Lars Thomassen

Haukeland University Hospital, Bergen, Hordaland, Norway

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Publications (99)166.7 Total impact

  • Stroke 01/2013; · 6.16 Impact Factor
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    ABSTRACT: Background. Migraine is prevalent in young patients and a frequent stroke mimic. To distinguish stroke mimics from true stroke can be difficult, and there is a possibility of misdiagnosing a stroke as a migrainous attack in patients with migraine. We aimed to investigate if a history of migraine affects the rate of thrombolytic therapy in young stroke patients. Methods. All patients below 50 years of age admitted in the period 2006-2013 to the Bergen Stroke Centre with acute ischaemic stroke were included. The rate of thrombolytic therapy in patients with migraine was compared to patients with no history of migraine. A multivariate analysis was performed to adjust confounding factors. Results. A total of 170 young stroke patients were enrolled, 49 with migraine and 121 with no migraine. In total, 10.2% of young patients with migraine received thrombolytic therapy, compared with 26.5% of young patients with nomigraine (P = 0.02). Migraine was associated with a low rate of thrombolytic therapy when adjusting for possible confounding factors (OR 0.19 CI: 0.05-0.72, P = 0.02). Conclusion. Migraine is associated with a low rate of thrombolytic therapy in young patients admitted with acute ischaemic stroke. Migraine patients admitted with acute ischaemic stroke are at risk of maltreatment.
    Stroke research and treatment. 01/2013; 2013:351064.
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    ABSTRACT: Approximately 30% of all stroke patients suffer from post-stroke visual impairment. Hemianopia is the most common symptom, but also neglect, diplopia, reduced visual acuity, ptosis, anisocoria, and nystagmus are frequent. Partial or complete recovery of visual disorders can occur, but many patients suffer permanent disability. This disability is often less evident than impairment of motor and speech functions, but is negatively correlated with rehabilitation outcome and can lead to a significant reduction in day-to-day functioning. To be visually impaired after stroke reduces quality of life and causes social isolation because of difficulties in navigating/orientating in the surroundings. A thorough diagnosis including targeted examination and later follow-up with eye examination and perimetry is essential in order to establish the extent of the visual impairment and to select the best rehabilitation strategy. Patients seem to profit from visual rehabilitation focused on coping strategies.
    Acta neurologica Scandinavica. Supplementum 01/2013;
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    ABSTRACT: Low body temperature is considered neuroprotective in ischemic stroke, yet some studies suggest that low body temperature may also inhibit clot lysis and recanalization. We hypothesized that low body temperature was associated with persistent proximal middle cerebral artery (MCA) occlusion in patients with acute ischemic stroke presenting with symptoms of proximal MCA occlusion, suggesting a possible detrimental effect of low body temperature on recanalization. All patients with acute ischemic stroke admitted to our Stroke Unit between February 2006 and August 2012 were prospectively registered in a database. Computed tomography (CT) angiography was performed in patients admitted <6 hours after stroke onset. Based on presenting symptoms, patients were classified according to the Oxford Community Stroke Project classification (OCSP). Patients with symptomatic proximal MCA occlusion were compared to patients with total anterior circulation infarct (TACI) without MCA occlusion on CT angiography. During the study period, 384 patients with acute ischemic stroke were examined with CT angiography. A total of 79 patients had proximal MCA occlusion and 31 patients had TACI without MCA occlusion. Median admission body temperatures were lower in patients with MCA occlusion compared to patients without occlusion (36.3°C versus 36.7°C, P = 0.027). Admission body temperature <36.5°C was independently associated with persistent MCA occlusion when adjusted for confounders in multivariate analyses (odds ratio 3.7, P = 0.007). Our study showed that low body temperature on admission was associated with persistent proximal MCA occlusion. These results may support a possible detrimental effect of low body temperature on clot lysis and recanalization.
    Vascular Health and Risk Management 01/2013; 9:297-302.
