Active neurocysticercosis,parenchymal and extra parenchymal: A study of 38 patients

In this retrospective study we have analysed a series of 38 patients seen from 1983 to 1992 (mean follow-up, 4.5 years) with active neurocysticercosis (NCC), 23 (60.5%) with parenchymal and 15 (39.5%) with extraparenchymal NCC. Classification into these two forms of NCC was based on computed tomography and magnetic resonance imaging criteria. The enzyme-linked immunosorbent assay performed in cerebrospinal fluid, for anti-Taenia solium antibodies, was positive in 18 of 23 (78%) cases. Epilepsy and/or intracranial hypertension were the most common clinical presentation (92%). Twenty-three (60.5%) of 38 patients were treated with praziquantel and/or albendazole. In parenchymal NCC, the efficacy of medical therapy was complete in 13 of 16 (81%) and partial in 3 of 16 (19%) patients. In contrast, in all cases of extraparenchymal NCC treated with cysticidal drugs the results were disappointing. A ventriculoperitoneal shunt was performed in 9 of 13 patients with extraparenchymal NCC and hydrocephalus. Severe complications, including two deaths, associated with the natural evolution of the disease or with surgery, occurred only in extraparenchymal NCC. Therefore, we confirm the existence of the two forms of active NCC, parenchymal and extraparenchymal, which are strikingly different in clinical presentation, medical therapy response, complications, morbidity and mortality.     

High-dose praziquantel for neurocysticercosis: efficacy and tolerability

Standard therapeutic regimens of praziquantel for neurocysticercosis use daily doses of 50 mg/kg for 15-21 days, with prolonged remission being achieved in 60-80% patients. In this prospective study, 100 mg/kg daily was used for 10 days in 13 patients aged 32 +/- 15 years (mean +/- SD) with severe intra-, extra-parenchymal or mixed forms of neurocysticercosis. Patients were monitored with computerized tomography and cerebrospinal fluid (CSF) examination on days 1, 5 and 10. Full blood count, sedimentation rate, blood sugar, urea, creatinine, bilirubin, liver transaminases, alkaline phosphatase, urine analysis and electrocardiogram were carried out before and after treatment. Doses of dexamethasone and of other drugs used concomitantly were controlled. There was no toxicity, clinical or detected by the methods employed in the study. After 22 +/- 5 (mean +/- SD) months follow-up, 6 patients needed ventriculoperitoneal shunting, 2 had died, 7 were improved and led useful lives and 4 were in prolonged remission. There was no correlation between serum or CSF praziquantel correlation and outcome of treatment. The proposed regimen is well tolerated, may be as efficient as previously advocated regimens, requires less hospitalization time and may be adopted routinely for therapy of neurocysticercosis.     

Neurocysticercosis in childhood. II. Computed tomography of 24 patients according to symptomatic and praziquantel treatment

We studied 24 children (15 months to 13 years old) which clinical, CSF and CT findings were compatible to the diagnosis of active neurocysticercosis. The patients were divided into three groups based on the type of treatment: Group I (10 patients) treated with analgesics and/or anticonvulsants; Group II (4 patients) treated with analgesics and or anticonvulsants and corticosteroids; Group III (10 patients) treated with analgesics and/or anticonvulsants, corticosteroids and praziquantel. The first patients CT scan were compared with the sequential CT scan findings (1 month to 5 years). The initial CT scan of 12 patients showed multiple active cysts, in 5 patients an isolated active cyst, in 3 patients partial calcified cysts, in 2 patients cerebral edema and in 2 patients were normal. The final results of the three groups of patients, as far as concern the normalization of CSF abnormalities or calcification of the cysts were the same, no matter the type of treatment applied to them. These results, although the small number of patients, showed that most of the children have good final results, with improvement of clinical symptoms and CT findings. We suggest that neurocysticercosis in children need multicenter study. So, a great number of patients can be followed and better definition can be established on the treatment of neurocysticercosis.     

