Differential diagnoses of cerebral hemiatrophy in childhood: a review of literature with illustrative report of two cases

Childhood cerebral hemiatrophy is an uncommon clinical entity. Its aetiologies are diverse but can generally be grouped into congenital and acquired. The congenital type is intrauterine in origin while the acquired type occurs early in life, usually before two year of life. When childhood cerebral hemiatrophy occurs, it evokes a spectrum of compensatory calvarial sequlae. These include ipsilateral calvarial thickening, diploe widening, hyper-pneumatization of paranasal sinues/ mastoids, elevation of petrous bone and small middle cranial fossa. MRI is very effective in high lightening brain atrophy, associated parenchymal changes and even the above enumerated skull changes. Our two case reports of left hemi-cerebral atrophy in male Cameroonian children seen in our MRI practice aptly demonstrated some of the aforementioned radiological features of childhood cerebral hemiatrophy noted in literature review.

[Cardiac surgery in Cameroon. Results at one year of the pilot phase]

In the framework of implementation of his national program for control and prevention of cardiovascular diseases, Cameroonian government has set up a cardiac surgery project. We report in this manuscript results of one year follow up of the patients operated during the pilot phase. From September 22 till 26, 2008, 11 patients have been operated in Cameroun. Surgical procedures were 5 mitral mechanic valve replacement, 2 aortic mechanic valve replacement, 1 atrial septal defect closure, 2 pace maker implantation. No intrahospital death was observed. One patient died at 11th month after the operation due to mitral valve thrombosis and attributed to lack of compliance. One patient presented low cardiac output, pneumonia and a pleural effusion. 2 patients presented 2 minor complications consisting of pericarditis and superficial wound infection. The results of the pilot phase of cardiac surgery in Cameroon are effective. However, the sustainability of the program require human, material capacity building, and funding mechanism as well.

Capacity-building in human genetics for developing countries: initiatives and perspectives in sub-Saharan Africa

BACKGROUND

Stakeholders who are committed to bridge the gap in genetics services need to be aware of current initiatives in sub-Saharan Africa.

METHODS

We reviewed selected experiences from African geneticists that led to specific recommendations.

RESULTS

The initiation of prenatal diagnosis of sickle cell anaemia founded the first medical genetic service in Cameroon. There remains a need for international collaborative effort to overcome the lack of human, technical and financial resources around the practice of medical genetics in Africa. The African Society of Human Genetics, Wellcome Trust and NIH have recently proposed a model on how to fully engage Africa in genomics. It includes a 'Health and disease' phase I: use of the case-control design to study genetic and epidemiological determinants of 7 important diseases in Africa, and a 'Genetic variation' phase II: comprehensive documentation of genetic variations in 100 carefully selected ethnic groups across Africa. The strategy would require the development of: (1) clinical phenotyping centres, (2) molecular phenotyping centres, (3) genotyping and sequencing capability, (4) data centres, and (5) a bio-repository in Africa.

CONCLUSIONS

Governments and international health agencies need to recognise that genetics is important to the global medical community. The initiatives of African geneticists need advocacy and encouragement from the international community.

[A new look at adult chronic heart failure in Africa in the age of the Doppler echocardiography: experience of the medicine department at Yaounde General Hospital]

OBJECTIVE

Heart failure is a frequent and severe condition in Africa, yet few African data are available that take into account modern advances like echocardiography in diagnosis. This study aimed to characterize the epidemiological, clinical, etiologic and therapeutic features of heart failure at Yaounde General Hospital.

METHODS

A descriptive study was carried from October 1998 to November 2001. One hundred and sixty-seven patients presenting with clinical and echocardiographic signs of heart failure were included, among which 99 men and 68 women, mean aged 57 years.

RESULTS

Heart failure was the reason for 5,77% of all hospital admissions. Rehospitalisation rate was 8,33%, the prevalence 30% and overall mortality was 9,03%. 44% of patients were in class III of the NYHA and 7% in class IV. Dyspnoea was a constant symptom (95,20%); hepatomegaly was the most frequent physical finding (41,92%). Cardiac cavities were dilated and left ventricular ejection fraction was low in patients with systolic (70%) and combined (20%) dysfunction. Isolated diastolic heart failure accounted for 10% of cases. Main aetiologies were: Hypertension (54,49%), cardiomyopathies (26,34%) and valvular heart diseases (24,55%). Ischaemic heart disease was the fifth aetiology (2,39%). Medical treatment consisted of loop diuretics (90%), angiotensin-converting enzyme inhibitor (64,7%), digoxin (30,5%) and beta blockers (19,8%).

CONCLUSIONS

The clinical syndrome of heart failure constitutes a major public health problem in Cameroon. Echocardiography is of paramount importance in confirming the diagnosis and precising its aetiology. Preventive and public health strategies need to be defined according to the local characteristics.

Variation in in-patient stroke management in ten centres in different countries: the INCLEN multicentre stroke collaboration

BACKGROUND AND PURPOSE

Large within-country variations have been described in stroke management and there have been a few studies of between-country variation (in the USA and the UK). We designed a study to examine stroke management across a wide range of countries representing different stages of economic development. Large variations would suggest the need to explore methods of increasing the uptake of evidence-based stroke practice.

