Therapy of parenchymal brain cysticercosis with praziquantel

Praziquantel in treatment of cerebral schistosomiasis

The effectiveness of standard single-day praziquantel treatment (60 mg/kg) was prospectively evaluated in nine patients with seizures caused by cerebral Schistosoma japonicum infection. Eight patients were cured when discharged from the study, an average of 6 months after receiving praziquantel. They were seizure-free in the absence of anticonvulsants, their electroencephalograms were normal, and no major abnormalities could be detected on neurological examination. Serial computed tomography scanning revealed rapid dissipation of cerebral oedema and complete or near-complete resolution of mass lesions. No serious adverse effects of praziquantel were encountered. The ninth patient was not cured but improved greatly in the months after treatment. Thus, single-day treatment with praziquantel is safe and effective in cerebral schistosomiasis.

Intramedullary cysticercosis

In 1976 a 28-year-old Ecuadoran male suffered paraparesis after a kick to his back. Iophendylate myelography was followed by thoracic laminectomy with incomplete resolution of the paraparesis. One year later, worsening of the paraparesis was managed by further thoracic laminectomy without improvement. In 1978 a spinal cord stimulator was implanted via low thoracic laminectomy as a measure to counter his spasticity. In 1984 metrizamide myelography and computed tomography scanning were performed for increasing spastic paraparesis that disclosed an intramedullary lesion at the T-4 level. Exploration and myelotomy revealed an intramedullary cysticercal cyst, which was totally removed.

Central nervous system cysticercosis simulating an acute cerebellar hemorrhage

We report the case of a Mexican man who suddenly developed severe occipital headache, vomiting, vertigo, and ataxia. Neurologic examination showed nystagmus and cerebellar findings. Computed tomography of the brain demonstrated a large left cerebellar cystic lesion consistent with the diagnosis of cysticercosis. The patient was treated with dexamethasone and praziquantel and required surgical removal of the lesion to prevent herniation. He recovered without neurologic sequelae. The abrupt onset of cerebellar findings is an unusual presentation of this disease. Central nervous system cysticercosis is being recognized with increasing frequency in the United States, where it is found primarily in Hispanic and Asian immigrants. The literature of central nervous system cysticercosis is reviewed and the pathogenesis, clinical presentation, and therapy are discussed.

Evaluation of enzyme-linked immunosorbent assay in serological diagnosis of human neurocysticercosis using paired samples of serum and cerebrospinal fluid

The applicability of micro-ELISA was evaluatd in human neuro-cysticercosis using paired samples of serum and CSF. A total of 355 cases who were mostly neurologic patients was subjected. Cystic fluid of C. cellulosae was used as antigen in protein concentration of 2.5 micro-g/ml. Serum was diluted to 1:100 and CSF was undiluted in the assay for the specific IgG antibody level. The differential criterion of the positive reaction was the abs. of 0.18 in both samples. The results were summarized as follows: The overall sensitivity of the micro-ELISA in 71 confirmed neurocysticercosis was 90.1%; the sensitivity by serum was 77.5% and that by CSF was 83.1%. CSF was a more sensitive and valuable material. Most of the false negative cases of neuro-cysticercosis showed far lower level of abs. rather than marginal. The overall specificity of the micro-ELISA in 52 confirmed other neurologic diseases was 88.5%; the specificities by serum and by CSF were 94.2% respectively. Cases of other neurologic diseases did not show false positive reactions in both samples. When serum was assayed, taeniasis(2/18), sparganosis(2/20), paragonimiasis(1/56), clonorchiasis(1/15) and fascioliasis(1/1) cases showed cross reactions. When CSF was assayed, 2 of 10 neuro-sparganosis showed cross reactions while none of 9 neuro-paragonimiasis showed it. Out of 71 confirmed neuro-cysticercosis cases, 6 and 11 showed cross reactions by serum and CSF to crude extract antigen of sparganum; but no case did show it to crude extract antigen of Paragonimus westermani. Ventricular CSF showed low or negative levels of IgG antibody than lumbar CSF unless the lesion was at the lateral ventricle itself. Out of 4 racemose cysticercosis cases, 3 showed positive reaction in serum while all of 3 examined CSF were positive. The above results indicated that the serological test for detecting the specific IgG antibody by micro-ELISA using paired samples of serum and CSF was very helpful for clinical differentiation of neuro-cysticercosis from neurologic diseases of other causes.

Mobile myelographic filling defects: spinal cysticercosis

Cysticercosis usually affects the brain and is easily demonstrated by CT. Spinal cysticercosis is much rarer and is usually diagnosed only at surgery. Myelographic demonstration of multiple rounded filling defects, some of which were mobile, allowed diagnosis of spinal extramedullary cysticercosis in an unsuspected case. The literature on spinal cysticercosis is briefly reviewed. Diagnosis is important in view of the recent development of medical treatment.