脑囊虫病患者免疫反应中一氧化氮作用的研究

目的 检测脑囊虫病、病毒性脑膜脑炎及非神经系统疾病患者脑脊液内一氧化氮（NO）含量变化,探讨NO参与人体对脑囊虫的免疫作用。方法 采用显色剂法检测实验组和对照组脑脊液NO含量,同时检测一般生化指标和细胞学指标。结果 脑囊虫病组脑脊液NO含量高于非神经系统疾病患者组,与病毒性脑膜脑炎患者无差异。结论 NO参与人体对囊虫的免疫过程,其作用长期存在,并可能通过某些作用影响中枢神经正常功能。     

Enzyme linked immunosorbent assay (ELISA) for the detection of IgG,IgM, IgE and IgA against Cysticercus cellulosae in cerebrospinal fluid of patients with neurocysticercosis

The objective of this study was to analyze different immunoglobulins classes (IgG, IgM, IgE and IgA) against Cysticercus cellulosae in the cerebrospinal fluid (CSF), through enzyme linked immunosorbent assay (ELISA), correlating them to clinical and tomographic profiles in patients with neurocysticercosis (NCC). Eighty-five specimens of CSF were obtained from 43 cases with NCC (26 with the active form and 17 with the inactive form) and from 42 patients with other neurological diseases. The inactive form of NCC presented a profile in CSF similar to the group without NCC. The active form of NCC presented elevation of specific immunoglobulins (IgG, IgM, IgE, and IgA) in decreasing order, with the highest values being detected among the cases with intraventricular cysts, or with inflammation signs in CSF or in those with multiple clinical manifestations. The highest sensitivity and specificity were obtained with ELISA-IgG (88.5% and 93.2%, respectively). This study confirmed the importance of ELISA in the immunologic diagnosis of NCC.     

Hemorrhage after an acute ischemic stroke.MAST-I Collaborative Group

BACKGROUND AND PURPOSE: Hemorrhagic transformation is frequently seen on CT scans obtained in the subacute phase of ischemic stroke. Its prognostic value is controversial. METHODS: We analyzed 554 patients with acute ischemic stroke enrolled in the Multicenter Acute Stroke Trial-Italy (MAST-I) study in whom a second CT scan was performed on day 5. Presence of 1) intraparenchymal hemorrhages (hematoma or hemorrhagic infarction), 2) extraparenchymal bleeding (intraventricular or subarachnoid) and 3) cerebral edema (shift of midline structure, sulcal effacement or ventricular compression) alone or in association were evaluated. Death or disability at 6 months were considered as "unfavorable outcome." RESULTS: Patients who developed intraparenchymal hemorrhages, extraparenchymal bleeding, or cerebral edema had unfavorable outcome (83%, 100%, and 80%, respectively), but multivariate analysis demonstrated that only extraparenchymal bleeding (collinearity) and cerebral edema (OR=6.8; 95% CI, 4.5 to 10.4) were significant independent prognostic findings. Unfavorable outcome correlated with size of intraparenchymal hemorrhage (chi2 for trend=30.5, P<0.0001). Nevertheless, when a large hematoma was present the negative effect was mostly due to concomitant extraparenchymal bleeding (chi2=51.6, P<0.0001), and when hemorrhagic infarction was detected the negative effect was mostly explained by the association with cerebral edema (chi2=36.6, P<0.0001). CONCLUSIONS: Extraparenchymal bleeding and cerebral edema are the main prognostic CT scan findings in the subacute phase of ischemic stroke. Stroke patients with a high risk for developing these 2 types of brain damage should be identified. Measures to prevent and adequately treat their development should be implemented.     

Specificity and correlation with disease activity of cerebrospinal fluid osteopontin levels in patients with multiple sclerosis

BACKGROUND: Despite recent advances in therapy that have improved the overall disease course in multiple sclerosis (MS), the prognosis at the outset remains unpredictable. OBJECTIVES: To investigate whether cerebrospinal fluid (CSF) osteopontin levels correlate with disability or active disease in MS and to determine whether elevated CSF osteopontin levels are only seen in MS. DESIGN: Cerebrospinal fluid osteopontin was assayed using enzyme-linked immunosorbent assay in duplicate by an observer blinded to the clinical status of the sample. Cerebrospinal fluid samples were not obtained from any patient who had received high-dose corticosteroid therapy in the month before analysis. SETTING: Medical research institute. PATIENTS: Thirty patients (18 women and 12 men; age range, 24-71 years) with clinically definite MS and 36 patients (22 women and 14 men; age range, 20-71 years) with other neurological diseases (ONDs) or nonneurological illnesses were included in the study. MAIN OUTCOME MEASURES: Disease activity for patients with MS was based on observations in the year preceding the study, including the number of relapses, the change in disability according to the Expanded Disability Status Scale, and increased T2-weighted or gadolinium-enhancing lesions on brain magnetic resonance imaging. RESULTS: Higher CSF osteopontin levels were seen in patients with MS having active disease and in patients with ONDs that are actively deteriorating or inflammatory. However, CSF osteopontin levels in patients with MS did not correlate with disability status. CONCLUSIONS: Cerebrospinal fluid osteopontin levels do not correlate with disability in MS but tend to be higher in patients with active disease. Elevated CSF osteopontin levels are not a specific marker for MS, as they are found in patients with ONDs and nonneurological illnesses. In ONDs, the highest CSF osteopontin levels are seen in patients with rapidly progressive neurological dysfunction or widespread inflammation of the central nervous system.     

