Publications by authors named "Paavilainen T"

Thalamus is among the first brain regions to become atrophic in multiple sclerosis (MS). We studied whether thalamic atrophy predicts disability progression at 5 years in a cohort of Finnish MS patients. Global and regional brain volumes were measured from 24 newly diagnosed relapsing MS (RMS) patients 6 months after initiation of therapy and from 36 secondary progressive MS (SPMS) patients.

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To study which brain volume measures best differentiate early relapsing MS (RMS) and secondary progressive MS (SPMS) patients and correlate with disability and cognition. To test whether isolated thalamic atrophy at study baseline correlates with NEDA (no evidence of disease activity) at 2 years. Total and regional brain volumes were measured from 24 newly diagnosed RMS patients 6 months after initiation of therapy and 2 years thereafter, and in 36 SPMS patients.

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Objective: To investigate the relationship of in vivo microglial activation to clinical and MRI parameters in MS.

Methods: Patients with secondary progressive MS (n = 10) or relapsing-remitting MS (n = 10) and age-matched healthy controls (n = 17) were studied. Microglial activation was measured using PET and radioligand [C]()-PK11195.

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Long-term neural differentiation of human pluripotent stem cells (hPSCs) is associated with enhanced neuronal maturation, which is a necessity for creation of representative in vitro models. It also induces neurogenic-to-gliogenic fate switch, increasing proportion of endogenous astrocytes formed from the common neural progenitors. However, the significance of prolonged differentiation on the neural cell type composition and functional development of hPSC-derived neuronal cells has not been well characterized.

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Clinical data and behavioral studies using transcranial magnetic stimulation (TMS) suggest right-hemisphere dominance for top-down modulation of visual processing in humans. We used concurrent TMS-EEG to directly test for hemispheric differences in causal influences of the right and left intraparietal cortex on visual event-related potentials (ERPs). We stimulated the left and right posterior part of intraparietal sulcus (IPS1) while the participants were viewing and rating the visibility of bilaterally presented Gabor patches.

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Traditionally, multiple sclerosis (MS) has been considered a white matter disease with focal inflammatory lesions. It is, however, becoming clear that significant pathology, such as microglial activation, also takes place outside the plaque areas, that is, in areas of normal-appearing white matter (NAWM) and gray matter (GM). Microglial activation can be detected in vivo using 18-kDa translocator protein (TSPO)-binding radioligands and PET.

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Heparan sulfate proteoglycans (HSPGs), ubiquitous components of mammalian cells, play important roles in development and homeostasis. These molecules are located primarily on the cell surface and in the pericellular matrix, where they interact with a multitude of macromolecules, including many growth factors. Manipulation of the enzymes involved in biosynthesis and modification of HSPG structures alters the properties of stem cells.

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Unlabelled: Patients with secondary progressive multiple sclerosis (SPMS) are lacking efficient medication to slow down the progression of their disease. PET imaging holds promise as a method to study, at the molecular level and in vivo, the central nervous system pathology of SPMS. PET might thus help to elucidate potential therapeutic targets and be useful as an imaging biomarker in future treatment trials of progressive multiple sclerosis.

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In this study, positron emission tomography (PET) imaging with a radioligand to adenosine A2A receptors (A2AR)-a potent regulator of inflammation-was used to gain insight into the molecular alterations in normal-appearing white matter (NAWM) and gray matter (GM) in secondary progressive multiple sclerosis (SPMS). Normal-appearing white matter and GM, despite seeming normal in conventional magnetic resonance imaging (MRI), are important loci of widespread inflammation, neuronal damage, and source of progressive disability in multiple sclerosis (MS). Dynamic PET imaging using A2AR-specific [(11)C]TMSX and brain MRI with diffusion tensor imaging were performed to eight SPMS patients and seven healthy controls.

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Introduction: Fabry disease is a rare lysosomal storage disorder leading to cellular accumulation of globotriaosylceramide, especially in blood vessels. It is associated with severe early onset cerebrovascular disease and kidney and heart failure. The purpose of this study was to reveal possible disturbances in white matter integrity in Fabry disease patients using voxelwise diffusion-tensor imaging (DTI) analysis.

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Background: White matter maturation is characterised by increasing fractional anisotropy (FA) and decreasing mean diffusivity (MD). Contradictory results have been published on the effect of premature birth on white matter maturation at term-equivalent age.

Objective: To assess the association of gestational age and low birth-weight-for-gestational-age (z-score) with white matter maturation.

