Surgical treatment of upper, middle and lower cervical injuries and non-unions by anterior procedures

The goals of any treatment of cervical spine injuries are: return to maximum functional ability, minimum of residual pain, decrease of any neurological deficit, minimum of residual deformity and prevention of further disability. The advantages of surgical treatment are the ability to reach optimal reduction, immediate stability, direct decompression of the cord and the exiting roots, the need for only minimum external fixation, the possibility for early mobilisation and clearly decreased nursing problems. There are some reasons why those goals can be reached better by anterior surgery. Usually the bony compression of the cord and roots comes from the front therefore anterior decompression is usually the procedure of choice. Also, the anterior stabilisation with a plate is usually simpler than a posterior instrumentation. It needs to be stressed that closed reduction by traction can align the fractured spine and indirectly decompress the neural structures in about 70%. The necessary weight is 2.5 kg per level of injury. In the upper cervical spine, the odontoid fracture type 2 is an indication for anterior surgery by direct screw fixation. Joint C1/C2 dislocations or fractures or certain odontoid fractures can be treated with a fusion of the C1/C2 joint by anterior transarticular screw fixation. In the lower and middle cervical spine, anterior plating combined with iliac crest or fibular strut graft is the procedure of choice, however, a solid graft can also be replaced by filled solid or expandable vertebral cages. The complication of this surgery is low, when properly executed and anterior surgery may only be contra-indicated in case of a significant lesion or locked joints.

Immunodeficiency at the start of combination antiretroviral therapy in low-, middle-, and high-income countries

OBJECTIVE To describe the CD4 cell count at the start of combination antiretroviral therapy (cART) in low-income (LIC), lower middle-income (LMIC), upper middle-income (UMIC), and high-income (HIC) countries. METHODS Patients aged 16 years or older starting cART in a clinic participating in a multicohort collaboration spanning 6 continents (International epidemiological Databases to Evaluate AIDS and ART Cohort Collaboration) were eligible. Multilevel linear regression models were adjusted for age, gender, and calendar year; missing CD4 counts were imputed. RESULTS In total, 379,865 patients from 9 LIC, 4 LMIC, 4 UMIC, and 6 HIC were included. In LIC, the median CD4 cell count at cART initiation increased by 83% from 80 to 145 cells/μL between 2002 and 2009. Corresponding increases in LMIC, UMIC, and HIC were from 87 to 155 cells/μL (76% increase), 88 to 135 cells/μL (53%), and 209 to 274 cells/μL (31%). In 2009, compared with LIC, median counts were 13 cells/μL [95% confidence interval (CI): -56 to +30] lower in LMIC, 22 cells/μL (-62 to +18) lower in UMIC, and 112 cells/μL (+75 to +149) higher in HIC. They were 23 cells/μL (95% CI: +18 to +28 cells/μL) higher in women than men. Median counts were 88 cells/μL (95% CI: +35 to +141 cells/μL) higher in countries with an estimated national cART coverage >80%, compared with countries with <40% coverage. CONCLUSIONS Median CD4 cell counts at the start of cART increased 2000-2009 but remained below 200 cells/μL in LIC and MIC and below 300 cells/μL in HIC. Earlier start of cART will require substantial efforts and resources globally.

Immunodeficiency in children starting antiretroviral therapy in low-, middle-, and high-income countries.

BACKGROUND The CD4 cell count or percent (CD4%) at the start of combination antiretroviral therapy (cART) is an important prognostic factor in children starting therapy and an important indicator of program performance. We describe trends and determinants of CD4 measures at cART initiation in children from low-, middle-, and high-income countries. METHODS We included children aged <16 years from clinics participating in a collaborative study spanning sub-Saharan Africa, Asia, Latin America, and the United States. Missing CD4 values at cART start were estimated through multiple imputation. Severe immunodeficiency was defined according to World Health Organization criteria. Analyses used generalized additive mixed models adjusted for age, country, and calendar year. RESULTS A total of 34,706 children from 9 low-income, 6 lower middle-income, 4 upper middle-income countries, and 1 high-income country (United States) were included; 20,624 children (59%) had severe immunodeficiency. In low-income countries, the estimated prevalence of children starting cART with severe immunodeficiency declined from 76% in 2004 to 63% in 2010. Corresponding figures for lower middle-income countries were from 77% to 66% and for upper middle-income countries from 75% to 58%. In the United States, the percentage decreased from 42% to 19% during the period 1996 to 2006. In low- and middle-income countries, infants and children aged 12-15 years had the highest prevalence of severe immunodeficiency at cART initiation. CONCLUSIONS Despite progress in most low- and middle-income countries, many children continue to start cART with severe immunodeficiency. Early diagnosis and treatment of HIV-infected children to prevent morbidity and mortality associated with immunodeficiency must remain a global public health priority.

