Browsing by Author "Karelis, Guntis"

Now showing 1 - 20 of 36
  • No Thumbnail Available
    Item
    Amygdala Nuclei Atrophy in Cognitive Impairment and Dementia : Insights from High-Resolution Magnetic Resonance Imaging
    (2025-01-15) Peiseniece, Evija; Zdanovskis, Nauris; Šneidere, Kristīne; Kostiks, Andrejs; Karelis, Guntis; Platkājis, Ardis; Stepens, Ainārs; Department of Radiology; Institute of Public Health; Department of Health Psychology and Paedagogy; Department of Infectology
    Background and Objectives: Cognitive impairment affects memory, reasoning, and problem-solving, with early detection being critical for effective management. The amygdala, a key structure in emotional processing and memory, may play a pivotal role in detecting cognitive decline. This study examines differences in amygdala nuclei volumes in patients with varying levels of cognitive performance to evaluate its potential as a biomarker.  Material and methods: This cross-sectional study of 35 participants was conducted and classified into three groups: the normal (≥26), moderate (15-25), and low (≤14) cognitive performance groups based on the Montreal Cognitive Assessment (MoCA) scores. High-resolution magnetic resonance imaging at 3.0 T scanner was used to assess amygdala nuclei volumes.  Results: Significant amygdala atrophy was observed in multiple amygdala nuclei across cognitive performance groups, with more pronounced changes in the low-performance group. The right hemisphere nuclei, including the lateral and basal nuclei, showed more significant differences, indicating their sensitivity to cognitive decline.  Conclusions: This study highlights the potential of amygdala nuclei atrophy as a biomarker for cognitive impairment. Additional research with larger sample sizes and longitudinal designs is needed to confirm these findings and determine their diagnostic value.
  • No Thumbnail Available
    Item
    Association of Baseline Lipopolysaccharide-Binding Protein with Expanded Disability Status Score Dynamics in Patients with Relapsing–Remitting Multiple Sclerosis : A Pilot Study
    (2025-01) Vilmane, Anda; Koļesova, Oksana; Nora-Krūkle, Zaiga; Koļesovs, Aleksandrs; Pastare, Daina; Jaunozoliņa, Līga; Kande, Linda; Egle, Jeļena; Kromane, Daniela; Mičule, Madara; Liepiņa, Sintija; Zeltiņa, Estere; Grāvelsiņa, Sabīne; Rasa-Dzelzkalēja, Santa; Vīksna, Ludmila; Karelis, Guntis; Institute of Microbiology and Virology; Department of Infectology; Department of Neurology and Neurosurgery; Department of Radiology
    Forecasting the progression of the disease in the early inflammatory stage of the most prevalent type of multiple sclerosis (MS), referred to as relapsing–remitting multiple sclerosis (RRMS), is essential for making prompt treatment modifications, aimed to reduce clinical relapses and disability. In total, 58 patients with RRMS, having an Expanded Disability Status Scale (EDSS) score less than 4, were included in this study. Baseline magnetic resonance imaging (MRI) was performed, and brain and spinal cord lesions were evaluated. The disability of the patients was evaluated using EDSS at baseline and follow-up; enzyme-linked immunosorbent assays (ELISAs) were also used to determine the level of blood-based inflammation markers in plasma at baseline. The main results demonstrated that the baseline level of LBP was correlated with an increase in EDSS in a short (8–10 months) follow-up period. Furthermore, the prognostic significance of LBP was only observed in patients who received disease-modifying treatment (DMT) before the study. Our results suggest that the baseline level of LBP may be among the predictors of disability progression in RRMS over short follow-up periods, particularly in those receiving treatment. It highlights the effect of endotoxins in the pathogenesis of RRMS.
  • No Thumbnail Available
    Item
    Biomarkers of Multiple Sclerosis
    (2019) Pastare, Daina; Bennour, Mohamed Ridha; Polunosika, Elīna; Karelis, Guntis; Department of Neurology and Neurosurgery; Department of Infectology
    The search for an ideal multiple sclerosis biomarker with good diagnostic value, prognostic reference and an impact on clinical outcome has yet to be realized and is still ongoing. The aim of this review is to establish an overview of the frequent biomarkers for multiple sclerosis that exist to date. The review summarizes the results obtained from electronic databases, as well as thorough manual searches. In this review the sources and methods of biomarkers extraction are described; in addition to the description of each biomarker, determination of the prognostic, diagnostic, disease monitoring and treatment response values besides clinical impact they might possess. We divided the biomarkers into three categories according to the achievement method: laboratory markers, genetic-immunogenetic markers and imaging markers. We have found two biomarkers at the time being considered the gold standard for MS diagnostics. Unfortunately, there does not exist a single solitary marker being able to present reliable diagnostic value, prognostic value, high sensitivity and specificity as well as clinical impact. We need more studies to find the best biomarker for MS.
