Quantitative muscle ultrasound of orofacial muscles in children with cerebral palsy

Children with cerebral palsy (CP) often have dysphagia (prevalence of 43 - 99%)
depending on the severity of the motor impairment. Observation of eating and
drinking and instrumental assessment (videofluoroscopic swallowing study) are
used to give a description of the eating and swallowing skills. However, these
assessments do not give insights in the underlying pathophysiology of the
problems: which muscles are affected in which way?
In the last years, quantitative muscle ultrasound is used in children with
neuromuscular disorders. With muscle ultrasound, the thickness and echogenicity
of a muscle can be determined. The echogenicity reflects the degree of density
of the measured tissue. Muscle tissue has a low echogenicity, and fat or
connective tissue and bone have a high echogenicity. Quantitative muscle
ultrasound of orofacial muscles provides insight into the underlying
pathological mechanisms of mastication and swallowing difficulties.
With the current research, a precise picture can be obtained of the (changed)
composition of the orofacial muscles and the relation with eating and
swallowing problems in children with CP. This knowledge can be a next step in
understanding the complex swallowing problems of the group of children with CP
and the way in which therapy has to be started in the form of exercises and
compensations. The different orofacial muscles (submental muscles, masticatory
muscles) all have their own function and influence on the activity to be
performed. If we have more insight in the affected muscles, we could also
examine whether influencing is possible through exercise. By visualizing these
muscles we can better explain the underlying mechanisms involved. With this
knowledge more differentiation can be made in therapy. This means an important
step for patients (and their parents) towards a better substantiated and more
targeted treatment of eating and swallowing problems in children with CP.

- What is the echogenicity (quantitative described as z-scores, based on own
laboratory values and qualitatively described as Heckmatt gradations) of
orofacial muscles (digastrics muscle, geniohyoid muscle, masseter muscle,
temporal muscle) in children with CP?
- What is the thickness (quantitative described as z-scores, based on own
laboratory normal values) of orofacial muscles (digastrics muscle, masseter
muscle, temporal muscle and the tongue) in children with CP?
- Is there a relation between the echogenicity of orofacial muscles in children
with CP and the EDACS-level or other functional outcome measurements (about
mastication, swallowing and saliva control) and/or patient characteristics
(GMFCS, age, BMI)?
- Is there a relation between the thickness of orofacial muscles in children
with CP and the EDACS-level or other functional outcome measurements (about
mastication, swallowing and saliva control) and/or patient characteristics
(GMFCS, age, BMI)?

In 50 children with CP, visiting the outpatient clinic for Speech Language
Therapy, orofacial muscle ultrasound will be performed. Thickness and
echogenicity of orofacial muscle will be determined and will be described as
z-scores, corrected for age, height and weight (based on own laboratory
values). Children will be classified using the Eating and Drinking Ability
Classification System (EDACS). In all EDACS- levels (I-V), 10 patients with CP
will be included. Functional outcome measurements on mastication, swallowing
and saliva control (regular measurements during assessment in the Amalia
Children*s Hospital of the Radboudumc) will be described.

Time investment: 10 minutes within a regular visit at the outpatient clinic for
Speech and Language therapy.
There are no risks associated with participation to the study. The ultrasound
assessment is not invasive. For other patientgroups (neuromuscular diseases)
the ultrasound assessment is within regular care.