Biomedical subjects
Publications and source records attributed to A P Vargas.
Thirteen patients with Schistosoma mansoni myelopathy are reported. Neurologic syndromes included acute areflexic flaccid paraplegia (three), thoracic myelopathy with hyperreflexia and Babinski sign (six), and a cauda equina syndrome (four). Inflammatory granulomas and a schistosome worm in a leptomeningeal vein of the spinal cord were observed in the one patient coming to necropsy.
BACKGROUND: American trypanosomiasis, known as Chagas' disease (CD) is a major cause of cardiomyopathy in South America. Irreversible damage to the heart can appear 10 to 20 years after chagasic infection. The frequency of cerebrovascular complications in chronic CD is unknown. OBJECTIVES: To describe a group of patients with chronic or latent CD affected by ischaemic stroke and identify predictive variables for stroke in CD patients. PATIENTS AND METHODS: Retrospective case series of stroke patients with CD was studied using a cross sectional, descriptive design. CD was confirmed by positive immunofluorescence and haemaglutination serology. Data were collected on age, sex, vascular risk factors, previous history of CD, diagnostic stroke subtype, electrocardiograph and echocardiography findings. Frequency of vascular risk factors were compared with a control group of 239 non-chagasic stroke patients. RESULTS: 136 consecutive CD stroke patients, mean age 56 years, 72 women and 64 men were identified. Vascular risk factors were observed in 81.6% of CD patients. Hypertension (70.29% versus 51.47%; p=0.0004), diabetes mellitus (15.9% versus 6.61%; p=0.0143), and tobacco use (53.98% versus 30.88%; p=0.00002) were significantly less frequent in the CD stroke group. Cardiomyopathy was significantly higher in CD stroke patients (45.58% versus 24.69%; p=0.00005). Abnormal electrocardiograms was observed in 82% of chagasic patients (right bundle branch block 39.5%, left anterior fascicular block 35.8%). Left ventricle (LV) diastolic dysfunction (61.47%), LV systolic dysfunction (51.18%), congestive cardiomyopathy (29.92%), and apical aneurysm (15.74%) were the most frequent echocardiographic findings. Aetiologies were cardioembolism (52.2%), undetermined (36.76%), atherothrombotic (8.82%), and small vessel stroke (2.2%). A diagnosis of CD was established after presentation with stroke in 38.23% of the patients. CONCLUSIONS: CD should be included in the differential diagnosis of stroke in patients of South American origin.
Movement disorders have rarely been the result of psychiatric disturbances. Psychogenic dystonia is caracterized by inconsistent findings, a known precipitant factor, onset in legs, pain, multiple somatizations and incongruent association with other movement disorders. We report two patients with clinically established psychogenic dystonia. Patient 1: a female that presented sudden loss of strength in her four limbs; she developed feet dystonia, alternant laterocollis, generalized and irregular tremor, and limb hypertonia that disappeared with distraction; psychological examination showed severe depression, hypochondria and obsessive disorder. Patient 2: a female that presented with irregular limb tremors that disappeared with distraction and left foot dystonia nine years ago; she gradually lost her walk capacity; she complained pain in lumbar area and in her left limb, psychological examination showed infantile behaviour, low frustration tolerance, impulsivity and self-aggression. Their complementary exams showed no alterations and they had no response to specific pharmacological treatment. Dystonia is rarely psychogenic, but this etiology is suggested when clinical characteristics are inconsistent and incongrous with a classical disorder. It should be part of differential diagnosis when appears in association with other somatization or psychiatric disorders.
Dementia is one of the manifestations of late syphilis and it is characterized by cognitive deterioration and behaviour disturbances. We report on a male patient with cognitive decline, behaviour disorder, hyperactivity, hallucinations, short-term memory and Argyll Robertson pupils due to neurosyphilis. Minimental state test (MST) was 16. Cerebrospinal fluid (CSF) protein concentration was 82 mg/dl, CSF-leucocyte count 128 cells/mm3 (98% mononuclear cells), CSF-VDRL 1:4, and CSF-T.pallidum haemaglutination assay 1:2560. MRI showed no cerebral alteration, but SPECT revealed left fronto-temporal hypocaptation. He received intravenous penicillin. MST done 3 months after the treatment scored 22. A new spinal tap showed normal CSF. Neurosyphilis should be part of the differential diagnosis of every patient showing cognitive deterioration and behaviour disturbances. During follow-up, MMS is an useful instrument to ++measure cognitive decline and response to treatment.