  • No Thumbnail Available
    Item
    Brain structural connectivity differences in patients with normal cognition and cognitive impairment
    (2021-07) Zdanovskis, Nauris; Platkājis, Ardis; Kostiks, Andrejs; Karelis, Guntis; Grigorjeva, Oļesja; Department of Radiology
    Advances in magnetic resonance imaging, particularly diffusion imaging, have allowed researchers to analyze brain connectivity. Identification of structural connectivity differences between patients with normal cognition, cognitive impairment, and dementia could lead to new biomarker discoveries that could improve dementia diagnostics. In our study, we analyzed 22 patients (11 control group patients, 11 dementia group patients) that underwent 3T MRI diffusion tensor imaging (DTI) scans and the Montreal Cognitive Assessment (MoCA) test. We reconstructed DTI images and used the Desikan-Killiany-Tourville cortical parcellation atlas. The connectivity matrix was calculated, and graph theoretical analysis was conducted using DSI Studio. We found statistically significant differences between groups in the graph density, network characteristic path length, small-worldness, global efficiency, and rich club organization. We did not find statistically significant differences between groups in the average clustering coefficient and the assortativity coefficient. These statistically significant graph theory measures could potentially be used as quantitative biomarkers in cognitive impairment and dementia diagnostics.
  • No Thumbnail Available
    Item
    Brief Cognitive Monitoring in Multiple Sclerosis Patients in Latvia
    (2015-09-01) Mekša, Liga; Karelis, Guntis; Vainšteine, Lana; Svilpe, Sandra; Gulbe, Gundega; Gudreniece, Anželika; Kalnina, Jolanta; Department of Neurology and Neurosurgery
    Cognitive changes are common in people with multiple sclerosis (MS). The neuropsychological testing requires specialised trained staff, time-consuming expert analysis and complicated test result interpretation. An expert committee recommended the Brief International Cognitive Assessment for Multiple Sclerosis (BICAMS), which is optimised for small centres. We conducted the Symbol Digit Modalities Test (SDMT) and Brief Visuospatial Memory Test (BVMT), for which the results were comparable with similar results in literature. Most MS patients showed decreased attention and processing speed, while visual memory was generally normal. Cognitive impairment occurrence is not strongly related to Expanded Disability Status Scale (EDSS) score.
  • No Thumbnail Available
    Item
    Brodmann Areas, V1 Atlas and Cognitive Impairment : Assessing Cortical Thickness for Cognitive Impairment Diagnostics
    (2024-04) Trišins, Maksims; Zdanovskis, Nauris; Platkājis, Ardis; Šneidere, Kristīne; Kostiks, Andrejs; Karelis, Guntis; Stepens, Ainārs; Department of Radiology; Militārās medicīnas pētījumu un studiju centrs; Department of Health Psychology and Paedagogy; Department of Infectology
    Background and Objectives: Magnetic resonance imaging is vital for diagnosing cognitive decline. Brodmann areas (BA), distinct regions of the cerebral cortex categorized by cytoarchitectural variances, provide insights into cognitive function. This study aims to compare cortical thickness measurements across brain areas identified by BA mapping. We assessed these measurements among patients with and without cognitive impairment, and across groups categorized by cognitive performance levels using the Montreal Cognitive Assessment (MoCA) test.  Materials and Methods: In this cross-sectional study, we included 64 patients who were divided in two ways: in two groups with (CI) or without (NCI) impaired cognitive function and in three groups with normal (NC), moderate (MPG) and low (LPG) cognitive performance according to MoCA scores. Scans with a 3T MRI scanner were carried out, and cortical thickness data was acquired using Freesurfer 7.2.0 software.  Results: By analyzing differences between the NCI and CI groups cortical thickness of BA3a in left hemisphere (U = 241.000, p = 0.016), BA4a in right hemisphere (U = 269.000, p = 0.048) and BA28 in left hemisphere (U = 584.000, p = 0.005) showed significant differences. In the LPG, MPG and NC cortical thickness in BA3a in left hemisphere (H (2) = 6.268, p = 0.044), in V2 in right hemisphere (H (2) = 6.339, p = 0.042), in BA28 in left hemisphere (H (2) = 23.195, p < 0.001) and in BA28 in right hemisphere (H (2) = 10.015, p = 0.007) showed significant differences.  Conclusions: Our study found that cortical thickness in specific Brodmann Areas—BA3a and BA28 in the left hemisphere, and BA4a in the right—differ significantly between NCI and CI groups. Significant differences were also observed in BA3a (left), V2 (right), and BA28 (both hemispheres) across LPG, MPG, NC groups. Despite a small sample size, these findings suggest cortical thickness measurements can serve as effective biomarkers for cognitive impairment diagnosis, warranting further validation with a larger cohort.
