[Two cases of cryptococcal meningitis revealed by an ischemic stroke]

The usual clinical expression of neuromeningeal cryptococcosis is a meningoencephalitis. We report two cases of neurocryptococcosis which have been revealed by an unusual clinical aspect: an ischemic stroke with a vasculitis mechanism. The two patients had a positive reaction for the HIV and we discussed the responsibility of the HIV or the Cryptococcus in the occurrence of the cerebral infarct.

[Epidemiology of epilepsy in sub-Saharan Africa: a review]

Epilepsy is, above all tropical, moreover, very african in its frequency and gravity. Data on the prevalence of epilepsy shows it to be two or three times more prevalent in tropical zones than in industrialized countries in non tropical areas, however it is rare to find data on the incidence and prognosis of epilepsy in sub-Saharan Africa. It is difficult to determine the relative contribution of each of the causes of epilepsy. Only a few case-control studies have been carried out in sub-Saharan Africa. Infectious diseases, in particular parasitic diseases such as neurocysticercosis or cerebral malaria, seem to be the cause of the majority of the cases of epilepsy. However it is necessary to do additional epidemiological studies to determine the etiologies of epilepsy more precisely in sub-Saharan Africa.

[Dépistage de l'épilepsie en zones tropicales: validation d'un questionnaire en Mauritanie]

Prevalence of epilepsy in developing countries is considered to be 2 to 5 times superior to the industrialized countries. In tropical areas, the diagnosis of epilepsy is still reliant on the clinic and requires a precise semiological description. A good epidemiological and clinical research requires standardized and validated screening tools. The objective of this work was to evaluate the validity of the screening module of the investigation questionnaire on epilepsy in tropical areas, in Nouakchott, Mauritania. All the patients included in the study were examined at first by a neurologist, then directed towards an investigator who asked the 5 screening items of the investigation questionnaire. Any person answering "yes" at least one question was regarded as "suspected of epilepsy" by the investigator. Secondly the neurologist re-examined the subjects and confirmed the diagnosis. The sensitivity and the specificity of the module of screening were calculated. On the whole, 236 patients were included in the study 131 had answered "yes" at least one of the questions of the module of screening and was regarded as "suspected" of epilepsy (55.5%) by the questionnaire. The diagnosis of epilepsy was made for 82 subjects by the neurologist. The sensitivity of the module of screening of the epilepsy was 95.1% (CI 95%: 87.3-98.4) and specificity was 65.6% (CI 95%: 57.5-72.9). The screening module of the investigation questionnaire of epilepsy in tropical zones, made up only by 5 questions, has diagnosis qualities acceptable and comparable with those reported in the literature. The use of this tool integrated in a more general questionnaire of investigation of the. epilepsy proves to be an essential instrument in conducting epidemiologic studies in epileptology' in tropical zones.

[Cognitive disorders in an Andean community located in a cysticercosis endemic zone of Ecuador]

Mini mental state tests (MMS) were administered to 227 adults over the age of 40 years living in an Ecuadorian urban Andean community known to be an endemic zone for Taenia solium taeniasis and cysticercosis. The overall prevalence of cognitive impairment was 8.4% (19/227). The prevalence of cognitive impairment was 23.5% (8 cases) in adults over 75 years (n=34). The Hachinski ischemic score for vascular dementia was abnormal in 4 of the 19 adults (21%) exhibiting cognitive impairment. This survey highlighted a high prevalence of dementia in comparison with industrialised countries. Parasitic encephalopathy that was present in one out of five persons in this Andean community could play a part in early damage of cognitive function.

[Japanese encephalitis]

Japanese encephalitis is an arboviral disease due to a flavivirus transmitted by a mosquito of the genus Culex. It is a major public health problem in Southeast Asia where it is endemo-epidemic. The socio-economic impact of Japanese encephalitis is great since most cases occur in children and young adults and lead to death in 25 to 30 % and neurological sequelae in survivors. The tendency of Japanese encephalitis to spread geographically and the existence of imported cases are particularly important issues. The clinical features are the same as other viral encephalitis. Suspicion of imported Japanese encephalitis depends on awareness of the epidemiological setting (return from endemic areas). Diagnosis must be confirmed by serology using ELISA capture method to detect anti-viral antibodies in blood and cerebrospinal fluid. Unlike herpes encephalitis, there is currently no specific treatment for Japanese encephalitis. Only preventive measures can be effective against infection. At the present time the most widely used vaccine is Biken's lyophilized vaccine produced from a reference strain (Nakayama strain), but its high cost prevents mass vaccination in endemic areas. Recent progress in molecular biology has raised hope for the discovery of a genetically engineered vaccine to improve overall protection against Japanese encephalitis.

