[Relationship between body temperature and prognosis, and neuroprotective effect of hypothermia in acute stroke patients]

AIMS

We review the relationship between body temperature and severity of acute stroke, and evaluate published evidence about the possible neuroprotective effect of hypothermia in these patients.

METHODS

In acute stroke patients, hypothermia increases oxygen consumption and metabolic demands of cerebral cells, favors liberation of oxygen radicals, glutamate, and other neurotransmisors involved in brain injury, and enhances biochemical processes leading to apoptosis. Preliminary data suggest that induced hypothermia is feasible and relatively safe in acute stroke patients; this may lead to a better outcome in terms of reduced mortality and less disabling sequelae in survivors. To enhance its possible efficacy, hypothermia should be started in the first 6 to 12 hours after the event, should be prolonged for at least 24 to 48 hours, and should be done with cooling blankets or ice pads, as antipyretics are not effective to induce hypothermia in normothermic subjects.

CONCLUSIONS

Hyperthermia is deleterious in acute stroke patients and must be treated. Hypothermia should not be considered a routine procedure in these patients until its safety and efficacy has been demonstrated in large trials. Patients with induced hypothermia should be closely monitorized to reduce the risk of adverse effects related to the procedure.

[Cerebrovascular disease in the tropics]

OBJECTIVES

To review the clinical manifestations, diagnosis, and therapy of diseases causing cerebrovascular disease (CVD) in the tropics.

DEVELOPMENT

Most prevalent conditions causing CVD in the tropics include: sickle cell disease, Takayasu s arteritis, cysticercosis, infective endocarditis, Chagas disease, viral hemorrhagic fevers, gnathostomiasis, leptospirosis, snake bites, cerebral malaria, puerperal venous thrombosis, and tuberculosis. These conditions may cause cerebral infarcts or hemorrhages, and in most instances are related to either vascular damage secondary to angiitis or hemorrhagic diathesis with bleeding in other organs. In some patients, the severity of the neurological picture makes impossible to identify an specific stroke syndrome and cerebrovascular complications are only recognized on neuroimaging studies or autopsy.

CONCLUSIONS

There is a group of tropical infectious and non infectious diseases that may cause cerebral infarcts or hemorrhages. Prompt diagnosis and therapy are needed to reduce the severity or brain damage and to avoid recurrent strokes.

[Cysticercosis of the cerebellopontine angle: treatment with single-dose praziquantel]

INTRODUCTION

Praziquantel has not been considered useful for therapy of subarachnoid cysticercosis. However, recent studies suggest that the introduction of a new regimen of praziquantel therapy, that includes the administration of higher doses of the drug at shorter intervals, may improve pharmacokinetic properties of praziquantel and increase its efficacy in this form of the disease.

CLINICAL CASE

A 28 year-old woman presented with a six month history of headache, vomiting, nystagmus, right peripheral facial palsy, and left hemiparesis. Computerized tomography (CT) scan of the head revealed a large cysticercus in the right cerebellopontine angle cistern compressing the brain-stem. She was treated with praziquantel 100 mg/kg in three divided doses at two hours apart. Thereafter, she received three 8 mg doses of intravenous dexamethasone given 6, 24 and 48 hours after the last dose of praziquantel. She improved after therapy, with total resolution of hemiparesis. Control CT showed progressive reduction and size and further disappearance of the cystic lesions three months later.

CONCLUSION

This single-dose regimen of praziquantel seems to be effective for therapy of subarachnoid cysticercosis. Further studies with a large number of patients are needed to confirm the efficacy of the drug in this form of the disease.

[Gliomatosis cerebri: clinico-pathological and neuroimaging characteristics and the results of treatment with radiotherapy]

INTRODUCTION

Gliomatosis cerebri is a rare form of malignant neoplastic glial transformation that involves large areas of the central nervous system.

OBJECTIVE

To describe clinical manifestations, pathognomonic neuroimaging findings and results of radiotherapy of gliomatosis cerebri.

PATIENTS AND METHODS

We review clinical records and neuroimaging studies of two patients with gliomatosis cerebri identified from the files of brain tumor registries of two university hospitals. One patient underwent radiotherapy after surgery.

