AMPA receptor antagonist NBQX attenuates later-life epileptic seizures and autistic-like social deficits following neonatal seizures

PURPOSE

To determine whether AMPA receptor (AMPAR) antagonist NBQX can prevent early mammalian target of rapamycin (mTOR) pathway activation and long-term sequelae following neonatal seizures in rats, including later-life spontaneous recurrent seizures, CA3 mossy fiber sprouting, and autistic-like social deficits.

METHODS

Long-Evans rats experienced hypoxia-induced neonatal seizures (HS) at postnatal day (P)10. NBQX (20 mg/kg) was administered immediately following HS (every 12 h × 4 doses). Twelve hours post-HS, we assessed mTOR activation marker phosphorylated p70-S6 kinase (p-p70S6K) in hippocampus and cortex of vehicle (HS + V) or NBQX-treated post-HS rats (HS + N) versus littermate controls (C + V). Spontaneous seizure activity was compared between groups by epidural cortical electroencephalography (EEG) at P70-100. Aberrant mossy fiber sprouting was measured using Timm staining. Finally, we assessed behavior between P30 and P38.

KEY FINDINGS

Postseizure NBQX treatment significantly attenuated seizure-induced increases in p-p70S6K in the hippocampus (p < 0.01) and cortex (p < 0.001). Although spontaneous recurrent seizures increased in adulthood in HS + V rats compared to controls (3.22 ± 1 seizures/h; p = 0.03), NBQX significantly attenuated later-life seizures (0.14 ± 0.1 seizures/h; p = 0.046). HS + N rats showed less aberrant mossy fiber sprouting (115 ± 8.0%) than vehicle-treated post-HS rats (174 ± 10%, p = 0.004), compared to controls (normalized to 100%). Finally, NBQX treatment prevented alterations in later-life social behavior; post-HS rats showed significantly decreased preference for a novel over a familiar rat (71.0 ± 12 s) compared to controls (99.0 ± 15.6 s; p < 0.01), whereas HS + N rats showed social novelty preference similar to controls (114.3 ± 14.1 s).

SIGNIFICANCE

Brief NBQX administration during the 48 h postseizure in P10 Long-Evans rats suppresses transient mTOR pathway activation and attenuates spontaneous recurrent seizures, social preference deficits, and mossy fiber sprouting observed in vehicle-treated adult rats after early life seizures. These results suggest that acute AMPAR antagonist treatment during the latent period immediately following neonatal HS can modify seizure-induced activation of mTOR, reduce the frequency of later-life seizures, and protect against CA3 mossy fiber sprouting and autistic-like social deficits.

Facial palsy and idiopathic intracranial hypertension in twins with cystic fibrosis and hypovitaminosis A

Facial nerve palsies are uncommon in infants. We report on 10-week-old monozygotic twins, diagnosed with cystic fibrosis by newborn screening, who developed facial palsy and increased intracranial pressure. Cranial imaging and cerebrospinal fluid analysis produced normal results. Levels of serum vitamin A were below normal range. Low levels of vitamin A are associated with facial nerve paralysis, and are at least partly implicated in the development of increased intracranial pressure in infants with cystic fibrosis.

Neuroprotective effects of leptin following kainic acid-induced status epilepticus

We investigated the potential neuroprotective effects of leptin (LEP) against cellular damage, long-term recurrent spontaneous seizures, and behavioral changes associated with kainate (KA)-induced status epilepticus (SE). Adult Sprague-Dawley rats were sacrificed 24 hours after KA injections, and hippocampi were subjected to histological analysis. In the acute condition, one group received 12 mg/kg KA intraperitoneally (KAac group), and another group received 12 mg/kg KA intraperitoneally, followed by two intraperitoneal LEP injections of 4 mg/kg each, 1 and 13 hours after KA (KALEPac group). For long-term outcomes, one group received KA (KA group), and the other group received three intraperitoneal LEP injections (4 mg/kg at 1 hour, and 2mg/kg at 13 and 24 hours) after KA (KALEP group). Controls were sham manipulated. Behavioral tests started 6 weeks after SE. All rats that received KA underwent behavioral seizures of comparable severity. Compared with the KAac group, the KALEPac group had significantly larger pyramidal cell surface areas and fewer black-stained degenerating neurons with silver stain. The KALEP and KA groups were comparable with respect to recurrent spontaneous seizures, aggression, hyperactivity, and impaired memory. We show that leptin reduces cellular injury associated with KA-induced SE, but does not prevent long-term recurrent spontaneous seizures and behavioral deficits.

