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Magda L Nunes

Publications and source records attributed to Magda L Nunes.

7 recordsLinked to original sources
PubMed2005

Regional neural activity within the substantia nigra during peri-ictal flurothyl generalized seizure stages.

Structures responsible for the onset, propagation, and cessation of generalized seizures are not known. Lesion and microinfusion studies suggest that the substantia nigra pars reticulata (SNR) seizure-controlling network could play a key role. However, the expression of neural activity within the SNR and its targets during discrete pre- and postictal periods has not been investigated. In rats, we used flurothyl to induce generalized seizures over a controlled time period and 2-deoxyglucose autoradiography mapping technique. Changes in neural activity within the SNR were region-specific. The SNRposterior was selectively active during the pre-clonic period and may represent an early gateway to seizure propagation. The SNRanterior and superior colliculus changed their activity during progression to tonic-clonic seizure, suggesting the involvement in coordinated regional activity that results in inhibitory effects on seizures. The postictal suppression state was correlated with changes in the SNR projection targets, specifically the pedunculopontine tegmental nucleus and superior colliculus.

Action Potentials↗
PubMed2004

Clinical correlates of periodic breathing in neonatal polysomnography.

OBJECTIVE: Periodic breathing is a respiratory pattern typical of preterm infants, but its clinical significance has not been clarified yet. The present study was designed to investigate whether the presence of periodic breathing is specifically associated to low post-conceptional ages, preterm birth, or common clinical disorders related to preterm birth. METHODS: The study included 271 consecutive infants submitted to neonatal polysomnography, of whom 138 were born before 37 complete gestational weeks (preterm) and 133 were full-term. The main outcome measure was periodic breathing. A multivariate analysis was performed to test the specific impact of preterm birth, respiratory distress syndrome and hypoxic-ischemic encephalopathy on the occurrence of periodic breathing, with adjustment for potential confounding factors such as the post-conceptional age by the time of the polysomnography. RESULTS: Periodic breathing was twice more frequent in infants born before term (83/138 [60%]) than in full-term babies (41/133 [31%], chi2 = 22.3, P < 0.0001). The presence of periodic breathing was not significantly associated to either hypoxic-ischemic encephalopathy or respiratory distress syndrome. After a multivariate analysis, only preterm birth remained in the regression model as a specific risk factor for periodic breathing (adjusted odds ratio=5.62, P < 0.0001). CONCLUSIONS: Periodic breathing is a respiratory pattern independently associated with preterm birth, and this association cannot be imputed to the coexistence of either respiratory distress syndrome or hypoxic-ischemic encephalopathy among preterm infants. SIGNIFICANCE: The finding of periodic breathing in neonatal polysomnography correlates with preterm birth but not with its associated clinical disorders.

Apgar Score↗
PubMed2004

[Use of psychoactive and antiepileptic drugs: guidelines for pediatricians].

OBJECTIVE: To review the guidelines for the use of psychoactive and antiepileptic drugs in childhood and adolescence. SOURCES OF DATA: Literature review. SUMMARY OF THE FINDINGS: The clinical indications, dosage and side effects of psychoactive and antiepileptic drugs are presented. The use of psychoactive drugs is increasing due to the release of new drugs and to the better understanding of emotional disorders in children and adolescents. CONCLUSIONS: The use of antiepileptic and psychoactive drugs in childhood requires extensive knowledge concerning pharmacokinetics and deleterious side effects. An adequate choice of drugs is essential to ensure a successful treatment.

Adolescent↗
PubMed2004

[Language and learning disorders].

OBJECTIVE: To aid health professionals, especially pediatricians, in the diagnosis and prevention of language and learning disorders. SOURCES OF DATA: Review of the relevant literature published in the past 5 years (MEDLINE and textbooks). SUMMARY OF THE FINDINGS: Multiple variables, among them neurological diseases, may be related to the etiology of language and learning disorders. CONCLUSION: An adequate diagnostic investigation may guide the choice of treatment.

Child, Preschool↗
PubMed2003

[Hopkins' syndrome in the differential diagnosis of flaccid paralysis in children: clinical and neurophysiological features. Case report].

INTRODUCTION: Hopkins syndrome is a motor neuron disease which leads to a flaccid paralysis affecting one or more limbs resembling poliomyelites. It follows an asthmatic attack and the prognosis is poor. All the 34 related cases occured after 13 months of age and there is no report in South America. Our objective is to describe a case of Hopkins Syndrome in Brazil affecting a patient younger than 1 year. CASE: Male 4 months-old infant, started presenting wheezing that turned into respiratory failure which required mecanical ventilation. Three days later he initiated with loss of strength in the lower limbs (LL). The patient was dismissed from hospital better of his respiratory complains but still paraparetic. Five months later, the patient returned with another episode of severe bronchospasm. At that time, he presented with flaccid paralysis, arreflexia and atrophy of the LL. There were no upper limbs and sensory abnormalities. The patient undergone to lumbar puncture, spinal MRI and SEPs which were all normal. MUSCLE BIOPSY: type grouping. EMG and NCS were in keeping with motor neuron disease affecting just the lumbosacral region. CONCLUSION: Hopkins syndrome should be included in the differential diagnosis of any flaccid paralysis when it is associated with an asthma attack.

Acute Disease↗
PubMed2003

Age-related differences in NMDA/metabotropic glutamate receptor binding in rat substantia nigra.

Both N-methyl-D-aspartate (NMDA) and quisqualate/AMPA-insensitive metabotropic glutamate (mGlu) receptors mediate glutamate neurotransmission in substantia nigra (SN). In this work, NMDA and mGlu receptor sites in substantia nigra pars compacta (SNC) and pars reticulata were autoradiographically mapped in rat brains using specific binding of (+)3H-MK801 or 3H-glutamate, with saturating concentrations of NMDA, AMPA and quisqualate. In brains of both adult and postnatal day 15 (PN15) male rats, prepared at subjective mid-day of a 12h light/12h dark (12h L/12h D) cycle, specific binding at NMDA and mGlu sites in substantia nigra was pronounced when compared with control binding. The (+)3H-MK801 binding in adults was spatially heterogeneous. Overall binding density in pars compacta was higher relative to binding density in pars reticulata with a mean percent change (Deltaxmacr;%) of 32%. Within the pars reticulata but not pars compacta, there were rostro-caudal differences with considerably denser binding in the posterior compared with the anterior pars reticulata (Deltaxmacr;%=108%). PN15 rats showed a less pronounced heterogeneity in pars compacta versus pars reticulata binding, (Deltaxmacr;%=27%), and less rostro-caudal differentiation in (+)3H-MK801 binding density throughout pars reticulata (Deltaxmacr;%=46%). 3H-glutamate binding in both adult and PN15 rats was less dense overall than (+)3H-MK801 binding. In adults, there was no difference in binding density between pars compacta and pars reticulata (Deltaxmacr;%=0.4%), but there were marked heterogeneities when binding was compared between anterior versus posterior pars compacta (Deltaxmacr;%=29%), and anterior versus posterior pars reticulata (Deltaxmacr;%=25%). This rostro-caudal heterogeneity in 3H-glutamate binding density was also present in PN15 pars compacta (Deltaxmacr;%=45%) but not in pars reticulata. Our findings mirror similar anterior/posterior heterogeneities in the GABAergic system in adult and PN15 male rats and may reflect a developmental change in both the structure and anticonvulsant/proconvulsant properties of substantia nigra pars reticulata (SNR) with age.

Aging↗