OBJECTIVE: To assess the value of quantitative ultrasound in patients with type 2 and 3 spinal muscular atrophy (SMA). METHODS: Twenty-five patients with SMA (15 type 2 and 10 type 3) and 21 normal subjects were enrolled for this observational study. Strength of biceps brachii, wrist extensors, quadriceps, and tibialis anterior were measured with hand-held dynamometry. In addition, these 4 muscles were studied with a standard ultrasound system using a 5-MHz probe, and luminosity values for each muscle and the overlying subcutaneous fat were obtained by subsequent image analysis. A luminosity ratio (LR) for each muscle was calculated by dividing the muscle by the subcutaneous fat luminosity. The LR and strength scores for all 4 muscles were averaged to provide a single summary value for each patient. RESULTS: The LRs increased with disease severity: 1.27 +/- 0.26 for normal subjects, 2.43 +/- 0.78 for type 3 SMA, and 3.85 +/- 1.3 for type 2 SMA (p < 0.001). Taking all the normal subject and patient data together, there was a good correlation between strength and LR (r = -0.711, p < 0.001). There was also a moderate relationship between LR and strength in the patients with SMA alone (r = -0.588, p = 0.008), and, as expected, a nonsignificant relationship between LR and strength in normal subjects (r = -0.011). CONCLUSIONS: Quantitative ultrasound has the potential of serving as a marker of SMA severity and may be useful in future clinical trials.
OBJECTIVE: To assess the value of quantitative ultrasound in patients with type 2 and 3 spinal muscular atrophy (SMA). METHODS: Twenty-five patients with SMA (15 type 2 and 10 type 3) and 21 normal subjects were enrolled for this observational study. Strength of biceps brachii, wrist extensors, quadriceps, and tibialis anterior were measured with hand-held dynamometry. In addition, these 4 muscles were studied with a standard ultrasound system using a 5-MHz probe, and luminosity values for each muscle and the overlying subcutaneous fat were obtained by subsequent image analysis. A luminosity ratio (LR) for each muscle was calculated by dividing the muscle by the subcutaneous fat luminosity. The LR and strength scores for all 4 muscles were averaged to provide a single summary value for each patient. RESULTS: The LRs increased with disease severity: 1.27 +/- 0.26 for normal subjects, 2.43 +/- 0.78 for type 3 SMA, and 3.85 +/- 1.3 for type 2 SMA (p < 0.001). Taking all the normal subject and patient data together, there was a good correlation between strength and LR (r = -0.711, p < 0.001). There was also a moderate relationship between LR and strength in the patients with SMA alone (r = -0.588, p = 0.008), and, as expected, a nonsignificant relationship between LR and strength in normal subjects (r = -0.011). CONCLUSIONS: Quantitative ultrasound has the potential of serving as a marker of SMA severity and may be useful in future clinical trials.
Authors: Natalia Maria Maurits; Ernesto Alexander Christiaan Beenakker; David Eric Christiaan van Schaik; Johanna Maria Fock; Johannes Harmen van der Hoeven Journal: Ultrasound Med Biol Date: 2004-08 Impact factor: 2.998
Authors: Sisir Koppaka; Irina Shklyar; Seward B Rutkove; Basil T Darras; Brian W Anthony; Craig M Zaidman; Jim S Wu Journal: J Ultrasound Med Date: 2016-07-14 Impact factor: 2.153