Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 73
Filtrar
Más filtros

Bases de datos
País/Región como asunto
Tipo del documento
País de afiliación
Intervalo de año de publicación
1.
Dermatol Online J ; 18(1): 11, 2012 Jan 15.
Artículo en Inglés | MEDLINE | ID: mdl-22301048

RESUMEN

OBJECTIVE: This is a multicentric, observational and controlled study designed to verify the existence of a significant association between plaque-type psoriasis and oral lesions, such as geographic tongue and/or fissured tongue. STUDY DESIGN: during a period of 9 months all consecutive patients with plaque-type psoriasis were enrolled using simple nonrandom (sequential) sampling. The control group included healthy subjects presenting to the same Dermatology centers to monitor pigmented skin lesions; the patients were matched for age and sex. All patients were examined for oral lesions. RESULTS: Out of a total of 535 psoriatic patients and 436 control group patients, oral mucosal lesions were detected in 188 (35.1%) and 86 (19.7%) cases, respectively, and the difference is statistically significant. Fissured tongue (FT) and geographic tongue (GT), which were most frequently detected, were seen more frequently in psoriatic patients (FT: 22.6%; GT: 9.1%) than the control group (FT: 10.3%; GT: 5.2%) (p<0.05). CONCLUSIONS: On the basis of the similar studies reported in the literature and the large number of patients involved in our study, we can conclude that FT and GT can be clearly suggested as oral manifestations of plaque-type psoriasis, although the reason for this association is not clear.


Asunto(s)
Glositis Migratoria Benigna/epidemiología , Psoriasis/complicaciones , Lengua Fisurada/epidemiología , Adolescente , Adulto , Anciano , Anciano de 80 o más Años , Estudios de Casos y Controles , Femenino , Glositis Migratoria Benigna/complicaciones , Humanos , Italia/epidemiología , Masculino , Persona de Mediana Edad , Prevalencia , Lengua Fisurada/complicaciones , Adulto Joven
2.
Annu Int Conf IEEE Eng Med Biol Soc ; 2021: 4200-4203, 2021 11.
Artículo en Inglés | MEDLINE | ID: mdl-34892150

RESUMEN

Iron accumulation in the brain is supposed to play a central role in the induction of oxidative stress and consequently in neurodegeneration. The sensitive balance of iron in the brain is maintained by the brain barriers system, i.e., the blood-brain barrier between the blood and brain interstitial fluid and the blood-cerebrospinal fluid barrier between the blood and cerebrospinal fluid (CSF). In this work, we proposed a three-compartmental mathematical model simulating iron trafficking between blood, CSF, and cerebral space, describing the direction of fluxes based on the structural and functional characteristics of the brain barriers system. Different techniques of sensitivity analysis were used to evaluate the most important parameters, providing an indication for the most relevant biological functions that potentially affect the physiological transport of iron across brain barriers.


Asunto(s)
Barrera Hematoencefálica , Enfermedades Neurodegenerativas , Encéfalo , Modelos Epidemiológicos , Humanos , Hierro
3.
Annu Int Conf IEEE Eng Med Biol Soc ; 2020: 2270-2273, 2020 07.
Artículo en Inglés | MEDLINE | ID: mdl-33018460

RESUMEN

Iron plays important roles in healthy brain but altered homeostasis and concentration have been correlated to aging and neurodegenerative diseases. Iron enters the central nervous system by crossing the brain barrier systems: the Blood- Brain Barrier separating blood and brain and the Blood-Cerebrospinal Fluid Barrier (BCSFB) between blood and CSF, which is in contact with the brain by far less selective barriers. Herein, we develop a two-compartmental model for the BCSFB, based on first-order ordinary differential equations, performing numerical simulations and sensitivity analysis. Furthermore, as input parameters of the model, experimental data from patients affected by Alzheimer's disease, frontotemporal dementia, mild cognitive impairment and matched neurological controls were used, with the aim of investigating the differences between physiological and pathological conditions in the regulation of iron passage between blood and CSF which can be possibly targeted by therapy.


