Incidence and outcome of acquired demyelinating syndromes in Dutch children: update of a nationwide and prospective study.

INTRODUCTION: Acquired demyelinating syndromes (ADS) are immune-mediated demyelinating disorders of the central nervous system in children. A nationwide, multicentre and prospective cohort study was initiated in the Netherlands in 2006, with a reported ADS incidence of 0.66/100,000 per year and MS incidence of 0.15/100,000 per year in the period between 2007 and 2010. In this study, we provide an update on the incidence and the long-term follow-up of ADS in the Netherlands. METHODS: Children < 18 years with a first attack of demyelination were included consecutively from January 2006 to December 2016. Diagnoses were based on the International Paediatric MS study group consensus criteria. Outcome data were collected by neurological and neuropsychological assessments, and telephone call assessments. RESULTS: Between 2011 and 2016, 55/165 of the ADS patients were diagnosed with MS (33%). This resulted in an increased ADS and MS incidence of 0.80/100,000 per year and 0.26/100,000 per year, respectively. Since 2006 a total of 243 ADS patients have been included. During follow-up (median 55 months, IQR 28-84), 137 patients were diagnosed with monophasic disease (56%), 89 with MS (37%) and 17 with multiphasic disease other than MS (7%). At least one form of residual deficit including cognitive impairment was observed in 69% of all ADS patients, even in monophasic ADS. An Expanded Disability Status Scale score of ≥ 5.5 was reached in 3/89 MS patients (3%). CONCLUSION: The reported incidence of ADS in Dutch children has increased since 2010. Residual deficits are common in this group, even in monophasic patients. Therefore, long-term follow-up in ADS patients is warranted.

Low risk of late intracranial complications in mild traumatic brain injury patients using oral anticoagulation after an initial normal brain computed tomography scan: education instead of hospitalization.

BACKGROUND AND PURPOSE: Mild traumatic brain injury (mTBI) is a common neurological disorder. Whether oral anticoagulation (OAC) use is a risk factor for secondary deterioration in mTBI patients after a normal computed tomography (CT) scan is unclear. Therefore data were retrospectively collected on patients with mTBI who used OAC to determine the incidence of secondary clinical deterioration after an initial normal head CT scan. METHODS: This was a retrospective single-centre patient record study. All patients with an mTBI who presented at the emergency department between January 2007 and October 2011 were selected. Inclusion criteria were mTBI and at least 1 week of OAC use resulting in an international normalized radio > 1.1. CT scans were re-evaluated for this study. RESULTS: A total of 211 mTBI patients using OAC and with an initial CT scan without abnormalities were included in the analysis. In five patients a secondary deterioration was found. One patient developed a subdural hematoma after 15 h of clinical observation. The other four patients became symptomatic between 2 and 28 days after trauma. CONCLUSIONS: A low risk of secondary deterioration within 24 h in mTBI patients taking OAC with a normal first head CT scan was found. Our study does not support the recommendation of the current guidelines that these patients should be clinically observed for at least 24 h. The fact that in our series the majority of secondary deteriorations occurred between 2 and 28 days after trauma underscores the importance of patient instructions upon discharge from the hospital.

Comparison of velocity profiles for different flow chamber designs used in studies of microbial adhesion to surfaces.

Flow chambers are commonly used to study microbial adhesion to surfaces under environmentally relevant hydrodynamic conditions. The parallel plate flow chamber (PPFC) is the most common design, and mass transport occurs through slow convective diffusion. In this study, we analyzed four different PPFCs to determine whether the expected hydrodynamic conditions, which control both mass transport and detachment forces, are actually achieved. Furthermore, the different PPFCs were critically evaluated based on the size of the area where the velocity profile was established and constant with a range of flow rates, indicating that valid observations could be made. Velocity profiles in the different chambers were calculated by using a numerical simulation model based on the finite element method and were found to coincide with the profiles measured by particle image velocimetry. Environmentally relevant shear rates between 0 and 10,000 s(-1) could be measured over a sizeable proportion of the substratum surface for only two of the four PPFCs. Two models appeared to be flawed in the design of their inlets and outlets and allowed development of a stable velocity profile only for shear rates up to 0.5 and 500 s(-1). For these PPFCs the inlet and outlet were curved, and the modeled shear rates deviated from the calculated shear rates by up to 75%. We concluded that PPFCs used for studies of microbial adhesion to surfaces should be designed so that their inlets and outlets are in line with the flow channel. Alternatively, the channel length should be increased to allow a greater length for the establishment of the desired hydrodynamic conditions.