Long-term effects of botulinum toxin A in children with cerebral palsy

The long-term effects of botulinum toxin A (BoNT-A) treatment in children with cerebral palsy (CP) are still elusive. We studied a prospective clinical cohort of 94 children with different subtypes (50% spastic diplegic CP, 22% hemiplegic CP, 25% tetraplegic CP, 3% dyskinetic CP), sex (55% male, 45% female), severity according to Gross Motor Function Classification System (29% Level I, 15% Level II, 16% Level III, 17% Level IV, 23% Level V), and age (median 5y 4mo, range 11mo-17y 8mo). The longest follow-up time was 3 years 7 months (median 1y 6mo) and included a maximum of eight injections per muscle (median two injections to a specific muscle). Outcome measurements were muscle tone (Modified Ashworth Scale) and joint range of motion (ROM). Assessments were made at a minimum before and 3 months after each injection. Ninety-five per cent confidence intervals for differences from baseline were used to identify significant changes. BoNT-A injections induced reduction of long-term spasticity in all muscle-groups examined: the gastrocnemius, hamstring, and adductor muscles. The reduction in tone was most distinct in the gastrocnemius muscle, and each repeated injection produced an immediate reduction in muscle tone. However, improvement in ROM was brief and measured only after the first injections, whereupon the ROM declined. Thus, the results suggest that BoNT-A can be effective in reducing muscle tone over a longer period, but not in preventing development of contractures in spastic muscles. The dissociation between the effects on muscle tone and ROM indicates that development of contractures is not coupled to increased muscle tone only, but might be caused by other mechanisms.

Co-activity during maximum voluntary contraction: a study of four lower-extremity muscles in children with and without cerebral palsy

This study was designed to determine whether children with cerebral palsy (CP) showed more co-activity than comparison children in non-prime mover muscles with regard to the prime mover during maximum voluntary isometric contraction (MVIC) of four lower-extremity muscles. Fourteen children with spastic diplegic CP (10 males, four females; age range 4-10y), seven children with spastic hemiplegic CP (five males, two females; age range 5-10y), and 14 comparison children (eight males, six females; age range 4-11y) participated in the study. Gross Motor Function Classification System levels of the children with CP were as follows: eight children at Level I, seven children at Level II, five children at Level III, and one child at Level I V. Surface electromyographic recordings were made simultaneously from the vastus lateralis (VL), medial hamstrings (MH), tibialis anterior, and lateral gastrocnemius (LG) muscles during maximal voluntary contraction. Children with CP showed higher co-activity than the comparison children in both antagonist and adjacent muscles. This was particularly true when VL, MH, or LG muscles were engaged in MVIC. These findings may contribute to the weakness and abnormal movement patterns seen in CP, and they have implications for treatment.

Synergistic muscle activation during maximum voluntary contractions in children with and without spastic cerebral palsy

We examined muscle recruitment patterns in children with cerebral palsy (CP) and comparison children without CP under conditions of maximum voluntary contractions. Three groups of children participated in the study: (1) 12 children with diplegic CP (eight males, four females; age range 4-10 y, mean age 7 y [SD 2 y 4 mo]); (2) six children with hemiplegic CP (four males, two females; age range 5-10 y, mean age 7 y 4 mo [SD 2 y]); and (3) 13 comparison children with normal motor function (seven males, six females; age range 4-11 y, mean age 7 y 2 mo, [SD 2 y]). The children with CP were classified according to the Gross Motor Function Classification System: eight were Level I, five were Level II, four were Level III, and one was Level IV. Surface electromyography was recorded from four proximal and distal lower extremity (LE) muscles. Children with CP more frequently activated a muscle other than the intended prime mover first, compared with the comparison children, especially when the prime mover was a distal muscle. For example, during ankle plantar flexion, when the lateral gastrocnemius muscle was the prime mover, children with hemiplegia showed preactivation of the tibialis anterior muscle and children with diplegia showed medial hamstring coactivation. In conclusion, children with CP showed considerable differences to the comparison children in how LE muscles were voluntarily activated. Greater understanding of muscle recruitment patterns under a variety of tasks may provide new directions for motor control retraining or other forms of intervention.

European consensus table 2006 on botulinum toxin for children with cerebral palsy

An interdisciplinary group of experienced botulinum toxin users and experts in the field of movement disorders was assembled, to develop a consensus on best practice for the treatment of cerebral palsy using a problem-orientated approach to integrate theories and methods. The authors tabulated the supporting evidence to produce a condensed but comprehensive information base, pooling data and experience from nine European countries, 13 institutions and more than 5500 patients. The consensus table summarises the current understanding regarding botulinum toxin treatment options in children with CP.

Centrotemporal spikes in families with rolandic epilepsy: linkage to chromosome 15q14

OBJECTIVE

To localize a gene predisposing to benign epilepsy of childhood with centrotemporal spikes (BECTS).

BACKGROUND

BECTS, or rolandic epilepsy, is the most prevalent idiopathic epilepsy syndrome in childhood. Functional relevant defects in the alpha 4 subunit of the neuronal nicotinic acetylcholine receptor (AChR) have been demonstrated in autosomal dominant nocturnal frontal lobe epilepsy, which, like BECTS, is an idiopathic partial epilepsy.

METHODS

A DNA linkage study was conducted screening all chromosomal regions known to harbor neuronal nicotinic AChR subunit genes. Twenty-two nuclear families with BECTS were analyzed.

RESULTS

In an "affected-only" study, best p values and lod scores were reached between D15S165 and D15S1010 on chromosome 15q14. In multipoint nonparametric linkage analysis a nominal p value of 0.000494 was calculated by GENEHUNTER. Best parametric results were obtained under an autosomal recessive model with heterogeneity (multipoint lod score 3.56 with 70% of families linked to the locus). These markers are localized in direct vicinity to the alpha 7 subunit gene of the AChR.

CONCLUSIONS

We found evidence for linkage of BECTS to a region on chromosome 15q14. Either the alpha 7 AChR subunit gene or a closely linked gene are implicated in pedigrees with BECTS. The disorder is genetically heterogeneous. Surprisingly, the same chromosomal area has been reported to be linked to the phenotype in families with an auditory neurophysiologic deficit as well as in families with juvenile myoclonic epilepsy, another idiopathic but generalized epilepsy syndrome.