Effect of acute hypoxia on maximal oxygen uptake and maximal performance during leg and upper-body exercise in Nordic combined skiers

We examined the effect of normobaric hypoxia (3200 m) on maximal oxygen uptake (VO2max) and maximal power output (Pmax) during leg and upper-body exercise to identify functional and structural correlates of the variability in the decrement of VO2max (DeltaVO2max) and of maximal power output (DeltaPmax). Seven well trained male Nordic combined skiers performed incremental exercise tests to exhaustion on a cycle ergometer (leg exercise) and on a custom built doublepoling ergometer for cross-country skiing (upper-body exercise). Tests were carried out in normoxia (560 m) and normobaric hypoxia (3200 m); biopsies were taken from m. deltoideus. DeltaVO2max was not significantly different between leg (-9.1+/-4.9%) and upper-body exercise (-7.9+/-5.8%). By contrast, Pmax was significantly more reduced during leg exercise (-17.3+/-3.3%) than during upper-body exercise (-9.6+/-6.4%, p<0.05). Correlation analysis did not reveal any significant relationship between leg and upper-body exercise neither for DeltaVO2max nor for DeltaPmax. Furthermore, no relationship was observed between individual DeltaVO2max and DeltaPmax. Analysis of structural data of m. deltoideus revealed a significant correlation between capillary density and DeltaPmax (R=-0.80, p=0.03), as well as between volume density of mitochondria and DeltaPmax (R=-0.75, p=0.05). In conclusion, it seems that VO2max and Pmax are differently affected by hypoxia. The ability to tolerate hypoxia is a characteristic of the individual depending in part on the exercise mode. We present evidence that athletes with a high capillarity and a high muscular oxidative capacity are more sensitive to hypoxia.

Snoring in preschool children: prevalence, severity and risk factors

Epidemiological data on snoring from preschool children are scarce, although habitual snoring (snoring on almost all nights) has been associated with poor long-term outcomes. In a population survey of 6,811 children aged 1-4 yrs (from Leicestershire, UK) the present authors determined prevalence, severity and risk factors for snoring, especially habitual snoring. In 59.7% of the children, parents reported snoring in the previous 12 months, including 7.9% with habitual snoring and 0.9% with habitual snoring and sleep disturbance. Prevalence of habitual snoring increased with age from 6.6% in 1-yr-olds to 13.0% in 4-yr-olds. Habitual snoring was associated with: one and both parents smoking (adjusted odds ratio (OR) 1.46 and 2.09, respectively); road traffic (OR 1.23); single parent (OR 1.60); and in White but not South Asian children, socioeconomic deprivation (OR 1.25 and 2.03 for middle and upper thirds of Townsend score, respectively). Respiratory tract symptoms related to atopic disorders and to respiratory infections were strongly associated with snoring; however, body mass index was not. In conclusion, habitual snoring is common in preschool children with one-third of cases attributable to avoidable risk factors. The strong association with atopic disorders, viral infections and environmental exposures suggests a complex aetiology, based on a general vulnerability of the respiratory tract.

Changes in blood flow velocity in the middle and anterior cerebral arteries evoked by walking

PURPOSE: Transcranial Doppler sonography (TCD) is an established method for assessing changes in blood flow velocity (BFV) coupled to brain activity. Our objective was to investigate whether walking induces measurable changes in BFV in healthy subjects. METHODS: Changes in BFV in both middle cerebral arteries (MCAs) of 40 healthy adult subjects during walking on a treadmill were measured using bilateral TCD. In 8 of the 40 subjects, 1 anterior cerebral artery (ACA) was monitored simultaneously with the contralateral MCA. The percentage increase in BFV (BFVI%) compared with the baseline velocity (V(0)), the percentage decrease in BFV (BFVD%) compared with the V(0), and the normalized ACA-MCA ratio were analyzed. RESULTS: The overall mean (+/- standard deviation [SD]) V(0) was 59.9 +/- 11.6 cm/second in the left MCA and 60.1 +/- 12.9 cm/second in the right MCA. Women had higher V(0) values than men had. Walking evoked an initial mean overall BFVI% in both left (8.4 +/- 5.1%) and right MCAs (9.1 +/- 5.1%), followed by a decrease to below baseline values in 38 of 40 subjects. A statistically significant increase of the normalized ACA-MCA ratio was measured, indicating that changes in BFV in the ACA territory were coupled to brain activation during walking. CONCLUSIONS: The use of functional TCD showed different changes in BFV in the ACAs and MCAs during walking. This method may be an interesting tool for monitoring progress in patients with motor deficits of the legs, such as paresis.

