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SUPPLEMENT ARTICLES: Mary K. Schroth Special Considerations in the Respiratory Management of Spinal Muscular Atrophy Pediatrics 2009; 123: S245-S249 [Abstract] [Full text] [PDF]

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More Follow-up on Spinal Muscular Atrophy Type 1

Joyce Cheng, Leila Ettefagh, MD, and John R. Bach, MD   (17 July 2009)

More Follow-up on Spinal Muscular Atrophy Type 1 17 July 2009
Joyce Cheng, Medical student Drexel University College of Medicine, Leila Ettefagh, MD, and John R. Bach, MD Send letter to journal: Re: More Follow-up on Spinal Muscular Atrophy Type 1 jcc92{at}drexel.edu Joyce Cheng, et al.	We read with interest the article entitled, “Special considerations in the respiratory management of spinal muscular atrophy (SMA)".(1) Although a good review, long-term follow-up studies of one of the author’s references on SMA 1(2) were overlooked.(3,4) The 22 surviving SMA 1 tracheostomy ventilation users’ mean age was 70.5±43.3 (range 2 to 159) months. Five others died at 66.2±114.2 (range 8 to 270) months of age. While the six trached patients who had comprehendible speech at tracheotomy retained ability to vocalize, none of the 21 who had not developed speech before tracheotomy did so after it and 25 of the 27 definitely lost all autonomous breathing ability immediately following tracheotomy. Considering the 47 SMA 1 patients managed noninvasively, including nine who were continuously noninvasively ventilator dependent (NIV) and were extubated to NIV after acute bouts of respiratory failure on over 40 occasions before age 4½, the NIV users subsequent hospitalization rates were 4 per 100 years, significantly less than the trach users after 4 years of age. Thirty-nine NIV users were 65.2±45.8 (range 11 to 153) months of age; and 8 died at 60.9±26.1 (range 36 to 111) months of age. Thirty-nine of the 47 could communicate verbally. Thus, while NIV and tracheostomy can both prolong survival for SMA 1 patients the latter results in continuous ventilator dependence and speech does not develop. Eleven NIV dependent SMA 1 patients are currently over age 10. Our extubation success rates exceeded 80% despite continuous NIV dependence in part because of the use of mechanical in-exsufflation at pressures of 40 to –40 cm H2O timed to the child’s breathing when too young to cooperate.(3) Long term survival of SMA 1 has resulted in complicating medical conditions including pancreatitis, bacterial endocarditis, autonomic involvement with bradycardias, and osteoporosis.(4) References: 1. Schroth MK. Special considerations in the respiratory management of spinal muscular atrophy. Pediatrics 2009;123:S245-S249. 2. Bach JR, Baird JS, Plosky D, Nevado J, Weaver B. Spinal muscular atrophy type 1: management and outcomes. Pediatr Pulmonol 2002;34:16-22. 3. Bach JR, Saltstein K, Sinquée D, Weaver B, Komaroff E. Long term survival in Werdnig-Hoffmann Disease. Am J Phys Med Rehabil 2007;86:339- 345. 4. Bach JR. Medical considerations of long-term survival of Werdnig- Hoffmann disease. Am J Phys Med Rehabil 2007;86:349-355. Conflict of Interest: None declared