BACKGROUND: Sydenham's chorea (SC) occurs in 26% of patients with rheumatic fever (RF). Despite usually being described as a self-limited condition, few reports indicate that SC may persist in rare subjects. OBJECTIVE: To investigate the proportion of subjects with SC lasting more than 2 years and if clinical features differentiate patients with SC with a duration of less than 2 years (Group 1) from those with SC lasting more than 2 years (Group 2). METHODS: Prospective assessment of all patients with SC seen at our service from July 1993 through March 1998 analyzing the following: gender; age at onset; frequency of arthritis, carditis, family history of RF and SC; topographic distribution; and chorea severity on a 0-4 scale. RESULTS: Thirty-two patients (19 female, 13 male) were studied. In Group 1 (16 subjects, 50%) the follow-up period was 36.2 +/- 20.0 months; 50% were female; age at onset was 10.9 +/- 2.6 years; arthritis and carditis were present in 37.5% and 31.2%, respectively; family history of SC was reported by 18.7%; hemichorea was seen in 25.8% of subjects; and the mean intensity of chorea was 2.6 +/- 0.8. In Group 2, with a follow-up period of 34.1 +/- 18.9 months, 68.8% were female; age at onset was 9.3 +/- 3.9 years; arthritis and carditis were diagnosed in 18.7% and 50%, respectively; no patient reported a family history of SC; hemichorea was observed in 6.2% of subjects; and the mean intensity of chorea was 2.8 +/- 0.5. No difference was statistically significant. CONCLUSIONS: SC persists in half of our patients. Female gender, possibly related to endocrine factors, as well as the presence of carditis, indicating a more severe disease, may be risk factors for a longer duration of SC.
BACKGROUND: Hemifacial spasm (HFS) is a form of segmental myoclonus often associated with vascular compression of the seventh nerve at its exit in the brain stem. Although a few uncontrolled studies describe the association of arterial hypertension (AH) with HFS, their relationship remains to be elucidated. OBJECTIVES: To compare the clinical and radiologic features of patients with HFS and subjects with blepharospasm (BLS) with special emphasis on the presence of AH. MATERIAL AND METHODS: Chart review of all patients with HFS and BLS seen at a hospital-based movement disorders clinic from July 1993 through March 1998, analyzing the following parameters: gender, age at onset, frequency of AH, and abnormalities on computerized tomography (CT) or magnetic resonance imaging (MRI) studies. Neuroimaging studies (52 CT and 14 MRI) were performed in 45 subjects with HFS and in 21 with BFS. All patients were examined by one of the authors (FC). RESULTS: HFS and BLS were diagnosed in 48 (31 women, 17 men) and 34 (28 women, 6 men) patients, respectively. The age at onset was 50.1 +/- 12.6 years in HFS and 50.3 +/- 16.5 years in BLS. AH was diagnosed in 32 (66.7%) subjects with HFS and in 13 (38.2%) patients with BLS (chi-square p = 0.01). Neuroimaging evidence of vascular tortuosity in the cerebello-pontine angle was identified in 16 (25.4%) patients, all of whom had HFS (38.1%). Thirteen of 37 patients with AH who had imaging studies displayed vascular tortuosity in the cerebello-pontine angle (chi-square p = 0.01). CONCLUSIONS: AH is significantly more common in HFS than in BLS. AH is related to vascular tortuosity in the cerebello-pontine angle. Our findings suggest that AH may be an important risk factor for HFS.
Salivary gland extract of Triatoma infestans prolonged thrombin time, prothrombin time, and activated partial thromboplastin time, while salivary gland extract of Panstrongylus megistus delayed thrombin time and activated partial thromboplastin time. However, saliva of P. megistus prolonged activated partial thromboplastin time and saliva of T. infestans delayed activated partial thromboplastin time and prothrombin time. T. infestans saliva interferes particularly with activity of factor VIII (intrinsic pathway) and factor V (common pathway), but also affects other factors. Saliva of the triatomine species studied presented distinct SDS-PAGE profiles. These results demonstrate that there are differences in anticoagulant activity and protein composition of triatomine saliva.
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Treatment with dexamethasone (DMS) in the early phases of the experimental Schistosoma mansoni infection causes an indirect effect on the cercaria-schistosomulum transformation process. This is observed when naive albino mice are treated with that drug (50 mg/Kg, subcutaneously) and infected intraperitoneally 01 hour later with about 500 S. mansoni cercariae (LE strain). An inhibition in the host cell adhesion to the larvae, with a simultaneous delay in the cercaria-schistosomulum transformation, is observed. This effect is probably due to a blockade of the neutrophil migration to the peritoneal cavity of mice, by an impairment of the release of chemotactic substances. Such delay probably favors the killing of S. mansoni larvae, still in the transformation process, by the vertebrate host defenses, as the complement system.
