Retinal degeneration is associated with brain volume reduction and prognosis in radiologically isolated syndrome.

BACKGROUND: The extent of neurodegeneration in the earliest stages of central nervous system (CNS) demyelination is not known. Optical coherence tomography (OCT) is a powerful tool to study neurodegeneration in demyelinating disorders. OBJECTIVES: To study neuroaxonal loss in the retina of individuals with radiologically isolated syndrome (RIS) and investigate whether OCT measurements are associated with brain volumetrics and clinical conversion to multiple sclerosis (MS). METHODS: Subjects fulfilling the Okuda criteria for RIS (n = 15 patients, 30 eyes) and age- and sex-matched healthy controls (HC) underwent spectral-domain OCT and magnetic resonance imaging for volumetric measurement of brain structures. RESULTS: Macular ganglion cell-inner plexiform layer (mGCIPL), macular retinal nerve fiber layer (mRNFL), and temporal peripapillary RNFL (pRNFL) thickness; normalized total brain volume (nTBV); and normalized thalamic volume (nTV) were reduced in RIS compared to HC. mGCIPL, mRNFL, and pRNFL measurements were associated with nTBV, nTV, and normalized gray and white matter volumes in the RIS group. pRNFL was thinner in individuals with RIS who converted to MS in 5 years. CONCLUSIONS: Retinal neurodegeneration can be detected in the papillomacular region in the earliest stages of CNS demyelination and reflects global disease processes in the brain. OCT can be potentially useful for predicting prognosis in RIS.

Clinical features and disease course of neurological involvement in Behcet's disease: HUVAC experience.

BACKGROUND/AIM: Neurological involvement (Neuro-Behcet's Disease: NBD) is a rare manifestation of Behcet's Disease (BD) and it is related with significant mortality and morbidity. We aimed to evaluate disease course and outcome of NBD patients registered in Hacettepe University Vasculitis Center (HUVAC) prospective database starting from October 2014. METHODS: Totally, 419 patients (329 of the patients had fulfilled the International Study Group (ISG) criteria and 90 patients were considered as incomplete BD) were recorded as BD to March 2018. We retrospectively reviewed the charts of 123 patients with neurological complaints/ symptoms according International Consensus Recommendations (ICR) Criteria for Neuro-Behçet's disease. In final analysis, 77 NBD patients (Definite NBD = 61, possible NBD = 16) were included. Demographics, clinical features, treatment characteristics, disability status and survival status of the patients were evaluated. RESULTS: Forty-seven (61%) of the patients were male. Median time to neurological involvement from first diagnosis of BD is 6 (IQR = 8.8) years in patients who had diagnosis of BD before neurological involvement. Distribution of NBD: parenchymal (pNBD), non-parenchymal (npNBD), mixed (mNBD) and peripheral nervous system (pnsNBD) were 47 (61%), 22 (28.6%), 5 (6.5%), 3 (3.9%), respectively. Eye involvement was more frequent in pNBD compared to npNBD. Brainstem (72.9%) was the most frequently affected parenchymal area and followed by cerebellum (43.8%) and diencephalon (37.5%). Twelve patients had spinal cord involvement (n = 12, 24.5%). Among the patients with pNBD and mNBD (total n = 52), 48 patients were considered as acute onset parenchymal disease and 4 patients were evaluated as chronic progressive disease. Fifty-eight percent of the patients with acute onset parenchymal disease had only one attack. Totally 14 BD patients deceased during a median 9.4 (IQR = 13) years disease duration and 9 of these patients had NBD (pNBD = 6, mNBD = 2, pnsNBD = 1). Corticosteroids (IV pulse = 75.5% and oral medium-high dose = 90%), alpha-interferon (76.9%), cyclophosphamide (57.1%), and TNF inhibitors (23.5%) were the most frequently preferred treatment options for pNBD. CONCLUSIONS: Neurological involvement is seen about 5 years after the diagnosis of BD, and ocular involvement more commonly seen in these patients than non-NBD patients. More than half of the patients with acute onset parenchymal NBD had only one attack. No death was observed in the patients with non-parenchymal NBD. Biologic agents (Interferon-alpha and anti-TNF agents) were used in most patients.