  • No Thumbnail Available
    Item
    Cerebellar Cortex and Cerebellar White Matter Volume in Normal Cognition, Mild Cognitive Impairment, and Dementia
    (2021-08-26) Zdanovskis, Nauris; Platkājis, Ardis; Kostiks, Andrejs; Grigorjeva, Oļesja; Karelis, Guntis; Department of Radiology
    The cerebellum is commonly viewed as a structure that is primarily responsible for the coordination of voluntary movement, gait, posture, and speech. Recent research has shown evidence that the cerebellum is also responsible for cognition. We analyzed 28 participants divided into three groups (9 with normal cognition, 9 with mild cognitive impairment, and 10 with moderate/severe cognitive impairment) based on the Montreal Cognitive Assessment. We analyzed the cerebellar cortex and white matter volume and assessed differences between groups. Participants with normal cognition had higher average values in total cerebellar volume, cerebellar white matter volume, and cerebellar cortex volume in both hemispheres, but by performing the Kruskal–Wallis test, we did not find these values to be statistically significant.
  • No Thumbnail Available
    Item
    Chronic Kidney Disease and Cerebrovascular Pathology : Incidence and Functional Outcomes in Riga East University Hospital
    (2024-02) Zubkova, Violeta; Ševčenko, Aleksejs; Miļuhins, Igors; Ķikule, Ilga; Haritončenko, Iveta; Karelis, Guntis; Department of Neurology and Neurosurgery; Department of Infectology
    Background and Objectives: The aim of this study was to investigate the incidence of cerebrovascular pathology in patients with chronic kidney disease and its effect on functional outcomes. Materials and Methods: In a retrospective cross-sectional study (2018-2021), the medical records of patients with acute hemorrhagic and ischemic stroke with concomitant chronic kidney disease who received treatment in Riga East University Hospital Stroke Unit were analyzed. Data were analyzed using IBM SPSS 26.0. The Kruskal-Wallis, Mann-Whitney U test, and Spearman's rank correlation coefficient methods were used.  Results: The final sample consisted of 305 acute cerebrovascular pathology patients (56.4% females). Overall, 57.3% of stroke patients had second-stage chronic kidney disease with average serum creatinine levels of 104.3 mmol/L (±32.8). The functional outcome of the stroke depended on the stage of chronic kidney disease. There was a statistically significant non-linear correlation between glomerular filtration rate and NIHSS (National Institute of Health Stroke Scale) score on admission (Rho -0.194, p = 0.016), glomerular filtration rate and NIHSS score on discharge (Rho -0.186, p = 0.020), and glomerular filtration rate and modified Rankin score on admission (Rho -0.237, p = 0.003) and discharge (Rho -0.224, p = 0.05). The mean NIHSS score of ischemic stroke patients was 8.3 ± 5.9 on admission and 6.5 ± 5.8 on discharge. In the hemorrhagic stroke patient group, the mean NIHSS score was 9.5 ± 7.3 on admission and 7.1 ± 6.9 on discharge. On average, 34.0% of ischemic stroke patients had an mRS score of 5 on admission, while in the hemorrhagic stroke patient group, this figure was 41%. There was no statistical difference in the glomerular filtration rate between the thrombolyzed versus non-thrombolyzed patient groups (Mann-Whitney U test = 1457, p = 0.794).  Conclusions: Chronic kidney disease is an important predictor of the severity and functional outcome of a stroke; furthermore, the early management and prevention of complications should be a top priority in the prophylaxis of this cerebrovascular pathology.
