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| 2. |
- Engström, Maria, et al.
(author)
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Working Memory in 8 Kleine-Levin Syndrome Patients : An fMRI Study
- 2009
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In: SLEEP. - 0161-8105. ; 32:5, s. 681-688
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Journal article (peer-reviewed)abstract
- Study Objectives: The objectives of this study were to investigate possible neuropathology behind the Kleine-Levin Syndrome (KLS), a severe form of hypersomnia with onset during adolescence.Design: Functional magnetic resonance imaging (fMRI) applying a verbal working memory task was used in conjunction with a paper-and-pencil version of the task. Participants: Eight patients with KLS and 12 healthy volunteers participated in the study.Results: The results revealed a pattern of increased thalamic activity and reduced frontal activity (involving the anterior cingulate and adjacent prefrontal cortex) while performing a reading span task.Discussion: This finding may explain the clinical symptoms observed in KLS, in that the thalamus is known to be involved in the control of sleep. Given the increasing access to fMRI, this investigation may aid clinicians in the diagnosis of patients suffering from severe forms of hypersomnia.
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| 3. |
- Gauffin, Helena, et al.
(author)
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Similar Profile and Magnitude of Cognitive Impairments in Focal and Generalized Epilepsy : A Pilot Study
- 2022
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In: Frontiers in Neurology. - Lausanne, Switzerland : Frontiers Media S.A.. - 1664-2295. ; 12
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Journal article (peer-reviewed)abstract
- Introduction: Cognitive impairments in epilepsy are not well-understood. In addition, long-term emotional, interpersonal, and social consequences of the underlying disturbances are important to evaluate.Purpose: To compare cognitive function including language in young adults with focal or generalized epilepsy. In addition, quality of life and self-esteem were investigated.Patients and Methods: Young adults with no primary intellectual disability, 17 with focal epilepsy and 11 with generalized epilepsy participated and were compared to 28 healthy controls. Groups were matched on age (mean = 26 years), sex, and education. Participants were administered a battery of neuropsychological tasks and carried out self-ratings of quality of life, self-esteem, and psychological problems.Results: Similar impairments regarding cognitive function were noted in focal and generalized epilepsy. The cognitive domains tested were episodic long-term memory, executive functions, attention, working memory, visuospatial functions, and language. Both epilepsy groups had lower results compared to controls (effect sizes 0.24-1.07). The total number of convulsive seizures was predictive of episodic long-term memory function. Participants with focal epilepsy reported lower quality of life than participants with generalized epilepsy. Lowered self-esteem values were seen in both epilepsy groups and particularly in those with focal epilepsy. Along with measures of cognitive speed and depression, the total number of seizures explained more than 50% of variation in quality of life.Conclusion: Interestingly, similarities rather than differences characterized the widespread cognitive deficits that were seen in focal and generalized epilepsy, ranging from mild to moderate. These similarities were modified by quality of life and self-esteem. This study confirms the notion that epilepsy is a network disorder.
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| 4. |
- Pipan, Eva, et al.
(author)
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Vagal Nerve Stimulation in Epilepsy : Experiences of Participants with Cognitive Deficits
- 2020
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In: Neuropsychiatric Disease and Treatment. - Auckland, New Zealand : DOVE MEDICAL PRESS LTD. - 1176-6328 .- 1178-2021. ; 16, s. 1181-1188
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Journal article (peer-reviewed)abstract
- Introduction: The purpose of this study was to examine patients experiences of vagal nerve stimulation (VNS) with a special interest in patients with cognitive deficit (CD). Materials and Methods: An open, retrospective study was conducted on 82 patients with pharmacoresistant epilepsy, who were treated with VNS for at least 10 months. Based on the inability to live independently, they were divided into two groups: patients with cognitive deficit (CD group) and patients without cognitive deficit (non-CD group). A specially designed questionnaire was used for semi-structured interviews about patients experiences of VNS treatment. Results: Approximately one-third described a continuous reduction of seizure frequency of 50% or more and were regarded as responders. Fewer subjects in the CD group were responders than in the non-CD group. Approximately one-third of all subjects had no positive effect of VNS treatment. More CD patients described additional improvements and the most common were milder seizures and improved alertness. The most commonly reported adverse effect was hoarseness. Discussion: VNS treatment in patients without CD had better effect on seizure frequency reduction than in patients with CD, but many patients with CD reported other benefits from the treatment.
