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Dive into the research topics where A. Siva is active.

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Featured researches published by A. Siva.


European Journal of Neurology | 2006

Fatigue and sleep disturbance in multiple sclerosis

Hakan Kaynak; Ayse Altintas; Derya Kaynak; Ö. Uyanik; Sabahattin Saip; J. Ağaoğlu; G. Önder; A. Siva

Considering the association of sleep disturbance and fatigue in multiple sclerosis (MS), we investigated the presence of sleep disturbances that may be related to fatigue by using objective and subjective measures. We included 27 MS patients with fatigue, 10 MS patients without fatigue and 13 controls. The Pittsburgh sleep quality index score showed significant differences between patient groups and controls. Beck depression inventory scores were significantly higher in fatigued than non‐fatigued patients. Comparison of patient groups and controls revealed significant differences for time in bed, sleep efficiency index, sleep continuity index, wake time after sleep onset, total arousal index and periodic limb movement arousal index. Our study confirms that MS causes sleep fragmentation in terms of both macro and microstructure. Fatigue in MS could be partially explained by disruption of sleep microstructure, poor subjective sleep quality and depression.


Multiple Sclerosis Journal | 2012

Clinical And Radiological Characteristics Of Tumefactive Demyelinating Lesions: Follow-up Study

Ayse Altintas; B Petek; N Isik; Murat Terzi; F Bolukbasi; M Tavsanli; Sabahattin Saip; Cavit Boz; T Aydin; O Arici-Duz; F Ozer; A. Siva

Background: Demyelinating lesions over 20 mm in size, referred to as tumefactive demyelinating lesions, can be misdiagnosed as being either a tumor or an abscess. Although some radiological characteristics can help make a differential diagnosis easier, a cerebral biopsy may still be necessary. Objective: Our objective was to assess the clinical characteristics of tumefactive lesions, with or without a diagnosis of multiple sclerosis (MS), and present follow-up data for 54 patients with tumefactive lesions. Methods: Demographic, clinical, radiological and laboratory data were gathered and treatment responses were evaluated in a total of 54 patients from five medical centers. Result: Twenty-nine patients were diagnosed with tumefactive lesions at the onset, whereas 25 patients were diagnosed with tumefactive lesions after a diagnosis of MS. Median follow-up was 38.12 months. At final examination, 19 of the patients with a tumefactive lesion diagnosis at the onset eventually developed relapsing–remitting MS, while 10 remained with the condition as a clinically isolated syndrome. The tumefactive lesions studied were mostly focal, with closed-ring enhancement. We found that oligoclonal band positivity was less frequent in the patients with tumefactive onset. Conclusion: Although our demographic data were similar to formerly collected Turkish MS data, we found that the distribution of the patients’ clinical course differed if there was an absence of primary progressive MS and that there was a lower frequency of secondary progressive MS cases in our group of patients. We believe that less frequent oligoclonal band positivity and the difference we witnessed in the clinical course of disease in our study groups suggest that there is a need for further studies to compare all the biological and immunological differences between MS and tumefactive lesion cases, in order to reveal whether there are different pathogenetic mechanisms involved.


Multiple Sclerosis Journal | 2009

Multiple sclerosis risk in radiologically uncovered asymptomatic possible inflammatory-demyelinating disease

A. Siva; Sabahattin Saip; Ayse Altintas; Anu Jacob; B. M. Keegan

Background Natural history of patients with incidentally discovered lesions that fulfill magnetic resonance imaging (MRI) criteria for multiple sclerosis (MS) in the absence of objective clinical symptoms suggestive of central nervous system (CNS) inflammatory-demyelinating disease is not well defined. Objective We evaluated the risk of developing symptomatic MS in patients with radiologically uncovered asymptomatic possible inflammatory-demyelinating disease (RAPIDD). Methods We identified and longitudinally followed a cohort of 22 patients from two tertiary care MS centers: Istanbul University, Cerrahpasa School of Medicine, Istanbul, Turkey, and Mayo Clinic, Rochester, Minnesota, after an initial MRI study fulfilling the Barkhof–Tintore MRI criteria completed for other reasons unrelated to MS. Results Eight of 22 patients developed an objective clinical symptom consistent with a CNS inflammatory-demyelinating syndrome and fulfilled dissemination in space and time criteria for definite MS. Median age at the time of diagnosis of MS was 44.8 years (range 28.3–71.4 years). Time taken for the development of definite MS was studied by survival analysis. Cumulative event rates were; 12 months: 9%, 24 months: 15%, 36 months: 30.4%, and 60 months: 44.6%. Six of 22 patients were followed beyond 60 months. Two of these six patients developed MS later (at 66 and 112 months, respectively). Three patients remained asymptomatic despite follow-up of 10 years. Conclusions Patients with RAPIDD develop MS at a similar rate to treated patients (and less frequently than placebo groups) with clinically isolated syndromes from prior randomized controlled studies. Some patients with RAPIDD continue to have radiological evolution of subclinical disease without MS symptoms despite long follow-up periods.


