1 INTRODUCTION
Spinal muscular atrophy (SMA) is an autosomal recessive disease caused
by deletion or mutation of the survival motor neuron 1 (SMN1) gene with
progressive muscle atrophy, weakness and paralysis. The incidence rate
of live births is approximately 1/11000. SMA in children is classified
into types 1-3 depending on the age of onset and maximal motor milestone
achieved.1 SMA is the primary genetic disease leading
to the death of children under two years old, and respiratory failure is
the most common cause of death.2 Nocturnal hypopnea is
the first respiratory problem in SMA, subsequently developing into
daytime hypopnea. Early pulmonary function can still be compensated.
However, patients are very prone to acute respiratory failure (ARF) once
pulmonary infection occurs. The more severe the case, the more likely
children are to have various respiratory complications, including
sleep-disordered breathing, recurrent pneumonia and
ARF.2,3 Appropriate and effective strategies of
respiratory management are crucial to stabilize lung function and reduce
the incidence of respiratory complications and mortality in children
with SMA. The literature and expert opinion support using a sleep study
to confirm when a patient has sleep-disordered breathing and needs to
use noninvasive ventilation to prevent recurrent respiratory tract
infections (RRTIs) and ARF. In addition, nutritional assessment and
intervention are also related to respiratory
management.2,4 However, there is still no specific
standard to evaluate and intervene in these respiratory problems.
Therefore, the aim of the present study was to obtain the risk factors
for RRTI and/or ARF and the specific values in children with SMA. This
is the largest study of polysomnography (PSG) in children with SMA
reported thus far.