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Introduction: A positive correlation has been observed between multiple sclerosis (MS) disease activity status and the apparent diffusion coefficient (ADC) of the brain. Moreover, the relapse frequency of MS has been reported to decrease during pregnancy and increase postpartum. The aim of this study was to evaluate whether ADC histograms correlate with MS activity during pregnancy and postpartum, with a leading hypothesis that the ADC would increase postpartum compared to pregnancy.

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Article Synopsis
  • The study focused on assessing the reproducibility of brain diffusion tensor measurements, specifically fractional anisotropy (FA) and mean diffusivity (MD), in a sample of 76 infants.
  • It found that both intra-observer and inter-observer reproducibility for FA and MD was generally excellent in certain key brain regions but varied across others, with some regions showing poor reproducibility.
  • Overall, the research concluded that the measurement of these diffusion tensor parameters has fair to good reproducibility, which is important for clinical applications.
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A malfunctioning heater caused a severe carbon monoxide (CO) intoxication leading to unconsciousness and predominantly right-sided extrapyramidal syndrome in a 29-year-old man. Follow-up included thorough clinical monitoring, and brain MRI and PET studies. Nine days after the poisoning, brain MRI showed symmetrical necrosis in the globus pallidi, but no abnormality was found in the substantia nigra.

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Salmonids in certain areas of North America and northern Europe suffer from reproductive disturbances manifested through the death of yolk sac fry. These disturbances are referred to as early mortality syndrome (EMS) in the Great Lakes region and M74 in the Baltic Sea. Both of these syndromes have been associated with reduced concentrations of thiamine in affected females and their eggs.

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Background And Purpose: Historically, a Schanz osteotomy of the femur has been used to reduce limp in patients with severely dysplastic hips. In such hips, total hip arthroplasty is a technically demanding operation. We report the long-term results of cementless total hip arthroplasty in a group of patients who had all undergone a Schanz osteotomy earlier.

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Diffusion-weighted (DW) magnetic resonance (MR) imaging in addition to conventional magnetic resonance MR images provide valuable information in multiple sclerosis (MS). Increased diffusivity measured with diffusion-weighted imaging (DWI) has been demonstrated in normal appearing brain tissue in MS. So far, longitudinal changes taking place in whole-brain histograms in patients with active relapsing-remitting MS have not been evaluated.

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Ingestion of windshield washer liquid resulted with an acute severe methanol intoxication in a 49-year old man. He developed optic atrophy with blindness, and an extrapyramidal syndrome. Putaminal injury and hyperintensity in the subcortical white matter was seen in a brain MRI.

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Unlabelled: We encountered late hardware-induced sciatic nerve lesions after acetabular revision in six patients. There were five female patients and one male patient. The mean age of the patients at the time of index acetabular revision was 59.

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Post-partum relapses are a frequent phenomenon in multiple sclerosis (MS). The purpose of this study was to evaluate the timing and extent of new or growing T2-lesions after delivery in a cohort of Finnish MS patients. In addition to serial magnetic resonance imaging (MRI), the patients were followed up clinically with determination of relapse rate and expanded disability status scale.

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Background: Weakness of the abductor muscles--or even their avulsion--is a potential risk when total hip arthroplasty (THA) is performed using the anterolateral approach. Avulsion of the re-attached gluteus medius leads to a limp, but can also provide an open canal for joint fluid to escape to the trochanteric region. Thus, our hypothesis was that arthrography can be used to diagnose such detachment.

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Background: The optimal surgical treatment for patients with high congenital dislocation of the hip remains controversial. The purpose of our study was to evaluate the mid-term to long-term results of cementless total hip arthroplasty in such patients.

Methods: The study included sixty-eight total hip replacements performed between 1989 and 1994 in fifty-six consecutive patients with high congenital hip dislocation at our hospital.

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Background: Diastrophic dysplasia results in severe disproportionate short stature, generalized joint deformities, and early osteoarthritis. The knee joint often has an abnormal valgus position and is unstable, and degeneration of all joint compartments occurs, even during growth. The purpose of our study was to evaluate the clinical and radiographic results of total knee arthroplasty in a series of patients with diastrophic dysplasia.

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Background: Diastrophic dysplasia results in severe disproportionate growth failure, multiple joint deformities, and early osteoarthritis of the hips. Mortality is increased in early childhood, but thereafter life expectancy is normal. Because of severe flexion deformities, resting pain, and diminished movements of the hip joints, total hip arthroplasty is indicated at an early age.

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Caspase-1 expression in synovial membrane-like interface tissue (SMLIT) around loosened hip prostheses and osteoarthritic synovial samples was studied. Caspase-1 mRNA was found in SMLIT and synovial tissue. There is no difference in the copy numbers of caspase-1 mRNA between these samples.

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