Dysphagia in Neuromuscular diseases, pathophysiology and treatment implications

Swallowing problems are not uncommon in different neuromuscular disorders (NMD)
including Duchenne Muscular Dystrophy (DMD). Common mechanism seem to be
present leading to dysphagia. The dysphagia can be partly explained from
neurological factors (paresis, coordination), but also biomechanical factors
appear to play a role (recent research in children with SMA type II). In
different types of NMD these problems are mostly described in chewing, but also
pharyngeal residues after the swallow are observed. In NMD little is known
about the contribution of the tongue, submental muscle group and movement of
the hyoid in the swallowing process. This last factor is influenced as well by
the position of the head on the neck and is therefore dependent on pareses of
the neck muscles. Also very little is known about the influence of the
consistency of the food. In children with SMA type II it is shown that apart
from neurological also biomechanical factors, like head position, play a role
in combination with the consistency of food.

The objective is to describe the nature and underlying (neuromuscular en
biomechanical) factors of dysphagia in different neuromuscular diseases in
relation to different consistencies of food. Identifying the contributing
factors are starting points for therapeutic interventions.

The design is a descriptive design (case series) with different groups of
children and adults involved, with dysphagia caused by neuromuscular diseases.
Variables are gathered with an extensive swallowing assessment. To gather
normal values some of the items of the swallowing assessment will be done in a
healthy control group with comparable ages.
The study consists of 3 sub studies:
- A study of the swallowing mechanisms in boys and young adults with DMD. The
increasing paresis is known which is leading to problems in chewing in this
population. The influence of progression of the disease on dysphagia will be
assessed, aimed to the neurological and biomechanical factors in relation to
different consistencies of food.
- A study of different types of NMD with known neurological head and mouth
problems but differing from each other. To what extend the neurological and
biomechanical factors play a role in the pathophysiology of dysphagia will be
assessed, as well the relation with different consistencies of food.
- Collecting normal values in healthy people. On this moment there are no
normal values for the innovative research methods that will be used in this
study

There will be minimal risk, because the measurements are not invasive, not long
standing and will be done only once. The risks for the group (children) are
negligible and the burden is minimal. The research will be done in presence of
the parents, who were informed. Also for the children is information available.