Handgrip and finger flexion strength is a sensitive functional marker in children with neuromuscular disorders such as spinal muscular atrophy (SMA) to identify minimal changes in the strength of distal muscles, according to a new study published in the journal Brain and Development.
It could also be used as a sensitive outcome measure to monitor the effect of new therapies, especially in patients who are not able to walk, according to the authors of the study. The emergence of potential new treatments for genetic neuromuscular conditions has brought with it the need for novel outcome measures.
To evaluate the usefulness of handgrip and finger flexion strength as a functional marker in children with neuromuscular disorders, a team of researchers, led by Maya Von Der Hagen, PhD, conducted a cross-sectional study in 33 children with a neuromuscular disorder and 233 healthy controls. Participants were 5 to 18 years of age.
Read more about nusinersen for the treatment of SMA
Of the children, 7 had SMA, and their handgrip and finger flexion strength were assessed before and after nusinersen treatment over 2 months.
The results showed that children with a neuromuscular disorder had a heterogenous pattern of handgrip and finger flexion strength, but this strength was lower than in healthy controls. There was also a correlation between the handgrip and finger flexion strength and respiratory function as well as performance and individual satisfaction with hand function.
Children with SMA showed a significant increase in handgrip and finger flexion strength after 2 months of nusinersen treatment.
The researchers concluded that handgrip and finger flexion strength “is an important marker to monitor therapeutic interventions in upcoming personalized targeted therapies.”
SMA is a rare neurodegenerative disorder characterized by progressive muscle weakness and loss of movement due to the degeneration of alpha motor neurons in the anterior horn of the spinal cord.
Weber C, Schallner J, Von Der Hagen M. Handgrip and finger flexion strength in children: A cross-sectional assessment of age-related normative data and application as a clinical functional marker in paediatric neuromuscular disorders. Brain Dev. 2022;1:S0387-7604(22)00164-4. doi:10.1016/j.braindev.2022.09.005