[Electroencephalograms (EEG) in 250 patients with epilepsy in a cysticercosis endemic area in Burundi]

OBJECTIVES

This work aimed at describing EEG abnormalities in epileptic patients living in areas endemic for cysticercosis, underlining the electroclinical correlations and discussing the interest of EEG examination in this context.

METHODS

During a case-control study, 250 EEGs from patients with epilepsy were recorded with a portable system. Types of seizures were assessed clinically and from information obtained through a standardised questionnaire, and along with EEG were related to the results of cysticercosis serological tests.

RESULTS

Among the 249 EEGs, 48% were normal, 5.2% had epileptic abnormalities, 6.8% showed an association between epileptic abnormalities and slow alterations. Slow theta and delta abnormalities were found in 21.8% of cases, and isolated deterioration of basic rhythms was observed in 17.3% of cases. Most seizures were generalized, and 61% of the patients had positive serology. One EEG was uninterpretable and another showed isolated spikes. Electroclinical agreement was considered to be satisfactory in 33 patients, and was better with the epileptic than with slow abnormalities. The existence of epileptiform EEG abnormalities confirmed clinically diagnosed epilepsy, but did not allow etiological diagnosis. Electroserological agreement was good in 24 patients. A significant association (Chi2, p = 0.03) existed between slow focal abnormalities and positive cysticercosis serology. Conversely, no significant association was detected between epileptic patterns and serology results.

CONCLUSION

While the EEG alone clearly does not allow aetiological diagnosis, its joint use with clinical and biological results was a key element of the etiological and therapeutic discussion. When it shows focal abnormalities in a patient with epilepsy living in a high prevalence cysticercosis area, it confirms the clinical suspicion of neurocysticercosis. Morphological imagery alone can provide etiological information on the seizures by showing the nature and localization of the parenchymal lesions.

[Polyradiculoneuritis and Campylobacter jejuni: clinical and physiopathological aspects]

Several explanations have been proposed to explain the relationship between axonal forms of acute auto-immune inflammatory polyradiculoneuritis and Campylobacter jejuni. The major hypothesis involving molecular imitation is based on the existence of common antigenic determinants (epitopes) in the lipopolysaccharides of the infectious agent and gangliosides, i.e. glycosphingolipides on the surface of the nervous system cells, especially peripheral nervous system cells. The purpose of this literature review is to improve understanding of the rather complex physiopathological mechanisms underlying Guillain-Barre syndrome.

[Neurological manifestations of fish, mollusk and shellfish poisoning]

Sea-food poisoning is observed in several areas of the world. Intoxication results from ingestion of fresh fish, mollusks, or shellfish contaminated by toxins produced by microorganisms (dinoflagellates). Neurological manifestations are sometimes associated with signs and may be life-threatening. We describe here the principle toxins, their geographic distribution, clinical manifestations, therapeutic management, and possible prevention measures.

[Contribution of computerized tomography in the diagnosis of cerebrovascular accidents in Nouakchott, Mauritania]

This prospective study was focused on the radiological features of stroke and the recent contribution of computerized tomographic scan (CT scan) to diagnosis of hospitalized stroke patients. All patients admitted for stroke to the Neurology Department of the Nouakchott Hospital between January 1, 1996 and June 30, 1997 were enrolled in this study. Patients were divided into two groups, i.e. CT group including patients that underwent CT scan during hospitalization and control group including patients that did not undergo CT scan for financial reasons. The etiology of stroke (35.1% of hospitalizations) was ischemic in 52% of cases and hemorrhagic in 48%. There were more men than women and mean age was 60 years for ischemic stroke versus 56 years for hemorrhagic stroke. Only 8% of patients presented documented diabetes. Deep infarction accounted for 52% of ischemic stroke including large-artery infarction in 61.2% and lacunar infarction in 38.8%. Superficial infarction usually involved the territory supplied by the superficial sylvian artery. Intraparenchymal hematomas accounted for 78% of hemorrhagic strokes in relation with the high incidence of arterial hypertension (65.2%). The most common locations were capsulo-lenticular (55%) and capsulo-thalamic (39%). Stroke-related mortality was high (20.3%) especially in patients presenting prolonged disturbances of consciousness and renal insufficiency. By allowing more accurate assessment of lesions, CT-scan improved patient management and therapeutic outcome.

