✓ The fourth ventricle is frequently affected in patients with cysticercosis of the central nervous system, due either to a large cyst occluding the cavity or to granular ependymitis (ventriculitis) as a consequence of diffuse inflammation within the intraventricular and subarachnoid spaces. In some cases, the differential diagnosis between these two forms of neurocysticercosis is difficult to make, even after special radiological procedures. It is important to establish the correct diagnosis, since a surgical approach is beneficial only when the fourth ventricle is obstructed by a large cyst. In this paper, the clinical differences between fourth ventricle cysts and ventriculitis are presented in 16 patients with neurocysticercosis who were subjected to surgical exploration of the posterior fossa. Patients with a large cyst occluding the fourth ventricle had a short evolution of signs and symptoms, Bruns' syndrome, and discrete or no inflammatory reaction in the cerebrospinal fluid (CSF). Patients with ventriculitis generally had a longer duration of signs and symptoms, Parinaud's syndrome, a consistently positive complement fixation test to cysticerci, and more cells and proteins in the CSF. The clinical picture and ancillary studies can give the precise diagnosis in most patients before surgical exploration is performed.
Abelardo Salazar, Julio Sotelo, Hector Martinez and Francisco Escobedo
A long-term follow-up review of 92 cases
Julio Sotelo and Cora Marin
✓ Ninety-two patients with hydrocephalus secondary to cysticercotic meningitis were followed for a mean period of 8 years 11 months. The mortality rate was 50%, with most patients dying within the first 2 years after cerebrospinal fluid (CSF) shunting. The prognosis was worse in females than in males. Multiple surgical procedures for shunt obstruction were necessary in half of the patients. Complications such as bacterial meningitis and shunt obstruction were more frequent in the patients who died than in those who survived. The follow-up data revealed that the clinical status was satisfactory in 78% of survivors and unsatisfactory in 22%. Spontaneous remission of the cysticercotic arachnoiditis, as shown by the CSF findings, occurred in only 18% of the cases. In most patients, arachnoiditis and positive immune reactions persisted unchanged even after several years. The results demonstrate the poor outcome of these patients and indicate the need for better medical and surgical therapy.
Oscar H. Del Brutto, Jaime Guevara and Julio Sotelo
✓ Eight patients with cysticerci located inside the sella turcica are presented, and the clinical and radiological features of this rare form of neurocysticercosis are discussed. Clinical features included nonspecific ophthal-mological and endocrinological disturbances similar to those produced by other sellar lesions. Computerized tomography (CT) usually showed a hypodense mass that simulated either a cystic tumor or an arachnoid cyst. Cerebrospinal fluid (CSF) findings were also nonspecific, as immunological reactions to cysticercosis were most often negative when inflammation was limited to suprasellar and intrasellar regions. An incorrect diagnosis of tumor was frequent in these cases. In contrast, when intrasellar cysticercosis was associated with other forms of neurocysticercosis, proper integration of CT and CSF data permitted an accurate diagnosis. Cysticercosis should be suspected in patients with hypodense juxtasellar lesions living in geographical areas where this disease is endemic. Prompt surgical resection of cysticerci will avoid irreversible damage to visual function.
Oscar H. del Brutto and Julio Sotelo
✓ Medical or surgical therapy for subarachnoid or ventricular cysticercosis is a controversial issue. The authors report a patient with cysticercus larvae in both ventricular and subarachnoid locations, who was successfully treated with albendazole. Thus, medical therapy has a role in the treatment of these forms of neurocysticercosis.
Roberto A. Suastegui Roman, José Luis Soto-Hernández and Julio Sotelo
✓ In a prospective open study, 15 patients with hydrocephalus secondary to cysticercosis who required insertion of a ventriculoperitoneal (VP) shunt were treated with 50 mg of prednisone given orally three times a week. Treatment began in the 1st postoperative week, with isoniazid and pyridoxine administered daily as antituberculous chemoprophylaxis. The drug regimen was continued with close follow up for 24 months. Clinical status, Karnofsky performance status (KPS) scores, and postoperative course in the prednisone-treated group were compared with 30 control patients with hydrocephalus due to cysticercosis. The control patients were matched by age and sex, underwent surgical shunting in the same period, and were followed routinely by the neurosurgery staff. Lumbar cerebrospinal fluid (CSF) was studied at 2, 16, and 32 weeks postoperatively in the prednisone group. At 24-month follow up two (13%) of 15 patients in the prednisone group and 18 (60%) of 30 patients in the control group required surgical shunt revisions for symptomatic shunt obstruction (p = 0.002). Follow-up studies of CSF performed at 32 weeks in the prednisone group revealed improvement of abnormal values with statistically significant differences for glucose (p < 0.02). Serial imaging studies in the prednisone group revealed persistence of cysticercal cysts with no change in size. Mean initial KPS scores were similar in both groups. At the end of the follow-up period, the mean KPS score was significantly higher in the prednisone group (p = 0.003). Prednisone and chemoprophylactic drugs were well tolerated. These results suggest that in selected patients with hydrocephalus secondary to cysticercosis, intermittent long-term prednisone therapy after VP shunting may reduce shunt malfunction and improve the functional status of the patients.
Julio Sotelo, Mario Izurieta and Nicasio Arriada
Object. Ventricular shunt placement is the neurosurgical procedure most frequently associated with complications. Over the years, it has been a growing concern that the performance of most shunting devices does not conform to physiological parameters. An open ventriculoperitoneal (VP) bypass with a peritoneal catheter for which the cross-sectional internal diameter was 0.51 mm as a distinctive element for flow resistance was evaluated for use in the treatment of adult patients with hydrocephalus.
