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Biomedical subjects

C Almárcegui

Publications and source records attributed to C Almárcegui.

14 recordsLinked to original sources
PubMed2000

[Why evidence-based medicine? 20 years of meta-analysis].

BACKGROUND: Meta-analysis, described within evidence-based medicine, has become a frequent issue in recent medical literature. An exhaustive search of reported meta-analysis from any medical specialty is described. MATERIAL AND METHODS: Search of papers included in Medline or Embase between 1973-1998. A study of intra and inter-reviewers liability about selection and classification have been performed. A descriptive analysis of the reported papers (frequency tables and graphics) is described, including differences of mean of reported meta-analysis papers by medical specialty and year. RESULTS: 1,518 papers were selected and classified. Most frequently found (45.91%) were: methodology (15.7%), psychiatry (11.79%), cardiology (10.01%) and oncology (8.36%). Inter personal agreement was 0.93 in selecting papers and 0.72 in classifying them. Between 1977-1987 overall mean of reported studies of meta-analysis (1.67 + 4.10) was significatively inferior to the 1988-1998 (49.54 + 56.55) (p < 0.001). Global number of meta-analysis was positively correlated (p < 0.05) with the number of studies about fundamentals and methodology during the study period. CONCLUSIONS: The method used to identify meta-analysis reports can be considered to be adequate; however, the agreement in classifying them in medical specialties was inferior. A progressive increase in the number of reported meta-analysis since 1977 can be demonstrated. Specialties with a greater number of meta-analysis published in the literature were: psychiatry, oncology and cardiology. Diffusion of knowledge about fundamentals and methodology of meta-analysis seems to have drawn and increase in performing and reporting this kind of analysis.

Evidence-Based Medicine↗
PubMed1998

[Electroclinical and neuroimaging studies in epilepsy].

INTRODUCTION AND MATERIAL: During 54 months, we have studied the electro-clinical and neuroimaging features in outpatients with active epilepsy. Each patient was interviewed for one of us. Then, we have reviewed the medical records about both the clinical featuring. EEG and neuroimaging (NI) studies and seizures frequency (SF) outcome. Differences in crude proportions were assessed by chi 2 test for independence by 2 x 2 tables. RESULTS AND CONCLUSIONS: It has been 207 patients with 49 +/- 19.6 years of mean age at review. Partial seizures was significantly related with both a higher SF at onset and politherapy. Also, with a focal EEG distribution but only in case of complex partial seizures. Abnormal NI was significantly more frequent in oldest patients. A greater proportion of patients were in politherapy in four situation: SF at onset > 1 by day, a focal EEG distribution, duration of epilepsy longer than 20 years and age of onset lesser than 60 years. A 37.2% was seizures-free in the last year and in 34% the SF was improved a 50% or more from the beginning. A significantly greater proportion of patients was following with seizures in four cases: when the SF at onset has been > or = 1 by day, being partial seizures, women and having politherapy.

Adult↗
PubMed1997

Evaluation of cerebral function after carotid endarterectomy.

Neuroimaging methods have failed to disclose correlation between degree of cerebral atrophy and blood flow in carotid artery stenosis patients. Moreover, intellectual improvement after carotid endarterectomy does not correlate fully with neuroimaging data in such patients. We performed brain electrical activity mapping and psychological testing before and 4 weeks after operation in 28 patients with symptomatic, high-grade, carotid stenosis. Postoperatively, electroencephalographic (EEG) mean frequency and absolute theta power improved significantly (p < 0.01). Mean frequency increased >1 Hz in most areas while power decreased dramatically, mainly because of resolution of high-voltage foci in 8 patients. Differences were conspicuous in both frontal lobes irrespective of the operated side, which suggests changes in perfusion affecting the whole brain. This is a positive effect of endarterectomy. Mini-Mental test and Set Test for verbal fluency had a positive correlation with the qEEG changes. Quantitative EEG as a measure of cerebral function has disclosed discriminative improvement in the early postoperative period. Our results support the thesis of improvement subsequent to endarterectomy.

Adolescent↗
PubMed1997

[Early diagnosis of glaucoma with pattern-ERG].