Neurocysticercosis

Neurocysticercosis is the most common helminthic disease of the nervous system and currently represents a major public health problem in developing countries of Latin America, Asia, and Africa, as well as in industrialized nations with a high immigration rate of people from endemic areas. The disease occurs when humans become the intermediate host in the life cycle of Taenia solium by ingesting its eggs from contaminated food. Neurocysticercosis is pleomorphic in its presentation due to individual differences in the number, size, and location of the parasites, as well as differences in the severity of the host's immune reaction to the parasite. Epilepsy, focal neurological signs, and intracranial hypertension are the most common clinical manifestations of the disease. The diagnosis of neurocysticercosis is based on clinical data, neuroimaging abnormalities, and the results of immunological tests. Two drugs, albendazole and praziquantel, are cysticidal and destroy most intracranial parasites; however, surgery may be necessary in the management of some forms of the disease, particularly hydrocephalus and intraventricular cysts. Although the development of modern diagnostic tests and the introduction of potent cestocidal drugs have increased our ability to make the diagnosis of neurocysticercosis and improved prognosis, some patients still have a torpid clinical course despite prompt diagnosis and proper therapy.     

Therapy for neurocysticercosis

Therapy for neurocysticercosis has advanced during the last 20 years with the advent of albendazole (Zentel) and praziquantel (Cysticide). Albendazole is the current medication of choice for the treatment of neurocysticercosis and is recommended for symptomatic patients with multiple viable cysts in the brain parenchyma. Albendazole may also be useful in extraparenchymal cysticercosis, especially in the subarachnoid racemose form, when complete surgical resection of the cysts is usually impracticable. Currently, there is an intense debate over the value and safety of anticysticercal therapy. Causes for failure of anticysticercal therapy include high inter-individual variability in plasma concentration of albendazole sulfoxide and the complex interactions of several drugs with the albendazole metabolite. Furthermore, albendazole sulfoxide is an enantiomeric mixture of (+)- and (-)-albendazole sulfoxide with accumulation of the (+)-enantiomer in the cerebrospinal fluid. However, the question over which enantiomer is effective against cysticerci remains to be clarified.     

Proposed diagnostic criteria for neurocysticercosis

Neurocysticercosis is the most common helminthic infection of the CNS but its diagnosis remains difficult. Clinical manifestations are nonspecific, most neuroimaging findings are not pathognomonic, and some serologic tests have low sensitivity and specificity. The authors provide diagnostic criteria for neurocysticercosis based on objective clinical, imaging, immunologic, and epidemiologic data. These include four categories of criteria stratified on the basis of their diagnostic strength, including the following: 1) absolute--histologic demonstration of the parasite from biopsy of a brain or spinal cord lesion, cystic lesions showing the scolex on CT or MRI, and direct visualization of subretinal parasites by funduscopic examination; 2) major--lesions highly suggestive of neurocysticercosis on neuroimaging studies, positive serum enzyme-linked immunoelectrotransfer blot for the detection of anticysticercal antibodies, resolution of intracranial cystic lesions after therapy with albendazole or praziquantel, and spontaneous resolution of small single enhancing lesions; 3) minor--lesions compatible with neurocysticercosis on neuroimaging studies, clinical manifestations suggestive of neurocysticercosis, positive CSF enzyme-linked immunosorbent assay for detection of anticysticercal antibodies or cysticercal antigens, and cysticercosis outside the CNS; and 4) epidemiologic--evidence of a household contact with Taenia solium infection, individuals coming from or living in an area where cysticercosis is endemic, and history of frequent travel to disease-endemic areas. Interpretation of these criteria permits two degrees of diagnostic certainty: 1) definitive diagnosis, in patients who have one absolute criterion or in those who have two major plus one minor and one epidemiologic criterion; and 2) probable diagnosis, in patients who have one major plus two minor criteria, in those who have one major plus one minor and one epidemiologic criterion, and in those who have three minor plus one epidemiologic criterion.     

