L. van den Engel-Hoek

Sucking and swallowing in infants and diagnostic tools

Preterm infants often have difficulties in learning how to suckle from the breast or how to drink from a bottle. As yet, it is unclear whether this is part of their prematurity or whether it is caused by neurological problems. Is it possible to decide on the basis of how an infant learns to suckle or drink whether it needs help and if so, what kind of help? In addition, can any predictions be made regarding the relationship between these difficulties and later neurodevelopmental outcome? We searched the literature for recent insights into the development of sucking and the factors that play a role in acquiring this skill. Our aim was to find a diagnostic tool that focuses on the readiness for feeding or that provides guidelines for interventions. At the same time, we searched for studies on the relationship between early sucking behavior and developmental outcome. It appeared that there is a great need for a reliable, user-friendly and noninvasive diagnostic tool to study sucking in preterm and full-term infants.

Dysphagia in spinal muscular atrophy type II More than a bulbar problem

Objective: In patients with spinal muscular atrophy (SMA) type II, feeding problems and dysphagia are common, but the underlying mechanisms of these problems are not well defined. This case control study was designed to determine the underlying mechanisms of dysphagia in SMA type II. Methods: Six children with SMA type II and 6 healthy matched controls between 6.4 and 13.4 years of age were investigated during swallowing liquid and solid food in 2 different postures using surface EMG (sEMG) of the submental muscle group (SMG) and a video fluoroscopic swallow study (VFSS). Results: The VFSS showed postswallow residue of solid food in the vallecula and above the upper esophageal sphincter (UES), which can be responsible for indirect aspiration. Better results in swallowing were achieved in a more forward head position. These findings were supported by the sEMG measurements of the SMG during swallowing. Conclusions: Dysphagia in spinal muscular atrophy type II is due to a neurologic dysfunction (lower motor neuron problems from the cranial nerves in the brainstem) influencing the muscle force and efficiency of movement of the tongue and the submental muscle group in combination with a biomechanical component (compensatory head posture). The results suggest an integrated treatment with an adapted posture during meals and the advice of drinking water after meals to prevent aspiration pneumonias.

Reduced mandibular range of motion in Duchenne Muscular Dystrophy: predictive factors.

Patients with Duchenne muscular dystrophy (DMD) experience negative effects upon feeding and oral health. We aimed to determine whether the mandibular range of motion in DMD is impaired and to explore predictive factors for the active maximum mouth opening (aMMO). 23 patients with DMD (mean age 16.7 ± 7.7 years) and 23 controls were assessed using a questionnaire about mandibular function and impairments. All participants underwent a clinical examination of the masticatory system, including measurement of mandibular range of motion and variables related to mandibular movements. In all patients, quantitative ultrasound of the digastric muscle and the geniohyoid muscle and the motor function measure (MFM) scale were performed. The patients were divided into early and late ambulatory stage (AS), early non-ambulatory stage (ENAS) and late non-ambulatory stage (LNAS). All mandibular movements were reduced in the patient group (P < 0.001) compared to the controls. Reduction in the aMMO (<40 mm) was found in 26% of the total patient group. LNAS patients had significantly smaller mandibular movements compared to AS and ENAS (P < 0.05). Multiple linear regression analysis for aMMO revealed a positive correlation with the body height and disease progression, with MFM total score as the strongest independent risk factor (R(2) = 0.71). Mandibular movements in DMD are significantly reduced and become more hampered with loss of motor function, including the sitting position, arm function, and neck and head control. We suggest that measurement of the aMMO becomes a part of routine care of patients with DMD.

Dystrophic changes in masticatory muscles related chewing problems and malocclusions in Duchenne muscular dystrophy

Dysphagia in Duchenne muscular dystrophy (DMD) worsens with age, with increasingly effortful mastication. The aims of this study were to describe mastication problems in consecutive stages in a group of patients with DMD and to determine related pathophysiological aspects of masticatory muscle structure, tongue thickness, bite force and dental characteristics. Data from 72 patients with DMD (4.3 to 28.0 years), divided into four clinical stages, were collected in a cross sectional study. Problems with mastication and the need for food adaptations, in combination with increased echogenicity of the masseter muscle, were already found in the early stages of the disease. A high percentage of open bites and cross bites were found, especially in the later stages. Tongue hypertrophy also increased over time. Increased dysfunction, reflected by increasingly abnormal echogenicity, of the masseter muscle and reduced occlusal contacts (anterior and posterior open bites) were mainly responsible for the hampered chewing. In all, this study shows the increasing involvement of various elements of the masticatory system in progressive Duchenne muscular dystrophy. To prevent choking and also nutritional deficiency, early detection of chewing problems by asking about feeding and mastication problems, as well as asking about food adaptations made, is essential and can lead to timely intervention.

The 6-min mastication test: a unique test to assess endurance of continuous chewing, normal values, reliability, reproducibility and usability in patients with mitochondrial disease

In patients with mitochondrial disease, fatigue and muscle problems are the most common complaints. They also experience these complaints during mastication. To measure endurance of continuous mastication in patients with mitochondrial diseases, the 6-min mastication test (6MMT) was developed. This study included the collection of normal data for the 6MMT in a healthy population (children and adults). During 6 min of continuous mastication on a chew tube chewing cycles per minute, total amount of chewing cycles and the difference between minute 1 (M1 ) and minute 6 (M2 ) were collected in 271 healthy participants (5-80 years old). These results were compared with those of nine paediatric and 25 adult patients with a mitochondrial disease. Visual analogue scale (VAS) scores were collected directly after the test and after 5 min. A qualitative rating was made on masticatory movements. The reproducibility of the 6MMT in the healthy population with an interval of approximately 2 weeks was good. The inter-rater reliability for the observations was excellent. The patient group demonstrated lower total amount of chewing cycles or had greater differences between M1 and M6 . The 6MMT is a reliable and objective test to assess endurance of continuous chewing. It demonstrates the ability of healthy children and adults to chew during 6 min with a highly stable frequency of mastication movements. The test may give an explanation for the masticatory problems in patient groups, who are complaining of pain and fatigue during mastication.

Development of the Drooling Infants and Preschoolers Scale (DRIPS) and reference charts for monitoring saliva control in children aged 0–4 years

OBJECTIVES To develop and validate a parent questionnaire to quantify drooling severity and frequency in young children (the Drooling Infants and Preschoolers Scale - the DRIPS). To investigate development of saliva control in typically developing young children in the age of 0-4 years. To construct sex-specific reference charts presenting percentile curves for drooling plotted for age to monitor the development of saliva control in infancy and preschool age. STUDY DESIGN The DRIPS was developed consisting of 20 items to identify severity and frequency of drooling during meaningful daily activities. Factor analysis was performed to test construct validity. A piecewise logistic regression was followed by a piecewise linear regression to construct sex-specific reference charts. RESULTS We obtained 652 completed questionnaires from parents of typically developing children. The factor analysis revealed four discriminating components: drooling during Activities, Feeding, Non nutritive sucking, and Sleep. To illustrate the development of saliva control, eight sex-specific reference curves were constructed to plot the scores of the DRIPS by age group, at the 15th, 50th, 85th and 97th percentile. About 3-15% of the preschoolers in our cohort did not acquire full saliva control at the age of 4 years. CONCLUSIONS With the DRIPS it is possible to validly compare and visualize the development of saliva control in an individual infant or preschooler and allow clinicians to timely initiate individually targeted interventions if children outperform.