Asunto(s)
Enfermedades Neurodegenerativas , Barrera Hematoencefálica , Encéfalo , Humanos , Hierro , Modelos Teóricos
4.
NeuroRehabilitation ; 46(4): 529-537, 2020.
Artículo en Inglés | MEDLINE | ID: mdl-32538880

RESUMEN

BACKGROUND: Pisa syndrome (PS) is a clinical condition frequently associated with Parkinson's disease (PD). It is characterized by a trunk lateral flexion higher than 10 degrees and reversible when lying. One pathophysiological hypothesis is the altered verticality perception, due to a somatosensory impairment. Osteopathic Manipulative Treatment (OMT) manages fascial-system alterations, linked to somatic dysfunctions. Fascial system showed to be implicated in proprioceptive sensibility. OBJECTIVE: The aim of the study was to assess OMT efficacy on postural control in PD-PS patients by stabilometry. METHODS: In this single-blinded trial we studied 24 PD-PS patients, 12 of whom were randomly assigned to receive a multidisciplinary physical therapy protocol (MIRT) and sham OMT, while the other 12 received four OMT plus MIRT, for one month. The primary endpoint was the eye closed sway area assessment after the intervention. Evaluation of trunk lateral flexion (TLF) with DIERS formetrics was also performed. RESULTS: At one month, the sway area of the OMT group significantly decreased compared to placebo (mean delta OMT - 326.00±491.24 mm2, p = 0.01). In the experimental group TLF showed a mean inclination reduction of 3.33 degrees after treatment (p = 0.044, mean d = 0.54). Moreover, a significant positive association between delta ECSA and delta TLF was observed (p = 0.04, r = 0.46). DISCUSSION: Among PD-PS patients, MIRT plus OMT showed preliminary evidence of postural control and TLF improvement, compared to the control group.


Asunto(s)
Osteopatía/métodos , Enfermedad de Parkinson/terapia , Equilibrio Postural , Femenino , Humanos , Masculino , Persona de Mediana Edad , Enfermedad de Parkinson/patología , Postura
5.
J Neurol Neurosurg Psychiatry ; 80(8): 924-7, 2009 Aug.
Artículo en Inglés | MEDLINE | ID: mdl-19608785

RESUMEN

Fatal insomnia is a rare human prion disease characterised by sleep-wake disturbances, thalamic degeneration and deposition of type 2 disease-specific prion protein (PrP(Sc)). This report details a patient with sporadic fatal insomnia who exhibited cerebral deposition of type 1 PrP(Sc) and neuropathological changes largely in the basal ganglia. Previous damage of this brain region by a surgically removed colloid cyst and the insertion of two intracerebral shunts may have influenced the distribution of PrP(Sc) through a chronic inflammatory process. These findings add to our knowledge of the phenotypic variability of human prion diseases with prominent sleep disturbances.


Asunto(s)
Insomnio Familiar Fatal/patología , Proteínas PrPSc/metabolismo , Western Blotting , Encéfalo/patología , Síndrome de Creutzfeldt-Jakob/patología , Electroencefalografía , Humanos , Inmunohistoquímica , Insomnio Familiar Fatal/genética , Insomnio Familiar Fatal/metabolismo , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Procedimientos Neuroquirúrgicos , Proteínas PrPSc/genética , Tomografía Computarizada por Rayos X
6.
Funct Neurol ; 34(3): 151-157, 2019.
Artículo en Inglés | MEDLINE | ID: mdl-32453996

RESUMEN

Multiple sclerosis (MS) is a chronic disease of the central nervous system, characterized by demyelinization and axonal loss resulting, in 66% of cases, in upper limb motor impairment. The effects of constraint-induced movement therapy (CIMT) have recently been investigated in MS patients. The aim of this randomized single-blind pilot study was to assess the effects of CIMT on upper limb activity, specifically smoothness of movement, in patients affected by progressive MS. Patients affected by MS, and reporting reduced use primarily of one upper limb, were enrolled and randomly allocated to two different groups: a CIMT group, where treatment was performed with the less affected limb immobilized by a splint, and a control group, submitted to intensive bi-manual treatment. All evaluations were performed at baseline (T0) and after two weeks of treatment (T1) by an operator unaware of the patients' allocation. The primary outcome was the difference in movement smoothness, measured by means of a bidimensional kinematic evaluation. Secondary outcomes were: endpoint error and arm trajectory mean speed. Furthermore, patients performed the Hand Grip Strength Test (HGS) and 9-Hole Peg Test (9HPT), for both arms, at both time points. Ten patients with MS (4 males, 6 females; mean age 51.0±7.7 years) were randomly allocated to the CIMT group (n=5) and control group (n=5). There were no significant differences between groups in any of the data assessed at baseline. In the CIMT group subjects, the treatment effect, in terms of movement smoothness, was significant at the more affected limb (p=0.0376). The CIMT group displayed statistically significant improvements, versus the baseline values, in muscle strength (HGS:22.4±8.3 vs 26.0±6.0; p<0.05) and dexterity (9HPT: 31.8±6.1 vs 27.4±4.9; p<0.05) of the more affected limb. A positive, although not significant, trend in terms of muscle strength and upper limb dexterity was observed, for both limbs, in the control group after the two-week treatment. Bi-dimensional kinematic evaluation demonstrated that the CIMT group showed a significant reduction of endpoint error and higher mean speed for the more affected arm; these data are in line with the significant improvements recorded on the HGS and 9HPT. Moreover, in the CIMT group, a non-significant worsening of muscle strength was recorded for the less affected upper limb.

