Alzheimer CSF biomarkers in routine clinical setting

OBJECTIVES

Our work was aimed to evaluate Alzheimer's disease diagnosis improvement using cerebrospinal fluid biomarkers (CSF) in neurological daily practice.

MATERIALS AND METHODS

For this purpose, 150 patients clinically and neurochemically classified as having AD or cognitive impairment with or without other dementia type were included in the study. The following CSF peptides were studied, blindly to the clinical diagnosis: beta-amyloid(1-42) peptide (Aβ(1-42)), Tau (T-tau), threonine-181 hyperphosphorylated tau protein (P-tau(181)), and beta-amyloid(1-40) peptide (Aβ(1-40)). From these measurements, Innotest® Amyloid Tau Index (IATI) was calculated for each patient.

RESULTS

This assessment allowed to separate 83 biochemical profiles of AD and 67 non-Alzheimer's disease (non-AD), both AD and non-AD categories match with clinical data amounting to 73% and 90%, respectively. Among mild cognitive impairment (MCI) patients, CSF biomarkers led to discriminate those who are likely to be AD. We devoted a special section to Aβ(1-40) which is not a routine parameter but can help to confirm a pathological amyloid process as Aβ(1-42)/Aβ(1-40) ratio underlining the real decline of the Aβ(1-42).

CONCLUSIONS

The interest of biomarkers and their ability to solve awkward cases were carefully noticed all the more when a discrepancy between clinical and CSF biological data was involved. The final proposed algorithm allowed to identify pathogenic forms of AD according to the prevailing role of hyperphosphorylated tau or amyloid beta peptide.

Epilepsy in onchocerciasis endemic areas: systematic review and meta-analysis of population-based surveys

Objective

We sought to evaluate the relationship between onchocerciasis prevalence and that of epilepsy using available data collected at community level.

Design

We conducted a systematic review and meta-regression of available data.

Data Sources

Electronic and paper records on subject area ever produced up to February 2008.

Review Methods

We searched for population-based studies reporting on the prevalence of epilepsy in communities for which onchocerciasis prevalence was available or could be estimated. Two authors independently assessed eligibility and study quality and extracted data. The estimation of point prevalence of onchocerciasis was standardized across studies using appropriate correction factors. Variation in epilepsy prevalence was then analyzed as a function of onchocerciasis endemicity using random-effect logistic models.

Results

Eight studies from west (Benin and Nigeria), central (Cameroon and Central African Republic) and east Africa (Uganda, Tanzania and Burundi) met the criteria for inclusion and analysis. Ninety-one communities with a total population of 79,270 individuals screened for epilepsy were included in the analysis. The prevalence of epilepsy ranged from 0 to 8.7% whereas that of onchocerciasis ranged from 5.2 to 100%. Variation in epilepsy prevalence was consistent with a logistic function of onchocerciasis prevalence, with epilepsy prevalence being increased, on average, by 0.4% for each 10% increase in onchocerciasis prevalence.

Conclusion

These results give further evidence that onchocerciasis is associated with epilepsy and that the disease burden of onchocerciasis might have to be re-estimated by taking into account this relationship.

Epilepsy is particularly common in tropical areas. One main reason is that many endemic infections have neurological consequences. In addition, the medical, social and demographic burden of epilepsy remains substantial in these countries where it is often seen as a contagious condition and where the aetiology is often undetermined. For several decades, field researchers had reported some overlapping between the geographical distributions of epilepsy and onchocerciasis, a parasitic disease caused by the filarial worm Onchocerca volvulus which afflicts some 40 million persons worldwide. Here, we conducted a statistical analysis of all the data available on the relationship between the two conditions to determine whether the proportion of people suffering from epilepsy in a community could be related to the frequency of onchocerciasis. The combined results of the eight studies carried out in west, central and east Africa indicate a close epidemiological association between the two diseases. Should a causative relationship be demonstrated, onchocerciasis, which is known as “river blindness” because of its most serious sequela and the distribution of its vectors, could thus also be called “river epilepsy”. More research is needed to determine the mechanisms explaining this association and to assess the burden of onchocerciasis-associated epilepsy.

