Effects of hypothermia and gender on survival and behavior after perinatal asphyxia in rats

Previous studies in rats have demonstrated that perinatal asphyxia (PA) produces long-term morphological alterations, particularly affecting hippocampus. neostriatum, and cerebral cortex. These changes were prevented by applying hypothermia during the asphyctic insult. Because these cerebral areas are involved in cognitive and motor functions, the aim of the present study was to determine whether periods of PA during normothermia or hypothermia produces long-term behavioral impairments in rats of both sexes. The cognitive and motor functions were studied using the spatial Morris water maze (MWM) task at 1.5 months, and the open field at 5 months, respectively. The present study revealed that female rats had a higher survival rate than males after PA in normothermic conditions (p < 0.014). and that hypothermia drastically prolonged the time of survival in both sexes (p < 0.001). There were no differences in learning and memory functions between groups or male and female rats when tested with MWM. Rats subjected to hypothermia treatment did not show differences in the MWM compared to controls. A lower locomotor activity in the open field test was only observed in male rats that suffered 15 and 20 min of PA in normothermia (p < 0.05). Hypothermia treatment prevented this hypoactivity. PA in females, even if severe, did not affect the motor activity. The data of both behavioral tests showed differences between sexes, i.e., the female rats learned the MWM task slower, and were more active in the open field. This work lends further support for the hypothesis that hypothermia can prevent mortality as well as long-term sequelae induced by PA.     

Anatomical Mapping of the External Obturator Footprint: A Study In Cadavers with Implications for Direct Anterior THA

BackgroundThe external obturator footprint in the trochanteric fossa has been suggested as a potential landmark for stem depth in direct anterior THA. Its upper border can be visualized during surgical exposure of the femur. A recent study reported that the height of the tendon has little variability (6.4 ± 1.4 mm) as measured on CT scans and that the trochanteric fossa is consistently visible on conventional pelvic radiographs. However, it is unclear where exactly the footprint of this tendon should be templated during preoperative planning so that it can be useful intraoperatively.Questions/purposesIn this study, we sought: (1) to provide instructions on exactly where to template the external obturator footprint on a preoperative planning radiograph, and (2) to confirm the small variability in height of the external obturator footprint found on CT scans in a cadaver study.MethodsTwo-dimensional (2-D) and three-dimensional (3-D) imaging was used to map the anatomy of the external obturator footprint. This dual approach was chosen because of their complementarity; conventional 2-D radiographs translate to clinical practice but 3-D navigation-based digitalization combined with CT allows for a better understanding of the cortical lines that comprise the outline of the trochanteric fossa. In 12 (four males, mean age 80 years, range 69 to 88) formalin-treated cadaveric lower extremities including the pelvis, the external obturator tendon was dissected, and the top and bottom end of its footprint marked with two small needles, and calibrated radiographs were taken. For another five (three males, mean age 75.7 years, range 61 to 91) fresh-frozen cadaveric lower extremities, including femoral reflective marker frames, CT scans were obtained and the exact location of the external obturator footprint was recorded using 3-D navigation-based digitalization. Qualitative analysis of both imaging modalities was used to develop instructions on where the external obturator footprint should be templated on a preoperative planning radiograph. Quantitative analysis of the dimensions of the external obturator footprint was performed.ResultsThe lowest point of the external obturator footprint was consistently found (± 1 mm) at the intersection of the vertical line comprised of the lateral wall of the trochanteric fossa and the oblique line formed by the intertrochanteric crest and therefore allows templating of this structure on the preoperative planning radiograph. The median (range) height of the footprint measured 6.4 mm and demonstrated small variability (4.7 to 7.6).ConclusionsWe suggest templating a 6.4-mm circle with its bottom on the intersection described above.Clinical RelevanceThe distance between the templated shoulder of the stem and the top of the circle can be used intraoperatively for guidance. Discrepancy should lead to re-evaluation of stem depth and leg length. Future work will investigate the usability, validity, and reliability of the proposed methodology in daily clinical practice.     

