PubMed Health⌕ Search

Biomedical subjects

P Andriessen

Publications and source records attributed to P Andriessen.

7 recordsLinked to original sources
PubMed2005

Epidemiology of pyridoxine dependent seizures in the Netherlands.

BACKGROUND: Pyridoxine dependent epilepsy is a rare cause of seizures in childhood. The diagnosis is made on clinical criteria, that in many cases are never met. Therefore, epidemiological data on pyridoxine dependency are scarce. AIMS: To study the epidemiology of pyridoxine dependent epilepsy in the Netherlands, and to determine whether the diagnosis is based on the appropriate criteria. METHODS: Nationwide all departments of paediatrics (n = 113) and of paediatric or neonatal neurology (n = 17) were asked to report cases of pyridoxine dependent seizures. Birth incidences were calculated using national data on live births from 1991 to 2003. RESULTS: Response was received from 67% of paediatric departments, including all university hospitals and 94% of child neurology departments. Thirteen patients were reported. Four definite (31%), three probable (23%), and four possible cases (31%) were identified. Two cases (15%) did not meet criteria for either of these groups. The birth incidence was 1:396,000 for definite and probable cases and 1:252,000 when possible cases are included. CONCLUSIONS: Thus far, epidemiological data on pyridoxine dependent seizures were only available from the UK and Ireland. A higher incidence was found in the Netherlands, in accordance with earlier suggestions of a regional difference. The study shows that the diagnosis is often made without performance of a formal trial of withdrawal. The importance of confirming the diagnosis, concerning the consequences as for individual prognosis, the potential side effects of prolonged pyridoxine substitution, and the possibility of treating the mother in case of future pregnancies are emphasised.

Epilepsy↗
PubMed2004

Customized spectral band analysis compared with conventional Fourier analysis of heart rate variability in neonates.

A customized filtering technique is introduced and compared with fast Fourier transformation (FFT) for analyzing heart rate variability (HRV) in neonates from short-term recordings. FFT is classically the most commonly used spectral technique to investigate cardiovascular fluctuations. FFT requires stability of the physiological signal within a 300 s time window that is usually analyzed in adults. Preterm infants, however, show characteristics of rapidly fluctuating heart rate and blood pressure due to an immature autonomic regulation, resulting in non-stationarity of these signals. Therefore neonatal studies use (half-overlapping or moving) windows of 64 s length within a recording time of 2-5 min. The proposed filtering technique performs a filtering operation in the frequency range of interest before calculating the spectrum, which allows it to perform an analysis of shorter periods of only 42 s. The frequency bands of interest are 0.04-0.15 Hz (low frequency, LF) and 0.4-1.5 Hz (high frequency, HF). Although conventional FFT analysis as well as the proposed alternative technique result in errors in the estimation of LF power, due to spectral leakage from the very low frequencies, FFT analysis is more sensitive to this effect. The response times show comparable behavior for both the techniques. Applying both the methods to heart rate data obtained from a neonate before and after atropine administration (inducing a wide range of HRV), shows a very significant correlation between the two methods in estimating LF and HF power. We conclude that a customized filtering technique might be beneficial for analyzing HRV in neonates because it reduces the necessary time window for signal stability.

Algorithms↗
PubMed2001

Supraventricular escape rhythms during transient episodes of bradycardia in preterm infants.

OBJECTIVE: To evaluate the origin of transient episodes of sinus bradycardia, atrial escape rhythm, and atrioventricular nodal escape rhythm in preterm infants. MATERIAL AND METHODS: The study was observational, and was carried out in a third level neonatal intensive care unit. We studied 19 spontaneously breathing infants born healthy but prior to term, the examinations being carried out between the ages of 3 and 28 days. The mean gestational age was 29.2 +/- 1.9 weeks, and the mean birth weight was 1154 +/- 264 g. Transient episodes of bradycardia were defined as a decline in heart rate equal to or greater than 25% from baseline, lasting for at least 3 successive RR-intervals. To discriminate between different types of escape mechanisms, we used the P wave and the P axis of the electrocardiogram. Sinus bradycardia was diagnosed when the P axis was from +0 to +90 degrees; atrial escape rhythm when it was from +91 to +359 degrees, and atrioventricular nodal escape rhythm when the P wave was absent, hidden, or followed the QRS complex. RESULTS: The mean P axis was +50 +/- 11 degrees. We observed 60 transient episodes of bradycardia in 11 of the 19 infants. Of these, 34 (57%) were classified as sinus bradycardia, and 13 (22%) as atrial escapes. Atrioventricular nodal escapes developed during 6 episodes (10%), while 7 episodes (11%) could not be classified. CONCLUSIONS: Atrial excitation as evidenced by the P axis during sinus rhythm is similar in very preterm infants to that seen in children and adults. Escape rhythms with different origins occur during transient episodes of bradycardia in healthy preterm infants. In at least one third, the episodes are due to atrial or atrioventricular nodal escape.

Atrial Premature Complexes↗
PubMed2000

A severe case of myasthenia gravis during pregnancy.

Myasthenia gravis is characterised by muscle weakness and fatigability, particularly of the facial and extremity muscles, deteriorating during the day. During pregnancy, myasthenia gravis is rare and the course of illness is unpredictable. The present case illustrates that first diagnosed during pregnancy, recurrent exacerbations can appear and lead to life-threatening situations.

Adult↗
PubMed1993

[Effect of age of erythrocyte concentration administered to premature infants: a retrospective study].

Traditionally fresh red blood cells (RBCs, age less than 10 days) are used for neonatal transfusion. Retrospectively we studied the influence of the age (range 2-34 days, divided into age groups 1-7, 8-14, 15-21, 22-28, 29-35 days) of RBCs on hemoglobin, pH, bicarbonate, and potassium after administration of a small amount of packed RBC (10-15 ml/kg). We reviewed the hospital records of 58 preterm infants (mean birth weight 1316 +/- 543 g, mean gestational age 30 6/7 +/- 3 weeks) who received 201 transfusions (mean of 3.5 RBC transfusions per infant; range 1-22). Following transfusion there was a significant increase in hemoglobin in all age groups. No significant change occurred in pH, bicarbonate or potassium. We conclude that RBCs used for neonatal transfusions do not need to be fresh. Multiple donor exposure of neonates can be limited by splitting blood of a single donor into small portions and using them up to 35 days.

Anemia↗
PubMed1993

[Congenital complete atrioventricular block in neonatal lupus erythematosus].

Fetal bradycardia of 60 beats per minute was diagnosed in the 22nd week of a normal pregnancy. Echocardiography showed a complete fetal atrioventricular heart block. The fetal heart was without structural abnormalities. Auto-antibodies (Ro/SS-A and antinuclear antibodies) could be demonstrated in both mother and child. The mother, however, showed no signs or symptoms of a connective tissue disease. We describe neonatal lupus erythematosus as an important cause of congenital heart block.

Adult↗