Abnormal developmental patterns of suck and swallow rhythms during feeding in preterm infants with bronchopulmonary dysplasia.

Infants with bronchopulmonary dysplasia (BFD) often have difficulty achieving coordinated suckle feeding. To analyze rhythmic differences during feeding in infants with BPD we performed weekly studies of 14 infants with BPD (eight male, six female; postmenstrual age [PMA] 32.1 to 39.7 weeks); and a PMA-matched control group without BPD (n=20), from initiation of bottle feeding until discharge, with simultaneous digital recordings of pharyngeal and nipple (teat) pressure. Unlike the control group, there was no significant correlation between PMA and stability of suckle rhythm, aggregation of suckles or swallows into runs, or length of suckle runs. Comparing those infants >35 weeks' PMA, the group with BPD had significantly decreased stability of suckle rhythm (increased coefficient of variation of suckle-suckle intervals: 0.34, SE 0.02 vs 0.254, SE 0.014; p=0.003), decreased aggregation into suckle runs (71.1, SE 3.4% vs 85.4, SE 2%;p=0.001), and decreased length of suckle runs (7.2, SE 0.9 vs 13.1, SE 1.9 suckles/run; p=0.003). Percentage of swallows in runs was also decreased in the cohort with BPD (58, SE 3.8% vs 77.2, SE 3.5%; p<0.001), as was length of swallow run (5.3, SE 0.5 vs 10.7, SE 1.1;p<0.001). Thus, in infants with BPD, anticipated maturational patterns of suckle and swallow rhythms did not occur. Delay in attainment of stable suckle and swallow rhythms in preterm infants, especially after 35 weeks' PMA, may predict subsequent feeding and neurological problems.

Developmental patterns of rhythmic suck and swallow in preterm infants.

Twenty healthy preterm infants (gestational age 26 to 33 weeks, postmenstrual age [PMA] 32.1 to 39.6 weeks, postnatal age [PNA] 2.0 to 11.6 weeks) were studied weekly from initiation of bottle feeding until discharge, with simultaneous digital recordings of pharyngeal and nipple (teat) pressure and nasal thermistor and thoracic strain gauge readings. The percentage of sucks aggregated into 'runs' (defined as > or = 3 sucks with < or = 2 seconds between suck peaks) increased over time and correlated significantly with PMA (r=0.601, p<0.001). The length of the sucking-runs also correlated significantly with PMA (r=0.613, p<0.001). The stability of sucking rhythm, defined as a function of the mean/SD of the suck interval, was also directly correlated with increasing PMA (r=0.503, p=0.002), as was increasing suck rate (r=0.379, p<0.03). None of these measures was correlated with PNA. Similarly, increasing PMA, but not PNA, correlated with a higher percentage of swallows in runs (r=0.364, p<0.03). Stability of swallow rhythm did not change significantly from 32 to 40 weeks' PMA. In low-risk preterm infants, increasing PMA is correlated with a faster and more stable sucking rhythm and with increasing organization into longer suck and swallow runs. Stable swallow rhythm appears to be established earlier than suck rhythm. The fact that PMA is a better predictor than PNA of these patterns lends support to the concept that these patterns are innate rather than learned behaviors. Quantitative assessment of the stability of suck and swallow rhythms in preterm infants may allow prediction of subsequent feeding dysfunction as well as more general underlying neurological impairment. Knowledge of the normal ontogeny of the rhythms of suck and swallow may also enable us to differentiate immature (but normal) feeding patterns in preterm infants from dysmature (abnormal) patterns, allowing more appropriate intervention measures.

Oral-motor skills following sensorimotor therapy in two groups of moderately dysphagic children with cerebral palsy: aspiration vs nonaspiration.