7.
Clin Neurophysiol ; 119(4): 959-67, 2008 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-18282740

RESUMEN

OBJECTIVE: Automatic methods developed to detect transient EEG events during sleep may present a degree of arbitrariness in the choice of appropriate channels or amplitude thresholds for the analysis. To overcome these limitations, we propose a multi-channel and temporal coincidences approach. METHODS: A two-step automatic detection (AD) of peculiar transient synchronized EEG events (TE) was performed in stage 2 and stage 3 sleep periods obtained from 10 normal sleep recordings and included: (a) detection of candidate TE from all the EEG traces and averaged signals, based on amplitude thresholds selections in both the time and frequency domains; (b) cross-checking of TE by evaluation of the coincidences in different EEG traces. TE found by AD but not confirmed by visual analysis (false positives, FP) and TE evidenced by visual analysis and missed by AD (false negatives, FN) were then counted. RESULTS: AD performed in averaged signals significantly reduced the number of FP but slightly increased FN, compared to single-channel analysis. However, when TE were confirmed by inter-channel temporal coincidences, a significant reduction of total errors (FN+FP) was achieved. The minimum error was obtained after C3-A2 and C4-A1 averaging and signal cross-checking with at least three channels (C3-A2 or C4-A1, plus both O1-A2 and O2-A1). CONCLUSIONS: This study describes a novel method for automatic detection of transient EEG events occurring during sleep that takes into account all the available channels. SIGNIFICANCE: This approach reduces the need of human supervision and may overcome most of the difficulties encountered by automatic methods based on single-channel analysis.


Asunto(s)
Encéfalo/fisiología , Electroencefalografía/métodos , Procesamiento de Señales Asistido por Computador , Sueño/fisiología , Adulto , Femenino , Humanos , Masculino , Programas Informáticos
8.
J Vestib Res ; 26(4): 359-374, 2016 11 03.
Artículo en Inglés | MEDLINE | ID: mdl-27814311

RESUMEN

OBJECTIVE: To analyze and model the effects of acoustic stimulus duration on cervical vestibular evoked myogenic potentials (cVEMPs). DESIGN: Subjects with normal hearing and no vestibular or cervical disorders were tested using 1 kHz tone bursts (TBs) of different durations to evoke cVEMPs from the ipsilateral sternocleidomastoid muscle. VEMP modeling was performed in Labview. RESULTS: The increase in TB duration initially resulted in a non-linear increase in cVEMP amplitude, followed by more complex cVEMP modifications that were mainly related to the appearance of a new wave (nX) that interfered with n23. With long TBs there were two distinct negative peaks with an identical threshold, suggesting a common vestibular nature. A two-level inhibition model qualitatively accounted for the two distinct negative peaks. However, good fitting of the cVEMP waveform required a multi-level model that included an excitatory phase after the inhibitory period. CONCLUSIONS: The two negative components (n23 and nX) observed in cVEMPs elicited by long TBs may result from the involvement of two different pathways with different dynamics or a single pathway with quick adaptation in the activity along the vestibulo-collic arc. Excitatory activity following the period of inhibition may represent rebound activity at the motor unit level.


Asunto(s)
Estimulación Acústica , Potenciales Vestibulares Miogénicos Evocados/fisiología , Adolescente , Adulto , Simulación por Computador , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos Neurológicos , Músculos del Cuello/fisiología , Vías Nerviosas/fisiología , Dinámicas no Lineales , Adulto Joven
9.
Surgery ; 97(4): 415-9, 1985 Apr.
Artículo en Inglés | MEDLINE | ID: mdl-3983816

