MR imaging of central nervous system tuberculosis.

TB involving the CNS and its coverings is a complex and potentially devastating disease. The increasing incidence of this disease in both immunologically normal as well as immunologically incompetent populations makes the subject of TB one of universal concern. Although its appearance on MR is not specific, it is important in the proper clinical setting to recognize the range of possible patterns that can be observed on images. The inclusion of TB in the differential diagnosis on the basis of the patient's region of origin, the socioeconomic background of the patient, and the presence of underlying predisposing disease may potentially promote timely initiation of appropriate therapy.

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.

Praziquantel treatment of porcine brain and muscle Taenia solium cysticercosis. 1. Radiological, physiological and histopathological studies.

Porcine Taenia solium cysticercosis, recognized as a model of the human disease, was used to analyze the effect of the anthelminthic drug praziquantel on hosts and parasites. The drug (50 mg/kg daily) was given over 15 days in the feed of 13 cysticercotic and 9 control pigs. Changes in the number, size and appearance of brain parasites were seen by computerized tomography immediately after the last dose of praziquantel, although not all cysticerci had disappeared by day 47 following the end of the treatment. Muscle parasites became small and hyperdense shortly after treatment and disappeared from tomographic images afterwards. No alterations were found in EEGs or in brain-stem auditory and somatosensory evoked potentials. Muscle cysticerci showed increasing degrees of degeneration with time after treatment, and an augmented inflammatory reaction was concomitantly observed. In contrast, more heterogeneous results were obtained in parasites lodged in the brain, since viable cysts and less intense inflammatory reactions were found in the brain at different times after treatment. Physiological evaluation of the parasites showed that evagination was inhibited immediately after treatment and that oxygen consumption decreased with time. The results of this investigation suggest that praziquantel damages cysticerci and that the inflammatory reaction destroys and eliminates them.

Histological description of tomographic images of Taenia solium cysticerci in pig brains.

In the computed tomography (CT) scans of five pigs with neurocysticercosis (Taenia solium), interesting lesions produced by the larvae were selected. The pigs were euthanized and the corresponding lesions in their brains identified and processed for histopathology. It was found that the hypodense areas in CT scans corresponded to vesicular larvae that are presumably viable. The hyperdense areas were either solid in nature or had formed a rim around a hypodense center and in the brain slice they were either solid granulomas or colloidal cysts with inflammatory reaction in the periphery, perivascular cuffing, and vasculitis. It was not always possible to classify larvae as meningeal or parenchymatous in the CT.

Occlusion of the middle cerebral artery due to cysticercotic angiitis.

Three patients with cysticercosis developed a cerebral infarct secondary to the occlusion of the middle cerebral artery or its major branches. Histopathologic examination revealed a large subarachnoid cysticercus surrounding the occluded arteries in two patients and diffuse thickening of the leptomeninges in one. Blood vessels around the parasite showed inflammatory changes that caused either occlusive endarteritis or thrombosis due to disruption of the endothelium. Cysticercosis should be considered as a cause of occlusion of the major intracranial vessels, particularly in young patients living in areas where this disease is endemic.

Swine cysticercosis treated with praziquantel, a short report.

Swines with cysticercosis are a useful model to study human disease. A multidisciplinary approach was undertaken to study in detail the effect of praziquantel treatment on hosts and parasites. Computerised tomographic scans showed changes in the number and size of parasites in treated pigs. These changes were more apparent in muscle than in brain cysticerci. Neurophysiologic data were normal in cysticercotic pigs before and after drug treatment. An increase in antibody response was seen immediately after treatment regarding the amount of antibodies and number of antigens recognised. A lower number of polyploid lymphocytes was seen after treatment in cysticercotic pigs as compared to untreated pigs. At different times after treatment pigs were humanely euthanised. Oxygen consumption rate of cysticerci decreased after treatment and evagination was abolished. The inflammatory reaction that surrounded parasites increased in number and type of cells. This was more apparent around cysticerci obtained from muscle than from the brain.

Intracranial tuberculoma: MR imaging.

MR studies of 6 patients with intracranial tuberculoma are reviewed. All patients also underwent CT scans which showed hypo- or isodense lesions with abnormal enhancement following contrast administration. MR showed lesions with prolongation of the T1 relaxation time in every case. On the T2-weighted sequences, the signal properties of the tuberculoma varied according to the stage of evolution of the lesion. Incipient tuberculomas appeared as scattered areas of hypointensity surrounded by edema. Mature tuberculomas were composed of a dark necrotic center surrounded by an isointense capsule which was, in turn, surrounded by edema. In one patient, the center of the lesion was hyperintense probably because of liquefaction and pus formation (tuberculous abscess). While both, CT and MR, were equally sensitive in visualizing the intracranial tuberculoma in every patient, MR was slightly superior in demonstrating the extent of the lesion, especially for brainstem tuberculomas. Nevertheless, the potential role for MR diagnosis of intracranial tuberculoma is limited by the fact that other infectious or neoplasic diseases may present similar findings. The diagnosis of intracranial tuberculoma should rest on a proper integration of data from clinical manifestations, cerebrospinal fluid analysis, and neuroimaging studies.

Comparative analysis of human and porcine neurocysticercosis by computed tomography.

Human and porcine cases of neurocysticerosis were compared by computed tomography in regard to the morphological characteristics of the parasites and the impact of the infection on the brain. In pigs and young people many parasites were usually found, but this was seldom the case in adult humans. These parasites were small and located mainly in the parenchyma and the subarachnoid space; no calcified cysticerci were found. In contrast, in adult humans cysticerci were heterogeneous in appearance and distribution. The brain of the pigs showed no evidence of inflammatory reaction while young people had oedema, enhancement and hydrocephalus; in contrast, adults showed diverse tomographic characteristics of brain response. Thus, the disease has at least 2 different forms. It may be mild with short development and parasites of similar appearance, as occurs in young hosts. In contrast, a long lasting disease occurs in adults, with diverse tomographic, neurological and parasitological features.