Botulinum toxin A and upper limb functional skills in hemiparetic cerebral palsy: a randomized trial in children receiving intensive therapy

The objective of this study was to determine whether the use of intramuscular botulinum toxin A (BTX-A) increases upper limb function and skills in the context of a specific therapy programme in children with hemiparetic cerebral palsy. Twenty children (nine females, 11 males) aged 4 to 16 years who were thought likely to benefit from BTX-A treatment were included. After matched pairs were made, on the basis of Zancolli grade and age, randomization took place. All patients were given structured rehabilitation (physiotherapy and occupational therapy three times a week for 6 months), and half of the patients received intramuscular BTX-A. No placebo injections were given in the control group. Participants were assessed at baseline, at 2 and 6 weeks, and at 3, 6, and 9 months after injection. The Ashworth scale, active range of motion of arm joints, the Melbourne assessment of upper limb function, the Pediatric Evaluation of Disability Inventory, and the nine-hole peg test were used for outcome measurement. Observers were blinded for treatment allocation only for scoring the Melbourne test. The children in the treatment group showed a clinically relevant increase in active dorsal flexion, and tone reduction of the wrist. For the functional outcome measures, no statistically significant differences between the groups could be demonstrated. Intramuscular BTX-A added to an intensive therapy programme reduces impairment for at least 9 months; the effect on activity level is still uncertain.     

Pre-hospital trauma care: a proposal for more efficient evaluation

Although mortality is an important outcome parameter for pre-hospital trauma care, it is influenced by many factors other than pre-hospital trauma care alone. We therefore studied an alternative method to evaluate pre-hospital trauma care by calculating the change in probability of survival (Ps) according to the TRISS methodology, before and directly after the pre-hospital trauma care. Correlations between patient characteristics and a change in Ps were assessed. Further, required sample sizes were calculated for an 80% power to detect a hypothetical 3% reduction in mortality and the corresponding change in Ps. In 140 of 191 patients with an Injury Severity Score > or =16, the Ps did not change. In 36, the Ps increased and in 15 patients, the Ps decreased. Between these three groups, significant differences were found in Revised Trauma Score and age, but no clear differences in Injury Severity Score or mortality. A 3% difference in mortality would require 6800 patients, in contrast to 3500 when the change in Ps was the primary outcome parameter. A change in Ps is a promising outcome parameter for a more efficient evaluation of pre-hospital trauma care. A good collaboration is, however, required between ambulance services and the trauma center for reliable registration.     

Intracranial pressure and cerebral blood flow velocity in preterm infants with posthaemorrhagic ventricular dilatation

AIM: To determine the volume of cerebrospinal fluid (CSF) that should be tapped in preterm infants with posthaemorrhagic ventricular dilatation as guided by intracranial pressure (ICP) and cerebral blood flow velocity (CBFV). METHODS: The total number of measurements was 106 in 22 infants. Birth weights ranged from 630 to 2050 g, gestational age from 24.5 to 30.3 weeks, and age at insertion from 12 to 67 days. A subcutaneous ventricular catheter reservoir for repetitive CSF drainage was placed when the diameter of a ventricle was > 4 mm above the 97th centile. A volume of 5 ml/kg body weight was removed twice daily. ICP and CBFV were determined before and after CSF tapping. RESULTS: If the ICP after tapping exceeded 7 cm H(2)O, tapping did not result in a significant improvement in CBFV. If the ICP before tapping was less than 6 cm H(2)O, tapping also had no effect on CBFV. Longitudinal studies in individual infants showed a slight correlation between ICP and CBFV. CONCLUSION: Volume of repetitive CSF drainage in preterm infants with posthaemorrhagic ventricular dilatation guided by ICP and CBFV may be a useful technique. An ICP of about 6 cm H(2)O is the cut off point for CSF drainage.