RESUMEN

The purpose of this study was to investigate the effect of pentobarbital, halothane, and chloralose anesthesia on the endogenous release of cholecystokinin-33 (CCK-33) in dogs prepared with duodenal fistulas. Release of CCK-33 was induced by intraduodenal infusion of a medium-chain triglyceride (corn oil, 1 gm/kg/hr). Plasma CCK-33 concentrations were measured by means of a specific radioimmunoassay. Pentobarbital and chloralose were administered intravenously, and halothane was administered by a vaporizer (semiclosed technique), with O2 and N2O used as carriers. No incidence of hypotension was found with the use of these anesthetic agents. Basal concentrations of plasma CCK-33 were elevated, although not significantly, during pentobarbital or chloralose anesthesia. In conscious dogs (control study), peak plasma CCK-33 concentrations of 529 +/- 53 pg/ml were measured 30 minutes after intraduodenal infusion of fat. Under pentobarbital anesthesia, peak plasma CCK-33 concentrations of 452 +/- 264 pg/ml were found 80 minutes after infusion of fat. Under halothane anesthesia, fat-induced release of CCK-33 was abolished, whereas chloralose anesthesia did not influence fat-induced release of CCK-33. These findings may have implications for the design of future studies of gastrointestinal physiology. In CCK-33 studies that require anesthesia, chloralose appears to be an appropriate anesthetic agent.


Asunto(s)
Anestésicos/farmacología , Colecistoquinina/metabolismo , Anestesia General , Animales , Cloralosa/farmacología , Colecistoquinina/sangre , Aceite de Maíz , Perros , Femenino , Halotano/farmacología , Masculino , Aceites , Pentobarbital/farmacología , Radioinmunoensayo
10.
Clin Neurophysiol ; 114(1): 147-53, 2003 Jan.
Artículo en Inglés | MEDLINE | ID: mdl-12495775

RESUMEN

OBJECTIVE: To characterize cortico-diaphragmatic pathway involvement in multiple sclerosis (MS) by means of transcranial magnetic stimulation (TMS), and verify its clinical impact. METHODS: TMS from diaphragm (Dia), and abductor digiti minimi (AbdV degrees ) was performed in 26 MS patients. Phrenic nerve (PN) conduction study was also performed. Expanded disability status scale (EDSS) and fatigue descriptive scale (FDS) were measured. Forced vital capacity (FVC), forced expiratory volume at the first second (FEV1), peak expiratory flow (PEF) were tested: the predicted percentage value (% pred) was considered. RESULTS: Cortical motor evoked potential (Cx-MEP) latency and central motor conduction time (CMCT) were prolonged, respectively, in 31 and 23% of patients from Dia, in 76 and 79% from AbdV degrees. PN-compound motor action potential (CMAP) was normal. EDSS correlated to Cx-MEP from AbdV degrees (P<0.01), and PN-CMAP amplitude (P<0.05), FEV1 % pred (P<0.01), PEF % pred (P<0.01). PN-CMAP amplitude correlated to FVC % pred P=0.05, FEV1 % pred P<0.01, PEF % pred P<0.01. Fatigue was related to AbdV degrees Cx-MEP and CMCT (P<0.05 and P<0.01). CONCLUSIONS: Cortico-diaphragmatic pathway is impaired only in a minority of MS patients. Lack of correlation between TMS findings from Dia and respiratory tests argues against its routinary use to detect subclinical respiratory alterations. Fatigue seems to be related to the motor impairment rather than to respiratory distress.


Asunto(s)
Corteza Cerebral/fisiopatología , Diafragma/inervación , Esclerosis Múltiple/fisiopatología , Nervio Frénico/fisiopatología , Respiración , Adulto , Diafragma/fisiopatología , Estimulación Eléctrica , Fenómenos Electromagnéticos , Femenino , Humanos , Masculino , Persona de Mediana Edad , Valor Predictivo de las Pruebas
11.
J Neural Transm Suppl ; 45: 163-70, 1995.
Artículo en Inglés | MEDLINE | ID: mdl-8748622

RESUMEN

The Long-Term Dopa Syndrome (LTDS) is one of the main problems in the management of advanced parkinsonian patients. A transient L-Dopa withdrawal (Drug Holiday, DH) can be useful to improve the drug response after DH, even if this approach presents risks due to patient akinesia. We tried to verify if Apomorphine sc administration during DH (DH with Apomorphine, DHA) can: a) reduce the risks connected with DH: b) maintain the benefits of DH: c) standardize the duration of DH. Twenty-five parkinsonian patients with LTDS were treated with Apomorphine sc during DH (14 days). No patient had any severe side effects. The follow-up at 180 days, conducted using the Unified Parkinson's Disease Rating Scale, demonstrated a significant improvement in the clinical conditions of about 70% of the patients, allowing a 27.1% reduction in daily L-dopa dosage. DHA can represent a valid therapeutical approach for parkinsonian patients with LTDS.


