E.W. van Zwet

Quantitative MRI and strength measurements in the assessment of muscle quality in Duchenne muscular dystrophy

The purpose of this study was to assess leg muscle quality and give a detailed description of leg muscle involvement in a series of Duchenne muscular dystrophy patients using quantitative MRI and strength measurements. Fatty infiltration, as well as total and contractile (not fatty infiltrated) cross sectional areas of various leg muscles were determined in 16 Duchenne patients and 11 controls (aged 8-15). To determine specific muscle strength, four leg muscle groups (quadriceps femoris, hamstrings, anterior tibialis and triceps surae) were measured and related to the amount of contractile tissue. In patients, the quadriceps femoris showed decreased total and contractile cross sectional area, attributable to muscle atrophy. The total, but not the contractile, cross sectional area of the triceps surae was increased in patients, corresponding to hypertrophy. Specific strength decreased in all four muscle groups of Duchenne patients, indicating reduced muscle quality. This suggests that muscle hypertrophy and fatty infiltration are two distinct pathological processes, differing between muscle groups. Additionally, the quality of remaining muscle fibers is severely reduced in the legs of Duchenne patients. The combination of quantitative MRI and quantitative muscle testing could be a valuable outcome parameter in longitudinal studies and in the follow-up of therapeutic effects.

Increased perinatal loss after intrauterine transfusion for alloimmune anaemia before 20 weeks of gestation.

To evaluate and compare perinatal outcome after intrauterine transfusions (IUT) performed before and after 20 weeks of gestation. To analyse contributing factors.

Laser surgery as a management option for twin anemia–polycythemia sequence

To evaluate the effectiveness of laser treatment for antenatally detected twin anemia–polycythemia sequence (TAPS) compared with intrauterine transfusion or expectant management.

The risk for hyperoxaemia after apnoea, bradycardia and hypoxaemia in preterm infants

Objective To investigate the occurrence and duration of oxygen saturation (SpO2) ≥95%, after extra oxygen for apnoea, bradycardia, cyanosis (ABC), and the relation with the duration of bradycardia and/or SpO2 ≤80%. Methods All preterm infants <32 weeks’ gestation supported with nasal continuous positive airway pressure (nCPAP) admitted to our centre were eligible for the study. We retrospectively identified all episodes of ABCs. In ABCs where oxygen supply was increased, duration and severity of bradycardia (<80 bpm), SpO2 ≤80%, SpO2 ≥95% and their correlation were investigated. Results In 56 infants, 257 ABCs occurred where oxygen supply was increased. SpO2 ≥95% occurred after 79% (202/257) of the ABCs, duration of extra oxygen supply was longer in ABCs with SpO2 ≥95% than without SpO2 ≥95% (median (IQR) 20 (8–80) vs 2 (2–3) min; p<0.001)). The duration of SpO2 ≥95% was longer than bradycardia and SpO2 ≤80% (median (IQR) 13 (4–30) vs 1 (1–1) vs 2 (1–2) min; p<0.001). SpO2 ≥95% lasted longer when infants were in ambient air than when oxygen was given before the ABC occurred (median (IQR)15 (5–38) min vs 6 (3–24) min; p<0.01). Conclusions In preterm infants supported with nCPAP in the neonatal intensive care unit (NICU), SpO2 ≥95% frequently occurred when oxygen was increased for ABCs and lasted longer than the bradycardia and SpO2 ≤80%.

Postdural puncture headache in migraineurs and nonheadache subjects: A prospective study

Objectives: To prospectively assess 1) the incidence and duration of postdural puncture headache (PDPH) in migraineurs and healthy subjects; 2) the associated risk factors; and 3) the risk of getting a migraine attack shortly before or after lumbar puncture (LP). Methods: As part of an extensive biochemical migraine research program, we assessed the occurrence, duration, and characteristics of PDPH in 160 migraineurs and 53 age- and sex-matched healthy controls. In addition, we evaluated potential risk factors for PDPH as well as the risk of developing a migraine attack before or after LP. Results: In total, 64 of 199 subjects (32.2%) developed PDPH. Young age, low body mass index, severe headache immediately after LP, and sitting sampling position, but not being a migraineur, increased the risk of PDPH (all p < 0.05). Duration of PDPH was prolonged by history of depression, sitting sampling position, high perceived stress during the LP procedure, and multiple LP efforts (all p < 0.05). Migraine attacks were less likely to occur before or shortly after LP. Conclusions: Migraineurs are not at increased risk of developing PDPH. PDPH duration is similar in migraineurs and age- and sex-matched controls. LP does not trigger migraine attacks, and the stress of an upcoming LP might even have a protective effect against onset of migraine attacks.

Cerebral injury in monochorionic twins with selective intrauterine growth restriction: a systematic review.

