Abstract
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder characterized by the degeneration of motor neurons in the spinal cord, and comprises a broad clinical spectrum. With the advent of new therapies (e.g., Nusinersen) for patients of all ages and disease stages, sensitive clinical measures are needed to detect slight changes in muscle force even in immobilized, severely affected patients often unable to move limbs. As for these patients, well-established outcome scales set out to evaluate motor function do not work properly, we propose measurement of maximum bite force which is able to detect subtle changes of bulbar function. Requirements for this approach are mentioned, challenges are discussed, and first insights from a pilot study are presented. Finally, a study design is proposed to evaluate the measurement of maximum bite force during the follow up of SMA patients with and without a disease modifying therapy.
Highlights
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder characterized by the degeneration of motor neurons in the spinal cord resulting in muscular atrophy, weakness and paralysis [1]
Approaches to measure bite force in SMA patients date back to 1999: Granger and colleagues showed that absolute levels of maximum bite force in SMA patients were reduced to 50% compared to a healthy control group [10]
Bite force measurement needs to be applied in SMA patients of different disease stages and should be compared with established scales as CHOP INTEND, Hammersmith Functional Motor Scale Expanded (HFMSE) or Revised Upper Limb Module (RULM)
Summary
Spinal muscular atrophy (SMA) is a severe neuromuscular disorder characterized by the degeneration of motor neurons in the spinal cord resulting in muscular atrophy, weakness and paralysis [1]. Additional open-label studies (CS1, CS2/CS12) confirmed the results. These are the only studies that included older patients (five patients were 15–16 years old suffering from SMA between 9 and 15 years) [4]. Treatment of adult SMA patients faces a lack of clinical data concerning efficacy and safety of treatment beyond childhood and long disease duration. Concerning disease severity and age many SMA patients are far away from the existing study populations [5]. Severely affected patients are immobilized, unable to walk, stand or sit, and often are even unable to move limbs. For these patients, well-established outcome scales set out to evaluate motor function do not
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a call