Silent, or masked, giant cell arteritis is associated with a strong inflammatory response and a benign short term course

OBJECTIVE

To determine the frequency, characteristics, and short term outcome of patients who have biopsy-proven giant cell arteritis (GCA) but no local symptoms that can be attributed to vasculitis inflammation [silent temporal arteritis (TA)] throughout the pretreatment course of the disease or an observational period lasting at least 2 months.

METHODS

Of 175 consecutive patients with biopsy-proven GCA, 130 had typical cranial arteritis, 21 had silent vasculitis, and the remaining 24 had either discrete cranial symptoms (19 cases) or isolated extracranial vasculitis (5 cases). We sought to determine which of 15 pretreatment characteristics were associated with silent TA, as compared with typical cranial arteritis, and assessed the short term outcome in these patients.

RESULTS

Of 21 patients with silent GCA, 14 met criteria for fever of unknown origin. Aside from their different clinical presentation, this population was characterized by a longer delay in diagnosis (p = 0.003), a higher mean erythrocyte sedimentation rate (p = 0.002), higher C-reactive protein (p = 0.002), and lower levels of albumin (p = 0.01) and hemoglobin (p < 0.0001). Permanent visual loss, which occurred in 24 patients (13.7%), exclusively involved those presenting with symptoms and/or signs suggesting cranial arteritis, especially those with frank cranial arteritis. This complication was associated negatively with the delay in diagnosis (p = 0.01), and marginally with the number of symptoms and/or signs suggesting cranial arteritis recorded in each patient (p = 0.07). Oral prednisone at a mean daily dose of 0.7 mg/kg resulted in satisfactory control of silent TA within 4 weeks in all patients but one, and could subsequently be safely tapered by half in a mean delay of 38 +/- 23 days. No differences were observed between patients with silent TA and other forms of the disease regarding the mean prednisone dose at 3 month followup (18.2 +/- 4.5 vs 20.9 +/- 5.9 mg/day) and 6 month followup (14 +/- 4.4 vs 15.6 +/- 6 mg/day ).

CONCLUSION

Silent TA may represent a distinct subset of giant cell arteritis, marked by a protracted inflammatory response and a relatively benign short term outcome, excellent response to corticosteroids, and no visual ischemic events, despite the long period of exposure to this complication before appropriate treatment.

[Quality of medical records in the "Medical Information System Program": application of the lot quality assurance sampling method]

BACKGROUND

The aim of this study was to validate a new method of quality control of medical records of the "Medicalisation of Information System Program" (P.M.S.I.) in Limoges university hospital.

METHODS

Lot quality assurance sampling (L.Q.A.S.), developed to meet industrial quality control needs, has been applied. This method allows to give an opinion on the quality of a lot from a sample randomised in this lot. Ten hospital units have been randomised. During three months, these medical units have recoded ten medical units abstracts (R.U.M.) which were randomised each month within their stays. If five or more R.U.M. had been modified on Principal Diagnosis (D.P.), Associated Significant Diagnosis (D.A.S.) or Diagnosis Related Group (D.R.G.), the lot was rejected. The hospital unit had then less 70% R.U.M. of good quality (alpha=5%). The global errors rates were compared to the results of usually performed quality control (1998).

RESULTS

Nine hospital units were included. Hospital units which already had a low quality rate during the 1998 quality control had also an insufficient quality by L.Q.A.S. method. Among these, 33.7 [CI(95%): 21.6-45.8] R.U.M. have been modified. Medical units had a poorer data quality than surgical ones. No statistically significant difference was shown between 1998 errors rates and L.Q.A.S. rates, except for D.P. (p=0.002).

CONCLUSION

L.Q.A.S. is easy to apply, could be repeated more frequently than usual controls, and allows to detect hospital units which require a faster action. This process could be applied to P.M.S.I., in which the search of quality is necessary because of the new cost model which includes secondary D.R.G.