RESULTS

Clinical manifestations and evolution were totally different in both patients despite the fact that both tumors had the same extension on neuroimaging studies. Magnetic resonance imaging revealed the extent of the lesion in both cases, comprising both cerebral hemispheres. Histopathological study revealed G-I and G-II astrocytomas. The patient treated with whole brain irradiation experienced clinical improvement and involution of the brain tumour on neuroimaging studies, and survived 20 months after surgery.

CONCLUSIONS

Clinical manifestations of gliomatosis cerebri are protean. Therefore, neuroimaging studies and histopathological analysis of brain tissue allow the correct diagnosis. Radiotherapy may improve neurological function in some patients. However, it is necessary to compare the long-term evolution of treated and non-treated patients to evaluate clinical efficacy of radiotherapy.

[Central nervous system mycotic infections]

INTRODUCTION

There has been an increased number of cases of fungal diseases of the central nervous system (CNS) during the past few years. This paper reviews current literature about these conditions, with emphasis on recent advances on diagnosis and therapy.

DEVELOPMENT

While some fungi may cause disease in normal hosts, most of these microorganisms are opportunistics and affect immunocompromised hosts. With the exception of Candida albicans, that is a normal inhabitant of the intestinal tract, most fungi enter the body by inhalation or through skin abrasions. Common fungal diseases include aspergillosis, blastomycosis, candidiasis, coccidioidomycosis, cryptococcosis, histoplasmosis, mucormycosis, paracoccidioidomycosis, and phaeohyphomycosis. In general terms, fungal invasion of the CNS may produce one or more of the following clinical syndromes: subacute or chronic meningitis, encephalitis, parenchymal brain abscesses or granulomas, stroke, or myelopathy. Diagnosis may be difficult on clinical grounds, and data provided by neuroimaging studies or CSF examination is non-specific. Definitive diagnosis usually rest on the demonstration of the causal agent on body fluids or tissue samples. Early administration of amphotericin B, associated or not with the new azoles, is indicated to arrest the often fatal course of these conditions.

CONCLUSIONS

Formerly considered rare diseases, the acquired immunodeficiency syndrome (AIDS) epidemic and the widespread use of corticosteroids and cytotoxic agents, have caused an increase in the prevalence of CNS mycosis. Development of potent antimycotic drugs have improved the prognosis of fungal diseases of the CNS. However, due to diagnostic delays or the presence of debilitating conditions, some patients still have torpid clinical courses despite proper therapy.

[Neurocysticercosis]

INTRODUCTION

This paper review current literature about neurocysticercosis with emphasis on recent advances on diagnosis and therapy.

DEVELOPMENT

Cysticercosis is the most common parasitic disease of the nervous system. The disease occurs when humans become the intermediate host in the life cycle of Taenia solium by ingesting its eggs from contaminated food. Endemic in developing countries of Latin America, Asia and Africa, massive immigration of people to industrialized nations caused a recent increase in the number of patients with cysticercosis in the United States of America and in some European countries. Neurocysticercosis is a pleomorphic disease due to individual differences in the number, size, and location of the parasites within the nervous system as well as to differences in the severity of the host's immune reaction against the parasite. Epilepsy, focal neurological signs, and intracranial hypertension are the most common clinical manifestations of neurocysticercosis. Since the diagnosis is not possible on clinical grounds, it is necessary the practice of complementary exams in every suspected case. Neuroimaging studies (CT or MRI) usually permit the diagnosis as they show objective evidence of the parasites and the inflammatory changes induced in the surrounding nervous tissue. Immunological tests developed to detect anticysticercal antibodies in serum or CSF present many problems inherent to the lack of specificity or sensibility; therefore, they should not be used by themselves to confirm or exclude the disease. Two drugs, albendazole and praziquantel, have been used with success to destroy most intracranial parasites; however, surgery still play a role in the management of some forms of the disease, particularly hydrocephalus and intraventricular cysts.

CONCLUSIONS

Development of modern diagnostic tests and introduction of potent cestocidal drugs have increased our knowledge on neurocysticercosis and have improved its prognosis. Nevertheless, some patients still have torpid clinical courses despite proper therapy.

[Neurocysticercosis in children: clinical and radiological analysis and prognostic factors in 54 patients]

INTRODUCTION AND MATERIAL

We studied 54 patients younger than 17 years of age with neurocysticercosis to determine the clinical manifestations, neuroimaging findings, and prognostic factors of this condition.