Tau protein and beta-amyloid<Subscript>1-42</Subscript> CSF levels in different phenotypes of Parkinson’s disease

Parkinson’s disease (PD) is a neurodegenerative disorder with highly heterogeneous clinical manifestations. This fact has prompted many attempts to divide PD patients into clinical subgroups. This could lead to a better recognition of pathogenesis, improving targeted treatment and the prognosis of PD patients. The aim of the present study was to obtain cerebrospinal fluid (CSF) samples in PD patients and to search for a relationship between neurodegenerative CSF markers (tau protein, beta-amyloid_1-42 and index tau protein/beta-amyloid_1-42) and the clinical subtypes. PD patients were divided into three subgroups: early disease onset (EDO), tremor-dominant PD (TD-PD), and non-tremor dominant PD (NT-PD) according to the previously published classification. Neurodegenerative markers in the CSF were assessed in these three groups of patients suffering from PD (EDO-17, TD-15, NT-16 patients) and in a control group (CG) of 19 patients suffering from non-degenerative neurological diseases and 18 patients with Alzheimer’s disease (AD). The NT-PD patients were found to have significantly higher levels of CSF tau protein and index tau/beta than the control subjects and other Parkinsonian subgroups, but no significant differences in these markers were found between AD and NT-PD patients. In the context of more rapid clinical progression and more pronounced neuropathological changes in the NT-PD patient group, our results corroborate the opinion that CSF level of tau protein may be regarded as a potential laboratory marker of the presence and severity of neurodegeneration.     

JCV detection in multiple sclerosis patients treated with natalizumab

Natalizumab therapy is associated with an increased risk of progressive multifocal leukoencephalopathy (PML). Because the prognosis of established PML is uniformly dismal, identification of highly susceptible patients to the disease may improve outcomes. We wanted to investigate whether serial plasma and cerebrospinal fluid (CSF) screening for polyomavirus would identify patients with laboratory evidence of viral infection prior to the development of clinical PML. Two hundred MS patients had pre-treatment CSF/plasma screening for JC virus (JCV) and BK virus (BKV) DNA, and thereafter every six treatments of natalizumab. In all positive patients treatment is stopped (due to potential risk of PML), they have follow-up clinical examinations and plasma/CSF JCV/BKV tests until all evaluations are normal. No patient developed clinical evidence of PML. Eight of the 200 patients had detectable JCV or BKV DNA. Five patients were positive for BKV DNA in the CSF and three patients were positive for JCV DNA (one in plasma, two in CSF). After cessation of natalizumab treatment, all patients converted to undetectable viral DNA. Screening for JCV in CSF in natalizumab-treated patients could help identify those at heightened risk for developing PML and discontinuing treatment in these patients may abort development of the clinical illness.     

血管性痴呆的生物学标记物研究进展

血管性痴呆与阿尔茨海默病、混合性痴呆的鉴别诊断面临困难。目前应用的血管性痴呆临床诊断标准的敏感度和特异度偏低。近年一些生物学标记物作为病理生理过程的客观指标被应用于与血管性痴呆的诊断和鉴别诊断。这些生物学标记物包括结构影像学、正电子发射断层扫描（positron emission tomography,PET）、脑脊液标记物[淀粉样β多肽（Amyloidβ-peptide,Aβ）和tau蛋白]、血浆细胞因子和脑血管血液动力学检查等。初步的研究结果提示脑脊液Aβ和脑的脱氧葡萄糖-PET显像对于血管性痴呆的诊断和鉴别诊断具有较高的应用价值。     

Tau protein, Abeta42 and S-100B protein in cerebrospinal fluid of patients with dementia with Lewy bodies

The intra vitam diagnosis of dementia with Lewy bodies (DLB) is still based on clinical grounds. So far no technical investigations have been available to support this diagnosis. As for tau protein and beta-amyloid(1-42) (Abeta42), promising results for the diagnosis of Alzheimer's disease (AD) have been reported; we evaluated these markers and S-100B protein in cerebrospinal fluid (CSF), using a set of commercially available assays, of 71 patients with DLB, 67 patients with AD and 41 nondemented controls (NDC) for their differential diagnostic relevance. Patients with DLB showed significantly lower tau protein values compared to AD but with a high overlap of values. More prominent differences were observed in the comparison of DLB patients with all three clinical core features and AD patients. Abeta42 levels were decreased in the DLB and AD groups versus NDC, without significant subgroup differences. S-100B levels were not significantly different between the groups. Tau protein levels in CSF may contribute to the clinical distinction between DLB and AD, but the value of the markers is still limited especially due to mixed pathology. We conclude that more specific markers have to be established for the differentiation of these diseases.     

