Medial gastrocnemius volume and echo-intensity after botulinum neurotoxin A interventions in children with spastic cerebral palsy

AIM

This cross-sectional investigation evaluated whether recurrent botulinum neurotoxin A (BoNT-A) interventions to the medial gastrocnemius have an influence on muscle morphology, beyond Gross Motor Function Classification System (GMFCS) level.

METHOD

A cohort of typically developing children (n=67; 43 males, 24 females; median age 9y 11mo [range 7y 10mo-11y 6mo]), a cohort of children with spastic cerebral palsy (CP) naive to BoNT-A interventions (No-BoNT-A; n=19; 10 males, nine females; median age 9y 3mo [range 8y 5mo-10y 10mo]) and a cohort of children with spastic CP with a minimum of three recurrent BoNT-A interventions to the medial gastrocnemius (BoNT-A; n=19; 13 males, six females; median age 9y 8mo [range 7y 3mo-10y 7mo]) were recruited. Three-dimensional freehand ultrasound was used to estimate medial gastrocnemius volume normalized to body mass and echo-intensity.

RESULTS

Normalized medial gastrocnemius volume and echo-intensity significantly differed between the two spastic CP cohorts (p≤0.05), with the BoNT-A cohort having larger alterations. Associations between normalized medial gastrocnemius volume and echo-intensity were highest in the No-BoNT-A cohort, followed by the BoNT-A cohort. Multiple regression analyses revealed that both GMFCS level and BoNT-A intervention history were significantly associated with smaller normalized medial gastrocnemius volume and higher echo-intensity.

INTERPRETATION

Recurrent BoNT-A interventions may induce alterations to medial gastrocnemius volume and echo-intensity beyond the natural history of the spastic CP pathology.

WHAT THIS PAPER ADDS

In spastic cerebral palsy, medial gastrocnemius volumes are smaller and echo-intensities higher compared with typical development. Alterations after botulinum neurotoxin A intervention (BoNT-A) are larger than in no BoNT-A intervention. Gross Motor Function Classification System level and BoNT-A history significantly associate with medial gastrocnemius and echo-intensity alterations.

Impact of a prison triage system on injuries seen in emergency departments

OBJECTIVES

1) To describe injuries experienced by the male prisoner population in the Kingston, Ontario area, and to compare them with those observed in the general population; and 2) to compare the incidence and patterns of prisoner injuries seen in emergency departments (EDs) before and after the introduction of a prison injury triage system.

DESIGN

A chart review.

SETTING

The catchment area surrounding 2 hospital-based EDs in Kingston, Ontario, which includes 8 federal and provincial prisons for adult males.

OBSERVATIONS

Injuries to male prisoners (ages 18-75 years) who were treated in the ED during 1996-98 were compared with injuries to the general male population of the same age range. An on-site emergency care triage system was introduced to area prisons in 1993. Prisoner injuries seen in the ED during 1996-98 were compared with those seen during a similar period prior to the introduction of the triage system (1981-84). Available comparators included patient demographics, disposition, intent and nature of injury, the need for surgery, and lengths of hospital stay.

RESULTS

148 prisoner injuries were identified for 1996-98. Prisoner injuries seen in the ED were relatively severe when compared with the general male population, as indicated by the higher frequency of fractures (31.8% prisoner vs. 13.4% general, p < 0.001), blunt head injuries (10.1% vs. 2.2%, p < 0.001), hospital admissions (42.6% vs. 4.1%, p < 0.001) and deaths (2.7% vs. 0.6%, p < 0.001). Since the introduction of the triage system there has been a reduction in the rate of prisoner injuries seen in local hospital EDs (6.1/100/yr [before] vs. 1.6/100/yr [after], p < 0.001). There has been an increase in the relative severity of prisoner injuries seen in the EDs as indicated by the increased hospital admission rate (42.6% vs. 22.7%, p < 0.001), increased rate of surgical intervention (27.7% vs. 12.1%, p < 0.001), and increased length of hospital stay (4.0 days vs. 2.1 days, p < 0.05). The mortality rate has remained low and unchanged (0.7% vs. 1.1%, p = 0.99).

CONCLUSIONS

The introduction of the new triage system appeared to be associated with a decrease in the total number of ED visits by prisoners. The relative acuity of prisoner injuries seen in the EDs appeared to increase following introduction of the triage system.