Identification of circulating MOG-specific B cells in patients with MOG antibodies.

OBJECTIVE: To identify circulating myelin oligodendrocyte glycoprotein (MOG)-specific B cells in the blood of patients with MOG antibodies (Abs) and to determine whether circulating MOG-specific B cells are linked to levels and epitope specificity of serum anti-MOG-Abs. METHODS: We compared peripheral blood from 21 patients with MOG-Abs and 26 controls for the presence of MOG-specific B cells. We differentiated blood-derived B cells in vitro in separate culture wells to Ab-producing cells via engagement of Toll-like receptors 7 and 8. We quantified the anti-MOG reactivity with a live cell-based assay by flow cytometry. We determined the recognition of MOG epitopes with a panel of mutated variants of MOG. RESULTS: MOG-Ab-positive patients had a higher frequency of MOG-specific B cells in blood than controls, but MOG-specific B cells were only detected in about 60% of these patients. MOG-specific B cells in blood showed no correlation with anti-MOG Ab levels in serum, neither in the whole group nor in the untreated patients. Epitope analysis of MOG-Abs secreted from MOG-specific B cells cultured in different wells revealed an intraindividual heterogeneity of the anti-MOG autoimmunity. CONCLUSIONS: This study shows that patients with MOG-Abs greatly differ in the abundance of circulating MOG-specific B cells, which are not linked to levels of MOG-Abs in serum suggesting different sources of MOG-Abs. Identification of MOG-specific B cells in blood could be of future relevance for selecting patients with MOG-Abs for B cell-directed therapy.

Comparative analysis of fingolimod versus teriflunomide in relapsing-remitting multiple sclerosis.

BACKGROUND: Fingolimod and teriflunomide are commonly used in the treatment of relapsing-remitting multiple sclerosis (RRMS). These have not been compared in controlled trials, but only in observational studies, with inconclusive results. Comparison of their effect on relapse and disability in a real-world setting is therefore needed. OBJECTIVES: The objective of this study was to compare the efficacy of fingolimod and teriflunomide in reducing disease activity in RRMS. METHODS: This multicenter, retrospective observational study was carried out with prospectively collected data from 15 centers. All consecutive RRMS patients treated with teriflunomide or fingolimod were included. Data for relapses, Expanded Disability Status Scale (EDSS) scores and brain magnetic resonance imaging (MRI) scans were collected. Patients were matched using propensity scores. Annualized relapse rates (ARR), disability accumulation, percentage of patients with active MRI and treatment discontinuation over a median 2.5-year follow-up period were compared. RESULTS: Propensity score matching retained 349 out of 1388 patients in the fingolimod group and 349 out 678 in the teriflunomide group for final analyses. Mean ARR decreased markedly from baseline after 1 and 2 years of treatment in both the fingolimod (0.58-0.17 after 1 year and 0.11 after 2 years, p < 0.001) and teriflunomide (0.56-0.29 after 1 year and 0.31 after 2 years, p < 0.001) groups. Mean ARR was lower in fingolimod-treated patients than in those treated with teriflunomide at years 1 (p = 0.02) and 2 (p = 0.004). Compared to teriflunomide, the fingolimod group exhibited a higher percentage of relapse-free patients and a lower percentage of MRI-active patients after 2.5-year follow-up. Disability worsening was similar between the two groups. Patients were less likely to discontinue fingolimod than teriflunomide (p < 0.001). CONCLUSION: Fingolimod was associated with a better relapse control and lower discontinuation rate than teriflunomide. The two oral therapies exhibited similar effects on disability outcomes.