  • No Thumbnail Available
    Item
    Clinical characteristics of patients with tick-borne encephalitis (Tbe) : A European multicentre study from 2010 to 2017
    (2021-07) Kohlmaier, Benno; Schweintzger, Nina A.; Sagmeister, Manfred G.; Švendová, Vendula; Kohlfürst, Daniela S.; Sonnleitner, Astrid; Leitner, Manuel; Berghold, Andrea; Schmiedberger, Erich; Fazekas, Franz; Pichler, Alexander; Rejc-Marko, Jana; Růžek, Daniel; Dufková, Lucie; Čejková, Darina; Husa, Petr; Pýchová, Martina; Krbková, Lenka; Chmelík, Václav; Štruncová, Věra; Zavadska, Dace; Karelis, Guntis; Mickiene, Aukse; Zajkowska, Joanna; Bogovič, Petra; Strle, Franc; Zenz, Werner; Department of Paediatrics; Rīga Stradiņš University
    Tick-borne encephalitis (TBE) virus is a major cause of central nervous system infections in endemic countries. Here, we present clinical and laboratory characteristics of a large international cohort of patients with confirmed TBE using a uniform clinical protocol. Patients were recruited in eight centers from six European countries between 2010 and 2017. A detailed description of clinical signs and symptoms was recorded. The obtained information enabled a reliable classification in 553 of 555 patients: 207 (37.3%) had meningitis, 273 (49.2%) meningoencephalitis, 15 (2.7%) meningomyelitis, and 58 (10.5%) meningoencephalomyelitis; 41 (7.4%) patients had a peripheral paresis of extremities, 13 (2.3%) a central paresis of extremities, and 25 (4.5%) had single or multiple cranial nerve palsies. Five (0.9%) patients died during acute illness. Outcome at discharge was recorded in 298 patients. Of 176 (59.1%) patients with incomplete recovery, 80 (27%) displayed persisting symptoms or signs without recovery expectation. This study provides further evidence that TBE is a severe disease with a large proportion of patients with incomplete recovery. We suggest monitoring TBE in endemic European countries using a uniform protocol to record the full clinical spectrum of the disease.
  • No Thumbnail Available
    Item
    Clinical Symptoms Influencing Parkinson's Patients' Quality of Life in Latvia : A Single-Center Cohort Study
    (2023-05-12) Minibajeva, Olga; Zeltiņa, Estere; Karelis, Guntis; Kurjāne, Nataļja; Ķēniņa, Viktorija; Department of Doctoral Studies; Department of Infectology; Department of Biology and Microbiology
    Background and Objectives: Parkinson's disease (PD) is a chronic, progressive illness with a profound impact on health-related quality of life, and it is crucial to know what factors influence the quality of life throughout the course of the disease. This study aimed to evaluate PD patients' motor and non-motor symptoms to compare symptom severity between PD clinical phenotypes and to assess the impact of disease symptoms on quality of life in a cohort of Latvian patients. Materials and Methods: We evaluated 43 patients with Parkinson's disease. Fourteen patients had tremor dominant (TD) PD, twenty-five patients had postural instability/gait difficulty (PIGD), and four patients had a mixed phenotype. Results: The patients' mean age was 65.21 years, and the disease's mean duration was 7 years. The most common non-motor symptoms were fatigue (95.3%), sleep disturbance (83.7%), daytime sleepiness (83.7%), and pain and other sensations (81.4%). PIGD patients had a higher prevalence of depressed mood, daytime sleepiness, constipation, lightheadedness on standing, cognitive impairment, and severe gastrointestinal and urinary disturbances (as assessed using the SCOPA-AUT domains) compared with TD patients. A high prevalence of fatigue was assessed in both disease subtypes. Health-related quality of life significantly statistically correlated with MDS-UPDRS parts III and IV (r = 0.704), the Hoehn and Yahr scale (r = 0.723), as well as the SCOPA-AUT scale's gastrointestinal (r = 0.639), cardiovascular (r = 0.586), thermoregulatory (r = 0.566) and pupillomotor domains (r = 0.597). Conclusions: The severity of motor symptoms, as well as non-motor symptoms, such as fatigue, apathy, sleep problems and daytime sleepiness, pain, and disturbances in gastrointestinal and cardiovascular function, negatively affect PD patients' health-related quality of life. Thermoregulatory and pupillomotor symptoms also significantly affect PD patients' well-being.
