Hasan Tekgul

Proinflammatory cytokines, prostaglandins and zinc in febrile convulsions

Abstract 
 Background : Some changes in the levels of proinflammatory cytokines, prostaglandins and zinc (Zn) in peripheral blood and cerebrospinal fluid (CSF) have been suggested to occur for the pathogenesis of febrile convulsions (FC).

HYPOZINCAEMIA IN FEBRILE CONVULSION

To understand further the role of trace elements in the pathogenesis of febrile convulsions, serum zinc (Zn), copper (Cu), magnesium (Mg) and CSF Zn, Cu, Mg and protein levels were measured by spectrometry in patients with febrile convulsion (n=19), bacterial meningitis (n=9), viral CNS infection (n=16) and in the control groupn=10) which consisted of children with signs of meningeal irritation due to upper respiratory tract infection but normal CSF findings. Samples were obtained within 6 h after admission to hospital. Mean serum and CSF Zn levels in the febrile convulsion group were significantly lower than in the other groups (for serum Zn: 0.66±0.03 mg/l vs 0.98±0.07 mg/l, 1.06±0.08 mg/l, 1.05±0.09 mg/lP<0.05; for CSF Zn: 22.96±1.62 μg/l vs 75.47 ±6.9 μg/l, 50.32±5.235 μg/l, 39.85 ±2.81 μg/lP<0.05). A linear relationship was established between serum Zn and CSF Zn levels (P<0.001). Mean CSF Zn, Cu and protein levels in the bacterial meningitis group were significantly higher than in the other groups (for CSF Cu 63.94±6.33 μg/l vs 38.77±2.70 μg/l, 35.84±3.48 μg/l, 33.86±2.88 μg/lP<0.05; for CSF protein 0.80 ± 0.12 g/l vs 0.22±0.02 g/l, 0.53±0.08 g/l, 0.19±0.01 g/lP<0.05). In children with meningitis, the elevation of the mean CSF Zn and Cu levels may result from the breakdown of the blood-brain barrier and subsequent leakage of trace elements and protein from serum to CSF. There was no significant difference between the four groups in terms of mean serum Mg and mean CSF Mg levels.ConclusionSerum and CSF Zn levels are decreased in children with febrile seizures. Zinc deprivation may play a role in the pathogenesis of febrile seizures.

Correlative value of magnetic resonance imaging for neurodevelopmental outcome in periventricular leukomalacia

The aim of this study was to evaluate the correlative value of magnetic resonance imaging (MRI) in children with periventricular leukomalacia (PVL) for neurodevelopmental outcome. MRI examinations of 89 children (46 males, 43 females) with PVL (median age 4y, range 1 to 14y) were reevaluated. PVL was graded as follows: grade I, unilateral or bilateral areas of periventricular hyperintensity (1–3); grade II, hyperintensity more than 3; grade III, hyperintense lesions more than 3 and ventricular wall irregularity; grade IV, diffuse PVL and ventricular dilatation. Localizations of PVL and brain abnormalities associated with PVL were also noted. Assignment to PVL grades on MRI was as follows: PVL I (n=22), PVL II (n=18), PVL III (n=30), and PVL IV (n=19). Cerebral palsy was slightly less common in children with PVL I and II compared with PVL III to IV. Motor function was normal in 50% of children with PVL grade I, but severely impaired in 73.7% of children with PVL grade IV. Results of visual function were normal in all with PVL I, but pathological in 42.1% of patients with PVL IV. Developmental tests were appropriate for age in 75% of patients with PVL I, but significantly delayed in all patients with PVL IV. Thinning of the corpus callosum and presence of cortical atrophy were also correlated with neurological outcome. Significant risk factors associated with developmental delay were asphyxia at birth (odds ratio [OR] 4.3), PVL localization numbers over 3 (OR 4.4), PVL III to IV (OR 15), thinning of corpus callosum, and cortical atrophy.