Acute hemorrhagic edema of infancy with abdominal pain and elevated transaminases

Acute hemorrhagic edema of infancy is a rare type of leukocytoclastic vasculitis characterized by a triad of fever, edema, and rosette-shaped purpura, mainly over the face, auricles, and extremities in a nontoxic infant. Visceral involvement is infrequent in acute hemorrhagic edema of infancy. We report a case of acute hemorrhagic edema of infancy with abnormal liver function tests and abdominal pain.

Diffusion-weighted imaging findings on MRI as the sole radiographic findings in a child with proven herpes simplex encephalitis

We present a case of herpes simplex encephalitis in an 8-year-old girl, in whom hyperintensity was detected on diffusion-weighted imaging (DWI) while conventional MRI sequences were normal 1 week after the onset of neurological symptoms. This case is rare in that a child beyond the neonatal period with focal herpes simplex encephalitis had an abnormal DWI sequence as the only MRI finding.

Expanding spectrum of paroxysmal events in children: potential mimickers of epilepsy

Paroxysmal events in children can mimic epileptic seizures, and many of them have only been recently described, or are only now being increasingly recognized. An awareness of the different mimickers of epilepsy and the art of history-taking will help pediatricians and neurologists differentiate epileptic from nonepileptic events. Nonepileptic paroxysms can present with drop attacks, limb or eye jerks, and abnormal postures. This review describes the different mimickers of epilepsy and focuses on their circumstances, precipitators, prodromes, pathophysiology, and other manifestations that help distinguish them from epilepsy.

Long-term effects of acute and of chronic hypoxia on behavior and on hippocampal histology in the developing brain

Ten-day-old rat pups (P10) subjected to acute hypoxia (down to 4% O2) had as adults increased aggression (handling test), memory impairment (water maze test), and decreased CA1 cell counts. Pups subjected to chronic hypoxia (10% O2 from P0 to P21) had increased aggression, hyperactivity (open-field test), and decreased CA1 cell counts. Chronic hypoxia with superimposed acute hypoxia resulted in consequences that were not different from those of chronic hypoxia.

A new patient with pure trisomy 4p resulting from isochromosome formation and whole arm translocation

Short arm isochromosome formation with translocation of the entire long arm of the same chromosome is an unusual constitutional abnormality that has been observed, to our knowledge, in 18 cases. Only one of these previously reported cases involved chromosome 4, resulting in pure trisomy 4p. Pure trisomy 4p has been reported in a number of cases, the majority of them due to familial chromosome rearrangements, and is associated with a distinct pattern of abnormal findings. We report here a second case of a de novo chromosome 4 whole arm translocation with short-arm isochromosome formation, which we have delineated further by FISH studies.

Pseudomonas pericarditis in an immunocompetent newborn: unusual presentation with review of the literature

Acute purulent pericarditis is a rare entity in the neonatal age group. The most common isolated organisms are Staphylococcus aureus, Haemophilus influenzae, and Streptococcus pneumoniae. Other organisms, like Pseudomonas aeruginosa, have been seldom implicated with only one case of Pseudomonas pericarditis reported in the neonatal period. The prognosis is often considered very poor in this age group. This article describes Pseudomonas pericarditis in a 1-week-old immunocompetent female newborn who was successfully managed with combined medical and surgical therapy.

Cardiac disease in children in Lebanon: the AUB-MC Children's Cardiac Registry experience

OBJECTIVE

To study the epidemiology of cardiac disease in children and their outcome in Lebanon, we established a Children's Cardiac Registry Center (CCRC) at the American University of Beirut-Medical Center.