  • Acta Neurologica Scandinavica 01/2013; 128(3). · 2.47 Impact Factor
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    ABSTRACT: Mild cognitive impairment (MCI) is a subtle memory disorder not matching criteria for dementia. There is evidence for vascular comorbidity in several types of dementia. We hypothesized that neurovascular workup would detect a high degree of vascular disease in patients with MCI. In cooperation with our memory clinic, patients with amnestic MCI were referred to our department for neurovascular investigation. The workup encompassed ultrasound examination with carotid duplex including Intima-Media-Thickness (IMT) measurement, and transcranial Doppler (TCD) including one-hour microemboli monitoring, cerebrovascular reactivity measurement and Bubble test. Cerebral MRI for the evaluation of vascular and white-matter lesions, brain atrophy, hippocampal volumes, and amyloid angiopathy was performed. Ten patients were included. Vascular risk factors were present in six patients. Four patients had atherosclerotic lesions, three classified as mild, and one as moderate carotid stenosis. IMT > 1 mm was found in two patients, with a maximum IMT of 1.11 mm. None of the patients with acceptable bone window had intracranial stenosis in TCD. Vasoreactivity was pathologically low in one patient. Permanent right-left shunt was found in three patients, of which one showed spontaneous cerebral microembolism. Hippocampal volume reduction and cortical atrophy were found in four patients. Chronic ischemic changes in MRI were present in one patient, and three patients had subcortical infarctions. Cortical infarctions, microbleeds, or amyloid angiopathy were not found. Pure amnestic MCI is probably less associated with cerebrovascular disease and may be more consistent with evolving Alzheimer's disease. However, vascular risk factors are common in these patients.
    Acta neurologica Scandinavica. Supplementum 01/2013;
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    ABSTRACT: BACKGROUND: Transient ischemic attack has been redefined as a tissue-based diagnosis and MRI recommended as the preferred imaging modality. We aimed to investigate whether an increased use of MRI leads to a decrease in the proportion of TIA as compared to cerebral infarction. We also sought to see whether DWI-positive patients with transient ischemic symptoms <24 h differ from DWI-negative TIA patients in terms of performed diagnostic investigations and clinical characteristics. METHODS: Patients admitted with cerebral infarction or TIA in the period 2006-2011 were prospectively registered. The use of MRI in patients with transient ischemic symptoms <24 h and proportion of TIA were annually recorded. DWI-positive and DWI-negative patients with transient ischemic symptoms <24 h were compared in univariate analyses regarding baseline data, diagnostic investigations, and etiology. Multivariate analyses were performed to identify predictors of DWI lesions. RESULTS: The use of MRI increased from 65.0% in 2006-2008 to 89.0% in 2009-2011 (P < 0.001). The proportion of TIA as compared to cerebral infarction decreased from 12.2% in 2006-2008 to 8.3% in 2009-2011 (P = 0.002). DWI-positive patients were more often examined with 24-h Holter monitoring (P < 0.001) and echocardiography (P < 0.001). Lower age (P < 0.001) and prior myocardial infarction (P < 0.029) were independently associated with DWI lesions in patients with transient ischemic symptoms <24 h. CONCLUSIONS: An increased use of MRI and a tissue-based TIA definition resulted in a decrease in the proportion of TIA at discharge as compared to cerebral infarction. DWI-positive patients had a more extensive cardiac work-up and were associated with lower age and prior myocardial infarction.
    Acta Neurologica Scandinavica 12/2012; · 2.47 Impact Factor
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    ABSTRACT: OBJECTIVE: Although patients >80 years were excluded in RCTs for tPA treatment of acute ischemic stroke (AIS), many centers treat old patients. We wanted to examine whether age ≥80 years is an independent predictor of outcome after tPA. MATERIALS: We included 77 consecutive patients ≥80 years and 83 patients <80 years treated with tPA within 4.5 h after onset of AIS. Baseline variables were analyzed by multiple stepwise logistic regression analyses against three outcomes: symptomatic intracerebral hemorrhage (sICH), death and good functional outcome (mRS, 0-1) at 3-month follow-up. RESULTS: Age ≥80 years was associated with increased risk of sICH (OR, 18.2 [95% CI, 1.0-324.1], P = 0.048), and death (OR, 3.3 [95% CI, 1.2-9.1], P = 0.018), but not with functional outcome at 3 months. Other factors associated with death were longer onset to treatment time (OTT) (OR, 1.007/min increase [95% CI, 1.00-1.015], P = 0.047), higher NIHSS (OR, 1.12 per point increase [95% CI, 1.04-1.19], P = 0.001), and previous stroke (OR, 4.0 [95% CI, 1.2-13.7], P = 0.03). Predictors of good functional outcome were shorter OTT (OR, 0.99 [95% CI, 0.98-1.00], P = 0.02) and lower NIHSS (OR, 0.80 [95% CI, 0.74-0.87] P ≤ 0.001). CONCLUSION: Age ≥80 years might be an independent risk factor for sICH and death the first 3 months after treatment with tPA for AIS, but does not influence the chance of a good functional outcome. We suggest to treat patients over 80 years with tPA, but be cautious if the time from onset (OTT) is long.