Outcome of axonal and demyelinating forms of Guillain-Barré syndrome in children

Previous reports have suggested that outcome is worse in the axonal compared with the demyelinating form of Guillain-Barré syndrome (GBS). We performed a retrospective study of 23 children with electrophysiologically confirmed cases of predominant subtypes of GBS to investigate this issue. The patients were classified based on the electrodiagnostic features: Ten (44%) had acute inflammatory demyelinating polyradiculoneuropathy, eight (35%) had acute motor axonal neuropathy, and five (21%) had acute motor-sensory axonal neuropathy. All patients received a standard intravenous immunoglobulin therapy (0.4 g /kg /day for 5 consecutive days). In the acute phase of the disease, patients with the axonal forms of GBS were more disabled than were those with the demyelinating GBS, as measured by GBS scores. Mechanical ventilation was required in five (38%) patients in the axonal group compared with one (10%) patient in the demyelinating group. There was no significant difference at 6 months in GBS scores between demyelinating and axonal forms of GBS. All 20 survivors recovered completely by 12 months. After standard intravenous immunoglobulin therapy, children with axonal forms of GBS recover more slowly than those with the demyelinating form, but outcome at 12 months appears to be equally favorable in two groups.

Bone Mineral Status in Pediatric Outpatients on Antiepileptic Drug Monotherapy

Drug-induced osteopenia has been reported in institutionalized children on chronic antiepileptic drug therapy. The aim of this study was to assess longitudinally bone mineral status in pediatric outpatients on antiepileptic drug monotherapy. The study group consisted of 30 ambulatory children on a normal diet: 15 on valproic acid, 11 on carbamazepine, and 4 on phenobarbital monotherapy. Bone mineral density, serum active vitamin D (1,25-dihydroxyvitamin D), and certain biochemical markers of bone formation (calcium, phosphorus, alkaline phosphatase, intact parathyroid hormone, osteocalcin, calcitonin, and urinary calcium to serum creatinine and urinary phosphorus to serum creatinine ratios) were studied at the beginning of antiepileptic drug monotherapy and at the end of 2 years of treatment. Age- and sex-specific Z-scores of bone mineral density were measured at anterior-posterior L2—L4 by dual-energy x-ray absorptiometry. Drug-induced osteopenia was defined in only two patients (one on carbamazepine and the other on phenobarbital monotherapy), with Z-scores of bone mineral density less than —1.5. Serum levels of active vitamin D and biochemical markers were not significantly correlated with the Z-scores of bone mineral density. We detected a frequency of antiepileptic drug—induced osteopenia of 6.7% in pediatric outpatients after 2 years of monotherapy. However, osteopenia was not attributed to a defect in serum active vitamin D production owing to hyperparathyroidism in children on antiepileptic drug monotherapy. ( J Child Neurol2006;21:411—414; DOI 10.2310/7010.2006.00066).

Subclinical Neurological Abnormalities in Children With Celiac Disease Receiving a Gluten-free Diet

Objectives: Because clinically evident manifestations are frequent in adults with celiac disease (CD), we aimed to investigate whether early neurological abnormalities may be detected in children with CD. Methods: Electroencephalography, electromyography, and somatosensory evoked potentials were performed in children with CD receiving a gluten-free diet. Results: The neurophysiological tests revealed subclinical neurological abnormalities associated with CD in 3 (11%) of 27 children: 2 had peripheral polyneuropathy documented with electromyography, and 1 had prolonged latencies in somatosensory evoked potential. Magnetic resonance imaging showed abnormalities in 2 (7.4%) of children: pontine demyelinization in 1 and cortical atrophy in the other. Conclusions: Because the rate of neurological problems is increased in children with CD, neurological abnormalities should be carefully investigated early after the diagnosis of CD is made.

Neuropsychologic Impairment in Children With Rolandic Epilepsy

Although patients with benign childhood epilepsy with centrotemporal spikes exhibit normal intelligence, they frequently display neuropsychologic abnormalities. Thirty-five patients with rolandic epilepsy were included in this study. They were divided into three subgroups. Group I comprised patients with rolandic focus who were not receiving treatment. Group II comprised patients with rolandic focus who were receiving treatment. Group III comprised patients who demonstrated improved foci and were not receiving treatment. The control group comprised 16 children who were similar to patients in terms of age, sex, and sociocultural level. All children underwent standardized neuropsychologic testing, including the Wechsler Intelligence Scale for Children-Revised subtests, Bender Gestalt Test, Stroop Test, Visual Aural Digit Span, Reading and Writing Performance, and Dichotic Listening Test. Patients exhibited significantly impaired visuomotor and reading ability and attention to verbal stimuli compared with control subjects. Reading disability persisted in patients in remission from seizures and epileptic discharges. Contrary to the presumed benign nature of rolandic epilepsy, this disorder may cause learning disabilities. Therefore, patients must be followed longitudinally to identify any learning problems.