  • No Thumbnail Available
    Item
    Combined Score of Perivascular Space Dilatation and White Matter Hyperintensities in Patients with Normal Cognition, Mild Cognitive Impairment, and Dementia
    (2022-07) Zdanovskis, Nauris; Platkājis, Ardis; Kostiks, Andrejs; Šneidere, Kristīne; Stepens, Ainārs; Naglis, Roberts; Karelis, Guntis; Department of Radiology; Militārās medicīnas pētījumu un studiju centrs; Department of Health Psychology and Paedagogy; Department of Infectology
    Background and Objectives: Cerebral perivascular spaces (PVS) are part of the cerebral microvascular structure and play a role in lymphatic drainage and the removal of waste products from the brain. White matter hyperintensities (WMH) are hyperintense lesions on magnetic resonance imaging that are associated with cognitive impairment, dementia, and cerebral vascular disease. WMH and PVS are direct and indirect imaging biomarkers of cerebral microvascular integrity and health. In our research, we evaluated WMH and PVS enlargement in patients with normal cognition (NC), mild cognitive impairment (MCI), and dementia (D). Materials and Methods: In total, 57 participants were included in the study and divided into groups based on neurological evaluation and Montreal Cognitive Assessment results (NC group 16 participants, MCI group 29 participants, D group 12 participants). All participants underwent 3T magnetic resonance imaging. PVS were evaluated in the basal ganglia, centrum semiovale, and midbrain. WMHs were evaluated based on the Fazekas scale and the division between deep white matter (DWM) and periventricular white matter (PVWM). The combined score based on PVS and WMH was evaluated and correlated with the results of the MoCA. Results: We found statistically significant differences between groups on several measures. Centrum semiovale PVS dilatation was more severe in MCI and dementia group and statistically significant differences were found between D-MCI and D-NC pairs. PVWM was more severe in patients with MCI and dementia group, and statistically significant differences were found between D-MCI and D-NC pairs. Furthermore, we found statistically significant differences between the groups by analyzing the combined score of PVS dilatation and WMH. We did not find statistically significant differences between the groups in PVS dilation of the basal ganglia and midbrain and DWM hyperintensities. Conclusions: PVS assessment could become one of neuroimaging biomarkers for patients with cognitive decline. Furthermore, the combined score of WMH and PVS dilatation could facilitate diagnostics of cognitive impairment, but more research is needed with a larger cohort to determine the use of PVS dilatation and the combined score.
  • No Thumbnail Available
    Item
    Comparison of Tick-borne Encephalitis (TBE) clinical disease in children and adults – population-based study in Latvia, 2018-2020
    (2023-10-22) Freimane, Zane; Karelis, Guntis; Harper, Lisa; Bender, Cody; Zhang, Pingping; Angulo, Frederick; Erber, Wilhelm; Bormane, Antra; Griškevica, Aija; Pilz, Andreas; Madhava, Harish; Zavadska, Dace; Department of Paediatrics; Department of Neurology and Neurosurgery
  • No Thumbnail Available
    Item
    Concomitant multiple sclerosis and ankylosing spondylitis: : a clinical case report
    (2022) Zeltiņa, Estere; Mekša, Liga; Kadiša, Anda; Karelis, Guntis; Pastare, Daina; Svilpe, Sandra; Polunosika, Elīna; Jaunozoliņa, Līga; Rīga Stradiņš University
    Background: The therapy of patients with concomitant multiple sclerosis (MS) and ankylosing spondylitis (AS) is a challenge for clinicians. Secukinumab is effective in the treatment of MS. In the clinical case, we present, substantial clinical and radiological remission in the case of both autoimmune diseases was observed. Case Presentation: A male adult was diagnosed with relapsing-remitting MS. The patient complained of severe thoraco-lumbar pain. Magnetic resonance imaging (MRI) led to a diagnosis of AS. Considering that nonsteroidal anti-inflammatory drugs were ineffective and tumor necrosis factor-α blockers are contraindicated in patients with MS, secukinumab was prescribed. MRI 8 months after initiation of therapy provided clinical stability in consideration of the two autoimmune comorbidities. Conclusion: Secukinumab is an effective therapy for concomitant MS and AS.