Interest of LQAS method in a survey of HTLV-I infection in Benin (West Africa)

HTLV-I is heterogeneously distributed in Sub-Saharan Africa. Traditional survey methods as cluster sampling could provide information for a country or region of interest. However, they cannot identify small areas with higher prevalences of infection to help in the health policy planning. Identification of such areas could be done by a Lot Quality Assurance Sampling (LQAS) method, which is currently used in industry to identify a poor performance in assembly lines. The LQAS method was used in Atacora (Northern Benin) between March and May 1998 to identify areas with a HTLV-I seroprevalence higher than 4%. Sixty-five subjects were randomly selected in each of 36 communes (lots) of this department. Lots were classified as unacceptable when the sample contained at least one positive subject. The LQAS method identified 25 (69.4 %) communes with a prevalence higher than 4%. Using stratified sampling theory, the overall HTLV-I seroprevalence was 4.5% (95% CI: 3.6-5.4%). These data show the interest of LQAS method application under field conditions to detect clusters of infection.

Parkinson's disease and environmental factors. Matched case-control study in the Limousin region, France

The study included 140 patients with Parkinson's disease (PD) and 280 non-Parkinson age-matched controls to evaluate environmental risk factors associated with PD. The effect of exposure to environmental and dietary factors was determined using conditional logistic regression. This multivariate analysis showed that PD in first-degree relatives and tea drinking were the main risk factors for PD. Smoking appeared to be a protective factor. Exposure to toxic compounds was not a significant risk factor. Further research is needed to validate that tea consumption increases the risk of PD.

Estimation of the amyotrophic lateral sclerosis incidence by capture-recapture method in the Limousin region of France

Amyotrophic lateral sclerosis (ALS) is a rapidly fatal degenerative neurological disease categorized among motor neuron diseases. In the literature, the incidence of ALS varies between 0.7 and 2.4 per 100, 000 inhabitants. A study using the capture-recapture method (multiple records system analysis) was undertaken in Limousin (France) ascertaining all patients having onset of definite or probable ALS during the period 1994-1995. Three information sources able to identify these new ALS cases were selected: the first source was a computerized database of the Neurology Department of the University Hospital of Limoges; the second source consisted of the neurologists of the Limousin region and neighboring provinces (county-sized regions); the third source grouped the hospitals of the Limousin region and neighboring provinces (county-sized regions). During this period, 46 new cases of ALS were seen, corresponding to an observed mean annual incidence of 3.2 (+/-0.6) per 100,000 inhabitants. After standardization for age, the annual incidence was 2.5 per 100,000 inhabitants. The number of new cases estimated by the capture-recapture method was 70, corresponding to an estimated mean annual incidence of 4.9 (+/-1.0) for 100,000 inhabitants. Hence, statistical modeling utilizing partially overlapping information sources permitted a more exhaustive compendium of the new cases of ALS and may be a truer reflection of actual disease incidence than has been previously reported.

Estimation of the prevalence of epilepsy in the Benin region of Zinvié using the capture-recapture method

BACKGROUND

The prevalence of epilepsy was estimated in two villages of 3134 inhabitants, in Benin, in April and May 1997 using the capture-recapture method.

METHODS

Information was obtained from (i) a door-to-door cross-sectional study, (ii) a non-medical source consisting of key informants (traditional practitioners, teachers, village leaders, and religious representatives) and (iii) a medical source through evaluation of medical records in health centres. In all the three situations, the diagnosis of epilepsy was confirmed by a neurologist.

RESULTS

The door-to-door survey found 50 epileptics, i.e. a prevalence of 15.9 per 1000. The non-medical source found 26 patients. The medical source found only four patients. In total, 66 epileptics were found by combining the three sources, giving a prevalence of 21.1 per 1000. After application of the capture-recapture method, the estimated number of cases from the door-to-door survey and non-medical source was 105, and 110 cases when the medical source was considered as well. The respective prevalences were 33.5 per 1000, and 35.1 per 1000.