Convulsive status epilepticus in children: Etiology, treatment protocol and outcome

This study aimed to determine the etiology, treatment protocol and outcome of convulsive status epilepticus (SE) in children. An institutional treatment protocol using benzodiazepines (diazepam and midazolam) was assessed in a retrospective case study. The treatment protocol (Ege Pediatric Status Epilepticus Protocol or EPSEP) was developed based on an operational definition of pediatric SE according to the duration of seizure activity. Pediatric SE is divided into three categories: initial SE (20-30 min), established SE (30-60 min) and refractory SE (>60 min). Eight (30%) of the studied episodes were initial SE, 10 (37%) were established SE, and 9 (33%) were refractory SE. With respect to the etiological spectrum of SE, 11 (40%) children had meningitis or encephalitis. Febrile SE was identified in 7 (26%) patients. Only 2 episodes of initial SE (7.5%) were controlled with first step of the protocol (two concomitant-doses of rectal diazepam). Midazolam bolus and infusions (up to 1.2 μg/kg/min) were used to treat 22 episodes of SE (9 refractory SE, 10 established SE and 3 initial SE). Complete arrest of convulsive SE was achieved in 21 of 22 (95%) episodes with midazolam infusion. We concluded that the combined use of benzodiazepines (diazepam+midazolam) was safe and effective in the treatment of convulsive SE in children.

Febrile Seizures: Interleukin 1β and Interleukin-1 Receptor Antagonist Polymorphisms

In order to investigate the association between IL-1beta -511 C-->T and IL-1 receptor antagonist intron 2 variable tandem repeat polymorphisms, and febrile seizures in children, 90 children (mean age, 19.7 +/- 11.2 months) diagnosed with febrile seizure and 106 healthy controls (mean age, 14.2 +/- 3.6 months) with no seizure or neurologic events were included in the study. The polymorphisms were analyzed using restriction fragment length polymorphism and agarose gel electrophoresis methods. In the patient group, the frequencies of IL-1beta genotypes CC, CT, and TT were 24.4%, 52.2%, and 23.3%, respectively, compared with 38.7%, 50.95%, and 10.4%, respectively, in the control group. The TT genotype was significantly more common in the patient group than in the control group (P = 0.044), and the T allele frequency was significantly higher in the patient group (0.50 vs 0.36, P = 0.040). Among the three genotypes (RN1/1, RN1/2, and RN2/2) of the IL receptor antagonist gene variable tandem repeat polymorphisms, the frequency of both the RN2/2 genotype and the RN2 allele were significantly higher in the patient group (P = 0.007). Also RN2 allele frequency was found higher in patient group than controls (0.29 vs 0.15, P = 0.020). IL-1beta -511 and IL-1 receptor antagonist intron 2 variable tandem repeat polymorphisms may be involved in susceptibility to febrile convulsions in children.

The effect of antiepileptic drugs on thyroid function in children

BACKGROUND Limited and conflicting data exist for the influence of antiepileptic drugs on thyroid function in children. OBJECTIVE The aim of this study was to investigate the effects of phenobarbital, valproate, carbamazepine, oxcarbazepine, and levetiracetam monotherapy on thyroid function in daily clinical practice during a 12-month treatment period. METHOD A total of 223 children (103 females and 120 males) with new onset and controlled epilepsy treated with valproate (n=129), phenobarbital (n=33), carbamazepine (n=36), oxcarbazepine (n=14), levetiracetam (n=11) were enrolled in the study. Serum free thyroxine (fT4) and thyroid-stimulating hormone (TSH) levels were measured before and at first, sixth and twelfth months of therapy. RESULTS At baseline, average fT4 and TSH concentrations were not different between the drug groups. Valproate-treated patients had decreased fT4 and increased TSH levels at months 1, 6, and 12. Carbamazepine-treated patients had decreased fT4 levels at months 1, 6, and 12 and increased TSH levels at months 1, and 6. Phenobarbital-treated patients had decreased fT4 levels at months 1, and 6, and increased TSH levels at months 6 and 12. Oxcarbazepine-treated patients had decreased fT4 levels at month 1. Levetiracetam-treated patients showed no significant change of fT4 and TSH at any times. The frequency of subclinical hypothyroidism at month 12 was 28% in valproate, 21.4% in oxcarbazepine, 18.2% in phenobarbital, 13.9% in carbamazepine, and 0% in levetiracetam groups. CONCLUSION Our data suggest that all antiepileptic drugs studied except levetiracetam had varying degrees of deleterious effects on thyroid function.