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| 6. |
- Vigren, Patrick, et al.
(author)
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Awake craniotomy in epilepsy surgery includes previously inoperable patients with preserved efficiency and safety
- 2023
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In: International Journal of Neuroscience. - : TAYLOR & FRANCIS LTD. - 0020-7454 .- 1563-5279.
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Journal article (peer-reviewed)abstract
- Introduction: Whilst awake craniotomy has been widely used historically in epilepsy surgery, the safety and efficacy of this approach in epilepsy surgery has been sparsely investigated in controlled studies. The objective of this study is to investigate the safety and efficacy of awake resection in epilepsy surgery and focuses on the possibility to widen surgical indications with awake surgery. Methods: Fifteen patients operated with awake epilepsy surgery were compared to 30 matched controls undergoing conventional/asleep epilepsy surgery. The groups were compared with regard to neurological complications, seizure control and location of resection. Results: Regarding seizure control, 86% of patients in the awake group reached Engel grade 1-2 compared to 73% in the control group, operated with conventional/asleep surgery, not a statistically significant difference. Neither was there a statistical significant difference regarding postoperative neurological complications. However, there was a significant difference in location of the resection when comparing the two groups. Of the 15 patients operated with awake intraoperative mapping, four had previously been considered as non-operable by epilepsy surgery centres, due to vicinity to eloquent brain regions and predicted risk of post-operative neurological deficits. Discussion: The results show that awake epilepsy surgery yields similar level of seizure control when compared to conventional asleep surgery, with maintained safety in regard to neurological complications. Furthermore, the results indicate that awake craniotomy in epilepsy surgery is feasible and possible in patients otherwise regarded as inoperable with epileptigenic zone in proximity to eloquent brain structures.
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| 7. |
- Vigren, Patrick, et al.
(author)
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Experiences of awake surgery in non-tumoural epilepsy in eloquent localizations
- 2020
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In: Clinical neurology and neurosurgery. - : ELSEVIER. - 0303-8467 .- 1872-6968. ; 199
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Journal article (peer-reviewed)abstract
- Background: Whilst modern awake intraoperative mapping has been widely accepted and implemented in the last decades in neuro-oncology, sparse reports have been published on the safety and efficiency of this approach in epilepsy surgery. Method: This article reports four cases with different locations of epileptogenic zones as examples of possible safe and efficient resections. Result: The results of the resections on seizure control were Engel 1 (no disabling seizures) in all cases and no patient experienced significant neurological deficits. Discussion: The discussion focuses on aspects of the future of epilepsy surgery in a hodotopical paradigm.
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| 8. |
- Vigren, Patrick, et al.
(author)
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Low Thalamic NAA-Concentration Corresponds to Strong Neural Activation in Working Memory in Kleine-Levin Syndrome
- 2013
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In: PLOS ONE. - : Public Library of Science (PLoS). - 1932-6203. ; 8:2
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Journal article (peer-reviewed)abstract
- BackgroundKleine Levin Syndrome (KLS) is a rare disorder of periodic hypersomnia and behavioural disturbances in young individuals. It has previously been shown to be associated with disturbances of working memory (WM), which, in turn, was associated with higher activation of the thalamus with increasing WM load, demonstrated with functional magnetic resonance imaging (fMRI). In this study we aimed to further elucidate how these findings are related to the metabolism of the thalamus.MethodsfMRI and magnetic resonance spectroscopy were applied while performing a WM task. Standard metabolites were examined: n-acetylaspartate (NAA), myo-inositol, choline, creatine and glutamate-glutamine. Fourteen KLS-patients and 15 healthy controls participated in the study. The patients with active disease were examined in asymptomatic periods.ResultsThere was a statistically significant negative correlation between thalamic fMRI-activation and thalamic NAA, i.e., high fMRI-activation corresponded to low NAA-levels. This correlation was not seen in healthy controls. Thalamic levels of NAA in patients and controls showed no significant differences between the groups. None of the other metabolites showed any co-variation with fMRI-activiation.ConclusionThis study shows negative correlation between NAA-levels and fMRI-activity in the left thalamus of KLS-patients while performing a WM task. This correlation could not be found in healthy control subjects, primarily interpreted as an effect of increased effort in the patient group upon performing the task. It might indicate a disturbance in the neuronal networks responsible for WM in KLS patients, resulting in higher effort at lower WM load, compared with healthy subjects. The general relationship between NAA and BOLD-signal is also discussed in the article.
