Browsing by Subject "neurologia"

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  • Fontell, Carl Wilhelm (Frenckell, 1832)
  • Soinne, Lauri (Helsingin yliopisto, 2009)
    Carotid atherosclerotic disease is a major cause of stroke, but it may remain clinically asymptomatic. The factors that turn the asymptomatic plaque into a symptomatic one are not fully understood, neither are the subtle effects that a high-grade carotid stenosis may have on the brain. The purpose of this study was to evaluate brain microcirculation, diffusion, and cognitive performance in patients with a high-grade stenosis in carotid artery, clinically either symptomatic or asymptomatic, undergoing carotid endarterectomy (CEA). We wanted to find out whether the stenoses are associated with diffusion or perfusion abnormalities of the brain or variation in the cognitive functioning of the patients, and to what extent the potential findings are affected by CEA, and compare the clinically symptomatic and asymptomatic subjects as well as strictly healthy controls. Coagulation and fibrinolytic parameters were compared with the rate microembolic signals (MES) in transcranial Doppler (TCD) and the macroscopic appearance of stenosing plaques in surgery. Patients (n=92) underwent CEA within the study. Blood samples pertaining to coagulation and fibrinolysis were collected before CEA, and the subjects underwent repeated TCD monitoring for MES. A subpopulation (n= 46) underwent MR imaging and repeated neuropsychological examination (preoperative, as well 4 and 100 days after CEA). In MRI, the average apparent diffusion coefficients were higher in the ipsilateral white matter (WM), and altough the interhemispheric difference was abolished by CEA, the levels remained higher than in controls. Symptomatic stenoses were associated with more sluggish perfusion especially in WM, and lower pulsatility of flow in TCD. All patients had poorer cognitive performance than healthy controls. Cognitive functions improved as expected by learning effect despite transient postoperative worsening in a few subjects. Improvement was greater in patients with deepest hypoperfusion, primarily in executive functions. Symptomatic stenoses were associated with higher hematocrit and tissue plasminogen activator antigen levels, as well as higher rate of MES and ulcerated plaques, and better postoperative improvement of vasoreactivity and pulsatility. In light of the findings, carotid stenosis is associated with differences in brain diffusion, perfusion, and cognition. The effect on diffusion in the ipsilateral WM, partially reversible by CEA, may be associated with WM degeneration. Asymptomatic and symptomatic subpopulations differ from each other in terms of hemodynamic adaptation and in their vascular physiological response to removal of stenosis. Although CEA may be associated with a transient cognitive decline, a true improvement of cognitive performance by CEA is possible in patients with the most pronounced perfusion deficits. Mediators of fibrinolysis and unfavourable hemorheology may contribute to the development of a symptomatic disease in patients with a high-grade stenosis.
  • Arnell, Henricus Eduardus (Frenckell, 1832)
  • Castren, Matthia Alexandro (Frenckell, 1833)
  • Heikinheimo-Connell, Terttu (Helsingin yliopisto, 2015)
    Background: Stroke is the second most common cause of death. It is also the leading cause of disability worldwide. Low-income countries, where infectious diseases play a major role, carry the biggest burden of growing numbers of stroke. Infections can trigger an acute stroke. Malawi is situated in Sub-Saharan Africa, where prevalence of chronic diseases like high blood pressure, diabetes mellitus, and stroke are increasing. The HIV-prevalence among young adults is 12%. HIV may cause milder neurocognitive impairments, which are called HIV-associated neurocognitive disorders (HAND). Methods: The Helsinki Young Stroke Registry (HYSR) includes over 1000 patients aged 15-49 years with acute ischemic stroke. We investigated how high leukocyte count and infections affect recovery after stroke. In Malawi, we defined the stroke characteristics, impact of HIV, and one-year outcome. A selected subset of patients were interviewed about their quality of life (QOL). A group of Finnish men were investigated to determine whether HIV has caused neurological or neurocognitive impairment when with best available treatment for even 30 years. Results: In Helsinki (781 patients) high leukocyte count weakened 3-month outcome, however, not the long-term outcome (8.1±4.2 years). In the other study (681patients) 10% had preceding infection (PI), most commonly upper respiratory tract infection, and 15% had post stroke infection (PSI), most commonly pneumonia. All the infections worsened 3-month outcome. PSI was associated with long-term (7.8±4.0 years) higher risk of all-cause death. In Malawi (147 patients) HIV-infected patients (34%) suffered more often from ischemic stroke than HIV-negative patients. They were younger and had less often conventional risk factors for stroke. More than half of all patients had a poor outcome at 1-year, and the mortality rate was 45%. This was related to stroke severity and female gender but not to presence of HIV. We interviewed 25 patients. Good functional outcome was positively associated with better QOL on the domains of self-care and ability for communication. Females scored worse on the