Sniff nasal inspiratory pressure and sleep disordered breathing in childhood neuromuscular disorders.

The ease of sniff nasal inspiratory pressure testing may extend application of respiratory muscle assessment to younger and cognitively-impaired children. We sought to quantify sniff nasal inspiratory pressure in childhood neuromuscular disorders, and to correlate this measure with conventional pulmonary function tests and overnight polysomnography. Thirty children (mean 9.7 ± 3.8 years, range 4.3-16.5 years) with diagnosed neuromuscular disorders (Duchenne muscular dystrophy, spinal muscular atrophy, Becker muscular dystrophy, congenital myopathy, facioscapulohumeral muscular dystrophy, myotonic dystrophy, multi-minicore disease) underwent assessment. Thirty-seven percent displayed cognitive impairment. Those with neuromuscular disorders were then compared with 32 volunteer age- and gender-matched controls (mean 10.9 ± 2.9 years, range 6.6-17.2 years) with normal respiratory function. Twenty-three children with neuromuscular disorders also underwent overnight polysomnography. Children with neuromuscular disorders demonstrated significantly impaired sniff nasal inspiratory pressure, maximal inspiratory pressure, FEV(1) and FVC (p<0.05). A positive correlation was identified between daytime sniff nasal inspiratory pressure and maximal inspiratory pressure (r=0.58), FEV(1) (r=0.55) and FVC (r=0.46), though not with polysomnography variables (respiratory disturbance index, nadir SpO(2), peak CO(2)). Moderate prevalence of nocturnal hypoxia was observed, and 32% of children demonstrated sleep disordered breathing. Sniff nasal inspiratory pressure assessment was well tolerated, representing a promising surrogate measure for assessment of respiratory function in childhood neuromuscular disorders.

Impaired joint proprioception at higher shoulder elevations in chronic rotator cuff pathology.

OBJECTIVES: To assess the degree of impairment of shoulder proprioceptive acuity in individuals with chronic rotator cuff pathology (CRCP), and to examine the effect of impingement-related shoulder pain on acuity using a reliable laboratory technique. DESIGN: Case-control study. SETTING: University human movement laboratory. PARTICIPANTS: A volunteer sample of individuals with CRCP (n=26) were recruited and screened, and compared with age-, sex-, and limb dominance-matched individuals (n=30) who acted as controls. Ten participants with CRCP underwent repeat assessment after 2 days to determine the intrarater reliability of proprioceptive measurement. INTERVENTIONS: Not applicable. MAIN OUTCOME MEASURES: Each participant underwent assessment of joint position sense at 40° and 100° of scapular plane abduction using an active position-matching task. Movements were recorded with reflective skin markers and a multidimensional motion analysis system. Self-reported pain intensity associated with the procedure was recorded with a visual analog scale. RESULTS: Intraclass correlation coefficients (model 3,5) between repeat assessments ranged from .54 to .99. On average, those with CRCP demonstrated reduced acuity at 40° and 100° test angles. In comparison with the control group, proprioceptive acuity was significantly impaired (P<.01) at the 100° test angle, where the pain intensity was significantly greater (P<.01). CONCLUSIONS: This study demonstrated impairment of shoulder joint position sense in CRCP. The degree of proprioceptive impairment was greatest at higher elevations in the setting of increased shoulder impingement and pain, which may serve to perpetuate the pathology. These findings provide a theoretic rationale for the continued implementation of proprioceptive rehabilitation programs in managing CRCP.