Asunto(s)
Antiparkinsonianos/uso terapéutico , Dihidroxifenilalanina/efectos de los fármacos , Dopaminérgicos/uso terapéutico , Síndrome de Abstinencia a Sustancias/tratamiento farmacológico , Adulto , Anciano , Apomorfina , Dihidroxifenilalanina/administración & dosificación , Dopaminérgicos/administración & dosificación , Dopaminérgicos/efectos adversos , Esquema de Medicación , Humanos , Infusiones Parenterales , Persona de Mediana Edad , Factores de Riesgo , Piel
12.
J Neurosurg Sci ; 44(2): 61-6; discussion 66-7, 2000 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-11105833

RESUMEN

BACKGROUND: We evaluated high cerebral functions 6 months after surgery for bleeding ACoA aneurysms comparing neurophysiological and neuropsycological tests. METHODS: Twelve patients were chosen among a series of cases operated on in the first 48 hours after ACoA aneurysm bleeding. All of them were in Hunt-Hess grade I or II. We excluded patients over 65 years, or with intracranial haematomas, intraventricular haemorrhage, hydrocephalus, or with multiple or giant aneurysms. All of them underwent neurophysiological evaluation with recording and mapping of long latency (P300) auditory and visual event-related potentials (ERPs) and a neuropsychological assessment for memory, intelligence, frontal lobe functions and language. RESULTS: Neuropsychological assessment: All patients were severely damaged on phonemic fluency. In a first group (group A: 3 cases) tests were all in a normal range. In a second (group B: 3 cases) the tests showed severe impairment on learning and long term memory. In a third (group C: 6 cases) tests showed memory and "frontal lobe" deficits. Neurophysiological assessment: The whole group of patients showed significant delay in ERPs recordings compared to controls. ERPs of patients in group A and B showed no significant differences from controls, while being significantly delayed in 5 patients out of 6 of group C. CONCLUSIONS: All patients had difficulties in the phonemic task in which a notable cognitive effort is necessary, while intelligence, short term memory, attention and language were within normal limits. Patients in group C showed severe frontal lobe type cognitive impairment. Those ones in groups A and B did not present cognitive derangements (A) or only memory and learning impairment (B). ERPs may be an objective parameter in the follow-up of cases with cognitive impairment, even if neurophysiological tests cannot be replaced.


Asunto(s)
Aneurisma Intracraneal/cirugía , Pruebas Neuropsicológicas , Potenciales Relacionados con Evento P300 , Potenciales Evocados Auditivos , Potenciales Evocados Visuales , Femenino , Lóbulo Frontal/fisiopatología , Humanos , Inteligencia , Aneurisma Intracraneal/fisiopatología , Aneurisma Intracraneal/psicología , Lenguaje , Aprendizaje , Masculino , Memoria , Persona de Mediana Edad , Neurofisiología
13.
J Neurosurg Sci ; 41(2): 209-14, 1997 Jun.
Artículo en Inglés | MEDLINE | ID: mdl-9385573

RESUMEN

We have neuroradiologically and neuropsycho-physiologically studied a case of chronic hydrocephalus due to congenital acqueductal stenosis, before and after ventriculoperitoneal shunting. The aims of the study were: 1) to point out the correlation between neuroimaging (Computerized Tomography/Magnetic Resonance Imaging) and mapping of Computerized Spectral Analysis EEG (CSA-EEG); 2) to monitor evoked bioelectrical activity by neurophysiological evaluation of acoustic and visual N1 and P3. Both bioelectrical activity and neuroimaging evaluation showed a considerable recovery of the neurobiological substratum after neurosurgical shunting, while neuropsychological investigation showed a slight improvement in all cognitive tasks.


Asunto(s)
Acueducto del Mesencéfalo/anomalías , Ventrículos Cerebrales/patología , Hidrocefalia/patología , Derivación Ventriculoperitoneal , Adulto , Enfermedad Crónica , Constricción Patológica , Electroencefalografía , Femenino , Humanos , Hidrocefalia/fisiopatología , Imagen por Resonancia Magnética , Tomografía Computarizada por Rayos X
14.
Vet J ; 166(1): 58-66, 2003 Jul.
Artículo en Inglés | MEDLINE | ID: mdl-12788018