domains of fatigue and cognition. Older age was associated with worse QOL on the domain of self care. HIV did not affect the QOL. We evaluated 17 Finnish HIV-patients. A third had signs of polyneuropathy, half suffered from fatigue, and mild depression was common. Magnet resonance image (MRI) showed signs of lacunar ischemic stroke in three patients. Conclusions: The high leukocyte count in HYSR patients was associated with vascular disease and stroke severity. The high leukocyte count, PI and PSI were associated with poor short-term outcomes. PSIs were also associated with higher long-term mortality. In Malawi, severe stroke and gender were associated with unfavorable outcome. HIV-infection is common especially among young stroke patients, but not related to unfavorable outcome. QOL was associated with age, gender, and functional recovery. Despite HIV, the surviving Finnish patients had no describing features of HAND. Polyneuropathy, fatigue and mild depression were common. The silent strokes in MRI support the hypothesis of HIV increasing the risk of strokes.
  • Putaala, Jukka (Helsingin yliopisto, 2010)
    Stroke is the second leading cause of death and the leading cause of disability worldwide. Of all strokes, up to 80% to 85% are ischemic, and of these, less than 10% occur in young individuals. Stroke in young adults—most often defined as stroke occurring under the age of 45 or 50—can be particularly devastating due to long expected life-span ahead and marked socio-economic consequences. Current basic knowledge on ischemic stroke in this age group originates mostly from rather small and imprecise patient series. Regarding emergency treatment, systematic data on use of intravenous thrombolysis are absent. For this Thesis project, we collected detailed clinical and radiological data on all consecutive patients aged 15 to 49 with first-ever ischemic stroke between 1994 and 2007 treated at the Helsinki University Central Hospital. The aims of the study were to define demographic characteristics, risk factors, imaging features, etiology, and long-term mortality and its predictors in this patient population. We additionally sought to investigate, whether intravenous thrombolysis is safe and beneficial for the treatment of acute ischemic stroke in the young. Of our 1008 patients, most were males (ratio 1.7:1), who clearly outnumbered females after the age of 44, but females were preponderant among those aged <30. Occurrence increased exponentially. The most frequent risk factors were dyslipidemia (60%), smoking (44%), and hypertension (39%). Risk factors accumulated in males and along aging. Cardioembolism (20%) and cervicocerebral artery dissection (15%) were the most frequent etiologic subgroups, followed by small-vessel disease (14%), and large-artery atherosclerosis (8%). A total of 33% had undetermined etiology. Left hemisphere strokes were more common in general. Posterior circulation infarcts were more common among those aged <45. Multiple brain infarcts were present in 23% of our patients, 13% had silent infarcts, and 5% had leukoaraiosis. Of those with silent brain infarcts, majority (54%) had only a single lesion, and most of the silent strokes were located in basal ganglia (39%) and subcortical regions (21%). In a logistic regression analysis, type 1 diabetes mellitus in particular predicted the presence of both silent brain infarcts (odds ratio 5.78, 95% confidence interval 2.37-14.10) and leukoaraiosis (9.75; 3.39-28.04). We identified 48 young patients with hemispheric ischemic stroke treated with intravenous tissue plasminogen activator, alteplase. For comparisons, we searched 96 untreated control patients matched by age, gender, and admission stroke severity, as well as 96 alteplase-treated older controls aged 50 to 79 matched by gender and stroke severity. Alteplase-treated young patients recovered more often completely (27% versus 10%, P=0.010) or had only mild residual symptoms (40% versus 22%, P=0.025) compared to age-matched controls. None of the alteplase-treated young patients had symptomatic intracerebral hemorrhage or died within 3-month follow-up. Overall long-term mortality was low in our patient population. Cumulative mortality risks were 2.7% (95% confidence interval 1.5-3.9%) at 1 month, 4.7% (3.1-6.3%) at 1 year, and 10.7% (9.9-11.5%) at 5 years. Among the 30-day survivors who died during the 5-year follow-up, more than half died due to vascular causes. Malignancy, heart failure, heavy drinking, preceding infection, type 1 diabetes, increasing age, and large-artery atherosclerosis causing the index stroke independently predicted 5-year mortality when adjusted for age, gender, relevant risk factors, stroke severity, and etiologic subtype. In sum, young adults with ischemic stroke have distinct demographic patterns and they frequently harbor traditional vascular risk factors. Etiology in the young is extremely diverse, but in as many as one-third the exact cause remains unknown. Silent brain infarcts and leukoaraiosis are not uncommon brain imaging findings in these patients and should not be overlooked due to their potential prognostic relevance. Outcomes in young adults with hemispheric ischemic stroke can safely be improved with intravenous thrombolysis. Furthermore, despite their overall low risk of death after ischemic stroke, several easily recognizable factors—of which most are modifiable—predict higher mortality in the long term in young adults.