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| 9. |
- Vigren, Patrick
(author)
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On the Kleine-Levin Syndrome
- 2017
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Doctoral thesis (other academic/artistic)abstract
- Populärvetenskaplig sammanfattning på svenska Kleine-Levins syndrom är en sömnsjukdom som beskrevs av Willi Kleine 1925 och därefter utvecklades i fallbeskrivningar av Max Levin och McDonald Chritchley. De symptom som beskrevs var återkommande sömnperioder (periodisk hypersomnia), en tendens att äta mycket i samband med dessa perioder (hyperfagi) och ökad sexdrift i samband med perioderna (hypersexualitet) och, i senare beskrivningar, kognitiva och beteendemässiga störningar. Enligt tidigare beskrivningar var patienterna återställda mellan sömnperioderna. Dessa varade i dagar-veckor och återkom flera gånger årligen. Sjukdomen debuterade vanligtvis i tonåren och beskrevs gå över efter åtta år.d avhandling beskriver diagnosens utveckling över tid och sätter forskningen i sitt teoretiska sammanhang. Med det senare menas att det diskuteras hur forskningen förhåller sig till en diagnos som förändras över tid och där olika läkare kan ha olika kunskap kring och förhållningssätt till diagnosen.De studier som ingår i avhandlingen har undersökt flera olika aspekter av Kleine-Levins syndrom. Den första studien undersökte arbetsminnet hos patienterna och kunde påvisa att det var nedsatt jämfört med friska försökspersoner, även mellan sömnperioderna, något som inte var visat systematiskt tidigare. Dessutom sågsandra aktiveringsmönster i hjärnan när patienterna försökte klara arbetsminnesuppgiften, jämfört med aktiveringsmönstren hos friska försökspersoner. Hos hälften av patienterna sågs dessutom avvikande blodflöde i delar av hjärnan även när ingen särskild arbetsuppgift utfördes. Detta sågs även hos patienter som tillfrisknat.Då det funnits hypoteser i annan forsking att sjukdomen kan ha ett genetiskt/ärftligt inslag undersöktes huruvida patienterna hade en gen som tidigare har kopplats till sjukdomen. I den grupp av patienter som undersöktes i avhandlingens sista artikel kunde dock ingen sådan koppling ses.Slutsatsen av forskningsresultaten är att (1) patienter med Kleine-Levins syndrom har en störning av arbetsminnet som verkar konstant. (2) De uppvisar andra hjärnaktiveringsmönster än friska personer som gör samma arbetsminnesuppgift. (3) Hälften av patienterna har ett avvikande blodflödesmönster även i vila och efter tillfrisknande. (4) En eventuell ärftlig komponent kan inte påvisas avseende de undersökta generna.
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| 10. |
- Vigren, Patrick, et al.
(author)
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SPECT in the Kleine–Levin syndrome, a possible diagnostic and prognostic aid?
- 2014
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In: Frontiers in Neurology. - Switzerland : Frontiers Research Foundation. - 1664-2295. ; 5:178
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Journal article (peer-reviewed)abstract
- Introduction: Kleine–Levin syndrome (KLS) is a rare syndrome of periodic hypersomnia and behavioral and cognitive symptoms based on clinical criteria. In the setting of differential diagnosis of hypersomnia disorders, an objective diagnostic aid is desirable. A promising modality is single photon emission computed tomography (SPECT). As intraepisodal investigations are difficult to perform, an interepisodal investigation would be very helpful. Another aim of the study was to correlate SPECT findings to prognosis.Methods and Materials: Twenty-four KLS-patients were categorized as severe or non-severe based on clinical characteristics. The clinical characteristics were analyzed in relation to SPECT-examinations performed between hypersomnia periods (interepisodal) or after remission, as a clinical routine investigation.Results: Forty-eight percent of the KLS-patients have hypoperfusion in the temporal or fronto-temporal regions. In patients that have undergone remission, 56% show that pattern. There were no specific findings related to prognosis.Discussion/Conclusion: SPECT might be a diagnostic aid, in a setting of hypersomnia experience. With a sensitivity of 48%, interepisodal SPECT alone cannot be used for diagnosing KLS.
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