The clinical significance of gastrointestinal helminths--a review

Gastrointestinal helminths (nematodes, trematodes and cestodes) constitute some of the most common and important infective agents of mankind and are responsible for much morbidity and some mortality. Whereas many symptoms and signs are confined to the intestine and less often the associated digestive organs, systemic manifestations are also numerous; this applies especially to indigenous populations of developing 'Third World' countries. Using a clinical classification these organisms can be broadly separated into those involving the small-intestine and those which have a colo-rectal distribution; of the former, a minority has been causally related to intestinal malabsorption. Clearly, however, not all gastrointestinal helminths are associated with disease and it is important to be able to separate these two groups; when present at high concentration and especially in infants and children some of the least pathogenic are not, however, entirely asymptomatic. Maintenance of a high 'index of suspicion' is necessary and this applied especially to 'western' populations in whom rapid and extensive travel to areas of the world with substandard sanitation and contaminated food and water supplies is now common; first evidence of infection in them may result from serious clinical complications. Recent advances have focussed on treatment, and especially the introduction of the benzimidazole compounds (especially albendazole) for nematode, and praziquantel for cestode, infections. Treatment of strongyloidiasis remains, however, unsatisfactory. Mass elimination of gastrointestinal helminths in developing 'Third World' countries remains a major challenge.

Immunochemical detection of antigens of larval Taenia solium and anti-larval antibodies in the cerebrospinal fluid of patients with neurocysticercosis

A simple and quantitative enzyme-linked immunosorbent assay (ELISA) has been developed for the detection of antigens of larval Taenia solium in the cerebrospinal fluid (CSF) of patients with cerebral cysticercosis. Another ELISA was developed for detecting antibodies in CSF against larval antigens. The examination of sixteen patients with clinical diagnosis of cerebral cysticercosis revealed that eleven patients had both circulating larval antigens and anti-larval IgG (but not IgM) antibodies in their cerebrospinal fluids. Of these patients, those with surgically and histologically confirmed infections were all positive by the two tests. CSF samples from nine normal individuals and from six patients suffering from proven neurological disorders other than neurocysticercosis were negative for both tests. In development of these assays it was found that cross-linking of antigens to microtiter plates further improved the performance of the ELISA. The results of this study suggest that either or both of these tests may be useful in discriminating between neurocysticerosis and other clinically related diseases.

Effect of praziquantel on intraocular cysticercosis: a case report

A patient with intravitreous cysticercosis was treated with the new anthelminthic drug, praziquantel. A transient toxic effect on the cysticerus was observed, but the drug was unable to kill the parasite.

Praziquantel in the cerebrospinal fluid in neurocysticercosis

In 10 patients with neurocysticercosis (NC), an assessment was made of the praziquantel (PZQ) concentration in the cerebrospinal fluid (CSF), in non-deproteinized serum and in protein-free serum: before administration of the drug and the 1st., 7th. and 21st. days of oral administration (50mg/kg/day during 21 days). Samples of CSF and blood were collected three hours after the last administration of the daily total dosage, on the 1st. and 21st. days; and from 2 to 6 hours after drug administration on the 7th. day. The total daily dosage was distributed into three equal parts of 1/3 each, with a 4 hours' interval between intakes, except in the last 5 cases, who on the 21st. day only were given the total daily dosage on a single administration. Results have shown dispersion in serum concentrations, which are similar to those seen in normal subjects as recorded in literature. There is a correlation between PZQ levels in the CSF and in the serum, the latter being very close to those found in protein-free serum fraction. The statistical treatment of results allowed the following considerations: PZQ concentrations in the CSF and in the protein free serum are in balance from the pharmacodynamic standpoint on the first day; this balance is maintained up to the 21st. day although at different levels from those seen on the 7th. day; on the 21st. day PZQ contents in CSF goes back to its similar values as recorded on the 1st. day, and this suggests that the participation of drug interaction factors has been reduced to non-significant levels. However, several factors can influence PZQ concentration in CSF, as absorption rate, liver first-pass effect and blood-brain barrier changes, and individual dose should be established for each patient based on drug concentration monitoring in the serum and/or in the CSF.

Intraparenchymal cerebral cysticercosis in children: a benign prognosis

This paper reports 26 consecutive cases of cerebral cysticercosis in children, 21 presenting with intraparenchymal mass lesions, two with encephalitic disease, and three with intraventricular (racemous) cysticercosis. The intraparenchymal and encephalitic forms of the disease were benign. Regression of the lesions occurred within four months of diagnosis in all children treated conservatively with antiepileptic drugs, but no antiparasitic drugs. Major morbidity was limited to those patients who were subjected to operative intervention. Intraventricular disease was most malignant; all three patients manifested acute, severely increased intracranial pressure, all required immediate surgical decompression, and one patient died. The apparent overall benign course of intraparenchymal cerebral cysticercosis in children appears not to warrant antiparasitic drug therapy.

Cerebral cysticercosis: diagnostic value of subcutaneous nodules. Report of two cases

In North America cysticercosis is a rare disease and may cause serious diagnostic difficulties. We report two patients with cysticercosis with neurologic involvement and subcutaneous nodules. In both cases the nodules were small and few in number. Histologic examination showed the diagnostic scolex of the parasite only after subserial sections of the biopsy specimen. The presence of subcutaneous nodules in patients who have lived in endemic areas should raise the possibility of cysticercosis, particularly if neurologic signs or symptoms are present. We stress the importance of careful histologic examination of subcutaneous nodules when cysticercosis is suspected.