  • Blank, Jacob Fredrik (Frenckell, 1847)
  • Keski-Säntti, Petra (Helsingin yliopisto, 2011)
    The occurrence of occupational chronic solvent encephalopathy (CSE) seems to decrease, but still every year reveals new cases. To prevent CSE and early retirement of solvent-exposed workers, actions should focus on early CSE detection and diagnosis. Identifying the work tasks and solvent exposure associated with high risk for CSE is crucial. Clinical and exposure data of all the 128 cases diagnosed with CSE as an occupational disease in Finland during 1995-2007 was collected from the patient records at the Finnish Institute of Occupational Health (FIOH) in Helsinki. The data on the number of exposed workers in Finland were gathered from the Finnish Job-exposure Matrix (FINJEM) and the number of employed from the national workforce survey. We analyzed the work tasks and solvent exposure of CSE patients and the findings in brain magnetic resonance imaging (MRI), quantitative electroencephalography (QEEG), and event-related potentials (ERP). The annual number of new cases diminished from 18 to 3, and the incidence of CSE decreased from 8.6 to 1.2 / million employed per year. The highest incidence of CSE was in workers with their main exposure to aromatic hydrocarbons; during 1995-2006 the incidence decreased from 1.2 to 0.3 / 1 000 exposed workers per year. The work tasks with the highest incidence of CSE were floor layers and lacquerers, wooden surface finishers, and industrial, metal, or car painters. Among 71 CSE patients, brain MRI revealed atrophy or white matter hyperintensities or both in 38% of the cases. Atrophy which was associated with duration of exposure was most frequently located in the cerebellum and in the frontal or parietal brain areas. QEEG in a group of 47 patients revealed increased power of the theta band in the frontal brain area. In a group of 86 patients, the P300 amplitude of auditory ERP was decreased, but at individual level, all the amplitude values were classified as normal. In 11 CSE patients and 13 age-matched controls, ERP elicited by a multimodal paradigm including an auditory, a visual detection, and a recognition memory task under single and dual-task conditions corroborated the decrease of auditory P300 amplitude in CSE patients in single-task condition. In dual-task conditions, the auditory P300 component was, more often in patients than in controls, unrecognizable. Due to the paucity and non-specificity of the findings, brain MRI serves mainly for differential diagnostics in CSE. QEEG and auditory P300 are insensitive at individual level and not useful in the clinical diagnostics of CSE. A multimodal ERP paradigm may, however, provide a more sensitive method to diagnose slight cognitive disturbances such as CSE.