METHODS

Members of the International Clinical Epidemiology Network (INCLEN) from 14 centres in ten countries agreed to review the records of the last 50 patients admitted to hospital with a clinical diagnosis of stroke. Information on demographic variables, the clinical diagnosis of stroke type, investigations performed and treatments given and the discharge destination of the patient were recorded and sent to the coordinating centre in Australia for analysis.

RESULTS

There were statistically significant between-centre differences in the proportions of patients cared for by a neurologist, staying in hospital for at least ten days and having CT or MRI scans. Significant between-centre differences were also seen for treatment, for example, the use of aspirin in non-haemorrhagic stroke varied from 11 to 79%. The variation (for all interventions studied) was no longer statistically significant when examined within strata according to availability of facilities.

CONCLUSIONS

The large variation between centres in the management of stroke is largely 'explained' by the availability of resources, even for interventions that do not depend on resource availability. It will be important to develop management guidelines that reflect evidence-based practice of relevance across a range of economic settings.

The prevalence of hypertension in seven populations of west African origin

OBJECTIVES

This study was undertaken to describe the distribution of blood pressures, hypertension prevalence, and associated risk factors among seven populations of West African origin.

METHODS

The rates of hypertension in West Africa (Nigeria and Cameroon), the Caribbean (Jamaica, St. Lucia, Barbados), and the United States (metropolitan Chicago, Illinois) were compared on the basis of a highly standardized collaborative protocol. After researchers were given central training in survey methods, population-based samples of 800 to 2500 adults over the age of 25 were examined in seven sites, yielding a total sample of 10014.

RESULTS

A consistent gradient of hypertension prevalence was observed, rising from 16% in West Africa to 26% in the Caribbean and 33% in the United States. Mean blood pressures were similar among persons aged 25 to 34, while the increase in hypertension prevalence with age was twice as steep in the United States as in Africa. Environmental factors, most notably obesity and the intake of sodium and potassium, varied consistently with disease prevalence across regions.

CONCLUSION

The findings demonstrate the determining role of social conditions in the evolution of hypertension risk in these populations.

Standardization of blood pressure measurement in an international comparative study

In the context of a collaborative study on the epidemiology of hypertension in populations of West African origin procedures for standardization of the measurement of blood pressure were evaluated. Comparisons of mean levels of blood pressure, which in large part determine prevalence rates, are highly sensitive to differences in technique. While rotating a single field team may be the ideal approach to multisite studies, it is not practical in international collaborative research. Appropriate techniques to standardize multiple teams over a long period of time have not been well developed, however. In the present study 8981 individuals were examined in eight sites in six countries with the standard mercury sphygmomanometer. An evaluation of the effectiveness of central training, site visits, monitoring of digit preference, and the use of an electronic device for internal standardization is described. In all but one of the sites reliability was high and comparable to the observers at the Coordinating Center. Digit preference for the entire set of measurements was limited (frequency of terminal zero = 23.5% for systolic and 28.9% for diastolic readings) and could be shown to have virtually no effect on prevalence rates or correlation estimates. Mean differences among observers within a given site and between sites were small (+/- 0-5 mmHg). While logistically complex, these methods can provide the basis for standardization in international comparative blood pressure surveys.

Circadian rhythm of hypertensives in a Cameroon population: a pilot study

The present study was designed to determine diurnal blood pressure (BP) variations in black hypertensive Africans in Cameroon. Also the study assessed sex differences associated with ambulatory BP measurements in this black population. A total of 69 adult Cameroonians aged 25-55 years, who attended a hypertensive clinic in Yaounde, Cameroon, were recruited on a voluntary basis. The mean ages of the males and females were 48.9 and 45.8 years, respectively. Ambulatory BP monitoring was recorded with Spacelabs ICR Model 5300 ambulatory BP monitoring systems. SBP, DBP and heart rate were measured every 30 min over a 24 h period. There were no significant mean differences observed between males and females on 24 h, daytime or night-time BPs. Among the Cameroonians, 31.7% (20 of 63) of the study population were 'non-dippers'. There were no sex difference for dippers compared with non-dippers. Significant nocturnal declines were noted for SBP, DBP, heart rate and mean arterial pressure. The results of the present study reveal that in this select Cameroonian population, there exists a nocturnal decline in BP.

Distribution of anthropometric variables and the prevalence of obesity in populations of west African origin: the International Collaborative Study on Hypertension in Blacks (ICSHIB)

A survey of the prevalence of hypertension and associated risk factors including obesity was carried out among persons of West African heritage currently living in societies at different stages of social, economic and technological development. We present here the distribution of several anthropometric variables and the prevalence of obesity in these populations. Using a standard protocol with centralized training of field staff, 7,439 men and women aged 24 to 75 from six multinational sites were recruited and examined. Although men were taller, women were more obese across sites. Body mass index (BMI) and consequently the prevalence of overweight and obesity increased with westernization from rural African subsistence farming communities to suburban Chicago. Average BMI increased with age until about age 54, and then began to decline or at least level off. The mean BMI for African-American men and women was 27.1kg/m2 and 30.8kg/m2, respectively. Men displayed high levels of centripetal fatness, measured as the waist-to-hip ratio (WHR), compared to the women across site. Based on the US Department of Agriculture guidelines, 22.6% and 56.9% of the African-American men and women had elevated WHR. Although account must be taken of the important contribution of an individual's genetic background, this multinational study of persons with similar heritage clearly shows the potent impact of current environmental factors on the distribution and level of obesity.