The Glycosylation Site of Myelin Oligodendrocyte Glycoprotein Affects Autoantibody Recognition in a Large Proportion of Patients.

Autoantibodies to myelin oligodendrocytes glycoprotein (MOG) are found in a fraction of patients with inflammatory demyelination and are detected with MOG-transfected cells. While the prototype anti-MOG mAb 8-18C5 and polyclonal anti-MOG responses from different mouse strains largely recognize the FG loop of MOG, the human anti-MOG response is more heterogeneous and human MOG-Abs recognizing different epitopes were found to be pathogenic. The aim of this study was to get further insight into details of antigen-recognition by human MOG-Abs focusing on the impact of glycosylation. MOG has one known N-glycosylation site at N31 located in the BC loop linking two beta-sheets. We compared the reactivity to wild type MOG with that toward two different mutants in which the neutral asparagine of N31 was mutated to negatively charged aspartate or to the neutral alanine. We found that around 60% of all patients (16/27) showed an altered reactivity to one or both of the mutations. We noted seven different patterns of recognition of the two glycosylation-deficient mutants by different patients. The introduced negative charge at N31 enhanced recognition in some, but reduced recognition in other patients. In 7/27 patients the neutral glycosylation-deficient mutant was recognized stronger. The folding of the extracellular domain of MOG with the formation of beta-sheets did not depend on its glycosylation as seen by circular dichroism. We determined the glycan structure of MOG produced in HEK cells by mass spectrometry. The most abundant glycoforms of MOG expressed in HEK cells are diantennary, contain a core fucose, an antennary fucose, and are decorated with α2,6 linked Neu5Ac, while details of the glycoforms of MOG in myelin remain to be identified. Together, we (1) increase the knowledge about heterogeneity of human autoantibodies to MOG, (2) show that the BC loop affects recognition in about 60% of the patients, (3) report that all patients recognized the unglycosylated protein backbone, while (4) in about 20% of the patients the attached sugar reduces autoantibody binding presumably via steric hindrance. Thus, a neutral glycosylation-deficient mutant of MOG might enhance the sensitivity to identify MOG-Abs.

Progressive Onset Multiple Sclerosis: Demographic, Clinical and Laboratory Characteristics of Patients With and Without Relapses in the Course.

AMAÇ: Primer progresif multipl skleroz (PPMS) ve progresif relapsing multipl skleroz (PRMS) baslangiçtan beri olan progresyon ile karakterize MS tipleridir. Nadir görülmelerinden dolayi, literatürde diger MS formlarina göre daha az bilgi bulunmaktadir. Bu çalismanin amaci progresif baslangiçli MS (PBMS) hastalarinda klinik ve laboratuvar özelliklerini ortaya koymaktir. YÖNTEM: PBMS hastalari 2010-2014 yillari arasinda degerlendirilip demografik, klinik özellikleri ve beyin omurilik sivisi (BOS) bulgulari belirlendi. BULGULAR: Otuz iki PBMS hastasi ile ilgili veriler degerlendirildi. Hastalik seyri 24 hastada relaps olmadan (PPMS), sekiz hastada ise relapsli progresifti (PRMS). Kadin/erkek orani tüm grupta 1'di. Ortalama baslangiç yasi tüm grup için 40 (23-55) yasti. Gruplar arasinda hastalik baslangiç yasi ortancasi anlamli farkli bulunmadi (p=0,053). En sik prezantasyon belirtisi motor bozukluklardi. Relapslar tüm hastalarda hastaligin ilk 10 yilinda görüldü. BOS analizinde oligoklonal bant pozitifligi ve artmis IgG indeksi açisindan gruplar arasinda fark saptanmadi (p=0,938, p=0,058). Hastalik süresi her iki grupta da benzer oldugu halde, PPMS grubunda degerlendirme sirasinda ortanca EDSS skoru daha yüksek bulundu (p=0,020). SONUÇ: Çalismamiz Türk PBMS hastalarinin klinik seyir ve laboratuvar bulgularina odaklanmis ilk çalismadir. Iki grubun klinik ve laboratuvar bulgularinin karsilastirilmasi benzer sonuçlar göstermistir. Gruplar arasinda hastalik baslangiç yasi ve artmis IgG indeksi açisindan farklilik olup olmadigini netlestirmek için gelecekte daha genis örneklemli çalismalar yapilmasi gerekmektedir.

