Epilepsy in children in Benin City, Nigeria.

The pattern of epilepsy in children in Nigeria showed little difference from that seen in children in western countries, except that birth asphyxia was relatively common as a cause and there was a longer time between onset of seizures and parents seeking medical care. It was estimated that good control of seizures was achieved in 52.9% of children, but more than a quarter attended the clinic only once or twice and the reasons for this are not known. The response to medication was less satisfactory for children under 1 year, a result consistent with most other studies. Some uncommon forms and associations of epilepsy were recognised. An EEG was not essential for management but was useful for the diagnosis of syndromes. Treatment was equally effective when commenced 5 years or more after the onset of seizures. The anti-convulsant used for most children was phenobarbitone which had to be discontinued in only two cases because of side-effects. Phenobarbitone has been successfully used to treat epilepsy by primary health workers in rural Africa and this is expected to continue in the future.

A functional study of uncrossed and crossed pulmonary afferent fibres in the cervical vagus nerves of the cat.

The functional distribution of uncrossed and crossed pulmonary afferent fibres in the cervical vagus nerves has been studied in the anaesthetized cat using acute and chronic unilateral pneumonectomized preparations. The heart and lungs were sympathectomized routinely. The vagal afferent pathways of three pulmonary reflexes were investigated: the Hering-Breuer respiratory reflex, the lung inflation cardio-accelerator reflex, and the pulmonary chemoreflex. Inflation of the remaining lung caused temporary inhibition of inspiration. It also resulted in acceleration of the heart, but only when the background cardiac vagal tone was augmented. These respiratory and cardiac responses were abolished in most animals by ipsilateral cervical vagotomy; however, in some, a small response persisted and this was abolished by contralateral vagotomy. Stimulation of pulmonary C-fibre endings with right atrial injections of phenylbiguanide caused a reduction in respiration, bradycardia and systemic hypotension, responses which occurred with a latency of 2.9 +/- 0.15 s. They were mostly abolished by ipsilateral cervical vagotomy, but reduced responses persisted in a few animals. The residual responses were abolished by contralateral cervical vagotomy and by selective denervation of the lung. These results indicate that most afferent fibres subserving the three pulmonary reflexes studied run in the ipsilateral cervical vagus, representing the uncrossed pathway. Some afferent fibres, however, cross to the contralateral cervical vagus. Degenerative changes in cells of the contralateral nodose ganglion in chronic unilateral pneumonectomized animals support these findings.

Acute intermittent porphyria, seizures, and antiepileptic drugs: a report on a 3-year-old Nigerian boy.

A 3-year-old Nigerian boy was treated with phenobarbitone after having a nonfebrile seizure. Two weeks later his urine was found to contain porphobilinogen, indicating that latent acute intermittent porphyria had been unmasked by phenobarbitone. The drug was discontinued and carbamazepine was substituted. The urine became free of porphobilinogen and the patient remained well. In developing countries phenobarbitone is the most widely used anticonvulsant; it must be avoided in acute intermittent porphyria, and carbamazepine may be tolerated.

Sickle cell disease, pneumococcal meningitis and paraplegia with recovery.

A 10-year-old boy without previous illness was found to have sickle cell disease and pneumococcal meningitis. On completion of 10 days of treatment with penicillin, the only abnormality still present was paraplegia. Movements of the legs recovered gradually, and after 3 months he was walking normally. Paraplegia is rare in sickle cell disease and the prognosis is not always poor.

Demonstration of glutamate immunoreactivity in vagal sensory afferents in the nucleus tractus solitarius of the rat.

To investigate whether glutamate is a neurotransmitter in vagus nerve sensory afferents terminating in the nucleus tractus solitarius, these terminals were identified by the anterograde transport and their glutamate content examined using the post-embedding immunogold technique. After injection of horseradish peroxidase into the nodose ganglion anterogradely labelled axonal boutons were visualized throughout the nucleus of the solitary tract (nTS), the dorsal motonucleus of the vagus nerve (DVN), predominantly ipsilateral to the injection, and to a lesser extent in the area postrema. Electron microscopic analysis of 47 anterogradely labelled boutons in the nTS following post-embedding immunocytochemistry for glutamate revealed that 43 of these boutons (> 91%) contained a level of glutamate immunoreactivity significantly greater (P < 0.001%) than that observed in the surrounding tissue. The observed enrichment of glutamate immunoreactivity in boutons identified as vagus nerve sensory afferents indicate that glutamate may be a transmitter in these neurones.