    Acta Neurologica Scandinavica 09/2012; · 2.47 Impact Factor
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    ABSTRACT: Purpose: Transcranial color-coded sonography (TCCS) and CT-angiography (CTA) are reliable tools for detection of intracranial stenosis. Current ultrasonographic criteria for middle cerebral artery (MCA) stenosis are usually limited to a dichotomized grading (< or ≥ 50 %). As for carotid arteries, continuity equation might provide a more accurate evaluation of degree of MCA stenosis. We aimed to apply continuity equation to calculate degree of MCA stenosis with TCCS and to compare these results with CTA. Materials and Methods: All patients admitted to our Neurovascular Center with ischemic stroke or TIA underwent TCCS examination. Degree of MCA stenosis was calculated based on continuity equation as (1 - [PSVprestenotic/PSVintrastenotic] × 100) %. CTA was performed when TCCS detected MCA stenosis, and degree of stenosis was calculated by diameter (D) as: (1 - [Dprestenotic/Dintrastenotic] × 100) %. Correlation between TCCS and CTA results was tested. Continuity equation method was compared to cut-off velocity method for detection of ≥ 50 % MCA stenosis. To assess TCCS inter-observer agreement, evaluation of MCA stenosis was repeated by another neurosonographer in a subgroup of patients. Results: The overall correlation coefficient between TCCS and CTA was 0.85 (p < 0.0001). Correlation coefficient for stenosis defined with CTA as ≥ 50 % was 0.94 (p < 0.0001). TCCS inter-observer agreement on degree of stenosis was 0.85 (p = 0.001). In detection of ≥ 50 % MCA stenosis, continuity equation method showed a sensitivity of 78 % (14/18) and a specificity of 86 % (19/22), while the cut-off velocity method showed a sensitivity of 67 % (12/18) and a specificity of 86 % (19/22). Conclusion: This study shows that ultrasonographic evaluation of MCA stenosis applying the continuity equation provides reproducible and accurate results, and is more sensitive in detection of ≥ 50 % MCA stenosis than cut-off velocity method.
    Ultraschall in der Medizin 08/2012; · 4.12 Impact Factor
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    ABSTRACT: We compared among young patients with ischemic stroke the distribution of vascular risk factors among sex, age groups, and 3 distinct geographic regions in Europe. We included patients with first-ever ischemic stroke aged 15 to 49 years from existing hospital- or population-based prospective or consecutive young stroke registries involving 15 cities in 12 countries. Geographic regions were defined as northern (Finland, Norway), central (Austria, Belgium, France, Germany, Hungary, The Netherlands, Switzerland), and southern (Greece, Italy, Turkey) Europe. Hierarchical regression models were used for comparisons. In the study cohort (n=3944), the 3 most frequent risk factors were current smoking (48.7%), dyslipidemia (45.8%), and hypertension (35.9%). Compared with central (n=1868; median age, 43 years) and northern (n=1330; median age, 44 years) European patients, southern Europeans (n=746; median age, 41 years) were younger. No sex difference emerged between the regions, male:female ratio being 0.7 in those aged <34 years and reaching 1.7 in those aged 45 to 49 years. After accounting for confounders, no risk-factor differences emerged at the region level. Compared with females, males were older and they more frequently had dyslipidemia or coronary heart disease, or were smokers, irrespective of region. In both sexes, prevalence of family history of stroke, dyslipidemia, smoking, hypertension, diabetes mellitus, coronary heart disease, peripheral arterial disease, and atrial fibrillation positively correlated with age across all regions. Primary preventive strategies for ischemic stroke in young adults-having high rate of modifiable risk factors-should be targeted according to sex and age at continental level.