Multiple Sclerosis Journal | 2012

Impact of pregnancy on conversion to clinically isolated syndrome in a radiologically isolated syndrome cohort

Christine Lebrun; E. Le Page; A. Siva; Daniel Pelletier; Darin T. Okuda

Background: In multiple sclerosis (MS), the relapse rate declines during pregnancy and increases during the first three months post-partum before returning to the pre-pregnancy rate. It is unknown whether pregnancy impacts the risk of clinical conversion in those within the presymptomatic period. Objectives: We investigate the impact of pregnancy on developing a clinical event in women diagnosed with radiologically isolated syndrome (RIS). Methods: All women with RIS underwent clinical and radiological assessments as part of an observational, prospective, longitudinal study. Clinical and MRI outcomes were analyzed during and after pregnancy. Subjects who became pregnant were compared with an age-matched female RIS group who did not become pregnant during the same follow-up period. Results: A total of 60 women with RIS were followed for up to seven years. Among them, seven became pregnant and were compared with 53 age-matched control women with RIS who did not become pregnant during the observation period. A significantly shorter time of conversion to the first neurological event was observed in the pregnant group [15.3 months (10–18)] compared with the non-pregnant controls [35.7 months (8–76)], yielding an absolute difference of 20.4 months (p<0.05). The mean (SD) number of active lesions on a subsequent brain MRI scan was significantly higher in the pregnant group [3.2 (±1.7)] compared with the control group [1.8 (±0.6)]. Conclusions: The risk for clinical conversion from RIS to a clinical event and new MRI disease activity seems to be influenced by pregnancy. Pregnancy related physiological changes could operate as early as the presymptomatic period in patients with MS.


Multiple Sclerosis Journal | 2014

Characterization of neuromyelitis optica and neuromyelitis optica spectrum disorder patients with a late onset

Nicolas Collongues; Romain Marignier; Anu Jacob; M I Leite; A. Siva; Friedemann Paul; H. Zephir; Gulsen Akman-Demir; Liene Elsone; Sven Jarius; Caroline Papeix; Kerry Mutch; Sabahattin Saip; Brigitte Wildemann; J Kitley; Rana Karabudak; Orhan Aktas; D Kuscu; Ayse Altintas; Jacqueline Palace; Christian Confavreux; J. De Seze

Background: Few data are available for patients with a late onset (≥ 50 years) of neuromyelitis optica (LONMO) or neuromyelitis optica spectrum disease (LONMOSD), defined by an optic neuritis/longitudinally extensive transverse myelitis with aquaporin-4 antibodies (AQP4-Ab). Objective: To characterize LONMO and LONMOSD, and to analyze their predictive factors of disability and death. Methods: We identified 430 patients from four cohorts of NMO/NMOSD in France, Germany, Turkey and UK. We extracted the late onset patients and analyzed them for predictive factors of disability and death, using the Cox proportional model. Results: We followed up on 63 patients with LONMO and 45 with LONMOSD during a mean of 4.6 years. This LONMO/LONMOSD cohort was mainly of Caucasian origin (93%), women (80%), seropositive for AQP4-Ab (85%) and from 50 to 82.5 years of age at onset. No progressive course was noted. At last follow-up, the median Expanded Disability Status Scale (EDSS) scores were 5.5 and 6 in the LONMO and LONMOSD groups, respectively. Outcome was mainly characterized by motor disability and relatively good visual function. At last follow-up, 14 patients had died, including seven (50%) due to acute myelitis and six (43%) because of opportunistic infections. The EDSS 4 score was independently predicted by an older age at onset, as a continuous variable after 50 years of age. Death was predicted by two independent factors: an older age at onset and a high annualized relapse rate. Conclusion: LONMO/LONMOSD is particularly severe, with a high rate of motor impairment and death.


