By Cathy Fox MS OT/L & Krisi Brackett MS SLP/CCC
Children with feeding problems often get stuck in the suckle oral transport pattern and have difficulty advancing to higher level oral skills. The suckle is a normal transitional pattern that emerges as a child transitions from lower to higher level oral skills. It is important to determine what is blocking the child from advancing to the next skill level.
We must first understand more about the suckle pattern. This pattern is described as an anterior-posterior lingual and mandibular movement which is used to transport a bolus through the oro- pharyngeal cavity. It is the pattern that is effective when there is structural instability and neurologic immaturity. This pattern reappears multiple times during oral skill development as new skills emerge, the suckle pattern will reappear until the new skill fully emerges and becomes stable and refined.
Infants are born with compact, stable structures that are reinforced by flexor tone. As the infant develops, extension increases through the neck and upper spine, resulting in decreased structural stability of the jaw and tongue. The infant sucking pattern loses some structural stability which results in the infant using the suckling pattern to continue to function and increase the positive practice of this movement pattern, while integrating the increased extensor tone. As flexor tone develops, it balances the existing extensor tone, allowing the development of control, stability, and refinement for return to the sucking pattern. The suckle pattern provides a transitional pattern between old and new skills. With positive practice the pattern becomes stable, it strengthens and is refined.
Another example of this occurs when the infant is learning to accept food from a spoon. The infant may have a sucking pattern on the nipple but they have to learn how to stabilize on the spoon. To do this the infant reverts to the suckle transport pattern until they learn how to stabilize the jaw while mobilizing the tongue during a single bolus transport pattern. This allows the child to continue to be functional. Similarly, this motor pattern emerges again when the infant transitions from a bottle to a cup.
There are many factors that can destabilize or alter the length tension relationship of structures along the entire course of the swallowing mechanism. Such changes result as compensatory responses to complete the swallowing processes safely. These changes are not intended to remain indefinitely and if unresolved can result in a patient getting “stuck” in a compensatory pattern. It is critical to understand this fact because changing this pattern must include minimizing the impact of the initial cause of the compensation. These factors can come from external and internal sources but they have a significant effect on the ability to use the aerodigestive system effectively. This may include change in the alignment of the oro- pharyngeal motor structures, ventilatory pattern and changes in the pressure gradient be- tween the thoracic and abdominal cavity. With any one change there is impact on the struc- tural alignment of swallowing, breathing and of course coordination with swallowing, and changes in forces with in the thoracic cavity and esophagus that can increase gastroesophageal reflux.
Reflux or motility along the aerodigestive tract is also a major internal factor that has well established impact on “supra-esophageal” function. The body goes to great length to pro- tect the airway from the threat of reflux. Scientific studies have now documented the body’s hard wired protective response to acid in the esophagus that results in increased tone in the upper esophageal sphincter, larynx, and posterior pharyngeal wall, all in an effort to protect the airway. The length – tension ratio of structures within the swallowing mechanism can be dramatically altered, frequently resulting in a compensatory pattern that is more immature and midline but more stable and effective. Swallowing is possible under these situations but often with smaller boluses using a suckle transport pattern. Once the factors change, the influence is reduced and the compensatory pattern is able to evolve into a mature pattern.
Many children experience medical and biomechanical alignment issues that cause them to shift into compensatory patterns. Often these patterns are not recognized because kids “grow out” of behaviors and patterns. However, when the underlying problems are not cor- rectly identified and eliminated, kids get stuck in compensatory patterns and do not get the practice, mobilization, sensory input and developmental sequencing of motor patterns that are needed for higher level skills. One of the biggest problems is the failure to look deeply enough into the underlying issues. This means that as clinicians treating children with feeding problems, we must look at the system beginning to end. The aerodigestive tract starts at the mouth and ends at the anus and it interacts with the respiratory, endocrine, motor, and sensory systems etc to determine where the issues are that affect the feeding process and how to prioritize which to address first.
Unfortunately many kids get stuck in the suckle transport pattern and are unable to move on to more mature patterns without a lot of help. Often this is due to the fact that the critical period for these skills have passed, which means that in order to change it there must be more of a cognitive effort. It is important to remember that a child’s oral motor skill will never be greater than their cognitive level.
Before you can change any oral motor pattern or sensory response you must first understand the impact of maximizing GI motility and function, obtaining optimal biomechanical alignment of the pelvis, trunk, neck and head for optimal ventilatory mechanics and proper tension, length relationship of the swallowing mechanism. On this foundation and with consistent positive practice you have a chance to begin changing your patient’s oral motor pattern.
A case example that illustrates the preceding discussion follows. Max, is a 15 month old who has been diagnosed with cerebral palsy , prematurity, hydrocephalus with VP shut x2 and GER. His parents wanted ideas specifically to move him up in texture to chewing. He is an oral feeder and his parents are proactive. They expressed a strong desire to get rid of the baby food and were slowly adding thicker textures to his smooth foods.
There were several factors slowing Max down with his oral skills. The big one- is his motor delay. He had just learned to crawl several weeks earlier, has difficulty sitting, weak trunk and poor upper extremity strength. The oral motor skills develop concurrently with the gross motor skills. Max had just learned to roll, a 4-5 month skill, his oral skills are following along at the same rate. He is and suckling his liquids and purees and has severe oral hypersensitivity related to his untreated GER that causes him to vomit on any crumb of solid food. In addition, he has had several hospitalizations that slowed or even stopped his feeding practice. It is easy to see that there are persistent barriers (motor delays, GER) which perpetuates the practice of the immature suckling pattern. It is extremely difficult to change his oral motor pattern unless the barriers are fully removed and the pathway is clear for high frequency positive practice. This will allow him to gain momentum to progress to the next skill level.
Gastrointestinal problems such as gastroesophageal reflux and motility disorders causing irritation, pain, oral defensiveness and food refusal can also result in immature oral motor patterns often characterized by a suckle movement. Often children can be normal neurologically and developmentally yet fail to progress their skills due to the impact of pain and the abnormal heightened sensory feedback that can come from GER and other GI is- sues. It sounds like common sense to treat it first but if the child’s behaviors do not cor- respond with treatment that is suppose to be working, talk to the doctor. Remember they see kids in clinic. As therapists, you see kids actually function and that is where the information lies.
Once you have all of the underlying issues well controlled, there are some options for decreasing the suckle pattern and moving toward a single bolus transport pattern, lateral tongue movement or prechewing skills. The goal is to move toward a pattern where the jaw is stable and the tongue moves separately with successful practice.