CONCLUSIONS

The door-to-door survey has been usefully improved by using key informants. The epilepsy prevalence estimate found by capture-recapture is clearly higher than that found by traditional cross-sectional methods, and could better depict the frequency of epilepsy in Africa.

[Postoperative incisional hernias: intra- or extraperitoneal prosthesis implantation?]

STUDY AIM

The aim of this retrospective study concerning the repair of postoperative incisional hernia using Dacron mesh was to compare results according to the extra- or intraperitoneal mesh position in order to assess the respective indications of each option.

MATERIALS AND METHODS

From January 1985 to December 1996, 172 patients (mean age: 61.3 years) were operated on using Dacron mesh extraperitoneally (n = 99) or intraperitoneally located (n = 73). For statistical analysis, both groups were compared using Chi square test or Fisher's test.

RESULTS

There were no postoperative deaths in the group with extraperitoneal mesh and two postoperative deaths in the group with intraperitoneal mesh. There were no significant differences when results comparing parietal complications (sepsis: 2% vs 2.7%, pain: 9.1% vs 16.9%), secondary intestinal disorders (2% vs 4.2%) and recurrence rate (4% vs 5.6%) were assessed between extraperitoneal and intraperitoneal mesh. Recurrences were related to pareital infection treated by partial removal of the mesh (n = 2) or to the lateral detachment of the mesh (n = 6).

CONCLUSIONS

In the group of patients receiving extraperitoneal mesh there were no postoperative deaths and morbidity was low (this technique is generally used in the treatment of large incisional hernia). In the group of patients receiving intraperitoneal mesh, similar parietal and general complications were observed. But the risk of serious complications and postoperative death is higher; this technique must be limited to the most serious incisional hernia and to high risk patients.

Intrafamilial clustering and 4-year follow-up of asymptomatic human T-cell leukaemia virus type I (HTLV-I) infection in Benin (West Africa)

BACKGROUND

Few data exist concerning familial human T-cell leukaemia virus type I (HTLV-I) carrier states and transmission in African countries. Two previous surveys performed in Benin in 1989 and 1990 using a three-level cluster sampling method allowed us to identify HTLV-I positive subjects. The evolution of HTLV-I within the families of these subjects is described over a 4-year period, 1991-1995.

METHODS

Since 1991, 37 HTLV-I seropositive subjects, six subjects with indeterminate Western-Blot pattern, and their relatives have been followed up once a year clinically and biologically.

RESULTS

Twenty-three mothers in the study group gave birth to 27 children between 1991 and 1995. Among the 13 infants born to the 12 seropositive mothers, two seroconverted before their second birthday. One adult woman whose husband was seropositive developed seropositivity 4 years after marriage. In March 1992, a family case-control study (proband study) was conducted. A seroprevalence of 27.5% was found among 138 relatives of 32 infected subjects and 1.4% among 142 relatives of 32 control subjects.

CONCLUSIONS

There is clearly an intrafamilial clustering of HTLV-I in Benin. The annual incidence density of HTLV-I in this cohort is estimated at 6 per thousand.

Survival prediction in sporadic amyotrophic lateral sclerosis. Age and clinical form at onset are independent risk factors

Amyotrophic lateral sclerosis is a progressive neurological disease of unknown etiology and fatal outcome. Patient management can be aided by careful assessment of prognostic factors. A prospective study of 158 patients was carried out to examine the prognostic significance of age and clinical form at onset. The overall 5-year survival rate was 14.7%. The higher the age was at first symptoms, the worse the prognosis. The bulbar and common forms had a worse prognosis than the pseudo-polyneuritic forms. After adjustment for age, the clinical form at onset remained a prognostic factor. In a multivariate analysis using the Cox model, these two factors remained independent despite the later onset of the bulbar forms. In view of the discrepancies between the different published studies, the evaluation of the survival of an individual patient is of doubtful value.

