How bad will it get?

A frequent question in our support group and in our monthly virtual “meet-ups” surrounds the need to know how severe respiratory involvement in Neuromuscular Disease (NMD) will get. It’s a question asked more often by those diagnosed with NMD later in life and/or the newly diagnosed. Sometimes the question comes from a parent of a child who has an NMD.  Understandably, they want to know if bi-level mechanical ventilation will eventually be needed all day to support breathing. Sometimes they also want to know how long their breathing may be adequately supported. It is wise to want to plan ahead with any chronic medical condition.
 
Questions surrounding respiratory involvement are just one example of why having a genetic diagnosis to confirm one’s exact form of NMD or disease subtype can be helpful. If the diagnosis is Amyotrophic Lateral Sclerosis (ALS), many scholarly articles reference the rate at which respiratory muscles are expected to decline and the degree of severity of weakness. Even for long-studied NMD diagnoses such as Duchenne Muscular Dystrophy (DMD) and Spinal Muscular Atrophy (SMA) Type 1, a lot of research has been published to advise of expectations for respiratory decline. For those with more slowly progressive and lesser studied NMDs, it may be impossible to know what to expect in terms of how weak the respiratory muscles will get and ultimately how much breathing support one living with that diagnosis might need. 
 
If you know your specific diagnosis, you may gain clarity about the rate of respiratory/breathing muscle decline and potential severity by reading papers published from natural history studies about your specific NMD type or disease subtype. For example, if you live with Limb Girdle subtype R1/2A, search an internet browser for “natural history limb girdle 2A.” If you struggle to find published papers on natural history, NMD-related nonprofit organizations (i.e. Cure CMD, Cure SMA, Parent Project Muscular Dystrophy, etc.) ​that raise funds to research treatments and/or cures for your specific condition may be able to assist you in obtaining published papers about the natural history of your disease. You may even find these publications on your own on the nonprofit organization's website. 

Some natural history studies include details like the average age to begin assisted/mechanical ventilation with that diagnosis and even the rate of annual decline of Forced Vital Capacity (FVC), a measure that is taken during Pulmonary Function Testing (PFT) that shows the total amount of air forcibly blown out after taking your deepest breath​. Any published details are based on the study participants and may or may not reflect all individuals with that diagnosis.
 
Physical changes to one’s body through skeletal abnormalities like scoliosis and kyphosis can amplify the degree of respiratory muscle weakness one may have. Other influencing factors can be retained airway secretions (mucus), micro atelectasis (the collapse of an area within the lung), and repeated respiratory infections that escalate to pneumonia. Some with the same diagnosis, including siblings, can have differences in their clinical presentation, which can mean one has more pronounced respiratory muscle weakness than the other. With all of these factors to consider, questions about respiratory/breathing muscle decline and severity are difficult to answer with 100% certainty.

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Many of us with congenital forms of NMD have lived decades with uncertainty about various aspects of our diseases, including the rate of respiratory decline.  Some have had clinicians make educated guesses and have been proven wrong. As research for the NMDs continues at an exciting pace and more patients get involved to participate in studies, one can only hope that more details about the rate and potential degree of respiratory decline will become known and shared within the individual disease communities.

​Uncertainty can be scary and frustrating, but one thing is certain: support is available! Join and participate in meaningful discussions in support groups for those with the same form or subtype of NMD. Facebook has dozens of these groups; you just need to search for and find the one that's for you.  And if a support group does not exist for your form of NMD or subtype, create one!  Then post a link to it in other general NMD groups where individuals with that disease may be members, helping to recruit them to join and participate in your group.  The Breathe with MD Support Group offers peer support specific to breathing muscle weakness in NMD. There are members who have used both noninvasive and invasive forms of mechanical ventilation for more than 25 and 30 years respectively. The feedback and insight from members can be extremely valuable, not to mention the feeling of camaraderie one can receive by communicating with individuals going through the same challenging journey. 

​Wishing you all the best,
Andrea

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