    Stroke 07/2012; 43(10):2624-30. · 6.16 Impact Factor
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    ABSTRACT: Newer Scandinavian data on intracerebral hemorrhage (ICH) are scarce. We aimed at providing updated community-based data on the incidence, characteristics and outcome of ICH leading to hospitalization in the southernmost region in Norway. We analyzed data from all consecutive patients hospitalized with a first-ever ICH in the five-year period 2005-2009 in a well-defined area served by one single hospital. Cases were found by computerized search in a register covering all in- and outpatients. Adjusted to the standard European population the annual incidence rate per 100,000 was 16.9 for men, 8.8 for women (p < 0.001) and 12.5 for both sexes. The incidence rates rose continuously with increasing age through all age groups in both sexes. The proportion with warfarin-associated ICH was 26.9%. The overall 30-day case fatality rate was 36.6%. The hematoma location was lobar in 36.6%, deep cerebral in 45.5%, cerebellar in 9.7%, and brain stem in 8.2%. The incidence of ICH in the southernmost region in Norway is in the midrange in Europe and lower than in previous Scandinavian studies. Men are at higher risk than women. The proportion with warfarin-associated ICH is higher than previously reported from Scandinavia.
    European Neurology 03/2012; 67(4):240-5. · 1.50 Impact Factor
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    Titto Idicula, Lars Thomassen
    01/2012; , ISBN: 978-953-307-983-7
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    ABSTRACT: Hypothermia is considered neuroprotective and a potential treatment in cerebral ischemia. Some studies suggest that hyperthermia may promote clot lysis. We hypothesized that low body temperature would prolong time to spontaneous clot lysis resulting in an association between low body temperature and severe neurological deficits in the early phase of ischemic stroke. In this prospective study, patients (n = 516) exhibiting ischemic stroke with symptom onset within 6 hours were included. Body temperature and National Institute of Health Stroke Scale (NIHSS) score were registered on admission. Because low body temperature on admission may be secondary to immobilization due to large stroke, separate analyses were performed on patients with cerebral hemorrhage admitted within 6 hours (n = 85). Linear regression showed that low body temperature on admission was independently associated with a high NIHSS score within 6 hours of stroke onset in patients with ischemic stroke (P < 0.001). The association persisted when NIHSS was measured at 24 hours after admission. No such associations were found in patients with cerebral hemorrhage admitted within 6 hours of stroke onset. Our study suggests that low body temperature within 6 hours of symptom onset is associated with severe ischemic stroke. This is in support of our hypothesis, although other contributing mechanisms cannot be excluded.
    Vascular Health and Risk Management 01/2012; 8:333-8.
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    ABSTRACT: Visual field defects (VFD) after stroke can cause significant disability and reduction in quality of life. Adequate diagnosis of VFD and referral to visual rehabilitation are important to improve outcome. Our aim was to conduct a retrospective clinical audit to investigate how neurologists detect and follow up VFD in stroke patients in a university hospital in Norway. All patients registered in the Bergen NORSTROKE Registry from February 2006 to May 2009 with (1) occipital lobe infarctions and (2) non-occipital infarction and clinically detected VFD were included in the study. Their medical records were reviewed for referral to perimetry for examination of VFD and for referral to a visual rehabilitation program within the first year after brain injury. Of 353 patients, 34 (9.6%) were referred to perimetry and 8 (2.3%) to visual rehabilitation. Patients referred to perimetry were younger (65.1 vs. 74.7 years, p < 0.001), had lower modified Rankin Scale scores (2.53 vs. 3.47, p = 0.003), and scored lower on the National Institutes of Health Stroke Scale upon admission (6.68 vs. 13.90, p < 0.001). Men were more often referred to perimetry than women (73.5 vs. 26.5%, p < 0.001), and those referred were younger (61.2 vs. 75.8 years, p = 0.03). Only few patients were referred to perimetry, and even fewer were offered visual rehabilitation. Age and gender were negative predictors for referral. Neurologists' awareness of the significant disability related to VFD must be increased. Focused diagnostics on visual impairment and early referral to a visual rehabilitation program should be mandatory in stroke unit services.
    Cerebrovascular diseases extra. 01/2012; 2(1):17-23.
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    ABSTRACT: Background and Purpose. We hypothesized that patients with persistent atrial fibrillation (AF) suffer from more severe cerebral infarction than patients with paroxysmal AF due to differences in clot structure and volume. Methods. This study includes consecutive patients with acute cerebral infarction and persistent or paroxysmal AF documented by ECG any time prior to stroke onset. The National Institute of Health Stroke Scale (NIHSS) was used to assess stroke severity on admission. Short-term outcome was determined by the modified Rankin scale (mRS) score, Barthel index, and NIHSS score 7 days after stroke onset. Risk factors were registered on admission. Eligible patients were treated with thrombolysis. Results. In total, 141 (52%) patients had paroxysmal AF, and 129 (48%) patients had persistent AF. NIHSS score on admission, mRS score at day 7, and mortality were significantly higher among patients with persistent AF. Thrombolysis was less effective in patients with persistent AF. Conclusions. Our study shows that patients with persistent AF and acute cerebral infarction have poorer short-term outcome than patients with paroxysmal AF. Differences in clot structure or clot volume may explain this.