DESIGN/METHODS

The CCRC included prospectively all pediatric patients with congenital heart disease (CHD) and/or acquired heart disease (AHD) who were evaluated at our center, between March 1, 1997 and July 31, 2000.

RESULTS

Out of the 1000 patients with cardiac anomalies enrolled in the CCRC, 917 (91.7%) had CHD and the rest had AHD. Ventricular septal defect was the most common cardiac malformation with a relative frequency of 25.3%, followed by pulmonary stenosis (14.6%), aortic anomalies (8%), ASD (8%) and tetralogy of Fallot (7.8%). Complex cardiac lesions like HLHS, TGA and AVC had lower frequencies at 0.4%, 3.7% and 3.5% respectively. The most common AHD was rheumatic heart disease (42.2%). 34.9% of the registry patients with CHD and 10.8% with AHD underwent surgical intervention. There were 4.8% and 2.4% mortality rates in the CHD and AHD groups, respectively during the 40-month study period.

CONCLUSION

The prevalence of many of the cardiac malformations in the CCRC was similar to that reported in the literature. However, some of the complex cardiac lesions were less common. The outcome of the two groups of patients is comparable to the outcome of children with cardiac malformation from developed countries. The establishment of a registry at the national level is important. Appropriate identification of the cardiac disease, its epidemiology, and outcome is of utmost importance in guiding adequate care.

Coronary artery bypass grafting after pneumonectomy

The need to perform coronary artery bypass grafting in patients who have a single lung is not uncommon. To date, the safety of such procedures has not been well documented. In this article, we review the literature using the Medline 1966 to September 2000 database to identify patients with pneumonectomy who underwent coronary artery grafting and we provide a compilation of all reported cases. We also present an additional case in whom the use of nasal bilevel positive airway pressure was beneficial in preventing postoperative pulmonary complications.

Cox-Maze procedure for treatment of atrial flutter associated with an atrial septal defect

A 52-year-old man presented with atrial flutter and was found to have an atrial septal defect (ASD). The paper describes an effective surgical approach for the treatment of this atrial arrhythmia utilizing a right sided Cox-maze III procedure concomitant with ASD closure. Review of the literature and clinical implications are discussed.

Paediatric infective endocarditis: 19-year experience at a tertiary care hospital in a developing country

A retrospective study was undertaken to study children who presented with infective endocarditis (IE) to a university teaching hospital in Beirut, Lebanon, between January 1977 and May 1995. Of 41 patients with IE (24F, 17M), 28 (68%) were diagnosed between 1977 and 1985. Patients' ages ranged from 3 to 18 y (mean age 11.3+/-2.8 y), and 13 patients were <10 y of age. Clinical presentations included: fever (in 88%), heart failure (in 39%), neurologic findings (in 20%) and embolic phenomena (in 22%). Nineteen patients (46%) had underlying congenital heart disease (CHD) with tetralogy of Fallot and pulmonary stenosis being the most common. Sixteen patients (39%) had underlying rheumatic heart disease (RHD). A total of 5 children (12%) with normal cardiac anatomy had IE. One had underlying acquired viral myocarditis with mitral insufficiency. Echocardiography showed vegetations in 60%. Blood cultures were positive in 31 patients (76%). IE occurred in three patients following cardiac surgery. In one patient it occurred within 2 mo of surgery and in the other two it occurred within 6 mo. Streptococcus viridans and Staphylococcus aureus were the two most commonly isolated bacteria. Overall mortality rate was 29% (not statistically significant between patients presenting between 1977-1985 and 1986-1995; p = 0.17). There was no statistically significant difference in mortality among the groups (five in the group with CHD, six with RHD and one with structurally normal heart). This study demonstrates that RHD is an important underlying cause of IE in children in our community. This finding is similar to those in other developing countries and different from those in developed countries. Distribution of pathogens and CHD in our study is comparable to some reports in the literature, except for the higher proportion of patients with underlying pulmonary stenosis. Bacterial endocarditis prophylaxis should be emphasized in patients with RHD or pulmonary stenosis.