Cerebrospinal fluid/serum lactic acid in Nigerian children with febrile convulsions.

Cerebrospinal fluid (CSF) and serum lactic acid levels were prospectively assayed in 42 children less than 5 years old with febrile convulsions who were divided into two groups for analytical purposes, irrespective of aetiology of pyrexia. One group (24 children) had brief febrile seizures and the remaining 18 children had prolonged febrile seizures. CSF and serum lactic acid values were obtained for brief and prolonged seizures. On admission, the mean CSF lactic acid was significantly higher (p < 0.05) in children with prolonged than with brief seizures, but the mean serum lactic acid was not significantly different between the two groups. Twelve of the 18 children (67%) with prolonged seizures and elevated CSF lactate had seizure recurrence. There were no recurrences of seizures in children with a brief initial seizure and low CSF lactate. CSF lactic acid is elevated in children with prolonged seizures and this may be useful in detecting those with a prolonged seizure where the history of the duration of the seizure is not clear. Prolonged seizure has been associated with the risk of recurrence and therefore such children with elevated CSF lactic acid levels might benefit from long-term anticonvulsant therapy.

Binding of [3H]-5-hydroxytryptamine to human coronary artery and bypass graft vessels.

OBJECTIVES: 5-Hydroxytryptamine (5-HT) has a wide range of vascular effects mediated via specific receptors and it has been suggested to be a mediator in ischemic heart disease. The aim of the present study was to localise the 5-HT receptors within the vessel wall. METHODS: Epicardial coronary arteries obtained from patients undergoing cardiac transplantation, internal mammary arteries from heart donors and saphenous veins from patients undergoing coronary bypass surgery, were sectioned and incubated with [3H]-5-HT for in vitro receptor autoradiography. RESULTS: Microscopic analysis of high resolution autoradiographic images revealed a similar pattern of [3H]-5-HT binding in epicardial coronary and internal mammary artery, where it predominated in the lamina muscularis. In the saphenous vein, binding increased towards the adventitia which showed dense, displaceable binding to the vasa vasorum as well as to nerve-like structures, from which binding was only partially displaced. Computer-assisted densitometric analysis of low resolution autoradiographs revealed a high degree of specific binding to all vessels examined. CONCLUSIONS: The distribution of the [3H]-5-HT binding is different in the saphenous vein compared to epicardial coronary and internal mammary artery. The dense binding to vasa vasorum in the saphenous vein suggests a role for 5-HT in closure of these nutrient vessels, which could contribute to the formation of atherosclerotic changes in saphenous vein grafts.

Cellular mechanisms underlying the increased duodenal iron absorption in rats in response to phenylhydrazine-induced haemolytic anaemia.

Haemolytic anaemia induced by phenylhydrazine (PZ) promotes iron absorption across rat small intestine. This present study investigates the role of the brush border potential difference (Vm) and mucosal reducing activity in the response. In addition, quantitative autoradiography was used to assess PZ-induced changes in the villus localization of brush border iron uptake. Iron transfer from duodenum to blood was increased significantly 5 days after treatment with PZ. Autoradiography showed that most brush border iron uptake occurred at the upper villus region and the maximal rate was increased fourfold by PZ. Duodenal villus length was increased in PZ-treated rats. PZ treatment did not influence mucosal reducing activity but Vm, measured using duodenal sheets, increased from -50 to -57 mV (P < 0.001) and this was due to a reduced brush border sodium permeability. Thus, an expanded absorptive surface and an enhanced electrical driving force for iron uptake across the duodenal brush border are important adaptations for increased iron absorption in PZ-induced haemolytic anaemia.

