Why breathing is such an issue with Congenital Myotonic Dystrophy

Breathing is a huge and life threatening issue in myotonic dystrophy. An article recently shed some light on the reasons for this. Because of ethical issues its difficult to do live tests on humans. However, our fine researchers have created mice that have the congenital form of myotonic dystrophy. Through detailed analysis of the mice and there breathing they have isolated the issue to the neuropathology of several body systems. That means its not only the muscle issues but there are some nerve conduction issues involved as well. This information will help the drug companies as they design drugs to help not only the muscle issues but the nerves that serve to coordinate the breathing mechanisms. As a drug is introduced testing it on these mice would see if it will help the respiratory function.

Results from the Study
Because it is not feasible to take biopsies of the nervous system from
patients with DM1 for histological examinations, animal models are
indispensable for the study of the mechanisms underlying respiratory
failure in this disease. In this study, the authors test the respiratory function
and analyze the structures involved in respiratory function in DMSXL
transgenic mice, an established animal model for congenital DM1 (the severest
form of the disease, which develops at birth) that carries a very long CTG
repeat in the DMPK gene. Statistical analysis of breathing function
measurements shows that DMSXL mice have impaired respiratory function.
Histological and morphometric analyses reveal pathological changes in the
diaphragmatic neuromuscular junctions and muscle fibers of DMSXL mice and
a significant decrease in the number of unmyelinated phrenic afferents. By
contrast, DMSXL mice exhibit no significant neuronopathy in either cervical
phrenic motor neurons or brainstem respiratory neurons.
Implications and future directions
By shedding new light on the cellular mechanisms of respiratory failure in
DM1, these findings improve understanding of the main cause of death in
congenital DM1. The denervation and the pathological changes of the
diaphragmatic neuromuscular junctions observed in DMSXL mice suggest that
a breakdown in communication between the diaphragmatic muscle fibers and
the nerve endings might be the main cause of respiratory failure; the loss of
phrenic unmyelinated afferents suggests that altered regulation of breathing is
also involved. As well as contributing towards the understanding of respiratory
failure in DM1, these findings suggest that the evaluation of respiratory
parameters in DMSXL mice by non-invasive pressure plethysmography could
be used to evaluate the effect of potential therapies. Moreover, future analyses
of gene expression in DMSXL mice might contribute to our understanding of
the molecular mechanisms involved in respiratory impairment.


Lung Function and Myotonic Dystrophy

A consortium of doctors met and came up with some definitive pathways for patients with myotonic dystrophy

A Multi-country conference was held with doctor from most major European Countries and the USA to review respiratory or lung function in patients with Myotonic Dystrophy. Patients with DM have a lot of issues with lung function and respiration. A framework or step by step checklist was reviewed and recommended at this conference. The conclusion of this conference is presented below. This is a very complex subject so print this and bring it with you to your doctor or  pulmonologist. When you have myotonic dystrophy its important to have your lung function checked every 6 months or so.


Management of respiratory insufficiency is challenging in
DM because of the pathophysiology of the disease, which
affects both muscles and central respiratory pathways and
patients’ cognitive and behavioral characteristics. Although
there are no natural history data on the effects of respiratory
care on survival and on morbidity in patients with DM, results
of ventilation on survival and on better care in other
neuromuscular diseases indicate that adequate ventilatory care
may improve survival and QoL of patients with DM1 [41–43].
NIV use varies greatly among the different centers, e.g. varying
from 20 to 60% in adults with DM1, 20–40% of patients with
the congenital form, and 15–20% of patients with DM2. All
participants agreed on the need for standard assessments and
recommendations for standard of care.
Discussion between the specialists from different countries
led to the construction of initial standard protocols which are
the necessary preliminary steps for validation processes to
follow. Specifically, the workshop led to the creation of: 1) a
respiratory symptom check-list to be applied in everyday DM
clinic (Table 1); 2) a preliminary version of a screening
respiratory protocol to be applied on first assessment during
clinic (Figure 1); 3) proposal of criteria for NIV prescription to
be used specifically in patients with DM, based on the existing
ACI (Consensus Statement from the Agency for Clinical
Innovation Respiratory Network on Domiciliary Non-Invasive
Ventilation in Adult Patients) guidelines for NIV, including
recommendations for timing and tests to be performed on
follow-up assessments; 4) proposal of a secretion management
protocol (Figure 2).
The need for validation of these recommendations and for
further research to extend the evidence-base in certain key areas
was also highlighted and outline proposals to resolve these
deficiencies put forward. All participants agreed on the urge for
more natural history data and for specific pathways for
emergency care of acute respiratory insufficiency in DM.

Watch your Weight!!! – It may affect your breathing!


A recently published article has great information about weight and breathing. Simple conclusion: is that being overweight with Myotonic Dystrophy can affect your breathing and respiratory function. Since respiratory failure and pneumonia are big issue with Myotonic Dystrophy pay special attention to your weight!!! It also showed that a great majority of people with DM have an abnormal body composition. ITs important to keep the weight off but you also must see a nutritionist to insure that you are getting proper nutrition and to look at your body weight/mass/BMI. Here is the summary

InDM1 patients, overweight is an independent factor for predicting TLC, and contributes independently of FIV1. Because overweight isr elated to increased work of breathing and inspiratory muscle strength is reduced inDM1, the fatigue threshold will be reached sooner. Therefore, muscle fatigue and the onset of respiratory failure will develop at an earlier stage in overweight patients, especially during increased ventilator demand. Moreover, over half of DM1patients are overweight, and nearly all patients have an abnormal body composition. To develop interventional strategies for weight loss, it will be important to categorize the individual type of body composition. Hence, preventing the development of overweight inDM1 patients may result in delaying respiratory failure and mortality in DM1.

Click below on the link for the full study

Overweight Myotonic Dystrophy

Pneumonia Lung Problems


Lung problems mostly occur during the advanced stage of the disease. Here too the weakness of the breathing muscles is not the main problem, because with MD in the worst case the breathing muscles are slightly affected. Chronic mechanical respiration, which is sometimes necessary with other muscular diseases, is seldom necessary with MD-patients.

The main problem with MD is the acute pneumonia. It is often caused by choking, though the patient is not always aware of it. Obviously he is choking on saliva when asleep, because swallowing is more difficult when lying down than being upright. Pneumonia mostly starts in the lower lobe of the lungs, but it can extend within a few days and become a serious and dangerous infection of a complete lung. This should be treated quickly with antibiotics and cough-medicine. Often admittance to hospital is necessary and sometimes patients require temporarily a mechanical ventilator at an Intensive Care. Sometimes the trachea must be sucked out with a bronchoscope, a flexible thin pipe, slid through the trachea by a lung-physician. Often this way of fighting pneumonia is successful. With some patients who frequently choke, within a few years several times pneumonia occurs. This can be prevented by sleeping at night in upright position, thus preventing choking.. In this case it is wise not to eat in the evening because from a filled stomach sometimes  food is belched up, which can reach the lungs