Gross muscle morphology and structure in spastic cerebral palsy: a systematic review

Abstract

PCSA Physiological cross-sectional area AIM This systematic review and critical evaluation of the literature was conducted to determine how gross muscle morphology and structure are altered in individuals with spastic cerebral palsy (CP).METHOD Electronic databases were searched for articles describing studies of muscle morphological and structural properties in individuals with spastic CP. Data describing muscle fascicle length, belly length, fascicle angle, cross-sectional area, volume, and thickness were extracted and effect sizes were computed for comparisons between individuals with spastic CP and typically developed individuals, between the paretic and non-paretic side in individuals with hemiplegia for all muscles examined, and across the full spectrum of gross motor function in individuals with spastic CP. RESULTSThe final yield consisted of 15 articles that met the inclusion criteria. The main finding of the review was the consistent evidence for reduced muscle belly length, muscle volume, crosssectional area, and muscle thickness in the comparisons between paretic and typically developed muscle and the paretic and non-paretic muscle across a range of muscles.INTERPRETATION Given the importance of muscle morphology and structure for generating muscle force, it is likely that the observed alterations that occur secondary to the neural lesion in individuals with spastic CP contribute to muscle weakness and the attendant loss of motor function in spastic CP.Cerebral palsy (CP) describes a group of permanent motor disorders that are attributed to disturbances that occur in the developing brain.1 Although the perinatal brain lesion is not progressive, it results in secondary muscle pathology. Spasticity, a velocity-dependent resistance to stretch, occurs in the first months of development owing to reduced inhibition of the stretch reflexes.2,3 Muscle contractures, which restrict joint range of motion, develop later in childhood and further compromise function. 4 Contractures are commonly assumed by clinicians to be caused by a fixed shortening of muscles; however, this view has not been substantiated in the scientific literature.5 A consistent finding is that muscle strength is severely compromised in individuals with spastic cerebral palsy (CP) [6][7][8][9] and that muscle weakness contributes to reduced functional capacity in these individuals. 10-12The mechanisms underlying the development and progression of muscle contracture and weakness and corresponding loss of motor function with age in individuals with spastic CP are complex and interrelated, 8 but it is clear that a combination of neural and muscular factors are involved. Individuals with spastic CP are less able to activate their muscles maximally 13,14 and use greater amounts of antagonistic muscle activation (co-contraction) than typically developing individuals. 7 In addition to neural factors, the ability of a muscle to generate force depends on its morphological and structural properties.15 Muscle force-generating capacity is directly related...

The effects of botulinum toxin injection frequency on calf muscle growth in young children with spastic cerebral palsy: A 12-month prospective study

“…A recent systematic review [20] concluded, on the basis of cross-sectional studies, that there was consistent evidence for reduced calf muscle size in the paretic limb in spastic CP compared to typically developing (TD) peers [21][22][23][24][25]. Barber et al [26] subsequently showed that medial gastrocnemius (MG) muscle physiological crosssectional area (PCSA), but not fascicle length, was reduced by 27 % in children aged 2-5 years with spastic CP who had not commenced BoNT-A treatment compared to TD peers.…”

Muscle volume alterations in spastic muscles immediately following botulinum toxin type‐A treatment in children with cerebral palsy

“…21,22 Children with CP have been shown to have smaller and weaker muscles. 23 Over the last decade, weakness has been increasingly recognised as a significant motor impairment, [22][23][24] purportedly affecting functional ability in children with CP. 25,26 A recent review of the literature on spastic CP found consistent evidence for small muscle size as indicated by reduced muscle volume, crosssectional area, thickness, and belly length in comparisons of paretic muscles with non-paretic and typically developing muscles.…”

“…25,26 A recent review of the literature on spastic CP found consistent evidence for small muscle size as indicated by reduced muscle volume, crosssectional area, thickness, and belly length in comparisons of paretic muscles with non-paretic and typically developing muscles. 24 Barber et al 25 described volumetric deficits of 22% in the medial gastrocnemii of young children (2-5y) with spastic CP compared with typically developing children. For a population already predisposed to decrements in muscle size and strength, a treatment that potentially leads to further atrophy and weakening of the muscle should be well understood.…”

Effects of low-level laser therapy (LLLT 808 nm) on lower limb spastic muscle activity in chronic stroke patients

“…Both are responsible for increasing lactic acid production, use of muscle glycogen, pain, and functional limitation characterized as an inability to perform motor tasks [4][5][6].…”