Rheumatic fever in children: a 15-year experience in a developing country

Clinical data from 91 patients with rheumatic fever (RF), who were hospitalized at a tertiary hospital in Lebanon between 1980 and 1995, were reviewed retrospectively. Age on hospitalization was 11.1+/-2.9 years (mean +/- SD, range 3-17 years). Nineteen patients were <6 years of age. Manifestations included carditis (93%), arthritis (39%), Sydenham's chorea (2%), erythema marginatum (4%), subcutaneous nodules (1%), fever (62%), arthralgia (55%), and acute congestive heart failure (CHF) on initial presentation (44%). Pericardial effusion occurred in 11%. There was positive family history of RF in 14%. Mitral insufficiency and aortic insufficiency occurred in 67 and 35%, respectively. Both mitral and aortic valves were involved in 30% of cases. Tricuspid insufficiency developed in 3% and pulmonary insufficiency in 1%. Mitral stenosis developed in 19%. Twenty-eight patients underwent surgical intervention: mitral valve repair and commissurotomy in 9/91 (10%), mitral valve replacement in 18/91 (20%), and aortic valve replacement in 9/91 (10%). Overall mortality was 12%: 5 following surgical intervention (3 after mitral valve surgery and 2 after mitral and aortic valve surgery). All patients that died had CHF on initial presentation (p = 0.006). This study includes hospitalized patients with predominant rheumatic heart disease. Initial presentation with CHF is a risk factor for surgical intervention and mortality. A significant high surgical intervention rate is noted that is probably related to the nature of the selected group studied. This study emphasizes the significant morbidity and death in patients with RF and carditis.

Congenital heart disease at a tertiary care center in Lebanon

OBJECTIVE AND METHODS

To study the epidemiology of congenital heart disease (CHD) at the American University of Beirut-Medical Center, we reviewed the medical records of all cardiac patients seen at our outpatient cardiology clinic (OPD) between 1980 and 1995. The charts of all patients with CHD seen as inpatients and/or outpatients at our center during the year 1995 were also reviewed. A cardiologist evaluated all patients and the diagnosis was confirmed at least by echocardiography. The frequency of CHD was reported among three groups: 1980-1995 OPD groups (Group A); the group with CHD seen during the year 1995 (Group B); and (Group C), a subgroup of group B, included all newborns with CHD born at our hospital during the year 1995. Stillbirth and premature infants with the diagnosis of patent ductus arteriosus were excluded from the study.

RESULTS

Group A included 883 patients. 344 patients were evaluated in Group B, with a mean age of 3.8 years. The incidence of CHD was 11.5/1,000 live births at our center. There was a relatively low prevalence of complex lesions (i.e., hypoplastic left heart syndrome, transposition of the great arteries) and a relatively high prevalence of the simpler cardiac malformation (i.e., ventricular and atrial septal defects, pulmonary stenosis) in Groups A and B.

CONCLUSION

The relatively low prevalence of complex cardiac lesions in our study is probably related to the age of the studied patients, and reflects the high mortality of these complex lesions in our country early in life. The incidence of CHD of 11.5/1,000 live births at our center is higher than that reported in the literature, with evidence of more frequent ventricular septal defects and pulmonary atresia lesions. This may be related to high rate of consanguinity in our population. This review underscores the need for a national cardiac registry center for children in a developing country like Lebanon. Such a database will allow referral and care of complex cardiac lesions.

Dextrocardia and corrected transposition of the great arteries (I,D,D) in a case of Kartagener's syndrome: a unique association

Kartagener's syndrome (KS) usually includes mirror-image dextrocardia. The incidence of congenital heart disease in KS is comparable with that in the general population. This paper reports on a case of Kartagener's syndrome associated with dextrocardia, corrected transposition of the great arteries (I,D,D), ventricular septal defect, and valvar pulmonary stenosis in an 8-year-old girl.