PURPOSE: Current electrophysiological techniques for diagnosis of glaucoma include pattern-electroretinogram (PERG) and visual evoked potentials (VEP) but PERG has been recognized over the last decade as a good functional indicator of retinal ganglion cells. METHODS: An investigation has been carried out on 171 eyes of 89 subjects using both PERG (gold foil electrodes) and VEP. One group of 32 subjects with ocular hypertension (OHT) and another group of 27 subjects having simple chronic glaucoma (SCG) were compared with a control group of 30 healthy age-matched subjects. RESULTS: For PERG, the amplitude of the P50 and N95 components was measured but statistically significant differences were shown for N95 only in SCG (p < 0.01) and OHT (p < 0.05). FFT analysis on each PERG showed a dominant frequency of 3.3 Hz for OHT subjects versus 9.9 Hz for those of the control group. For VEP, the amplitude and latency of P100 was analysed. P100 latency showed significant delay (p < 0.05) in the SCG group only. CONCLUSIONS: These findings suggest that N95-amplitude is the most sensitive electrophysiologic parameter for early glaucoma detection. By comparing data of this work with a previous study using wire (anchor shaped) electrodes we demonstrate higher amplitude and lesser variability of the N95 component for gold foil electrodes, therefore this latter type of recording is acknowledged as the most sensitive for detection of early impairment of ganglion cells in HTO patients.

Adult↗
PubMed1997

[Cerebral mapping in patients with dementia of Alzheimer's type].

INTRODUCTION: The electric cerebral activity maps complement the conventional electroencefalography quantifying electric cerebral activity. One of the applications is in Alzheimer's dementia. OBJECT: The object of this study is to analyse the differences in the electric cerebral activity, by means a quantified EEG, in DAT and SDAT when compared with a control group of the same age. MATERIAL AND METHODS: Thirty patients meeting the criteria of probabledementia (NINCDS-ADRDA) in the senile (n = 19) and presenile (n = 11) form were studied. They were compared with a control group of the same age, 20 individuals older than and 17 younger than 65. RESULTS: The patients suffering from senile dementia as well as those suffering from the presenile form showed a significative increase of the delta and theta bands. On the other hand, a significant reduction of the alfa frequency bands and mainly those of beta was observed in the patients with ADT but not in the ADST ones. The significant increase of the slow bands in ADT and ADST and the significant decrease of the fast bands in ADT have been found in wide areas. Topographically the biggest affect has been registered in the frontal regions for the beta bands in ADT. CONCLUSIONS: The differences found in the electrical activity, depending on the age, would support Alzheimer's disease heterogeneity.

Aged↗
PubMed1996

[Etiology in complex partial epilepsy. II. Correlation between EEG topography and neuroimaging].

Neuro-imaging studies (NI) in patients with complex partial seizures (CPC) demonstrate the epileptogenicity of a more or less localized underlying lesion. Correlation with the topography of the EEG focus permits affirmation of the origin. We analyze anomalies on NI and on the EEG of 151 patients with CPC. The EEG was abnormal in 128 and showed a unilateral epileptic focus in 117. NI was focal and unilateral in 72 of the 102 abnormal cases. Topographic correlation was 78.5%. This close correlation in our series makes us consider the localized lesions to be the probable aetiological factor.

Adult↗
PubMed1994

Quantitative EEG in children with headache.

The object of this work is to determine if Brain Mapping can reveal significant differences between a normal control group and a group whose members suffer from one of three types of headache: tension-type, migraine with aura and migraine without aura. Both groups were formed by children aged between 6 and 14; the latter were undergoing no treatment and were in a headache-free phase. Results demonstrate that there are no significant differences between the control group and the tension-type headache group. Neither were differences found in migraine without aura group but in migraine with aura there was an increase of the theta/alpha ratio in the temporal posterior and occipital zones. This ratio could be used as a neurophysiological indicator in the evolution of the migraine with aura pathology.

Adolescent↗
PubMedDate not supplied

[Neurological sciences based on evidence].

OBJECTIVE: An exhaustive search of reported metanalysis from any medical speciality is described. MATERIAL AND METHODS: Search of papers included in MEDLINE or EMBASE between 1973-1998. A descriptive analysis of the reported papers (frequency tables and graphics) is described, including differences of mean of reported metanalysis papers by medical speciality and year. RESULTS: 1,514 papers were selected and classified. Between 1977-1987 overall mean of reported studies of neurologic metanalysis (1.20 +/- 1.10) was significatively inferior to the 1988-1998 (11.20 +/- 7.85) (p < 0.001). Global number of neurologic metanalysis was positively correlated (p < 0.05) with the number of studies about fundamentals and methodology during the study period. CONCLUSIONS: A progressive increase in the number of reported neurologic metanalysis since 1977 can be demonstrated. Diffusion of knowledge about fundamentals and methodology of metanalysis seems to have drawn and increase in performing and reporting this kind of analysis.