Multiple Sclerosis Journal | 2018

ECTRIMS/EAN Guideline on the pharmacological treatment of people with multiple sclerosis:

Xavier Montalban; Ralf Gold; Alan J. Thompson; Susana Otero-Romero; Maria Pia Amato; Dhia Chandraratna; M. Clanet; Giancarlo Comi; Tobias Derfuss; Franz Fazekas; Hans-Peter Hartung; Eva Havrdova; Bernhard Hemmer; Ludwig Kappos; Roland S. Liblau; Catherine Lubetzki; Elena Marcus; David H. Miller; Tomas Olsson; Steve Pilling; Krysztof Selmaj; A. Siva; Per Soelberg Sørensen; Maria Pia Sormani; Christoph Thalheim; Heinz Wiendl; Frauke Zipp

Background: Multiple sclerosis (MS) is a complex disease with new drugs becoming available in the past years. There is a need for a reference tool compiling current data to aid professionals in treatment decisions. Objectives: To develop an evidence-based clinical practice guideline for the pharmacological treatment of people with MS. Methods: This guideline has been developed using the Grading of Recommendations Assessment, Development and Evaluation (GRADE) methodology and following the updated EAN recommendations. Clinical questions were formulated in Patients–Intervention–Comparator–Outcome (PICO) format and outcomes were prioritized. The quality of evidence was rated into four categories according to the risk of bias. The recommendations with assigned strength (strong and weak) were formulated based on the quality of evidence and the risk-benefit balance. Consensus between the panelists was reached by use of the modified nominal group technique. Results: A total of 10 questions were agreed, encompassing treatment efficacy, response criteria, strategies to address suboptimal response and safety concerns and treatment strategies in MS and pregnancy. The guideline takes into account all disease-modifying drugs approved by the European Medicine Agency (EMA) at the time of publication. A total of 21 recommendations were agreed by the guideline working group after three rounds of consensus. Conclusion: The present guideline will enable homogeneity of treatment decisions across Europe.


European Journal of Neurology | 2001

Hepatitis B vaccine related‐myelitis?*

Feray Karaali-Savrun; Ayse Altintas; Sabahattin Saip; A. Siva

We present four incidental cases that developed partial myelitis following the administration of hepatitis B vaccine in 1998. The first two cases, a 33‐year‐old man and a 42‐year‐old woman developed progressive sensory symptoms without motor involvement within 4 weeks following the vaccination. Their magnetic resonance imaging (MRI) disclosed similar lesions consistent with myelitis at their cervical spinal cord. A comparable inflammatory lesion was seen at the T9–T10 levels of the spinal cord in the third case, who was a 40‐year‐old woman presenting with numbness in her legs and urinary retention following the vaccination. The fourth case who was a 42‐year‐old woman, presented with sensory symptoms in her left extremities, which developed 3 months after the vaccination. Her MRI showed a hyperintense lesion at C6. She also had two tiny lesions in her cranial MRI. In all cases, there was no history of preceding infections and no clinical evidence suggestive of any other disorders that may cause myelopathy. All patients recovered completely within 3 months with the exception of the third patient who developed new neurological symptoms after 12 months. Similar clinical and imaging presentation of myelitis following hepatitis B vaccination within a 1 year period with no other demonstrable clinical and laboratory evidence for any other disorder raise the probability of a causal link between these two events.


European Journal of Neurology | 2018

ECTRIMS/EAN guideline on the pharmacological treatment of people with multiple sclerosis

Xavier Montalban; R. Gold; Alan J. Thompson; Susana Otero-Romero; Maria Pia Amato; Dhia Chandraratna; M. Clanet; Giancarlo Comi; Tobias Derfuss; Franz Fazekas; H.-P. Hartung; Eva Havrdova; B. Hemmer; L. Kappos; Roland S. Liblau; Catherine Lubetzki; Elena Marcus; Dh Miller; Tomas Olsson; Stephen Pilling; Krzysztof Selmaj; A. Siva; P. S. Sørensen; Maria Pia Sormani; Christoph Thalheim; Heinz Wiendl; Frauke Zipp

Multiple sclerosis (MS) is a complex disease with new drugs becoming available in the past years. There is therefore a need for a reference tool compiling current data to aid professionals in treatment decisions. The objective was to develop an evidence‐based clinical practice guideline for the pharmacological treatment of people with MS.


European Journal of Neurology | 2018

Hemodialysis-related headache and how to prevent it

G. Gozubatik-Celik; Baki Goksan; N. Akkaya; M. Sohtaoglu; U. Uygunoglu; F. Kircelli; A. Sezen; Sabahattin Saip; F. Karaali Savrun; A. Siva

Hemodialysis (HD) may have some adverse effects on the nervous system. Headache is the most commonly reported neurological symptom amongst HD patients. Our aim was to determine the frequency, clinical characteristics and triggering factors of HD‐related headache (HRH) and to evaluate preventive strategies for reducing HRH.


Archive | 1998

Frontiers in multiple sclerosis

A. Siva; Jürg Kesselring; Alan J. Thompson

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Friedemann Paul

Humboldt University of Berlin

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Giancarlo Comi

Vita-Salute San Raffaele University

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