  • No Thumbnail Available
    Item
    Electrocardiographic Abnormalities and Mortality in Epilepsy Patients
    (2021-05-16) Suna, Normunds; Suna, Inga; Gutmane, Evija; Kande, Linda; Karelis, Guntis; Viksna, Ludmila; Folkmanis, Valdis; Department of Infectology
    Background and Objectives: People with epilepsy (PWE) have a 2-3 times higher mortality rate than the general population. Sudden unexpected death in epilepsy (SUDEP) comprises a significant proportion of premature deaths, whereas sudden cardiac death (SCD) is among the leading causes of sudden death in the general population. Cardiac pathologies are significantly more prevalent in PWE. Whether electrocardiographic (ECG) parameters are associated with remote death in PWE has yet to be elucidated. The study objective was to assess whether interictal ECG parameters are associated with mortality in the long-term. Materials and Methods: The study involved 471 epilepsy patients who were hospitalized after a bilateral tonic-clonic seizure(s). ECG parameters were obtained on the day of hospitalization (heart rate, PQ interval, QRS complex, QT interval, heart rate corrected QT interval (QTc), ST segment and T wave changes), as well as reported ECG abnormalities. Mortality data were obtained from the Latvian National Cause-of-Death database 3-11, mean 7.0 years after hospitalization. The association between the ECG parameters and the long-term clinical outcome were examined. Results: At the time of assessment, 75.4% of patients were alive and 24.6% were deceased. Short QTc interval (odds ratio (OR) 4.780; 95% confidence interval (CI) 1.668-13.698; p = 0.004) was associated with a remote death. After the exclusion of known comorbidities with high mortality rates, short QTc (OR 4.631) and ECG signs of left ventricular hypertrophy (OR 5.009) were associated with a remote death. Conclusions: The association between routine 12-lead rest ECG parameters-short QTc interval and a pattern of left ventricular hypertrophy-and remote death in epilepsy patients was found. To the best of our knowledge, this is the first study to associate rest ECG parameters with remote death in an epileptic population.
  • No Thumbnail Available
    Item
  • No Thumbnail Available
    Item
    Evaluating the need for standardised disease manifestation categories in patients infected with the tick-borne encephalitis virus : A Delphi panel
    (2025-01) Halsby, Kate; Dobler, Gerhard; Easton, Ava; Karelis, Guntis; Krbková, Lenka; Kyncl, Jan; Sellner, Johann; Strle, Franc; Veje, Malin; Zajkowska, Joanna; Zavadska, Dace; Angulo, Frederick J.; Pilz, Andreas; Erber, Wilhelm; Gabriel, Meghan; Russo, Jon; Price, Mark; Madhava, Harish; Meyding-Lamadé, Uta Katharina; Rīga Stradiņš University; Department of Paediatrics
    Categorization systems for tick-borne encephalitis virus (TBEV) infection lack consistency in classifying disease severity. To evaluate the need for a standard, consensus-based categorisation system for TBEV infection across subtypes, we gathered an expert panel of clinicians and scientists with diverse expertise in TBEV infection. Consensus was sought using the Delphi technique, which consisted of 2 web-based survey questionnaires and a final, virtual, consensus-building exercise. Ten panellists representing 8 European countries participated in the Delphi exercise, with specialities in neurology, infectious disease, paediatrics, immunology, virology, and epidemiology. Panellists reached unanimous consensus on the need for a standardised, international categorisation system to capture both clinical presentation and severity of TBEV infection. Ideally, such a system should be feasible for use at bedside, be clear and easy to understand, and capture both the acute and follow-up phases of TBEV infection. Areas requiring further discussion were (1) the timepoints at which assessments should be made and (2) whether there should be a separate system for children. This Delphi panel study found that a critical gap persists in the absence of a feasible and practical classification system for TBEV infection. Specifically, the findings of our Delphi exercise highlight the need for the development of a user-friendly classification system that captures the acute and follow-up (i.e., outcome) phases of TBEV infection and optimally reflects both clinical presentation and severity. Development of a clinical categorisation system will enhance patient care and foster comparability among studies, thereby supporting treatment development, refining vaccine strategies, and fortifying public health surveillance.
