Publications by authors named "N F Kalkers"

Importance: Increasing numbers of people with multiple sclerosis (MS) use disease-modifying therapy (DMT). Long-term stable disease while taking such medications provides a rationale for considering DMT discontinuation given patient burden, costs, and potential adverse effects of immunomodulating therapy.

Objective: To investigate whether first-line DMT can be safely discontinued in patients with long-term stable MS.

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Background: Biomarkers of neuronal and axonal damage (serum neurofilament light (sNfL) and serum glial fibrillary acidic protein (sGFAP)) may provide insight into the aetiology of natalizumab wearing-off symptoms (WoSs).

Objectives: We investigated the longitudinal association between and predictive value of sNfL and sGFAP and the occurrence of WoS in MS patients treated with natalizumab.

Methods: We performed longitudinal measurements of sNfL and sGFAP in NEXT-MS trial participants who completed a questionnaire about WoS.

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Background And Objectives: Wearing-off symptoms during natalizumab treatment in multiple sclerosis are characterized by an increase of MS-related symptoms prior to natalizumab administration. The influence of extended interval dosing (EID) on wearing-off symptoms are important to consider, as this might cause hesitancy in initiating or continuing EID.

Methods: Participants of the NEXT-MS trial, in which treatment intervals are adjusted based on drug concentrations, were divided into two groups: an extended group containing participants with at least one week of additional interval extension, and a group with a fixed interval during the trial (range 4-7 weeks).

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Background: Extended interval dosing (EID) of natalizumab is a promising strategy to optimise treatment in multiple sclerosis (MS). Personalised EID by therapeutic drug monitoring can enable further extension of treatment intervals.

Methods: The NEXT-MS trial is an investigator-initiated prospective phase IV non-randomised study.

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Background: The Arm Function in Multiple Sclerosis Questionnaire (AMSQ) is the first validated disease specific patient-reported outcome measure (PROM) designed to assess upper extremity function in patients with multiple sclerosis (MS).

Objective: To determine correlations between the AMSQ and established physician- and performance based outcome measures.

Methods: In a cross-sectional cohort of 533 patients correlations between the AMSQ and the Expanded Disability Status Scale (EDSS), its functional systems, the 9-Hole Peg Test (9-HPT) and the Timed-25 Foot Walk (T25FW) were determined.

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