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INTRODUCTION: Cassava (Manihot esculenta) is the basic foodstuff of more than 500 million persons in developing countries. Its edible root contains a glucoside with a high cyanogenic content, linamarina, which is hydrolysed in the human intestinal tract by the resident microbial flora, with liberation of HCN. Inadequate preparation and cooking followed by consumption whilst half-raw, especially in diets based almost exclusively on cassava for a long period of time, may lead to a neurological syndrome of damage to the upper motor neuron and the appearance of spastic paraparesia. CLINICAL CASE: We present the case of a 44 year old male agricultural worker from the Amazon region who had a predominantly crural spastic paraparesis which had been present for four years. His main food was 'mandioca brava' or wild cassava which was insufficiently cooked. Study of the CSF ruled out infection by HTLV and neurosyphilis. On magnetic resonance there was slight thoracic atrophy. CONCLUSIONS: In patients with spastic paraparesis, normal neuroimaging and CSF findings, and a normal family history, one should specifically investigate exposure to potentially toxic plants and foods, especially in regions in which nutrition is based on potentially cyanogenic roots or plants. It is necessary to improve the methods of processing and cooking cassava, and to avoid diets based almost entirely on this root, in order to reduce the potential neurotoxic damage which may be caused by this plant.
INTRODUCTION: Type I human T-cell lymphotropic virus (HTLV-I) is a retrovirus with affinity for CD4 cells. This infection may give rise to a broad spectrum of disorders including T-cell leucemia/lymphoma, the myelopathy/tropical spastic paraparesis complex (M/TSP), and to a lesser extent, uveitis, arthritis, polymyositis and peripheral neuropathy. M/TSP is a progressive, chronic myelopathy characterized by spasticity, hypereflexia, muscle weakness and sphincter disorders. Much less frequently it may precede, or give rise to, a cerebellar syndrome with ataxia and intention tremor. CLINICAL CASE: We describe the case of a 13 year old adolescent girl who presented with a neurological syndrome which had started with tremor of the head and limbs, ataxia, dysmetria, frequent falls and sphincter disorders. During the two and a half years that she had had this illness she had developed spastic paraparesis of the legs and had repeated urinary infections. Serology of blood and CSF was positive for HTLV-I using the ELISA technique and confirmed by Western-blot. EMG showed predominantly axonal sensomotor neuropathy. A neurogenic bladder was detected on functional urodynamic studies. On MR there was moderate atrophy of the thoracic spinal cord and slight alterations of the subcortical white matter. CONCLUSIONS: The presence of a cerebellar syndrome or neuropathy of uncertain origin, in endemic areas, should lead to the inclusion of HTLV-I infection in the differential diagnosis, even in the absence of pyramidal symptoms or defined M/TSP. Maternal seropositivity supports the hypothesis of mother-daughter transmission during lactation.
INTRODUCTION: American trypanosomiasis, Chagas disease is caused by Trypanosoma cruzi. Between 10% and 30% of infected persons develop the chronic form, with predominance of the cardiac and gastrointestinal forms. Chagas myocardiopathy leads to congestive heart failure, dysrhythmias and thromboembolic phenomena, and may cause strokes. PATIENTS AND METHODS: We report two patients, a 57 year old woman and a 52 year old man, carriers of the chronic cardiac form of Chagas disease, with cardioembolic strokes. In both persons, serology was positive for Chagas disease (indirect hemagglutination and indirect immunofluorescence). The causes of atherothrombotic stroke were ruled out on carotid and transcranial Doppler studies. RESULTS: The woman had previously had an infarct of the left middle cerebral artery. She was admitted with a stroke involving the vertebrobasilar territory. On Holter studies there was second degree atrioventricular block and the electrocardiogram showed severe dilated myocardiopathy. On magnetic resonance studies there was an old left temporoparietal infarct and recent ischaemia of the pons and cerebral peduncle. She was anticoagulated and a pacemaker implanted. The man had a right middle cerebral artery infarct. His electrocardiogram showed atrial fibrillation and left anterosuperior block. The echocardiogram showed left ventricular dysfunction and concentric ventricular hypertrophy. CONCLUSIONS: The chronic cardiac form of Chagas disease should be included in the differential diagnosis of stroke of cardioembolic origin both in endemic areas and in countries to which persons exposed to infection during the early years of life emigrate.