RESUMEN

The purpose of this study was to assess quantitative electroencephalography (q-EEG) in 10 healthy beagle dogs under propofol anaesthesia in order to determine objective guidelines for diagnostic electroencephalographic (EEG) recordings and interpretation. The basic pattern after preliminary visual examination of EEG recordings was characterized by spindles, k-complexes, vertex sharp transients, and positive occipital transients that were superimposed on the slow background activity. The results of the q-EEG were characterized by the prevalence of slow rhythms delta and theta, both in absolute and relative power spectrum analysis, while fast rhythms (alpha and beta) were poorly represented. The distribution of single frequency bands was widespread for delta, focal for frontal and central for theta, as well as for most alpha and beta patterns. The present study has shown that the use of quantitative EEG gives information on the frequency content of the bio-electrical activity and defines the distribution of the single frequency bands under a standardized anaesthetic protocol.


Asunto(s)
Anestesia General/veterinaria , Anestésicos Intravenosos/farmacología , Perros/fisiología , Electroencefalografía/efectos de los fármacos , Electroencefalografía/veterinaria , Propofol/farmacología , Animales , Electroencefalografía/métodos , Femenino , Masculino , Estadísticas no Paramétricas
15.
G Ital Dermatol Venereol ; 125(5): 183-6, 1990 May.
Artículo en Italiano | MEDLINE | ID: mdl-2253948

RESUMEN

Thirty-nine HIV-negative men, without apparent genital warts, were evaluated for evidence of subclinical genital condylomata by visual examination of the genitalia with colposcopy after the application of 5% acetic acid. 24 patients (group I) had a history of recurrent genital condylomata; 8 (group II) were sexual partners of women with HPV-related lesions and 7 (group III) presented another sexually transmitted disease. Under colposcopic magnification, acetowhite areas were biopsied for conventional histology and in situ hybridization using 6/11, 16/18 and 31/35/51 HPV-DNA probes. Colposcopy and histologic features were positive for condylomata acuminata in 16 patients of group III (14%). HPV 16/18 - whose oncogenic potentiality is well known - was detected in 3 patients: of these, one patient of group I presented a histologic picture suggestive of bowenoid papulosis.


Asunto(s)
Colposcopía , Condiloma Acuminado/diagnóstico , Neoplasias de los Genitales Masculinos/diagnóstico , Adolescente , Adulto , Condiloma Acuminado/patología , Sondas de ADN de HPV , Diagnóstico Diferencial , Neoplasias de los Genitales Masculinos/patología , Humanos , Masculino , Persona de Mediana Edad
16.
G Ital Dermatol Venereol ; 125(6): 247-9, 1990 Jun.
Artículo en Italiano | MEDLINE | ID: mdl-2279749

RESUMEN

In January 1989, the Center for Sexually Transmitted Diseases (STD) of Galliera Hospital-Genoa was equipped with a network of 5 Personal Computers connected by a Token Ring to another Personal Computer which is the "server" unit. The Authors report their experiences in the use of the computer system and examine the advantages of networking in the management of a Center for Sexually Transmitted Disease.


Asunto(s)
Hospitales Especializados , Microcomputadores , Enfermedades de Transmisión Sexual , Italia
18.
Artículo en Inglés | MEDLINE | ID: mdl-21096666

RESUMEN

Sleep is a dynamic process aimed at obtaining the required neurophysiological states at certain times, according to circadian and homeostatic needs and despite external or internal interfering stimuli. In this context, peculiar transient synchronized EEG patterns (TSEP) are supposed to play the main role in the building up of EEG synchronization and in the flexible adaptation against perturbations Our study aimed at disclosing and quantifying attractor driven, hidden periodicity or, conversely, chaotic oscillation patterns in the series of these TSEP related to sleep stage transitions and sleep maintenance. At first we devised a multistep algorithm, able to capture TSEP from EEG during sleep in 10 healthy volunteers. The time series of TSEP were then analyzed according to the Recurrence Plot (RP). TSEP series showed to form a pseudo-periodic series which becomes progressively denser and more stable until steady slow wave NREM sleep is reached, but looses stability just before REM sleep starts. This suggests that deterministic oscillatory patterns maybe adequate descriptors of the balance between homeostatic needs for NREM sleep and REM sleep pressure, supported by different cortical neuronal populations interactions.


Asunto(s)
Relojes Biológicos/fisiología , Encéfalo/fisiología , Electroencefalografía/métodos , Polisomnografía/métodos , Fases del Sueño/fisiología , Adulto , Femenino , Humanos , Masculino
SELECCIÓN DE REFERENCIAS
DETALLE DE LA BÚSQUEDA