  • No Thumbnail Available
    Item
    A fatal case of COVID-19-associated acute necrotizing encephalopathy
    (2021-11) Ziemele, Dace; Ķauķe, Gundega; Skrējāne, Krista; Jaunozoliņa, Līga; Karelis, Guntis; Rīga Stradiņš University
    Introduction: An increasing number of published reports on SARS-CoV-2 neurological manifestations have revealed a wide spectrum of symptoms, diagnostic features, and outcomes. We report a fatal case of a COVID-19-associated acute necrotizing encephalopathy (ANE). Case report: We report a 70-year-old man brought to the hospital after a generalized tonic-clonic seizure. He was confused and disoriented. Nasopharyngeal swab testing for SARS-CoV-2 was positive. A head computed tomography (CT) scan and cerebrospinal fluid (CSF) analysis showed no signs of acute pathology. After recurrent seizures, he was sedated and intubated. Throughout the days that followed he remained in a therapeutic coma. After discontinuation of sedatives, he remained unconscious. A repeated head CT scan showed signs of pontine edema, and brain magnetic resonance imaging (MRI) revealed inhomogeneous hyperintensities with microhemorrhages and small autonecrotic cavities in both thalami, brain stem, and cerebellar peduncles. With a high suspicion of a COVID-19-associated ANE, the patient was started on high-dose glucocorticoids; however, he died the next day. The CSF tested negative for SARS-CoV-2. Discussion: A variety of COVID-19 neurological manifestations have been reported to date, including various forms of encephalitis and encephalopathy. In our patient, encephalopathy with seizures was the presenting symptom of SARS-CoV-2 infection. The radiological findings on days 8 and 9 were consistent with an ANE. The precise pathogenesis of ANE remains unclear; however, an immune-mediated mechanism is suspected. Early diagnostics with prompt administration of immunomodulators may be lifesaving. Suspicion of a COVID-19-related encephalopathy/encephalitis should be raised in all patients with altered mental status, seizures, and/or coma.
  • No Thumbnail Available
    Item
    First Experience and the Effectiveness of Immunomodulating Treatment in Inflammatory Demyelinating CNS Diseases : Analysis of Nine Patients
    (2015-09-01) Vainšteine, Lana; Kostiks, Andrejs; Karelis, Guntis; Kenina, Viktorija; Zlobina, Natalja; Krumina, Angelika; Department of Infectology; Department of Neurology and Neurosurgery
    Therapeutic plasma exchange (TPE) is used in many neurological disorders to remove immunoglobulin and other immunologically active substances. We observed patients that were admitted in Riga East Clinical University Hospital "Gaiezers", Clinic of Neurology and Neurosurgery, Multiple Sclerosis Unit, and were diagnosed with relapsing remitting multiple sclerosis (MS), according to McDonald criteria 2010 (five patients), Neuromyelitis optica (NMO) spectrum disorders (three patients) and one with NMO, according to Wingerchuk 2006 criteria. All relapses were confirmed according to clinical criteria. Visual acuity was assessed by an ophthalmologist, and neurological status by a neurologist. All patients received at least 1 cycle of 1000 mg methylprednisolone intravenous for five to seven days. The expanded disability status scale score in the MS patient group was in range 4.0-9.0 before TPE and 3.5-6.5 range after TPE. Best improvement was observed in the MS group: mean symptom reduction of 20%. Patients with NMO spectrum disorder had an EDSS score of 8.0-8.5 range on admission and 6.5-8.0 range after TPE. After one month, one patient in the NMO spectrum disorder group had good response to TPE and EDSS was 3.5, two patients had only slight improvement (EDSS scores 8.0 and 7.5). Condition of patients with NMO did not improve even after a month.