  • Sjöman, Steno Eduardus (J. C. Frenckell & fil., 1832)
  • Leisiö, Timo (Helsingin yliopiston kirjasto, 2022)
    Kielen pohjana on kielioppi ja kieli konkretisoituvat puhumalla. Laulu konkretisoituu musiikiksi melodisten ja rytmisten kuvioiden avulla laulamalla, jolloin sen pohjalla ei voi olla kielioppi vaan musiikkioppi. Vaikkei musiikki ei ole kieli, senkin pohjana on sisäisesti looginen sääntöjärjestelmänsä eli syntaksinsa. Tässä kirjoituksessa kohteena on melodian rakentumisen pohjalla oleva säännöstö, jolloin rytmiikkaan liittyvät seikat jäävät huomiotta. Kysymyksenä on, miksi unkarilaisen lauluopin syntaksissa on piirteitä, jotka yhdistävät ne enemmänkin samojedeihin ja eteläsaamelaisiin kuin pelkästään obinugrilaisiin tai mareihin? Tarkoittamani piirteet liittyvät unkarilaisten nelisäkeisen laulun siihen genreen, jonka kuka tahansa tunnistaa unkarilaiseksi, koska esisäeparin pentatoninen melodia kertautuu muunneltuna yleensä viittä sävelaskelta alempana. Lauluja leimaavaa “kvinttisiirtymää” on arveltu unkarilaisen laulun suomalais-ugrilaiseksi piirteeksi. Analyysin kohteena ei kuitenkaan ole itse siirtymä vaan pienempi syntaktinen piirreryhmä melodiassa, ryhmä, jota ei heti voi kuvitella löytyvän neljän loppusoinnullisen säkeen muodostamasta unkarilaisesta säkeistölaulusta. Analyysi päätyy näkemykseen, jonka mukaan keskieurooppalaistuneen nelisäkeisen riimillisen laulun melodisessa syntaksissa on piirteitä, jotka näyttävät palautuvan pohjoisen Euraasian esiuralilaiseen laulutraditioon. Yleisenä lähtöoletuksena on, että unkarilaisten varhaiset esivanhemmat elivät Uralin eteläosien alueilla ja puhuivat kantauralia ja eri vaiheiden jälkeen monelta suunnalta vaeltaneet populaatiot olivat asettuneet 800-luvun kuluessa keskiseen Eurooppaan, Karpaattien länsipuoliselle alankoalueelle, jossa muodostui kulttuurisesti suhteellisen homogeeninen unkarinkielinen yhteiskun-ta. Unkarilaisen kulttuurin kehkeytymiseen liittyy keskenään ristiriitaisia tulkintoja (ks. esim. Bálint 2010), mutta oleellista on vanhimman kulttuurin keskeisten ainesten yhteydet monien uralilaisia kieliä puhuvien väestöjen aineksiin.
  • Mertsalmi, Tuomas (Helsingin yliopisto, 2021)
    Parkinson’s disease (PD) is a movement disorder associated with widespread neurodegeneration in the central, autonomic, and enteric nervous systems. PD is not restricted to its cardinal motor symptoms (bradykinesia, rigidity, and rest tremor), as it also manifests in a variety of non-motor symptoms such as gastrointestinal dysfunction, which may predate the onset of motor symptoms by several years. The early involvement of the gastrointestinal tract and evidence from animal, neuropathological, and epidemiologic studies have given rise to a hypothesis that the pathogenesis of PD could originate in the gastrointestinal tract. Interestingly, PD has also been associated with alterations in the composition of gut microbiota – the ecological community of commensal, symbiotic and pathogenic organisms living in the gastrointestinal tract. The aim of this thesis was to explore the possible associations between the microbiota-gut-brain axis (MGBA) and PD. This thesis includes a cross-sectional study and two retrospective registry-based studies utilizing the Finnish Care Register for Health Care (HILMO) and other nationwide registers. In study I, we assessed the diversity and clinical associations of gastrointestinal symptoms and gut microbiota in PD patients and controls. The symptomatic Rome III criteria for irritable bowel syndrome (IBS) were fulfilled in 24.3% of PD patients and 5.3% of controls (p=0.001). Moreover, IBS-like symptoms were associated with other non-motor symptoms and microbiota composition, such as a decreased abundance of genus Prevotella. In study II, the associations between PD-risk and antibiotic exposure were investigated. The adjusted odds ratio for PD patients exposed to macrolides and lincosamides was up to 1.42 (95% confidence interval 1.05-1.90). The strongest associations were observed for exposure to broad-spectrum and anti-anaerobic antibiotics that potentially have the strongest impact on gut microbiota. In study III, we investigated the associations between PD-risk and IBS. IBS was significantly associated with a higher hazard of PD, but only during the first two years of follow-up (adjusted hazard ratio 2.96, 95% confidence interval 1.78-4.92). This finding suggests that the association between IBS and PD might be explained by different sources of bias, including detection bias, reverse causation, and competing risk of death. The observations presented in this thesis provide new insights into the role of the MGBA in the pathogenesis and clinical, including non-motor, manifestations of PD. A more systemic assessment of gastrointestinal dysfunction in PD could improve the quality of care in PD patients. The gut microbiota also provides a potential target for future therapies for PD.