Arginase expression in peritoneal macrophages and increase in circulating polyamine levels in mice infected with Schistosoma mansoni

We investigated the nitric oxide (NO) synthase and arginase pathways in resident peritoneal macrophages of mice infected with the tropical parasite Schistosoma mansoni. The two enzymes may have opposite effects, insofar as NO may be involved in the killing of the parasite whereas arginase may stimulate parasite growth via polyamine synthesis. We determined the effects of the infection on the expression and activity of the two enzymes in macrophages, before and after cytokine activation. Cells from infected mice expressed the hepatic type I arginase, whereas in control cells, the enzyme was expressed only after cytokine activation, as were NO synthase II and type II arginase in both groups of cells. Moreover, we found that in infected mice, arginase expression in macrophages was associated with a ten fold increase in the concentration of circulating ornithine-derived polyamines. This may be of pathological importance, since parasitic helminths are though to be dependent on their hosts for the uptake and interconversion of polyamines.

Inhibition of nitric oxide synthase activity reduces liver injury in murine schistosomiasis

We investigated the involvement of nitric oxide in Schistosoma-induced liver injury. We found that inducible nitric oxide synthase mRNA became detectable in the liver at the onset of parasite egg laying and levels then increased as the eggs accumulated in the organ. Enzyme concentration and activity paralleled mRNA levels. The event was a direct effect of egg deposition, as it occurred in the liver after natural infection, or in the lungs after i.v. injection of the eggs. However, nitric oxide seems to have no direct effect on the eggs since in vitro assays showed that the nitric oxide donor SIN-1 did not alter the ability of the eggs to hatch. L-Arginine and L-NAME, a nitric oxide synthase inhibitor, were administered to infected mice in an attempt to increase or reduce nitric oxide production, respectively. Arginine had no effect on the disease, whereas the inhibitor led to a marked decrease of hepatic injury with, in particular, reduced fibrosis and decreased lipid peroxidation. In conclusion, not only is inducible nitric oxide synthase activity unlikely to exert an anti-microbicidal effect against the egg stage of S. mansoni but it might lead to deleterious effects in the liver and therefore contribute to the pathology.

[Treatment of status epilepticus in a developing country]

Status epilepticus (SE) is a condition requiring emergency care, which is often poorly managed in developing countries due to the lack of personnel, drugs, and insufficient technical and medical means. This study aims at determining the epidemiologic and etiologic characteristics and the difficulty in treating SE under the existing medical practice conditions in a developing country such as Senegal. A retrospective study was therefore carried out based on SE medical files at the University Hospital of Dakar over the period January 1988 to December 1998, and included several hospital departments, i.e., paediatrics, infectious diseases and neurology. Over an 11-year period 697 cases were recorded; of these, 48.2% of patients were under 5 years of age. The seizures were generalized in 58.2% of cases, partial in 21.2%, partial secondarily generalized, or with an association of both clinical presentations in 20.6% of cases. The etiology was as follows: mainly infectious (67%), followed by resistant and/or unbalanced epilepsy (9.9%), epilepsy of vascular origin (8%), and various other causes. The overall mortality rate was 24.8%. A long period between the onset of clinical symptoms and hospital treatment was noted, with an average time lapse of 16.6 h before treatment. The drugs utilized were diazepam and phenobarbitol, administered by injection. The overall outcome could be improved by better management, i.e., better prevention and an efficient treatment of infectious diseases, a reduction in the time before treatment, and improved means of intensive care.

[Tuberculosis spondylodiscitis in a neurological service in Nouakchott]

It is about a retrospective study dealing with the place of tuberculous spondylitis with discitis among medullary wounds hospitalized in our service from January 1995 to June 1998 and their medical care. Twenty reports have been done making: 30.30% of our medullary wounds. We have noted a male prevalence and precocity. The flaccido-spastic paraplegia with sensitive level prevails the clinical chart (45%) this in correlation with thoracic and lumbar localization predominance (75%) at the radiography. All patients have had for their benefit an anti-tuberculous treatment and eleven among them had also tetracosactide (synactène retard). This has allowed us to observe a quick recovery of the motor deficit for nine patients: 81.8% of the patients who have had the therapeutic association; 45% of the whole. No patient had an operation.

[Sociocultural approach to epilepsy in Mauritania]

In Black Africa, treatment of epilepsy is affected by sociocultural attitudes. The purpose of this report is to describe attitudes towards epilepsy in Mauritania and assess repercussions in 150 patients. Most patients were deprived of educational and occupational opportunities. Seventy-seven percent of patients were treated by traditional remedies. Regardless of ethnic origin, a widely held notion was that epilepsy was caused by djinns (evil spirits). An additional cause almost consistently cited by the Moorish population was diet. In these ethnic groups, the term iguindi refers to all clinical manifestations including seizures attributed to excessive eating. Traditional treatment involves ingestion of foods considered as antidotes for iguindi. These findings underline the need for information campaigns to enhance public awareness and understanding of epilepsy.