Pattern and antibiotic susceptibility of bacteria in pyogenic meningitis in a children's emergency room population in Maiduguri, Nigeria, 1988-1992.

From January 1988 to November 1992, 107 (3.5%) of 3074 postneonatal children admitted to the Children's Emergency Room, University of Maiduguri Teaching Hospital, Nigeria, had sporadic pyogenic meningitis; 66 (61.7%) were aged < or = 12 months. Streptococcus pneumoniae, Neisseria meningitidis and Haemophilus influenzae together were responsible for 77.3% (58) of 75 culture-proven cases, 13.4% (10) had Enterobacteriaceae, 5.3% (4) had Staphylococcus aureus and 4% (3) untyped alpha-haemolytic streptococci. Fifty percent of 62 bacteria were resistant to ampicillin, 47.2% of 36 to penicillin and 10.7% of 56 to chloramphenicol; none of 21 bacteria was simultaneously resistant to all three antibiotics. Up until 1992, we have encountered treatment failure with a regimen containing chloramphenicol in only 2 of 53 patients; the 2 patients had coliform meningitis. Non-meningococcal bacteria are an important cause of sporadic pyogenic meningitis in sub-Saharan Nigeria and chloramphenicol is the most appropriate initial drug of choice at the present time for the management of sporadic meningitis.

Central distribution of substance P, calcitonin gene-related peptide and 5-hydroxytryptamine in vagal sensory afferents in the rat dorsal medulla.

The central distribution of vagal afferents in the medulla containing either substance P, calcitonin gene-related peptide or 5-hydroxytryptamine was examined using a double-labelling technique and laser scanning confocal microscopy. Areas of the nucleus tractus solitarii, dorsal motonucleus of the vagus nerve and area postrema were scanned for double-labelled axon profiles. Analysis of this material revealed that all three neurochemicals were contained within the central terminals of vagal nerve sensory neurons. However, the distribution of vagal nerve afferents containing each of these putative transmitters differed. Afferents containing 5-hydroxytryptamine were detected mainly in the areas postrema and the adjacent nucleus tractus solitarii, with a smaller number in the ventral subnuclei of the solitary tract. In contrast afferents containing calcitonin gene-related peptide were found primarily in the medial and commissural regions of the nucleus tractus solitarii. Afferents containing substance P-immunoreactivity were surprisingly few in number and did not appear to be associated with any particular region. These results establish the presence of 5-hydroxytryptamine, substance P and calcitonin gene-related peptide in the central axons of vagal sensory afferents. Furthermore, the differential distribution of afferents immunoreactive for these neurochemicals seen in this study, together with previous demonstrations of the viscerotopic organization of vagal sensory afferents suggests a possible "chemical coding" for individual end organs.

Convulsions with malaria: febrile or indicative of cerebral involvement?

Evaluation of 446 infants and young children (6 months to 5 years olds) with malaria parasitaemia showed a significant relationship (P < 0.05- < 0.001) (a) between coma and age, pattern of convulsions, haematocrit, and blood glucose, and (b) between the severity of parasitaemia and risk of convulsions, prevalence of hepatosplenomegaly, and severe anaemia. No significant relationship was observed between convulsions and temperature or haematocrit. Comatose children were older and had a higher prevalence of repeated convulsions, severe anaemia, and hypoglycaemia than non-comatose children. Convulsions, hepatosplenomegaly, and severe anaemia were more prevalent in children with moderate-severe parasitaemia. It is concluded that convulsions with malaria are more often a manifestation of cerebral dysfunction rather than being simply febrile in nature. All forms of cerebral dysfunction in malaria, including repeated convulsions, should be managed as being clinical manifestations of cerebral malaria.

Convulsions with fever of acute onset in school-age children in Benin City, Nigeria.

Of 92 school-age children who had convulsions with fever (CWF) of acute onset, seen in a 1-year period in an emergency room in Benin City, Nigeria, 49 per cent had malaria parasitaemia, 15 per cent bacterial meningitis, 8 per cent focal extracranial infections, and 1 per cent bacteraemia while 27 per cent had acute fever of undetermined origin. The prevalence of meningitis increased with presence of temperature > or = 40 degrees C (P < 0.01), focal seizures (P < 0.05), and rousable coma (P < 0.05). Bacterial meningitis is an important illness in school-age children with CWF, although malaria parasitaemia is the commonest infection.