Neuroinvasive Listeriosis: Could Petechial Hemorrhages be a Diagnostic Clue?

INTRODUCTION: Listeria monocytogenes-related central nervous system infections may involve the cerebral parenchyma. Meningitis and meningoencephalitis are the most commonly seen forms and mainly affect immunocompromised patients; however, a less frequent form, rhombencephalitis, can occur in otherwise healthy people. Early treatment with appropriate antibiotic therapy is crucial for this otherwise fatal disorder. However, it is not always possible to rapidly establish the diagnosis because of varying presentations and discrepancies in diagnostic tests. CASE REPORT: Herein we report 3 cases of listerial infections involving the central nervous system parenchyma, with versatile diagnostic challenges and related possible solutions and radiologic hints to overcome similar issues in the future. CONCLUSIONS: We point out the importance of nonconventional magnetic resonance imaging techniques in the diagnosis, as we detected petechial hemorrhages in the brain parenchyma in all cases, which can be a diagnostic clue.

Progressive multifocal leukoencephalopathy in a patient with lymphoma and presumptive hyper IgE syndrome.

We, herein, report a 23-year-old male with a rare inherited immunodeficiency disease, hyperimmunoglobulin IgE syndrome (HIES), who developed progressive multifocal leukoencephalopathy (PML) and lymphoma simultaneously. Primary immunodeficiency of the patient has remained undiagnosed until adulthood. PML is a severe demyelinating disease of the central nervous system caused by John Cunningham virus. HIES is a rare, inherited immunodeficiency characterized by high serum levels of IgE, recurrent staphylococcal infection, eczema, and hypereosinophilia. PML may accompany primary immunodeficiency syndromes, but the association with HIES is exceedingly rare. We discuss the imaging findings, medical management, and a review of related literature on primary immunodeficiency cases complicating with PML.

Effects of different exercise modalities on ataxia in multiple sclerosis patients: a randomized controlled study.

PURPOSE: To investigate the effects of different exercise protocols on ataxia in patients with multiple sclerosis (MS). METHOD: A total of 42 MS patients, 17 male and 25 female (Expanded Disability Status Scale (EDSS): 3-5), were enrolled in this randomized controlled study. The patients were divided into three groups: a balance training (BT) group, a lumbar stabilization (LS) group and a task-oriented training (TT) group. All groups received balance training; additionally, the LS group received lumbar stabilization exercises, and the TT group received task-oriented training. The Berg Balance Scale (BBS), International Cooperative Ataxia Rating Scale (ICARS), Functional Reach Test (FRT), 2-Minute Walk Test (2MWT), Sensory Organization Test (SOT), and measurement of Somatosensory Evoked Potentials (SSEPs) were performed before and at the end of the 18 training sessions. RESULTS: The BBS, ICARS, FRT, 2MWT, and composite balance score of the SOT were improved in all groups. The ICARS kinetic function sub-score and the left limb cortical onset amplitudes of SSEPs were increased significantly in both the TT and the LS groups. The ICARS total score, composite balance score, and 2MWT were different between groups (p < 0.05). According to multiple comparison analyses of the ICARS total score and the composite balance score, the LS, and the TT group were different from the BT group (p < 0.005), while the LS and the TT groups improved similarly (p > 0.005). The 2MWT results were better for the LS group than the BT group, while the BT and the TT groups improved similarly. CONCLUSION: Balance training alone is not sufficient for rehabilitation of ataxic MS patients. A combination of lumbar stabilization exercises or task-oriented training increases the success of balance rehabilitation. Implications for rehabilitation Multiple sclerosis is a chronic inflammatory and autoimmune disease of central nervous system and ataxia is one of the most challenging symptoms of this disease. Different exercise modalities are commonly employed to control ataxic symptoms in MS patients. Lumbar stabilization exercises or task-oriented training should be considered as complementary approach to improve balance and coordination in ataxic multiple sclerosis patients.