Middle and Late Pleistocene humid periods recorded in palaeolake deposits of the Nafud desert, Saudi Arabia

Present climate in the Nafud desert of northern Saudi Arabia is hyper-arid and moisture brought by north-westerly winds scarcely reaches the region. The existence of abundant palaeolake sediments provides evidence for a considerably wetter climate in the past. However, the existing chronological framework of these deposits is solely based on radiocarbon dating of questionable reliability, due to potential post-depositional contamination with younger 14C. By using luminescence dating, we show that the lake deposits were not formed between 40 and 20 ka as suggested previously, but approximately ca 410 ka, 320 ka, 200 ka, 125 ka, and 100 ka ago. All of these humid phases are in good agreement with those recorded in lake sediments and speleothems from southern Arabia. Surprisingly, no Holocene lake deposits were identified. Geological characteristics of the deposits and diatom analysis suggest that a single, perennial lake covered the entire south-western Nafud ca 320 ka ago. In contrast, lakes of the 200 ka, 125 ka, and 100 ka humid intervals were smaller and restricted to interdune depressions of a pre-existing dune relief. The concurrent occurrence of humid phases in the Nafud, southern Arabia and the eastern Mediterranean suggests that moisture in northern Arabia originated either from the Mediterranean due to more frequent frontal depression systems or from stronger Indian monsoon circulation, respectively. However, based on previously published climate model simulations and palaecolimate evidence from central Arabia and the Negev desert, we argue that humid climate conditions in the Nafud were probably caused by a stronger African monsoon and a distinct change in zonal atmospheric circulation.

Stratospheric age of air variations between 1600 and 2100

The current understanding of preindustrial stratospheric age of air (AoA), its variability, and the potential natural forcing imprint on AoA is very limited. Here we assess the influence of natural and anthropogenic forcings on AoA using ensemble simulations for the period 1600 to 2100 and sensitivity simulations for different forcings. The results show that from 1900 to 2100, CO₂ and ozone-depleting substances are the dominant drivers of AoA variability. With respect to natural forcings, volcanic eruptions cause the largest AoA variations on time scales of several years, reducing the age in the middle and upper stratosphere and increasing the age below. The effect of the solar forcing on AoA is small and dominated by multidecadal total solar irradiance variations, which correlate negatively with AoA. Additionally, a very weak positive relationship driven by ultraviolett variations is found, which is dominant for the 11 year cycle of solar variability.

A 3-year survey of assault-related maxillofacial fractures in central Switzerland

AIM: The aim of this study was to analyse the character of assault-related facial fractures in central Switzerland and to compare their prevalence with the data presented in similar reports from other countries. MATERIAL: The present study comprised 65 patients with assault-related maxillofacial fractures treated in the Department of Cranio-Maxillofacial Surgery, University Hospital of Bern between 2000 and 2002. METHODS: The mechanism, the causes of the injuries and the location of the fractures were analysed by reviewing emergency and hospital records. Concomitant injuries were also studied. RESULTS: The mean age of the patients was 33 years with the largest group being below 25 years. The male-to-female ratio was 56:9. The most common causes of assault-related injuries were fights, most frequently facial blows, accounting for 92.5% of all patients. Seventy-six per cent of the fractures occurred in the middle and upper facial skeleton with a predominance of 2:1 for the left side. In 39 patients (60%) surgery was necessary, with a mean hospital stay of 3.3 days. Thirty-five patients (54%) had concomitant injuries. Alcohol and drug abuse was found in 15 patients (23%). CONCLUSION: It seems that mostly young men suffer assault-related maxillofacial injuries. A contributing factor to the increased disposition for violence could be alcohol and drug abuse. Therefore, national prevention programmes for alcohol or drug abuse and addiction might have a positive effect on reducing the incidence of assault-related maxillofacial injuries.