INTRODUCTION: As a chronic chagasic myocardiopathy, Chagas disease (CD) may give rise to cardiac insufficiency, arrhythmias, thromboembolism and stroke. Occlusive vascular disease of the rostral portion of the basilar artery or of its emergent branches may cause ischemia and necrosis in different areas of the midbrain, thalamic nuclei, cerebellum and occipital lobe. CASE REPORTS: We describe four patients (three males and a female, the average age being 54 years) with positive chagasic serology (indirect immunofluorescence and hemagglutination) and suffering from CD and top of the basilar syndrome. All of them underwent tests to determine proteins C and S, antithrombin III, factor V Leiden, and lupic anticoagulant, as well as being submitted to explorations using electrocardiogram (ECG), echocardiogram, carotid and transcranial echo Doppler, computerised tomography (CAT) and magnetic resonance imaging (MRI). RESULTS: The coagulopathy studies were normal or negative in the four patients. We also describe the findings from the electrocardiograms (blockage in right branch, two cases; auricular fibrillation, one case; repolarization disorder, one case) and the echocardiograms (left ventricular dysfunction, two patients; apical aneurysm, one patient; mural thrombus, one patient). Neuroimaging revealed one case of each of the following infarctions: bilateral thalamic, bilateral cerebellar and occipital, cerebellar, thalamic mesencephalic and occipital, and thalamic mesencephalic and occipitotemporal. CONCLUSIONS: In a patient with positive chagasic serology, with or without findings in the ECG and in the electrocardiogram that can be put down to a cardioembolic source, a vascular syndrome produced by occlusion of the distal basilar artery suggest a cardioembolism. We recommend secondary anticoagulation because of the high risk of recurrence.
INTRODUCTION: Pantothenate kinase deficiency (Hallervorden-Spatz syndrome, HSS) triggers cerebral neurodegeneration with iron deposition in the basal ganglia. The classical form has an early onset in infancy, a progressive course, the presence of extrapyramidal symptoms (dystonia, chorea, rigidity) and pigmentary retinitis. There are atypical late onset forms with predominance of symptoms of Parkinsonism and dementia, which progress slowly and course somewhat less progressively. CASE REPORT: We describe three patients with HSS and an atypical presentation, with onset during the second decade of life. In all cases magnetic resonance imaging showed areas of hyposignal in T2 sequences in medial globus pallidus, with central hypersignal, which gave rise to a tiger's eye image. Other aetiologies, such as Wilson's disease, gangliosidosis GM1, hypoprebetalipoproteinemia, hexosaminidase A deficiency, aminoacidurias and infantile Huntingdon's chorea, were precluded. In the 20-year-old male the initial manifestations at the age of 17 were superposed over Gilles de la Tourette syndrome, with complex motor and vocal tics, palilalia, behavioural disorders and postural instability. The 13-year-old patient presented symptoms of chorea, hemiballic movements and dystonia in the lower limbs, which limited walking at the age of 12. The 28-year-old female patient presented a progressive rigid akinetic syndrome, with dementia and partial response to levodopa. CONCLUSIONS: The clinical spectrum of HSS is broad and its differential diagnosis must include hemiballism, Tourette syndrome and juvenile Parkinsonism.
INTRODUCTION: Schistosomiasis is a parasitic infection caused by Schistosoma sp that affects over 200 million people worldwide. The neurological manifestations, caused by the eggs or by anomalous migration of the parasite, can be epileptic seizures and myeloradicular syndromes. S. mansoni is endemic in Brazil and is an underdiagnosed cause of transverse myelitis and myeloradiculopathy. CASE REPORTS: We present the cases of two Brazilian women, aged 28 and 32, who suffered from conus medullaris and cauda equina syndrome, and a thoracolumbar myelopathy, respectively. Diagnosis was based on the epidemiological exposure, suggestive neurological syndrome and positive serological studies in blood or cerebrospinal fluid (CSF) by means of indirect immunofluorescence (IFI) for S. mansoni. Other causes of myeloradiculopathy were dismissed. The first patient presented progressive sphincteric, motor and dysesthetic symptoms that suggested cauda equina and conus medullaris syndrome. Examination of the CSF revealed pleocytosis, eosinophils and high protein levels; (IgG) IFI was positive for S. mansoni. Spinal cord magnetic resonance imaging showed an increased volume in the conus and epiconus, areas of hypersignal in T2 and heterogeneous contrast enhancement. Case 2 presented an acute picture of paresthesias and myoclonias in the lower limbs. Serological analysis for S. mansoni in blood was positive. S. mansoni eggs were found in faeces. Results of the CSF study were normal. Both patients were treated with praziquantel and prednisone and responded well both clinically and radiologically. CONCLUSIONS: In patients with epidemiological evidence of exposure to S. mansoni, lumbosacral myeloradiculopathy is suggestive of neuroschistosomiasis.