Malaria with bacteraemia in acutely febrile preschool children without localizing signs: coincidence or association/complication?

Data were collected on 642 preschool children who presented consecutively to casualty with fever and no localizing signs. Four hundred and forty-six (69%) had malaria parasitaemia. The proportion of children with bacteraemia was similar in those children with malaria (43/446, 9.6%) and those without malaria (24/196, 12.2%, P < 0.5). The pathogens in both groups of children were mainly Staphylococcus aureus and coliform bacteria. Although children with malaria/bacteraemia had a significantly higher prevalence of anaemia (P = 0.001), hepatosplenomegaly (P < 0.01) and combination of hepatosplenomegaly and severe anaemia (P = 0.02), compared with children with malaria alone, there was no correlation between the severity of parasitaemia and prevalence of malaria with bacteraemia. The association of malaria with bacteraemia appears to be coincidental.

Pattern of infections in children under-six years old presenting with convulsions associated with fever of acute onset in a children's emergency room in Benin City, Nigeria.

Five-hundred-and-twenty-two infants and children aged 1 month to 6 years presenting at the Children's Emergency Room of the University of Benin Teaching Hospital with convulsions associated with fever (CAF) of acute onset were prospectively evaluated to determine the pattern of infections. Twenty-six per cent had localized infections of which 38 per cent were intracranial (meningitis = 16 per cent, cerebral malaria = 19 per cent, and encephalitis = 3 per cent) and 62 per cent were extracranial with respiratory tract infections contributing 51 per cent. Although, the prevalence of meningitis was significantly higher in 1-6 months old infants when compared with older children (47 per cent v. 12 per cent; P < 0.005), it was, none-the-less, present in all the other age groups (with a prevalence of 8-17 per cent). Seventy-four per cent of the children had no localizing signs of infection. Of these 68 per cent had malaria, 4 per cent bacteraemia, and 7 per cent malaria with bacteraemia, while no infections were identified in 21 per cent. Among children with bacteraemia Staphylococcus aureus was the commonest single isolate (33 per cent) although, overall, enterobacteriaceae were the commonest. We conclude, first, that meningitis should be excluded in all children aged under 6 years who present with CAF of acute onset and, secondly, that although anticipatory treatment for malaria is justified in children with CAF of acute onset without localizing signs of infection, consideration should also be given to the problem of bacteraemia.

Acute fevers of unknown origin in young children in the tropics.

Bacteremia was documented in 14 of 156 previously healthy children with temperatures of at least 40.0 degrees C but without focal signs, seen in an emergency department; 116 children had malaria, and no infections were identified in 26. Concurrent malaria infection was frequent in children with bacteremia. The highly febrile child without focal signs in the tropics requires evaluation for bacteremia even when a diagnosis of malaria has been confirmed.

gamma-Aminobutyric acid immunoreactive structures in the nucleus tractus solitarius: a light and electron microscopic study.

gamma-Aminobutyric acid immunoreactive perikarya and boutons in the nucleus tractus solitarius of the cat were examined at both the light and electron microscopic level. Immunoreactive neurones were found predominantly in the parvocellular subdivision of the nucleus tractus solitarius and to a lesser degree in all the other subdivisions of the nucleus tractus solitarius and the dorsal vagal motonucleus. All the immunoreactive perikarya observed were similar in size and morphology. gamma-Aminobutyric acid immunoreactive boutons were observed throughout the nucleus tractus solitarius. However, in contrast to its high content of immunoreactive perikarya the parvocellular subdivision contained the lowest density of immunoreactive boutons. Ultrastructural examination of immunoreactive boutons in the different regions of the nucleus tractus solitarius revealed that they formed synaptic specializations, predominantly with dendritic shafts, all of which were of the symmetric type. This pattern of innervation was observed throughout the medial, commissural, ventrolateral and parvocellular subdivisions of the nucleus tractus solitarius.