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Biomedical subjects

R Simón

Publications and source records attributed to R Simón.

At least 19 recordsLinked to original sources
PubMed2001

Spontaneous carotid and vertebral artery dissection in children.

Carotid and vertebral artery dissection is a rarely reported cause of stroke in childhood and adolescence, especially if there is not a direct trauma to the neck. Four patients, under 15 years of age, presented with an internal carotid artery dissection, and one patient presented with a vertebral artery dissection. They were all making a physical effort when the event occurred. The five patients had ischemic symptoms, and in two the events were preceded by transient ischemic attacks. Headache was associated in four patients. The diagnosis was made by magnetic resonance imaging and angiography, which included transfemoral angiography in two patients. All improved before leaving the hospital, and four patients did not suffer recurrent episodes. The diagnostic accuracy of artery dissection has improved because of noninvasive neuroimaging testing, but it should still be suspected in any pediatric ischemic stroke, especially if there is headache or cervical pain associated.

Adolescent↗
PubMed2000

Differences in the composition of the subgingival microbiota of two periodontitis populations of different geographical origin. A comparison between Spain and The Netherlands.

The purpose of this study was to compare the subgingival microbiota of two geographically distinct patient populations using identical clinical and bacteriological methods. Adult patients with a diagnosis of periodontitis were consecutively selected according to pre-defined clinical criteria. Microbiological samples were taken from the deepest four sites with bleeding. The samples were plated on blood agar plates, for the determination of the total anaerobic counts and identification of specific bacterial pathogens, and on TSBV and McConkey for isolation of Actinobacillus actinomycetemcomitans and enteric rods, respectively. Thirty-one patients in Spain and 30 patients in The Netherlands were selected. Both patient groups showed similar clinical characteristics, both in terms of age, gender and periodontal clinical variables. A. actinomycetemcomitans was significantly more prevalent (23.3% vs. 3.2%) in the Dutch group, while Porphyromonas gingivalis was significantly more prevalent (64.5% vs. 36.7%) in the Spanish group. Bacteroides forsythus and most commensal periodontal pathogens showed similar prevalences, except Peptostreptococcus micros that was significantly more frequent in the Dutch group (96.7% vs. 74.2%). In summary, the subgingival microbiota from the Spanish group was characterised by a high prevalence of P. gingivalis and low of A. actinomycetemcomitans, while the flora from the Dutch group was characterised by a high prevalence of A. actinomycetemcomitans and P. micros.

Aggregatibacter actinomycetemcomitans↗
PubMed1999

Mitochondrial diseases in children: neuroradiological and clinical features in 17 patients.

Mitochondrial diseases result from structural, biochemical or genetic defects of mitochondria, which contain the respiratory chain. They usually affect children and young adults. We report the CT and MRI findings in 17 patients under 14 years of age, the youngest reported to date, with various mitochondrial diseases. Although imaging studies may be normal negative in the early stages, follow-up usually shows many abnormalities, which depend on clinical status and the disease. We have recognised a spectrum of findings that can be divided into four patterns: nonspecific myelin lesions (8/17); grey-matter nuclei involvement (6/17); a leukodystrophic pattern; and calcification of the brain (1/17), although mixed forms, particularly myelin and grey-matter lesions are frequent.

Brain↗
PubMed1998

[Ischemic stroke in children].

OBJECTIVE: Ischemic stroke in children and infants is a rare condition. We present a series of 23 pediatric patients of ischemic stroke. PATIENTS AND METHODS: A retrospective series of 23 patients, aged between 1 month and 13 years, diagnosed by anamnesis, clinical examination and neuroimaging. The clinical picture, neuroimaging findings, etiology, evolution and sequelae are evaluated. RESULTS: Eighteen of the patients had an ischemic stroke in the carotid territory (78.3%) and 5 in the vertebro-basilar (21.7%). Idiopathic (30.4%), cardiopathy (21.7%) and migraine (17.4%) were the most frequent etiologies. The recovery was complete in 9 patients (39.1%). There was a death as a result of systemic complications caused by dehydration (4.3%), and 13 patients (56.6%) were disabled: 6 with hemiparesis of diverse grades, 5 with epilepsy and hemiparesis, one with epilepsy, and one with mental retardation. CONCLUSIONS: Ischemic stroke in children and infants is an unusual entity. The causes are multiple, although there is an elevated percentage of idiopathic cases. In our series, we highlight the significative percentage of vertebro-basilar strokes and the finding of three unusual etiologies in ischemic stroke in childhood, such as migraine, Mycoplasma pneumoniae infection and smallpox.

Adolescent↗
PubMed1997

A comprehensive knowledge-based system for laboratory hematology.

The Coulter FACULTY knowledge-based systems, Professor Petrushka for peripheral blood interpretation, Professor Fidelio for flow cytometry immunophenotyping and Professor Belmonte for bone marrow reporting, have been installed in several hospitals in Spain, Portugal and the United Kingdom. In Spain and Portugal, the systems are part of the IZASA-Coulter CITOTECA workstation, which includes a video camera for capturing microscopic images and a networkable laboratory information system supporting color reports. At the Royal Hospitals Trust (St. Bartholomew's Hospital and The Royal London Hospital, London, UK), networked workstations are available and the system is used daily to generate bone marrow reports in the hematology laboratories. There have been considerable benefits from adopting Coulter FACULTY for bone marrow reporting, including faster turnaround time, improved quality of the reports and cost savings.