The association of cognitive impairment with gray matter atrophy and cortical lesion load in clinically isolated syndrome.

BACKGROUND: Multiple sclerosis can impair cognition from the early stages and has been shown to be associated with gray matter damage in addition to white matter pathology. OBJECTIVES: To investigate the profile of cognitive impairment in clinically isolated syndrome (CIS), and the contribution of cortical inflammation, cortical and deep gray matter atrophy, and white matter lesions to cognitive decline. METHODS: Thirty patients with clinically isolated syndrome and twenty demographically- matched healthy controls underwent neuropsychologic assessment through the Rao Brief Repeatable Battery, and brain magnetic resonance imaging with double inversion recovery using a 3T scanner. RESULTS: Patients with clinically isolated syndrome performed significantly worse than healthy controls on tests that evaluated verbal memory, visuospatial learning and memory, and verbal fluency. Significant deep gray matter atrophy was found in the patients but cortical volume was not lower than the controls. Visual memory tests correlated with the volume of the hippocampus, cerebral white matter and deep gray matter structures and with cerebellar cortical atrophy. Cortical or white matter lesion load did not affect cognitive test results. CONCLUSION: In our patients with CIS, it was shown that cognitive impairment was mainly related to cerebral white matter, cerebellar cortical and deep gray matter atrophy, but not with cortical inflammation, at least in the early stage of disease.

Unfavorable outcome of pediatric onset multiple sclerosis: Follow-up in the pediatric and adult neurology departments of one referral center, in Turkey.

BACKGROUND: The prevalence of MS starting under 18 years of age ranges between 2-10% of the total MS population. OBJECTIVE: We aimed to examine the clinical and long term follow-up data of pediatric-onset cases in our institutional MS database. METHOD: We evaluated the clinical data from the MS database of the Departments of Neurology and Pediatric Neurology of Hacettepe University Hospital. RESULTS: The clinical features of 74 patients who had experienced the first attack before age 18 years comprised 3.9% of our MS population. Median age at onset was 15 (3, 5-17, IQR=3.63) years, and female: male ratio was 2.4. The most frequent symptom at onset was brainstem/cerebellar dysfunction (32.4%). Seventy two patients (97.3%) initially had relapsing remitting course and in the follow-up, 17 (23%) of them developed secondary progressive (SP) course. The median interval to develop SPMS course was 10 (5-21, IQR=8) years. At the last visit, median disease duration was 6.67 (0.83-25, IQR=9.06) years, 41 (55.4%) of them had EDSS of ≥4. CONCLUSION: These findings illustrate the profile of our pediatric MS patients: almost all are relapsing-remitting initially; about one fourth become secondarily progressive in 10 years, and about half acquire disability EDSS ≥4 in mean 8 years.

Acute Disseminated Encephalomyelitis after Oral Therapy with Herbal Extracts: A Case Report.