Evidence-Based Medicine↗
PubMedDate not supplied

[Pattern electroretinogram in anterior ischemic optic neuropathy].

INTRODUCTION: Anterior ischemia optic neuropathy is defined as ischemia of the disc optic papilla nerve. The aetiology is multifactorial and causes ischemia of the optic disc and apoptosis of the nerve cells of the retina. OBJECTIVE: To study the retina of patients with anterior ischemia optic neuropathy by means of the electroretinogram pattern (PERG) to assess the function of ganglion cells of the inner layers of the retina. PATIENTS AND METHODS: We studied 12 patients referred from the Ophthalmology Department with the diagnosis of anterior ischemia optic neuropathy. The electrophysiological study consisted of PERG and PEV within 20 days of the episode. The latencies and amplitudes of the different components of the responses and the ratios of the PERG amplitudes were determined. RESULTS: No significant differences were seen in the P50 component of the PERG or the latency of the N95 component. However, statistically significant values were obtained for the amplitude N95. These differences were greater when measured from a nonlinear baseline. CONCLUSIONS: The PERG is useful for early diagnosis of patients with anterior ischaemia optic neuropathy. Measurement of the N95 is more useful when a nonlinear baseline is used. This shows dysfunction of the ganglion cells of the inner retina caused by ischaemia and retrograde degeneration of axons and cell bodies of the optic nerve.

Aged↗
PubMedDate not supplied

[Peripheral neuropathy in systemic lupus erythematosus].

INTRODUCTION: Systemic lupus erythematosus (SLE) is the connective tissue disorder in which neuropsychiatric complications are most often seen. The prevalence of peripheral neuropathy varies from 5 to 27% depending on the series of cases described, with subclinical forms being most frequent. OBJECTIVES: To determine the prevalence of subclinical peripheral neuropathy in a group of patients with SLE, define their characteristics, and investigate any possible associations with clinico analytical parameters of the disease. PATIENTS AND METHODS. 32 patients with SLE were diagnosed in an Internal Medicine Outpatient Clinic and followed up for at least a year. They were studied prospectively and consecutively by clinical examination, laboratory test and neurophysiological studies (electroneurogram). RESULTS: Neurophysiological study showed peripheral neuropathy to be present in 50% of the patients, who were mainly asymptomatic (75%) and found to be normal on neurological examination (81.2%). The most frequent type of neuropathy was polyneuropathy (37.5%) which was predominantly axonal symmetrical and sensomotor followed by isolated mono neuropathy (6.2%) and multiple mononeuritis (6.2%). No clinical or analytical parameter was significantly associated with the development of peripheral neuropathy. CONCLUSIONS: The considerable frequency of subclinical peripheral neuropathy in patients with SLE and the absence of associated clinical or analytical parameters makes it necessary to carry out neurophysiological studies in these patients to detect its presence and establish the precise extent of the disorder.

Adolescent↗
PubMedDate not supplied

[Post traumatic partial seizures].

INTRODUCTION: Post traumatic epilepsy represents 4% of the prevalence of the disorder and is one of the sequelas which is most difficult to prevent. Risk factors have been described to predict the appearance of seizures. CLINICAL CASE: A seven year old boy with a severe head injury was admitted to the Intensive Care Unit. On neuroimaging studies there were multiple foci of contusion, mainly in the left hemisphere, and blood in the III and IV ventricles and frontal horn of the left lateral ventricle. The patient had severe sequelae of head injury with a right spastic hemiplegia and hemiparesia with hypertony of the left side, together with complete blindness of both eyes due to bilateral atrophy of the optic nerve. Serial EEG were done, in which a recording showed alternating periods of hypervoltage grapho elements superimposed on a trace of very low voltage, with continuous activity of low voltage and low frequency. There were no grapho elements with acute morphology. However, the patient had a first partial seizure a year and a half after his head injury. On the EEG an epileptogenic focus was identified in the left hemisphere. Within two years of his head injury he had seven seizures. He had not received prophylactic antiepileptic treatment after the head injury. CONCLUSIONS: We report a case of epilepsy secondary to a head injury, in which the first seizure occurred one and a half years after injury. In view of the risk factors, we discuss whether prophylactic anti epileptic treatment might have been beneficial.

Brain↗