Artificial Intelligence↗
PubMed1997

[Spontaneous intracranial hemorrhages in childhood].

INTRODUCTION: Spontaneous or non-traumatic intracranial haemorrhages seen in children of under 15 years old are most frequently due to cerebral vascular malformations, followed at a considerable distance by blood disorders, vasculopathies, tumours and the complications of radio-therapy. OBJECTIVE: To present the cases of spontaneous and non-traumatic cerebral haemorrhage seen at our hospital. MATERIAL AND METHODS: We reviewed all the paediatric cases of spontaneous cerebral haemorrhage diagnosed in our hospital over the previous sixteen years, excluding bleeding in the neonatal period. Computerized tomography was done in all cases, study of the cerebrospinal fluid, angiography and/or magnetic resonance in some cases. RESULTS: We selected 44 patients, of who the aetiology could be determined in 30. Of these, 20 cases were due to vascular malformations, 7 were associated with haematological disorders, 2 with cerebral tumours and one case with meningococcal sepsis. The commonest form of presentation was that of an acute intracranial hypertension syndrome, also showing focal deficits, partial crises and meningism. CONCLUSIONS: The commonest cause of spontaneous intracranial haemorrhage in children is due to rupture of a vascular malformation, namely an arterio-venous malformation. Angiography and/or magnetic resonance are the techniques of choice for diagnosis. The various causes of disorders of haemostasia also are important in giving rise to intracranial bleeding.

Adolescent↗
PubMed1996

Miller Fisher syndrome in infancy.

Miller Fisher syndrome (MFS) is characterized by the triad of ataxia, areflexia and ophthalmoplegia. It is exceptional for infants to be involved. Two infants, aged 11 and 16 months, developed acute-onset MFS. Both patients had prodromal upper respiratory tract infection. Pupillary responses to light, strength and sensation modalities were preserved. One patient was lethargic for a day; the electroencephalogram disclosed slightly slow background activity that later became normal. The other received high-dose intravenous immunoglobulins for 5 consecutive days starting at once on admission; within the next 7 days he became asymptomatic. Increased cerebrospinal fluid protein content and delayed nerve conduction studies with prolonged distal latencies were encountered in both patients.

Ataxia↗
PubMed1996

[Treatment of refractory infantile epilepsy with vigabatrin in a series of 55 patients].

We present the results of treatment with vigabatrin in the polytherapy of resistant infantile epilepsy. A retrospective review of 55 children with resistant epilepsy aged between 2 months and 15 years was carried out between January 1992 and January 1995. Semiologically, the crises treated were simple partial crises (CPS), complex partial crises (CPC), West's syndrome, the Lennox-Gastaut syndrome and polymorphic crises. The efficacy of the drug (defined as a 50% or more reduction in crises), secondary effects and the reduction in the number of drugs necessary were evaluated. 60% of the children studied improved. 20% became completely free of crises. 34% remained unchanged and 3% became worse. In West's syndrome 100% responded satisfactorily, as did 80% of the cases of partial crises, but only 40% of those with Lennox's syndrome responded. Generalized tonic-clonic crises did not respond, and myoclonic crises became worse. Aetiologically, there was greater improvement in the symptomic cases than in the essential cases, the improvement being 70% while 5 patients with tuberose sclerosis responded particularly well. Medication was stopped in one case because of side-effects, due to a psychiatric disturbance, and in another case vigabatrin caused transitory side-effects. In 10% of the subjects the initial efficacy wore off around 6 months later. We have shown the usefulness of vigabatrin in the polytherapy of infantile epilepsy, which is resistant to conventional epileptic drugs, mainly in simple and complex partial crises and in West's syndrome. Its minimal side-effects and the favourable response in over 50% of cases make it an extremely useful drug.

Adolescent↗
PubMed1994

[Axilla skin biopsy in the diagnosis of Lafora's disease].

Skin biopsy is the method of choice for the diagnosis of Lafora's disease. The presence of PAS (+) inclusions characteristic of Lafora's disease has been thought to be more evident in aprocrine glands of the axillary skin than in the duct cells of the eccrine glands. We describe 4 patients with Lafora's disease diagnosed by axilla skin biopsy, confirming the usefulness of this procedure.

Adolescent↗
PubMed1991

[Congenital fiber-type disproportion: analysis of a series of 11 cases].

We present 11 patients with congenital fiber type disproportion suggesting the existence of two different clinical groups. The first group not associated with other diseases, presents a uniform clinical picture and a generally good prognosis, although the patients with severe respiratory involvement can die. The second group includes the cases in which CFTD is associated with other congenital diseases such as Lowe's Syndrome, Möbius' Syndrome, hypothyroidism and hydrocephalus. In this group the clinical presentation and prognosis is that of the associated disease added to that of CFTD. The frequent association of CFTD with other congenital diseases suggests that CFTD may not be a specific myopathy but a histological abnormality due to different pathogenic insults which interfere with the normal growth and maturation of the muscle fibres.

Abnormalities, Multiple↗