Prevalence of neurological disorders in Haute-Vienne department (Limousin region-France)

The Limousin region had at present one of the largest elderly populations in France and in Europe. To determine the frequency of certain neurological disorders in the elderly, a neuroepidemiological survey was conducted in 1986-1987 on a representative sample of the population in Haute-Vienne (the most population-dense department in the Limousin region). This study used a WHO protocol which was first introduced at the beginning of the 1980s. It had been previously tested in France on a pilot population in 1984. The prevalences of the principal neurological disorders encountered per 100,000 inhabitants were as follows: nonmigraine headache 5,059, migraine 4,270, epilepsy 788, completed stroke 1,445, transient ischemic attacks 657, neuropathy 1,642, Parkinson's disease 328, and dementia 197.

Prevalence of headache in a representative sample of the population in a French department (Haute-Vienne-Limousin)

In 1986-1987, a neuroepidemiologic survey was undertaken to study the prevalence of the most frequently encountered neurologic disorders, and in particular headache, in a representative sample of the population in the Haute-Vienne Department (Limousin). A door-to-door survey was made using a protocol developed by the W.H.O. at the beginning of the 1980's. The calculated prevalences (according to Poisson's distribution) per 100,000 inhabitants were 5,059 for nonmigraine headache, and 4,270 for migraine headache. This disorder preferentially affected young adults and essentially involved females. It was the most frequently encountered disorder (50%) during the different surveys of similar methodology.

[Pain during peritoneum pinching, a pathognomonic sign of peritoneal disease. Clinical research. Semiological value]

Pain induced by pinching the peritoneum betrays a pathology of that membrane. It is absent when the peritoneum is perfectly healthy. Pain is elicited by a special palpation technique. Clinically and statistically, the presence of this pain is pathognomonic, but it does not inform on the aetiology. In the present study the most frequent causes of positive abdominal peritoneal pinching test were peritoneal tuberculosis, followed by portal hypertension with or without liver cirrhosis.

[Reference values for maximal midexpiratory flow in black females]

The aim of this publication is to contribute to the establishment of reference values for the forced expiratory flow between 25 and 75% of the vital capacity (FEF25-75) among black females in West Africa. 316 of them, aged between 10 and 70 years, were submitted to this test. They were considered free from cardiopulmonary disease after a questionnaire and clinical examination. FEF25-75 in absolute value was lower than in the white Euro-americans. It increased up to 18-19 years of age, then decreased steadily thereafter. The main equations of regression for the FEF25-75 (l X s-1) were: 10-18 years, 0.177A + 1.058 and 0.157A + 0.826H + 0.005; 19-70 years, -0.028A + 4.211 and -0.025A + 2.206H + 0.512, (where A is the age in years and H the height in metres). The results are compared with the reference values published in Black Africa, Europe and the United States.

[Spirometric reference values in black females]

The aim of this paper is to give spirometric reference values for black females. Having eliminated those with abnormal hemoglobin, we studied 298 females aged between 10 to 70 years: 15 from bordering countries of the Ivory Coast and the others being Ivorian. That is, they are all from West Africa. It is shown that FVC and FEV1 are reduced in the black population when compared with European whites. Volume and flow values are also lower than those in Ivorian men. Correlations and linear regression equations were calculated between FVC, FEV1 and age, height, and weight. FVC and FEV1 (l BTPS) were found as a function of height H (m) and age A (years) as follows: from 10 to 25 years, FVC = 0.465 H3 + 0.01735 A + 0.58; FEV1 = 0.451 H3 + 0.0035 A + 0.61; from 25 to 70 years, FVC = 0.450 H3 - 0.02002 A + 1.54; FEV1 = 0.309 H3 - 0.02050 A + 1.44.

[Study on correlations between certain biological parameters and the Achillean reflexogram in a homogeneous African population (author's transl)]

Study of a homogenous population comprising 25 male Africans. The following parameters have been measured: proteinemia, hematocrit, natremia, calcemia, globular and plasmatic magnesemia, duration of the achillean reflexogram. Hyperproteidemia and hypomagnesemia, which are usually observed in African people, were found. A negative linear relationship significant at the 10 0/0 threshhold has been demonstrated between the reflexogram and the P.B.I. value.