Cerebral cysticercosis in pigs studied by computed tomography and necropsy.

An original technique for computed tomography (CT) of the pig's brain is described. Brains of 11 cysticercotic pigs were studied by CT and by macroscopic and microscopic examination after necropsy, in order to compare the tomographic images with the anatomic findings. By CT, cysticerci could be seen in all the brains except one which had only one parasite. Good correlation was found when the CT sections were compared with the anatomic slices, nevertheless not all cysticerci seen during necropsy examination could be identified in the CT images. Only two parasites were found in the ventricles. There were difficulties in differentiating submeningeal and parenchymal localization of the cysticerci. Most cysticerci had similar morphologic appearance; inflammatory reactions of different degrees and characteristics were observed around some of them.

The role of computed tomography (CT) in the diagnosis of neurocysticercosis.

With the introduction of computed tomography (CT), the diagnosis of cysticercosis of the central nervous system (CNS) has been considerably improved. This is very important, especially for the countries in which the disease is still endemic. Plain skull radiographs or invasive procedures such as pneumography, ventriculography, and cerebral angiography can be used, but now CT has become the examination of choice because it is a safe, noninvasive, and accurate method thus making the other procedures unnecessary. In the present paper, 8,676 CT scans are reviewed from which 710 are selected patients with neurocysticercosis. CT has provided the diagnosis with greater precision than before. Its localization in the series was as follows: parenchymal, 473 patients, 65.2%; meningeal, 125 patients, 18.3%; mixed, 96 cases, 14%; intraventricular, 16 cases, 2.5%.

Praziquantel in the treatment of neurocysticercosis: long-term follow-up.

Thirty-five patients with active neurocysticercosis were treated with praziquantel and followed for 1 year after therapy. CT and CSF analysis showed that 91% of patients with parenchymal cysts improved, and 47% of patients with chronic arachnoiditis had remission. A single treatment with praziquantel for 2 weeks, administered in a daily dose of 50 mg/kg of body weight, was highly effective in parenchymal cysticercosis but less effective in meningeal cysticercosis. The benefits were sustained for at least 1 year.

Therapy of parenchymal brain cysticercosis with praziquantel.

Twenty-six patients with cysticercosis of the brain parenchyma were treated with the antihelmintic agent praziquantel (50 mg per kilogram of body weight daily for 15 days). During treatment a strong inflammatory reaction occurred, as evidenced by increased protein and cells in the cerebrospinal fluid. This finding correlated with headache, exacerbation of neurologic symptoms, and edema and inflammation around cystic lesions. After three months of treatment all patients had improved clinically, and 13 (50 per cent) were asymptomatic. The total number of cysts on CT scans had decreased from 152 at the beginning of treatment to 51, and the mean diameter of cysts was reduced by 72 per cent. CT scans showed improvement in 25 of the 26 patients, with total remission of all cysts in nine. Seventeen control patients followed with CT studies for a mean of 9 +/- 2 months had no spontaneous remission of lesions, and in many cases the scans showed worsening during the observation period. Our results indicate that praziquantel is effective in cysticercosis of the brain parenchyma.

The acute encephalitic phase of neurocysticercosis: computed tomographic manifestations.

Brain infestation by Cysticercus cellulosae, the larval form of Taenia solium, is a common disorder in Mexico and other Latin American countries, Asia, Africa, and some Eastern European countries. Recent immigration has caused an increase in the number of cases of neurocysticercosis in the United States. This work describes the acute encephalitic form of neurocysticercosis in 26 cases. The clinicopathologic and neuroradiologic manifestations are discussed with particular emphasis on the use of computed tomography as a main diagnosis modality which demonstrates multiple diffuse (85%) or localized (15%) enhancing nodules associated with severe edema.

Wernicke's encephalopathy. A case report with neurophysiologic and CT-scan studies.

A case of Wernicke's encephalopathy with ataxia, confusion, memory loss, partial seizures of complex behavior and hypothermia, subsequent to thiamine depletion due to chronic malnourishment and triggered by an episode of acute vomiting and diarrhea, is reported, Computerized tomography (CT-scan) depicted small bilateral lesions in areas adjacent to the walls of the third ventricle, common location of the lesions seen in autopsy material of Wernicke's encephalopathy. Early diagnosis and treatment with vitamin B complex supplemented with intensive mnemonic and cognitive therapy led to complete recovery in a ten day period.

Cisternografia de la base del craneo con metrizamida y tomografia computada. / Cisternography of the skull basis with metrizamide and computed tomography

Se menciona la experiencia obtenida con la metrizamida, un material de contraste hidrosoluble no ionizado usado en la neurorradiologia desde 1973. Los autores de este trabajo lo usaron en 48 casos descritos, corroborando asi lo expuesto por otros investigadores, de la utilidad, su tolerancia bien aceptada por el tejido nervioso y sus meninges con muy poca toxicidad. Ademas se menciona que en los casos en los que aparecen efectos colaterales, estos son moderados y transitorios, solo en un caso hubo una crisis convulsiva, que cedio facilmente con la administracion de diacepam. Proporciona una calidad excelente como radiopaco cuando se inyecta en el espacio subaracnoideo raquimedular, en las cisternas basales del cerebro y directamente en la cavidad de los ventriculos laterales del encafalo, permitiendo obtener un diagnostico claro y preciso en los casos usados en esta comunicacion