The purpose of this study was to determine the effect of oral sensorimotor treatment on oral-motor skills and measures of growth in moderately eating impaired children with cerebral palsy who were stratified by state of aspiration/nonaspiration. Twenty-seven children aged 2.5-10.0 years participated in this study (aspiration: n = 7, nonaspiration: n = 20). Weight and skinfold measures were taken. Children were observed at lunch time and six domains of feeding were examined: spoon feeding, biting, chewing, cup drinking, straw drinking, swallowing, and drooling. Children underwent 10 weeks of control and 10 weeks of sensorimotor treatment, 5-7 minutes/day, 5 days/week. Treatment compliance for the entire group was 67%. Children who aspirated had significantly poorer oral-motor skills in spoon feeding, biting, chewing, and swallowing than children who did not aspirate. There was significant improvement in eating: spoon feeding (fewer abnormal behaviors, p < 0.03), chewing (more normal behaviors, p < 0.003), and swallowing (more normal behaviors, p < 0.008). There were no significant changes in drinking skills. Children as a group maintained their pretreatment weight-age percentile but did not show any catch-up growth. Children showed adequate energy reserves as measured by skinfold thicknesses. Improvement in oral-motor skills may help these children to ingest food more competently (i.e., less spillage). However, their weight remains at the lowest level of age norms.

Effect of oral sensorimotor treatment on measures of growth, eating efficiency and aspiration in the dysphagic child with cerebral palsy.

Twenty-seven children (mean age 5.1 years) with cerebral palsy and moderate eating impairment were studied to determine frequency of aspiration and the effect of 10 and 20 weeks of oral sensorimotor therapy on eating efficiency and measures of growth (weight, skinfold thickness). The eating efficiency of the children did not change markedly in response to oral sensorimotor therapy. Children maintained their centile rank in weight-for-age and skinfold-for-age measurements. However, there was no catch-up growth. The findings suggest that eating efficiency is not a good estimator of treatment outcome, but rather a diagnostic indicator of the severity of eating impairment. Monitoring of these children's growth is essential in order to provide nutritional rehabilitation as soon as their eating skills can no longer keep up with growth demands.

Correlation of cervical auscultation with physiological recording during suckle-feeding in newborn infants.

Pharyngeal swallows during infant suckle-feeding are associated with a characteristic sequence of sounds audible by stethoscope or by an accelerometer or microphone held over the larynx. In rhythmically feeding term-born neonates, the delineating acoustic elements are discrete sounds which precede and succeed pharyngeal swallows. Digital signal processing shows similarities in morphological detail between the discrete sounds preceding swallows and between those succeeding swallows; those succeeding swallows are more variable in temporal relation to swallows, amplitude and morphological detail. Variations in the pattern of interswallow respiration, including apnea, are correlated with variations in the discrete sounds. Specification of physiological correlates of these internal feeding sounds increases the utility of cervical auscultation as a method of investigation and of clinical observation of feeding.

Ligaments of the larynx and the adjacent pharynx and esophagus.

Two ligament systems of the larynx are demonstrated by dissection. The suspensory ligament of the esophagus is attached to the posterior aspect of the cricoid cartilage and is also a part of the fascial sheath which is common to the hyoid, thyroid, and cricoid. The ligaments at the inner margins of the vocal, ventricular, and aryepiglottic folds are distinctive in site and, inferentially, in function. The aryepiglottic ligaments join at the incisura between the arytenoid cartilages and are continued as the corniculopharyngeal ligament which splays into the flexible tissues in the anterior wall of the hypopharynx, posterior to the suspensory ligament of the esophagus. These ligament systems are involved in two different actions in swallow. The gross superior and anterior motions of the larynx are transmitted to the esophagus by the suspensory ligament, so that the esophagus is elevated in relation to the bolus and is also opened. These esophageal displacements resemble, in effect, the swallow displacements of the pharyngoesophageal segment and of the constrictor wall of the hypopharynx. The marginal ligaments of the laryngeal folds help to implement the constriction and closure of the larynx during swallow. By anatomical inference, the corniculopharyngeal ligament effects vertical traction within the flexible tissues of the anterior wall of the hypopharynx.

Cervical auscultation of suckle feeding in newborn infants.

The authors recorded the sound signals during suckle feeding of six normal infants within the first two postnatal days. The sounds were recorded onto a cassette tape-recorder from a small microphone attached to the infant's neck, then displayed on an oscilloscope and analysed by digital signal processing techniques. These displays demonstrated acoustic patterns and temporal relationships which are not otherwise audible. The method and findings are described in detail, and the method should be useful in the clinical investigation of feeding and swallowing problems associated with more subtle neurological impairment and preterm birth.