To estimate incidence and risk factors of severe cerebral injury in survivors from monochorionic pregnancies with selective intrauterine growth restriction (sIUGR) and/or birth weight discordance (BWD).

Pretransplantation Donor-Recipient Pair Seroreactivity Against BK Polyomavirus Predicts Viremia and Nephropathy After Kidney Transplantation.

Kidney transplant donors are not currently implicated in predicting BK polyomavirus (BKPyV) infection in kidney transplant recipients. It has been postulated, however, that BKPyV infection originates from the kidney allograft. Because BKPyV seroreactivity correlates with BKPyV replication and thus might mirror the infectious load, we investigated whether BKPyV seroreactivity of the donor predicts viremia and BKPyV‐associated nephropathy (BKPyVAN) in the recipient. In a retrospective cohort of 407 living kidney donor–recipient pairs, pretransplantation donor and recipient sera were tested for BKPyV IgG levels and correlated with the occurrence of recipient BKPyV viremia and BKPyVAN within 1 year after transplantation. Donor BKPyV IgG level was strongly associated with BKPyV viremia and BKPyVAN (p < 0.001), whereas recipient BKPyV seroreactivity showed a nonsignificant inverse trend. Pairing of high–BKPyV‐seroreactive donors with low‐seroreactive recipients resulted in a 10‐fold increased risk of BKPyV viremia (hazard ratio 10.1, 95% CI 3.5–29.0, p < 0.001). In multivariate analysis, donor BKPyV seroreactivity was the strongest pretransplantation factor associated with viremia (p < 0.001) and BKPyVAN (p = 0.007). The proportional relationship between donor BKPyV seroreactivity and recipient infection suggests that donor BKPyV seroreactivity reflects the infectious load of the kidney allograft and calls for the use of pretransplantation BKPyV serological testing of (potential) donors and recipients.

Increased metallothionein expression reflects steroid resistance in renal allograft recipients.

Steroid‐refractory acute rejection is a risk factor for inferior renal allograft outcome. We aimed to gain insight into the mechanisms underlying steroid resistance by identifying novel molecular markers of steroid‐refractory acute rejection. Eighty‐three kidney transplant recipients (1995–2005), who were treated with methylprednisolone during a first acute rejection episode, were included in this study. Gene expression patterns were investigated in a discovery cohort of 36 acute rejection biopsies, and verified in a validation cohort of 47 acute rejection biopsies. In the discovery set, expression of metallothioneins (MT) was significantly (p < 0.000001) associated with decreased response to steroid treatment. Multivariate analysis resulted in a predictive model containing MT‐1 as an independent covariate (AUC = 0.88, p < 0.0000001). In the validation set, MT‐1 expression was also significantly associated with steroid resistance (p = 0.029). Metallothionein expression was detected in macrophages and tubular epithelial cells. Parallel to the findings in patients, in vitro experiments of peripheral blood mononuclear cells from 11 donors showed that nonresponse to methylprednisolone treatment is related to highly elevated MT levels. High expression of metallothioneins in renal allografts is associated with resistance to steroid treatment. Metallothioneins regulate intracellular concentrations of zinc, through which they may diminish the zinc‐requiring anti‐inflammatory effect of the glucocorticoid receptor.

Right ventricular outflow tract obstruction in complicated monochorionic twin pregnancy

Severe right ventricular outflow tract obstruction (RVOTO) is a potential complication in recipient twins of twin‐to‐twin transfusion syndrome (TTTS) that requires postnatal follow‐up or treatment. We aimed to evaluate pregnancy characteristics of neonates with RVOTO from complicated monochorionic twin pregnancies, determine the incidence of RVOTO in TTTS cases and construct a prediction model for its development.

How general practitioners treat migraine patients—evaluation of a headache guideline

Aim: The aim of the study was to evaluate the pharmacological treatment of migraine patients by general practitioners before referral to a neurologist. First, was the pharmacological treatment in accordance with the Dutch College of General Practitioners headache guideline? Second, which migraine characteristics were associated with receiving migraine-specific medication? Methods: Migraine patients (age ≥18 years) who visited the neurology outpatient clinic for the first time were included. Migraine characteristics and pharmacological status were collected retrospectively for each patient from the general practitioner’s referral letter, hospital record and a headache characteristics questionnaire. Results: A total of 420 migraine patients were included. Only 18.3% of the patients with two or more migraine attacks per month were using prophylactic medication. Furthermore, only 11.7% of patients with symptoms of nausea and/or vomiting were using anti-emetic medication. More than half of patients (51.7%) were using triptans and were likely to have typical migraine symptoms and a long history of migraine. Conclusions: Migraine prophylactic medication and anti-emetics are underutilized in the primary care setting for migraine patients in the Netherlands, when compared to the general practitioners guideline. It is important to enhance the knowledge of general practitioners regarding the diagnosis of migraine, and to increase awareness of the headache guideline.