Cerebral blood flow in normal pressure hydrocephalus

A xenon-133 method was used to measure cerebral blood flow (CBF) before and after cerebrospinal fluid (CSF) removal in patients with normal pressure hydrocephalus (NPH). Preliminary results suggested that shunting should be performed on patients whose CBF increased after CSF removal. There was a significant increase in CBF in patients with NPH, which was confirmed by the favorable outcome of 88% of patients shunted. The majority of patients with senile and presenile dementia showed a decrease or no change in CBF after CSF removal. It is suggested that although changes in CBF and clinical symptoms of NPH may have the same cause, i.e., changes in the cerebral intraparenchymal pressure, there is no simple direct relation between these two events. The mechanism underlying the loss of autoregulation observed in NPH is also discussed.     

Neurocysticercosis and acquired cerebral toxoplasmosis in children

Neurocysticercosis, prevalent wherever pigs are raised in the presence of poor sanitation, is the most common identifiable cause of new-onset epilepsy throughout the developing world. As immigration patterns have changed, children with neurocysticercosis are seen throughout the United States. Acute cysticercosis, the most common manifestation in children, reflects the host response to the dying parasite. Children typically present with seizures and have an excellent prognosis. Neuroimaging demonstrates a single ring or nodular enhancing lesion surrounded by edema. Short-term anticonvulsant therapy is indicated, but treatment with antiparasitic agents is not required. Other forms, such as active cysts (intact organism), intraventricular or subarachnoid racemous cysticercosis, and cysticercal meningoencephalitis, are less common manifestations of parasitic infection. Toxoplasmosis, caused by the parasite Toxoplasma gondii, can be acquired by ingestion of infected undercooked meat or from oocytes shed in cat feces. Acquired cerebral toxoplasmosis, due to primary or reactivated infections, rarely occurs in immunocompetent children. In children who are immunodeficient as the result of AIDS, chemotherapy, tissue transplantation, or congenital immunodeficiency, toxoplasmosis may be difficult to distinguish from cerebral lymphoma. A variety of techniques, including neuroimaging, Thallium-201 SPECT, polymerase chain reaction analysis of CSF, and special histological methods, may be used to diagnose acquired toxoplasmosis. Antiparasitic therapy, using pyrimethamine and sulfadiazine, and serial neuroimaging often enable clinicians to differentiate toxoplasmosis from other central nervous system lesions. Toxoplasmosis may respond to other antimicrobials, including macrolide antibiotics, dapsone, clinidamycin, and atovaquone. Suppressive treatment is generally required for life in immunodeficient patients. Immunodeficient children with acquired toxoplasmosis have high rates of mortality and neurological sequelae.     