RESULTS

Seizures were present in 48 patients, representing the most common clinical manifestation. Forty-eight patients had a normal neurological examination, and only 3 patients had clinical evidence of increased intracranial pressure. CT scan of the brain revealed parenchymal brain cysticerci in 52 patients; one patient had a pure subarachnoid form of the disease and the remaining patient had a mixed (subarachnoid and parenchymal) form. The most common CT finding in patients with parenchymal neurocysticercosis was a single colloidal cyst (19 cases). All patients with seizures were treated with anti-epileptic drugs with an excellent rate of seizure-control. In addition, 23 patients received albendazole that caused resolution of cystic lesions in 19 cases. Anti-epileptic drugs were withdrawn in 13 patients who remained free of seizures during two years. However, 9 (69%) of these patients had recurrent seizures.

CONCLUSION

This evidence is in contrast with the reported benign course of neurocysticercosis in children, since most patients had seizure relapses despite therapy.

[Angiographic findings among Ecuadorian metis population with occlusive cerebrovascular disease of the anterior circulation]

INTRODUCTION AND OBJECTIVE

This study was conducted to determine the location of arterial lesions in a population of Ecuadorian Mestizos with cerebral infarcts in the carotid territory caused by large-artery atherosclerosis.

MATERIAL AND METHODS

Such patients were prospectively entered into a protocol of investigation that included cerebral angiography as the gold standard for evaluation of the extra and intracranial vascular bed.

RESULTS

Twelve (60%) of the 20 patients included in this study had symptomatic intracranial lesions, and the remaining 8 (40%) had extracranial lesions. Intracranial lesions were most often located in the middle cerebral artery stem. With the exception that systemic markers of arteriosclerosis were present in 3 of 8 patients with extracranial disease and in none of 12 patients with intracranial disease, we found no differences in stroke risk factors among patients with intra or extracranial lesions.

CONCLUSIONS

This study provides suggestive evidence that the distribution of arterial lesions in Ecuadorian mestizos with occlusive cerebrovascular disease is different from that in whites, but similar to that in blacks and orientals.

[Cerebrovascular complications of Takayasu's disease]

We report four young women with Takayasu's arteritis who developed an ischemic stroke. In three of these patients, this complication heralded the onset of the disease. Three patients also had seizures. In all cases, the diagnosis was suspected on the basis of an abnormal cardiovascular examination showing absent carotid or radial pulses, carotid bruits or significant asymmetries in blood pressure determinations. The aortogram showed that three patients had Takayasu's arteritis type I, with affection confined to the aortic arch and supra-aortic trunks, and the other patient had Takayasu's arteritis type III with additional involvement of the descending aorta. Three patients had an elevated erythrocyte sedimentation rate and were treated with corticosteroids. Takayasu's arteritis should be suspected in young patients, especially women, presenting with a cerebral infarct or seizures who also have an abnormal cardiovascular examination. The diagnosis is usually confirmed by aortography, following Ishikawa's diagnostic criteria. Corticosteroid therapy may be of value in patients with an elevated erythrocyte sedimentation rate.

Albendazole therapy for subarachnoid and ventricular cysticercosis. Case report

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.

Comparison of therapeutic regimen of anticysticercal drugs for parenchymal brain cysticercosis

The efficacy of different regimens of therapy for parenchymal brain cysticercosis either with praziquantel (PZQ) or with albendazole (ALB) was compared in 114 patients. Four schemes of treatment were used: PZQ 50 mg/kg per day for 15 days, PZQ 50 mg/kg per day for 8 days, ALB 15 mg/kg per day for 30 days, and ALB 15 mg/kg per day for 8 days. Three months after therapy, it was apparent that both PZQ and ALB were effective, as shown by the disappearance of cystic lesions in computed tomographic scans. Thirty-three control patients followed for a mean of 11 months had no spontaneous remission of lesions. When comparing PZQ with ALB, the latter was found to be more effective than the former for both the full and the short course of treatment: 85% vs 60% and 85% vs 48% disappearance of lesions, respectively (P less than 0.001). Comparison of the full vs the short course of PZQ showed that the short course had a further 12% reduction in drug effectiveness. In contrast, the length of ALB therapy could be shortened without lessening its efficacy. Based on these results, an 8-day course of ALB is recommended as treatment for parenchymal brain cysticercosis; a 15-day course of PZQ could be subsequently used in those patients who show only partial response to ALB.