Upper limb function in children with cerebral palsy : range of motion, botulinum neurotoxin A and accelerometry metrics

Abstract

Cerebral palsy (CP) is the most common cause of movement disorders in children and may result in diverse levels of severity of the disability, from very mild to very severe. The underlying neurological pathology in CP is by definition not progressive, but motor symptoms may cause permanent and progressive secondary movement complications, which often change over time. Movement disorders are a prominent component in individuals with CP and treatments are often aimed at affecting movement disorders. Since CP is caused by a permanent lesion to the brain, the lesion will affect the individual in different ways throughout life and in daily life activities. Thus, it is particularly important to understand how secondary complications develop from early childhood until adulthood in this population. Measurement tools that are evaluating individuals’ daily life need to be psychometrically evaluated, and we also need to evaluate the treatments outcome of the secondary complications within CP efficiently. Gaining more knowledge about secondary complications to CP is a priority in CP research.

This thesis focuses on upper limb (UL) passive range of motion (pROM) and contracture development over time, botulinum neurotoxin A (BoNT-A) and on accelerometry based metrics evaluated in daily life in children and adolescents. Upper limb passive range of motion change over time and BoNT-A treatment were investigated by population-based data sourced from the Swedish national CP registry. Upper limb clinical assessments and accelerometry based metrics were obtained from 20 children and adolescents, who were residents of Sörmland or Västmanland in Sweden.

Results show that one-third of children and adolescents with CP developed upper limb contractures and the pROM deteriorated over time. The contracture development started already at preschool age. The first and most severe contractures were found in wrist extension with extended fingers. Children with the most affected level of manual ability were at highest risk for contracture development.

One-fifth of children with spastic or dyskinetic CP had been treated with BoNT-A in the ULs, 45% of them early at age, 1–3 years. Children with lower levels of manual ability or full pROM with resistance at the end of the movement range were most likely to receive a first UL BoNT-A treatment. At the first treatment occasion, thumb and forearm muscles were the most targeted. Interestingly, a first UL BoNT-A treatment at an early age, 1-3 years implied a favourable pROM development over time compared to children treated first time at a later age, 4-15 years. Early detection of a first sign of muscle shortening and thus early intervention before contractures are manifested can be one of the keys to successful outcomes. In daily life, during sedentary time and light-intensity physical activity, accelerometry metrics provide objective information about UL asymmetry and relative use. Thus, accelerometry metrics may provide complementary information to clinical assessments in daily life.