Participation in daily life activities and its relationship to strength and functional measures in boys with Duchenne muscular dystrophy

Duchenne muscular dystrophy (DMD) is characterized by a progressive replacement of muscle by fat and fibrous tissue, muscle weakness, and loss of functional abilities. Impaired vasodilatory and blood flow responses to muscle activation have also been observed in DMD and associated with mislocalization of neuronal nitric oxide synthase mu (nNOSμ) from the sarcolemma. The objective of this study was to determine whether the post-contractile blood oxygen level-dependent (BOLD) MRI response is impaired in DMD and correlated with established markers of disease severity in DMD, including MRI muscle fat fraction (FF) and clinical functional measures. Young boys with DMD (n=16, 5-14 years) and unaffected controls (n=16, 5-14 years) were evaluated using post-contractile BOLD, FF, and functional assessments. The BOLD response was measured following five brief (2 s) maximal voluntary dorsiflexion contractions, each separated by one minute of rest. FF from the anterior compartment lower leg muscles were quantified via chemical shift encoded imaging. Functional abilities were assessed using the 10m walk/run and the 6-minute walk distance (6MWD). The peak BOLD response in the tibialis anterior and extensor digitorum longus were reduced (P<0.001) in DMD compared to controls. Furthermore, the anterior compartment peak BOLD response correlated with function (6MWD ρ=0.87, P<0.0001; 10 m walk/run time ρ=-0.78, P<0.001) and FF (ρ =-0.52, P=0.05). The reduced post-contractile BOLD response in DMD may reflect impaired microvascular function. The relationship observed between the post-contractile peak BOLD response and functional measures and FF suggests that the BOLD response is altered with disease severity in DMD.

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The association of hand grip strength with functional measures in non-ambulatory children with Duchenne muscular dystrophy

Arquivos de Neuro-Psiquiatria ◽

10.1590/0004-282x20190161 ◽

2019 ◽

Vol 77 (11) ◽

pp. 792-796 ◽

Cited By ~ 1

Author(s):

Numan Bulut ◽

Ipek Gürbüz ◽

Öznur Yilmaz ◽

Güllü Aydin ◽

Ayşe Karaduman

Keyword(s):

Duchenne Muscular Dystrophy ◽

Muscular Dystrophy ◽

Grip Strength ◽

Upper Limb ◽

Functional Capacity ◽

Assessment Tool ◽

Hand Grip Strength ◽

Dominant Hand ◽

Hand Grip ◽

Functional Measures

ABSTRACT Duchenne muscular dystrophy (DMD) is a disease characterized by progressive loss of muscle fiber, gradually from proximal to distal. Although a few studies have investigated hand grip strength in non-ambulatory DMD patients, a lack of literature was found determining its relationship with functional capacity. Objective: The aim of this study was to determine the associations between hand grip strength and functional measures in non-ambulatory children with DMD. Methods: Hand grip strength was evaluated using a dynamometer in children with DMD. The children with DMD were evaluated with the Turkish version of the Egen Klassifikation Scale Version 2 (EK2) for global functional capacity, the Performance of Upper Limb (PUL) for upper limb functional performance and the ABILHAND-Kids for hand ability. Results: The mean age of 38 DMD children was 12.02 ± 1.99 years. Dominant hand grip strength of the children with DMD was higher than the non-dominant hand (p < 0.05). The EK2 was 13.02 ± 5.50, PUL was 49.86 ± 14.34 and ABILHAND-Kids was 26.81 ± 7.59. Hand grip strength was found to be correlated with the EK2 (p < 0.05). Conclusions: It is known that measuring functional ability and strength in very weak children with DMD has been difficult and complex for therapists/clinicians in the clinical environment. Although there is a moderate correlation, hand grip strength may be used in clinical practice as a practical assessment tool to have an immediate insight into the global functional capacity in non-ambulatory DMD children.

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