BACKGROUND: Acute disseminated encephalomyelitis (ADEM) is a rare demyelinating disease of the central nervous system, commonly attributed to infections or vaccinations. Toxic or allergenic compounds can also trigger a response in the immune system and may cause demyelination. We present a case with ADEM after using oral herbal medications. CASE REPORT: A 25 year-old male developed bilateral central facial palsy and severe quadriparesis after taking herbal drugs (containing echinacea and many other herbal ingredients) for two weeks. He had used the extract to increase his potency and reproductivity. He had no past history of recent immunization or viral infection. The clinical findings, cerebrospinal fluid (CSF) analysis and brain magnetic resonance imaging (MRI) were compatible with ADEM. The neurological findings were improved after seven doses of pulse methylprednisolone treatment. To our knowledge, this is the third report in the literature that links herbal therapy and demyelinating disease. CONCLUSION: Most of the ADEM cases related to herbal therapy in the literature similarly used echinacea. It is our opinion that other ingredients of the herbal extract used by our case, besides echinacea, could have the potential to cause a trigger in the immune system. Further studies are needed to clarify the immunological effects of different kinds of herbal compounds, as well as the effects of different parts of the plants and the results of various dosages. Moreover, ingredients should also be tested for toxicity, adverse effects and drug interactions.

Influence of cigarette smoking on white matter in patients with clinically isolated syndrome as detected by diffusion tensor imaging.

PURPOSE: Cigarette smoking has been associated with increased occurrence of multiple sclerosis (MS), as well as clinical disability and disease progression in MS. We aimed to assess the effects of smoking on the white matter (WM) in patients with clinically isolated syndrome (CIS) using diffusion tensor imaging. METHODS: Smoker patients with CIS (n=16), smoker healthy controls (n=13), nonsmoker patients with CIS (n=17) and nonsmoker healthy controls (n=14) were included. Thirteen regions-of-interest including nonenhancing T1 hypointense lesion and perilesional WM, and 11 normal-appearing white matter (NAWM) regions were drawn on color-coded fractional anisotropy (FA) maps. Lesion load was determined in terms of number and volume of WM hyperintensities. RESULTS: A tendency towards greater lesion load was found in smoker patients. T1 hypointense lesions and perilesional WM had reduced FA and increased mean diffusivity to a similar degree in smoker and nonsmoker CIS patients. Compared with healthy smokers, smoker CIS patients had more extensive NAWM changes shown by increased mean diffusivity. There was no relationship between diffusion metrics and clinical disability scores, duration of the disease and degree of smoking exposure. CONCLUSION: Smoker patients showed a tendency towards having greater number of WM lesions and displayed significantly more extensive NAWM abnormalities.

Assessment of the effect of cigarette smoking on regional brain volumes and lesion load in patients with clinically isolated syndrome.

PURPOSE: Smoking has been associated with an increased risk of developing multiple sclerosis, disease progression and clinical disability. We detected the effects of smoking on regional brain volumes and lesion load in patients with clinically isolated syndrome using quantitative magnetic resonance imaging. MATERIALS AND METHODS: Smoker patients (n = 16), smoker healthy controls (n = 13), non-smoker patients (n = 17) and non-smoker healthy controls (n = 14) underwent magnetic resonance imaging and neocortical volumes were measured. Lesion load was calculated in terms of number and volume of white matter hyperintensities. RESULTS: Smoking was associated with increased gray matter volumes in several regions of the brain. A tendency towards greater lesion load in smoker patients was found. Smoking duration was significantly negatively correlated with intracranial volume and left hemisphere cortical gray matter volume. There was no relationship between regional brain volumes and clinical disability scores, lesion load duration of the disease and degree of smoking exposure. CONCLUSIONS: Clinically isolated syndrome related regional brain atrophy might vary in extent and severity with smoking. Despite increased lesion load, less cortical and deep gray matter damage with a possible neuroprotective effect occurs in smoking.

Fulminant Central Plus Peripheral Nervous System Demyelination without Antibodies to Neurofascin.

