Antenatal and Perioperative Mechanisms of Global Neurological Injury in Congenital Heart Disease.

Congenital heart defects (CHD) is one of the most common types of birth defects. Thanks to advances in surgical techniques and intensive care, the majority of children with severe forms of CHD survive into adulthood. However, this increase in survival comes with a cost. CHD survivors have neurological functioning at the bottom of the normal range. A large spectrum of central nervous system dysmaturation leads to the deficits seen in critical CHD. The heart develops early during gestation, and CHD has a profound effect on fetal brain development for the remainder of gestation. Term infants with critical CHD are born with an immature brain, which is highly susceptible to hypoxic-ischemic injuries. Perioperative blood flow disturbances due to the CHD and the use of cardiopulmonary bypass or circulatory arrest during surgery cause additional neurological injuries. Innate patient factors, such as genetic syndromes and preterm birth, and postoperative complications play a larger role in neurological injury than perioperative factors. Strategies to reduce the disability burden in critical CHD survivors are urgently needed.

Fetal asphyctic preconditioning protects against perinatal asphyxia-induced behavioral consequences in adulthood.

Perinatal asphyxia is one of the major causes of neuronal injury and impaired development in infants. We recently have shown that a brief episode of experimental fetal asphyxia (FA) can provoke an endogenous neuroprotection against subsequent severe perinatal asphyxia (SPA). The long-lasting functional consequences of FA preconditioning are not clear yet. The aim of the study was to determine if FA preconditioning can provide a long-lasting behavioral protection against SPA. FA was induced, as a preconditioning stimulus, by clamping the uterine vasculature for 30 min on E17. At birth, SPA was induced by placing the uterine horns in a water bath for 19 min. At 6 months of age, functional outcome was assessed using different behavioral tests: the open field for locomotor activity, the elevated zero maze for anxiety-related behavior, the forced swim test for depression-related behavior and the object recognition task for cognition. Data showed that FA preconditioning improved postnatal mortality after SPA. At the age of 6 months, the total distance moved in the open field and elevated zero maze was significantly less in the SPA group compared to the control groups. In addition, cognitive performance in the object recognition task was impaired in the SPA offspring compared to the control groups. Most importantly, FA preconditioning was able to preserve both locomotor activity and cognition function. In conclusion, FA preconditioning induces a long-lasting, functional protection against SPA. Therefore, this model seems to offer good opportunities for the identification and characterization of the underlying mechanisms of preconditioning.

Kinematic aiming task: measuring functional changes in hand and arm movements after botulinum toxin-A injections in children with spastic hemiplegia.

OBJECTIVE: To describe different aspects of a kinematic aiming task (KAT) as a quantitative way to assess changes in arm movements within 2 wks after botulinum toxin-A (BTX-A) injections in children with spastic hemiplegia. DESIGN: Intervention study randomized clinical trial; follow-up within 4 wks after baseline measurement. RESULTS: The KAT gave a high intraclass correlation on movement time, spread of end points (END), and index of performance effective (IP-E). After BTX-A, a significant increase of END and IP-E was shown if precision demand in the KAT was high, whereas the inverse occurred when speed was more important. These functional changes coincided with a significant decrease of the maximum voluntary contraction of the flexor muscles of the forearm. Muscle tone measured with the Ashworth scale did show a nonsignificant decrease of muscle tone, as did the stretch restricted angle and the active and passive ranges of motion of the elbow and wrist. CONCLUSIONS: Muscle force decreased immediately after BTX-A, showing the direct effect of BTX-A. The KAT is an adequate, reproducible way to quantify functional changes after BTX-A in the upper limb. BTX-A has an inverse effect in the precision task when accuracy is important, and it has a positive effect when speed prevails.