009
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In: Seizure. - : Elsevier BV. - 1059-1311 .- 1532-2688. ; 18:5, s. 374-375
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Journal article (peer-reviewed)abstract
- 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 50–60 Hz ‘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 3 ms interpulse interval) in addition to 1–3 s 50 Hz stimulation.The patient had speech arrest from both types of stimulation techniques during a naming task. It was however critical that the short (14.5 ms) 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.
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- Axelson, Hans W, et al.
(author)
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Trigeminal Nerve Stimulation Does Not Acutely Affect Cortical Excitability in Healthy Subjects
- 2014
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In: Brain Stimulation. - : Elsevier BV. - 1935-861X .- 1876-4754. ; 7:4, s. 613-617
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Journal article (peer-reviewed)abstract
- 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.
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- Backman, Sofia, et al.
(author)
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Swedish consensus reached on recording, interpretation and reporting of neonatal continuous simplified electroencephalography that is supported by amplitude-integrated trend analysis
- 2018
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In: Acta Paediatrica. - : WILEY. - 0803-5253 .- 1651-2227. ; 107:10, s. 1702-1709
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Journal article (peer-reviewed)abstract
- 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.
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- Bialek, Fatima, et al.
(author)
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Outcomes after resective epilepsy surgery in patients over 50 years of age in Sweden 1990-2009-A prospective longitudinal study
- 2014
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In: Seizure-European Journal of Epilepsy. - : Elsevier BV. - 1059-1311 .- 1532-2688. ; 23:8, s. 641-645
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Journal article (peer-reviewed)abstract
- 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 1949 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.
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- Bjellvi, Johan, et al.
(author)
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Complications of epilepsy surgery in Sweden 1996-2010 : a prospective, population-based study
- 2015
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In: Journal of Neurosurgery. - 0022-3085 .- 1933-0693. ; 122:3, s. 519-525
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Journal article (peer-reviewed)abstract
- 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% Cl 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.
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- Bjellvi, Johan, et al.
(author)
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[Status epilepticus in children and adults]. : Status epilepticus hos barn och vuxna - Orsaken är ofta akut sjukdom – utredning och behandling bör ske parallellt.
- 2018
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In: Lakartidningen. - 1652-7518. ; 115
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Journal article (peer-reviewed)abstract
- 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.
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