BACKGROUND: Combined central and peripheral nervous system demyelination is a rare and poorly described phenomenon. Recently, anti-neurofascin antibodies were reported to be positive in 86% of these patients in a Japanese cohort. Yet, there seems to be a clinical, radiological, and serological heterogeneity among these patients. In this report, our aim is to describe characteristics of our patients with this entity and compare with others in the literature. METHODS: We report clinical, electrophysiological, radiological, and laboratory characteristics of five patients with both multiple sclerosis and chronic inflammatory demyelinating polyradiculoneuropathy from our institutional database containing 1890 MS patients. RESULTS: Three patients presented with extensive, active demyelination of both central nervous system and peripheral nervous system with hypertrophic peripheral nerves. Plexuses, trunks, division and cords were involved in the process. Oligoclonal band was negative. Conduction block was not detected. Corticosteroid treatment was not adequate. Others had a slowly progressive clinical course. Serum anti-neurofascin antibody was negative. Review of the literature revealed similar cases with active disease, early-onset hypertrophic peripheral nerves, and central demyelination, in addition to other cases with an insidious course. CONCLUSIONS: Patients with combined central and peripheral demyelination form a spectrum. Some patients may have an antibody-mediated syndrome with or without anti-neurofascin antibodies and others seem to represent a coincidence.

Neuromyelitis Optica and Neuromyelitis Optica Spectrum Disorder Patients in Turkish Cohort: Demographic, Clinical, and Laboratory Features.

BACKGROUND: Neuromyelitis optica (NMO) is an immune-mediated, chronic relapsing, inflammatory disease characterized by severe attacks of optic neuritis and myelitis. OBJECTIVE: To determine the demographic, clinical, and laboratory features; antibody status; and treatment modalities of patients with NMO and neuromyelitis optica spectrum disorders in a Turkish cohort from 11 centers. METHODS: A total of 182 patients were included in this study. Data on age at disease onset, sex, type of attacks, clinical presentation, analysis of cerebrospinal fluid, serum antiaquaporin-4 antibody status, annual progression index, and medical and family histories were collected. RESULTS: Mean age was 38.43±12.40 years (range, 13 to 75 y), and mean age at disease onset was 31.29±12.40 years (median, 29 y; range, 10 to 74 y). In NMO group, the rate of NMO immunoglobulin (Ig)G positivity was 62.5%. The annual progression index was significantly higher in the longitudinally extending spinal cord lesion. The mean Expanded Disability Status Scale score was higher in the late than early-onset NMO group. CONCLUSION: Our results revealed a lower rate of NMO IgG positivity, more severe disability in patients with NMO/neuromyelitis optica spectrum disorders presenting with either transverse myelitis or late-onset NMO, and no correlation between disability and NMO IgG status.

Urinary detection of toscana virus nucleic acids in neuroinvasive infections.

BACKGROUND: Toscana virus (TOSV) is a sandfly-borne pathogen causing febrile diseases and neuroinvasive infections in humans. Definitive diagnosis of TOSV infections frequently requires the detection of viral RNA in cerebrospinal fluid (CSF) or in circulation, which can be achieved prior to seroconversion. OBJECTIVES: To evaluate TOSV excretion in urine and impact of urine as a diagnostic specimen. STUDY DESIGN: A total of 82 plasma, CSF and urine samples were collected from 24 individuals with a preliminary diagnosis of atypical viral encephalitis, where frequent bacterial fungal and viral causes were ruled out. Phlebovirus and WNV nucleic acids were investigated via real-time and nested polymerase chain reaction (PCR) assays. Commercial immunofluorescence assays were employed for viral IgM detection. Amplicons were characterized via cloning and sequencing. RESULTS: Phlebovirus PCR yielded positive results in 7 out of 14 samples that comprise 4 plasma and 3 urine specimens from 3 individuals. Amplicons were characterized as TOSV genotype A. Investigation of the follow-up samples suggested that virus shedding in urine coincides or follows viremia. Despite conserved sequences observed in paired or sequential plasma-urine specimens, L693S substitution in the viral polymerase was characterized in a urine sample. CONCLUSIONS: These preliminary findings indicate that urine can be employed as a additional clinical sample for TOSV RNA detection in suspected cases, especially in individuals where specimens for viral diagnostics during the early stages of the infection are not available.