Methods. During a 2-year period, open shunts were surgically implanted in 54 adults with hydrocephalus; conventional shunts were implanted in 80 matched controls. Periodic evaluations were performed using neuroimaging studies and measures of clinical status. All patients were followed from 12 to 36 months, 18.5 ± 4 months for patients with the open shunt and 19.1 ± 8.1 months for controls (mean ± standard deviation). The device continued to function in 50 patients with the open shunt (93%) and in 49 controls (61%; p < 0.001). The Evans index in patients with the open shunt was 0.33 ± 0.09 throughout the follow up. No cases of infection, overdrainage, or slit ventricles were observed; the index in controls was 0.28 ± 0.08; 60% of them developed slit ventricles. During the follow-up period occlusion occurred in four patients with the open shunt (7%) and in 31 controls (39%; p < 0.001).
Conclusions. The daily cerebrospinal fluid (CSF) drainage through the open VP shunt is close to 500 ml of uninterrupted flow propelled by the hydrokinetic force generated by the combination of ventricular pressure and siphoning effect. It complies with hydrokinetic parameters imposed by a bypass connection between the ventricular and peritoneal cavities as well as with the physiological archetype of continuous flow and drainage according to CSF production. The open shunt is simple, inexpensive, and an effective treatment for hydrocephalus in adults.
Julio Sotelo and Oscar H. Del Brutto
In the neurosurgical services in many developing countries, treatment of neurocysticercosis (NCC) accounts for greater than 10% of brain surgical procedures and approximately 15% of neurological consultations. In these areas brain cysticercosis is the leading cause of hydrocephalus in adults and the first cause of late-onset epilepsy. During the last two decades, successful medical treatment has been established. Additionally, neuroimaging and immunological studies have clearly defined the topography, pathophysiological mechanisms, and biological status of these lesions. Thus, selection of cases for medical or surgical treatment has improved; in a significant number of cases, both interventions are required. New therapies with either albendazole or praziquantel have respectively reduced to 8 days and to 1 day the course of anticysticidal therapy, which now is fast, effective, inexpensive, atoxic, and convenient, particularly in endemic areas where most patients belong to the lower socioeconomic groups. Additionally, the rational use of steroid agents facilitates the treatment of inflammation, a conspicuous accompaniment in cases of NCC. A major effort, however, is still required to eradicate this disease.
Eduardo Briceño, Sandra Reyes and Julio Sotelo
Therapy of malignant tumors is frequently curtailed by the emergence of chemoresistant cell clones. Experimentally, the authors have demonstrated that chemotherapy for glioma in rats is markedly improved by the administration of the antimutagenic quinacrine. They studied the effects of chloroquine, an antimutagenic with an optimal pharmacological profile for human use, as adjuvant for the treatment of patients with glioblastoma multiforme (GBM).
In a prospective controlled randomized trial, 18 patients with GBM underwent standard treatment with surgery, chemotherapy, and radiotherapy; nine received an additional 150-mg dose of chloroquine daily starting 1 day after surgery and continued through the observation period. Nine matched patients were included as controls. Neuroimaging studies and clinical response were periodically compared. The follow-up period ranged from 24 to 50 months.
Survival time was defined as the main outcome measure. Survival was significantly longer in chloroquine-treated patients than in controls (33 ± 5 and 11 ± 2 months, respectively [p < 0.0002]). At the end of the observation period, four patients (46%) treated with chloroquine were alive, two had evidence of tumor remission after 2 years; in another two, tumor recurrence developed after 2 and 4 years of remission, respectively. No control patient survived more than 22 months after surgery.
Chronic administration of chloroquine greatly enhanced the response of GBM to antineoplastic treatment. Because the cytotoxicity of chloroquine on malignant cells is negligible, these favorable results appear mediated by its strong antimutagenic effect that precludes the appearance of resistant clones during radiotherapy and chemotherapy.
Nicasio Arriada and Julio Sotelo
Object. Management of hydrocephalus caused by expansive lesions of the posterior fossa is complicated by two main drawbacks of shunt devices: sudden decompression and overdrainage. The ventriculoperitoneal (VP) continuous-flow (CF) shunt is characterized by a peritoneal catheter with an internal diameter of 0.51 mm that promotes continuous drainage of cerebrospinal fluid (CSF) at its production rate. The authors have previously demonstrated in adult patients with hydrocephalus that sudden decompression and overdrainage are absent when this shunt is used; here they report the findings of a prospective study in which the goal was to test the performance of this shunt in patients with severe hydrocephalus due to lesions of the posterior fossa.
Methods. During a 5-year period, 103 patients with severe hydrocephalus caused by lesions of the posterior fossa were treated by placement of a VP shunt. In 53 of these patients (control group) a shunt and valve system was surgically implanted and in 50 patients a CF shunt was implanted. All patients were followed up for a minimum of 2 years after surgery.
Shunt revision or change was necessary in 21 patients (40%) with conventional shunts and in four patients (8%) with the CF shunt (p < 0.003). Signs of overdrainage were observed in 18 patients (34%) in the control group, four of whom had ascending transtentorial herniation; this complication was not seen in patients with the CF shunt.
Conclusions. The CF shunt had a low rate of dysfunction and an absence of complications caused by overdrainage, which were frequently associated with the control shunts. The hydrodynamic properties of the CF shunt make it effective, even in severe cases of hydrocephalus caused by lesions of the posterior fossa.