  • No Thumbnail Available
    Item
    Functional and Cognitive Impairment in Patients with Relapsing–Remitting Multiple Sclerosis: Cognitive Tests and Plasma Neurofilament Light Chain Levels
    (2025-01-03) Polunosika, Elīna; Simrén, Joel; Akmene, Arta; Klimovskis, Ņikita; Blennow, Kaj; Pastare, Daina; Zetterberg, Henrik; Erts, Renārs; Karelis, Guntis; Department of Neurology and Neurosurgery; Department of Infectology
    Background and Objectives: Multiple sclerosis (MS) is a chronic inflammatory, autoimmune, and neurodegenerative disease of the central nervous system. The disease can manifest and progress with both physical and cognitive symptoms, affecting the patient’s daily activities. The aim of our study was to investigate the correlation between functional status, cognitive functions, and neurofilament light chain levels in plasma in MS patients. Materials and Methods: In a cross-sectional study, MS patients with a relapsing–remitting course (according to McDonald’s criteria, 2017) (n = 42) from Riga East University Hospital and a control group (n = 42) were included. In the MS group, the functional status was determined using the Expanded Disability Status Scale (EDSS), and neurofilament light chain levels in plasma (pNfL) were detected using single molecule array (Simoa) technology. The symbol digit modalities test (SDMT), brief visuospatial memory test—revised (BVMT-R), and the nine-hole peg test (9-HPT) were performed on the MS and control groups, dividing the groups by education level. Results: On the SDMT spreading speed, the MS group performed worse than the control group. The median score for the control group was 94.0, and for the MS group, it was 81.3. Slower performance on the SDMT also correlated with a higher EDSS in the MS group. Cognitive processing speed and memory were better in the control group and among individuals with higher education in both groups. For the BVMT-R, we found no difference between the two groups; both groups were able to learn the task equally well, but we found a weak correlation between age and learning in both groups, which could be related to the normal aging process. Execution reaction speed on the 9-HPT with the dominant hand was slower in the MS group (24.1 s) than in the control group (19.4 s). In the MS group, we observed a trend between SDMT performance and pNfL levels: higher pNfL levels were found in individuals who performed more slowly on the SDMT. Conclusions: Cognitive and fine motor dysfunction correlates with neurological impairment and plasma neurofilament light chain levels in MS patients.
  • No Thumbnail Available
    Item
    Human Leukocyte Antigen Polymorphism and Blood Biomarker Profiles in Parkinson’s Disease : A Pilot Study in a Latvian Cohort
    (2024-12) Minibajeva, Olga; Karelis, Guntis; Zolovs, Maksims; Ķēniņa, Viktorija; Department of Doctoral Studies; Department of Infectology; Department of Neurology and Neurosurgery; Statistics Unit; Department of Biology and Microbiology; Institute of Oncology and Molecular Genetics
    Background: Parkinson’s disease (PD) is a neurodegenerative disorder characterised by a high prevalence of sporadic cases. Various molecular mechanisms are involved in its pathogenesis. This pilot study aimed to identify potential risk and protective human leukocyte antigen (HLA) alleles in PD, discover candidate alleles for further research, and evaluate potential blood biomarkers. Methods: A total of 43 PD patients and 79 unrelated sex-matched controls were enrolled in this study. We analysed the polymorphism of HLA-DRB1, HLA-DQA1, and HLA-DQB1 alleles and the blood levels of biomarkers such as S100 calcium-binding protein A9 (S1000A9), kynurenic acid (KYNA), neurofilament light chain (NfL), and glutamate decarboxylase (GAD1). Results: We found that the frequencies of the HLA-DRB1*04, -DQA1*02:01, and -DQA1*03:01 alleles were significantly higher in the PD patients than in the controls, suggesting that these alleles are potential risk factors. Furthermore, the HLA-DQA1*02:01 allele was detected more frequently in the PD group when the disease onset was at 60 years or older. On the contrary, the HLA-DRB1*01 and HLA-DQA1*05:01 alleles were less common in the PD patients, indicating a possible protective effect. Regarding biomarkers, the blood levels of S100 calcium-binding protein A9 were significantly higher, and the kynurenic acid levels were significantly lower in the PD group. The NfL levels were also higher in the PD group but did not reach statistical significance, possibly due to the sensitivity limitations of the ELISA method used. The GAD1 levels showed no significant differences between the two groups. Conclusions: Our findings indicate that the HLA-DRB1*01 and -DRB1*04 alleles and the HLA-DQA1*02:01, -DQA1*03:01, and -DQA1*05:01 alleles are associated with PD. Moreover, S100 calcium-binding protein A9 and kynurenic acid can be considered potential blood biomarkers for PD. These findings contribute to the growing body of knowledge on PD and offer new directions for further research in Latvian cohorts.