    ISRN cardiology. 01/2012; 2012:650915.
  • Tidsskrift for den Norske laegeforening 11/2011; 131(23):2334.
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    ABSTRACT: A possible synergic role of serum uric acid (SUA) with thrombolytic therapies is controversial and needs further investigations. We therefore evaluated association of admission SUA with clinical improvement and clinical outcome in patients receiving rt-PA, early admitted patients not receiving rt-PA, and patients admitted after time window for rt-PA. SUA levels were obtained at admission and categorized as low, middle and high, based on 33° and 66° percentile values. Patients were categorized as patients admitted within 3 hours of symptom onset receiving rt-PA (rt-PA group), patients admitted within 3 hours of symptom onset not receiving rt-PA (non-rt-PA group), and patients admitted after time window for rt-PA (late group). Short-term clinical improvement was defined as the difference between NIHSS on admission minus NIHSS day 7. Favorable outcome was defined as mRS 0 - 3 and unfavorable outcome as mRS 4 - 6. SUA measurements were available in 1136 patients. Clinical improvement was significantly higher in patients with high SUA levels at admission. After adjustment for possible confounders, SUA level showed a positive correlation with clinical improvement (r = 0.012, 95% CI 0.002-0.022, p = 0.02) and was an independent predictor for favorable stroke outcome (OR 1.004; 95% CI 1.0002-1.009; p = 0.04) only in the rt-PA group. SUA may not be neuroprotective alone, but may provide a beneficial effect in patients receiving thrombolysis.
    BMC Neurology 09/2011; 11:114. · 2.56 Impact Factor
  • Tidsskrift for den Norske laegeforening 08/2011; 131(16):1558.
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    ABSTRACT: The basic stroke unit studies selected patients primarily for rehabilitation and did not deal with the critical first hours after stroke. The aim of this study was to analyse a unselected cohort of patients admitted to an acute stroke centre with primary focus on emergency diagnosis and treatment. All patients with suspected stroke were admitted as emergencies. Patients with definite cerebrovascular disease were prospectively included in the Bergen Stroke Study, patients with other diseases were excluded, but final diagnosis was registered. Fifty per cent of the admitted patients had other diagnosis than stroke. Of 1267 consecutive patients with cerebrovascular disease, 70% had no or minor neurological deficits on admission. After 1 week, 56% were independent, 30% needed long-term rehabilitation, 10% were bedridden and 4% were dead. An acute stroke centre today requires a high degree of neurological expertise in assessing patients admitted with possible stroke. Most patients with stroke have no or mild deficits and need above all rapid diagnostic work-up, acute and prophylactic treatment. In-hospital rehabilitation is essential for a smaller number of patients who suffer from persisting neurological deficits after stroke.
    Acta Neurologica Scandinavica 08/2011; 125(6):410-5. · 2.47 Impact Factor
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    ABSTRACT: Hypercoagulability leading to arterial or venous thrombosis and embolism in patients with cancer is a known phenomenon. We describe a 62 year old woman with a clinical course compatible with catastrophic antiphospholipid syndrome but seronegative findings and mucinous lung cancer. The case is discussed with reference to literature from a non-systematic PubMed search. Diagnoses of cerebral and cardiac infarcts, deep venous thrombosis and lung embolism led to a diagnosis of lung cancer by biopsy and positron emission tomography (PET). Early recurrence of venous and arterial thromboses or poor response to anticoagulation and antiplatelets should initiate cancer search in the assessment of such stroke patients. Especially the combination of venous and arterial thromboses should raise suspicion of cancer. PET and surgical cancer treatment should be evaluated at an early stage.
    Tidsskrift for den Norske laegeforening 07/2011; 131(13-14):1303-6.

Publication Stats

555 Citations
166.70 Total Impact Points

Institutions

  • 2002–2014
    • Haukeland University Hospital
      • Department of Neurology
      Bergen, Hordaland, Norway
    • University of Bergen
      • Department of Clinical Medicine
      Bergen, Hordaland, Norway
  • 2009–2012
    • Sørlandet Hospital
      Arendal, Aust-Agder county, Norway