Ultrasound demonstration of tongue motions during suckle feeding.

In this study the authors used ultrasound to demonstrate characteristic internal actions of the tongue during suckling. Its medial portion, into which the genioglossus is inserted, moves in relation to its lateral portions, into which the styloglossus and hyoglossus are inserted. A peristaltic wave of successive inferior and superior displacements moves posteriorly in the medial portion, compressing or 'milking' the nipple and propelling the expressed milk towards the pharynx. The lateral portions of the tongue enclose the nipple and the bolus and serve as reference for the displacements of the medial portion. These observations are related to anatomical studies of the tongue. The coordination pattern of suckle is compared with that of pharyngeal swallow. In instances where suckle and swallow are immediately sequential, the peristalsis which is common to both is continuous in the oral and pharyngeal portions of the food pathway.

Lines of the pharynx.

This superbly illustrated article is an invaluable guide to the interpretation of double contrast pharyngograms.

Anatomy and physiology of the pharynx.

Radiographic evaluation of the passage of a bolus from the mouth through the pharynx into the esophagus is based upon identification of specific anatomical landmarks and the integrated motion accomplished by the oral and pharyngeal muscles during swallowing. Twenty-six muscles and 6 cranial nerves must be coordinated to enable the safe performance of the complex physiological task of transporting liquids and firm food from the mouth into the esophagus. The following discussion and illustrations of pharyngeal anatomy and physiology are pertinent to an understanding of normal swallowing function.

Adaptation, compensation, and decompensation of the pharyngeal swallow.

Under normal circumstances, the act of swallowing adjusts to varying demands of different bolus characteristics and different head and neck postures. When the swallowing mechanism is impaired by disease, adjustment is essential to compensate for the impairment and allow swallowing. Evidence of adjustment can be demonstrated by cineradiography which provides important clues to the presence of underlying disease. When adjustment to disease is inadequate, swallowing decompensates. In this case, gross changes in swallowing performance are evident from clinical evaluation and cineradiography.

The Swallowing Center: concepts and procedures.

This paper describes the purpose and organization of a dedicated center at The Johns Hopkins Medical Institutions for the evaluation of swallowing problems. The multidisciplinary approach outlined will permit a better understanding and more accurate diagnosis of the functional or organic lesions affecting the swallowing mechanisms. Illustrative cases are presented.

Hypoplasia of the nose and eyes, hyposmia, hypogeusia, and hypogonadotrophic hypogonadism in two males.

Two males, 9-11 and 29-31 years of age, with severe hypoplasia of the nose, hypoplasia of the eyes, sensory abnormalities of taste and smell, and hypogonadism were studied. The nasal septum, cribriform plates and foramina of the vomeronasal (vn) nerves were demonstrated in both; the capsule of the vn organ was shown in one. Their nasal skeleton, demonstrated by tomoradiography, had grown in early embryological form. The nose was not patent in either patient. In both, the cranial vaults, orbits, epipharynges, and oral cavities were indented toward the hypoplastic nasal composite and the peripheral dimensions of their faces were normal for their respective ages. Each patient had impaired visual function with cataracts and colobomata. Each was unable to recognize the smell of any vapor (Type I hyposmia), and had severe impairment of recognition of any tastant (recognition hypogeusia); detection of vapors and of tastants were in appropriate anatomical areas. Each was unable orally to recognize standard plastic forms (astereognosis) though each could recognize the forms manually. Each patient had bilateral inguinal hernias, one or two undescended testes, and hypogonadotrophic hypogonadism. These patients do not fall within the spectrum of arrhinencephaly because of the presence of medial structure of attachment of the falx cerebri and because of their normal intelligence. Distinction of patients with this pattern of abnormalities from arrhinencephaly is important by reason of their potentiality of normal mental development. We hypothesize that their abnormalities resulted from an embryological disruption that occurred in the first trimester of pregnancy. The embryogenesis of the nasal composite is presumed to have been adequate for reciprocal induction of the anlagen of the forebrain. Development of their faces to normal peripheral dimensions indicates that the nasal composite is not essential for gross facial enlargement.