A unifying theory for the definition and classification of hydrocephalus

If the cerebrospinal fluid (CSF) is considered to be all the fluid (liquid), other than blood or the derivatives of its breakdown, that is normally contained within the brain, its cavities, and its spaces, this could be regarded as brain fluid in its most elemental form. Pathological increases in intracranial CSF volume, independent of hydrostatic or barometric pressure, then, could be considered a definition of hydrocephalus. The observation of significant episodic variation in intracranial pressure (ICP) suggests the necessity of substituting the concept of time-related pressure variations for the older one of level of pressure in patients with defective ICP control mechanisms. It has been assumed that the subarachnoid channels are the first CSF compartment to dilate in response to the hydrocephalic process, reducing the CSF pressure and thereby establishing an equilibrium. When the equilibrium is disturbed, with progressive dilation of the subarachnoid channels, the increase in CSF pressure is transmitted to the ventricular system, resulting in its dilation (extraprenchymal hydrocephalus). Progressive ventricular dilation causes cerebral edema (intraparenchymal hydrocephalus) and obliterates the subarachnoid spaces as the hemispheres are compressed against the dura, resulting in apparent internal hydrocephalus in the absence of external hydrocephalus. Thus, subarachnoid space or ventricular dilation occur as a result of intermittent increases in extraparenchymal CSF volume: the primary pressure force emanating from the subarachnoid and subdural spaces and from the intraventricular compartment. Hydrocephalus, therefore, may be present in a child who does not yet have dilated ventricles but in whom both CSF volume and pressure are increased. Thus, it becomes obvious that the term internal hydrocephalus is of little significance, since increases in intraparenchymal fluid-cerebral edema-cause the same volumetric changes as increases in intraventricular fluid volume. I suggest that hydrocephalus is a pathologic increase in intracranial CSF (brain fluid) volume, whether intra- or extraparenchymal, independent of hydrostatic or barometric pressure. It may be classified as (1) intraparenchymal (cerebral edema) and (2) extraparenchymal, with the extraparenchymal types subclassified into subarachnoid, cisternal, and intraventricular forms.Presented at the Consensus Conference: Hydrocephalus '92, Assisi, Italy, 26–30 April 1992     

Effect of Anticysticercal Treatment on the Prognosis of Epilepsy in Neurocysticercosis: A Pilot Trial

Epilepsy secondary to active or inactive neurocysticercosis (NCC) is a major public health problem in Latin American countries. In an open-label pilot trial, we evaluated and followed (mean = 13 months) 16 patients with epilepsy resulting from active NCC which was treated with anticisticercal (ACC) drugs. These patients were aged 12–68 years with confirmed active NCC and seizures not controlled by adequate antiepileptic drug (AED) therapy. Patients were treated with albendazole or praziquantel (ALB and PZQ, ACC drugs) and AED monotherapy. The number of NCC cysts was markedly reduced by ACC therapy. Thirteen patients remained seizure-free and 2 had only one seizure during follow-up. Our data suggest a positive effect of ACC treatment on the prognosis of epilepsy caused by active NCC, but a prospective, double-blind, controlled study with long-term follow-up must be performed to determine whether ACC therapy improves long-term seizure control.     

Cysticidal therapy: impact on seizure control in epilepsy associated with neurocysticercosis

OBJECTIVE: To evaluate the clinical features and seizure control of epilepsy related to neurocysticercosis. METHOD: 18 patients with partial epilepsy and neurocysticercosis were treated with albendazol or praziquantel and followed from 3 months to 12 years. We analyzed results from the CSF exam, interictal electroencephalogram (EEG), head computerized tomography and/or magnetic resonance imaging. RESULTS: The patients' mean age was 36.4 years. The mean duration of epilepsy was 16 years. 83% patients had simple partial seizures; 17% had complex partial seizures. All patients underwent routine EEGs: 62% had abnormalities and 38% were normal. A relationship was observed between focal EEG abnormality and the location of cyst in 28% of the patients. The CSF exams showed pleocytosis in 33% of the patients, and 28% had elevated protein levels. Only 22% of patients had positive titer for cysticercosis in the CSF. In all patients who had somatosensory and special sensory seizures there was a relationship between location of the cysts and seizure semiology (n=11). After cysticidal therapy, 83% patients had a significant improvement in controlling seizures. CONCLUSION: In this group, we found a predominance of simple partial seizures and a relationship between somatosensory and special sensory seizures and the location of the cysts. Cysticidal therapy was effective in controlling seizures in these patients and should be considered for patients with partial seizures and semiology related to cyst location.     

Plasma and CSF levels of albendazole and praziquantel in patients with neurocysticercosis

Albendazole or praziquantel were measured in plasma and cerebrospinal fluid (CSF) in 29 patients with neurocysticercosis. Mean levels of albendazole in plasma were 0.918 microgram/ml and in CSF were 0.392 microgram/ml and levels of praziquantel were 1.640 micrograms/ml in plasma and 0.398 microgram/ml in CSF, after doses of 15 and 50 mg/kg, respectively. Drug concentrations in CSF were 43% for albendazole and 24% for praziquantel. The drug levels obtained for both drugs showed ample individual variations that were not related to age, sex, presence of inflammation in the subarachnoid space, or therapeutic effectiveness; such variations seem to be due to individual differences in pharmacokinetics. Both drugs were effective and the doses currently used of each drug seem to be optimal for therapy of neurocysticercosis.