Accuracy of pedicle screw placement for upper and middle thoracic pathologies without coronal plane spinal deformity using conventional methods

There is a growing interest in the implantation of pedicle screws into the middle and upper thoracic spine. However, usage of the technique is still under debate for these levels because the pedicles in these regions are small and exhibit a high degree of inter- and intraspecimen variability. Twenty-four consecutive patients treated for upper and middle thoracic pathologies by pedicle screw instrumentation under biplanar or uniplanar fluoroscopy were evaluated retrospectively. The rate of screw misplacement on postoperative computerized tomography and complications caused by misplaced screws were determined. In 24 cases, a total of 113 upper-middle thoracic pedicle screws were inserted. Fifty-one of them were inserted between T2 and T5 with guidance of biplanar fluoroscopy, and 62 were inserted between T6 and T8 with uniplanar fluoroscopy. The rate of misplacement was 20.3% for 113 screws (27.4% for T2 to T5 screws, and 14.5% for 62 T6 to T8 screws). Four screws were incorrectly inserted which could have clinical significance (3.5%), and 1 of them required revision. The difference between the upper and middle thoracic screws was not statistically significant (P=0.089). Screw insertion with laminectomy did not cause significant difference in both upper and middle thoracic regions. Only 2 complications were seen because of screw insertion. Pedicle screw insertion with guidance of fluoroscopy may be a reliable and safe method for upper and middle thoracic pathologies.     

ABCC8 (SUR1) and KCNJ11 (KIR6.2) mutations in persistent hyperinsulinemic hypoglycemia of infancy and evaluation of different therapeutic measures

Persistent hyperinsulinemic hypoglycemia of infancy (PHHI) can occur as a result of mutations in the subunits that form the ATP-sensitive potassium channel (K+ATP) in pancreatic beta-cells which play a major role in modulating insulin secretion from the beta-cells. Mutations have been shown in the genes for these subunits, namely for the plasma membrane sulfonylurea receptor (SUR1), ABCC8, and its associated inwardly rectifying potassium channel (KIR6.2) KCNJ11. Drugs which act on K+ATP channels, such as diazoxide, seem to need intact ABCC8 to be able to show their effects. Thus, it would be desirable to know the exact locus of the abnormality in the beta-cell to be able to choose the right therapeutic agent or to perform early pancreatectomy. The aim of this study was to search for the correlation between the mutations of the K+ATP channel and the outcome of therapeutic measures in patients with PHHI followed for a duration of 4 months to 7.3 years. Thirteen patients (5 F, 8 M) with PHHI with a median age of 2.5 months (8 days-12.1 years) were included in the study. Therapy for PHHI was initiated either with diazoxide (n = 9) or with calcium channel blocker (n = 4) as the agent of first choice. Three patients unresponsive to drugs underwent 95% pancreatectomy. Mutation analysis was performed by polymerase chain reaction (PCR) and single strand conformation polymorphism (SSCP) in DNA samples extracted from patients' peripheral leukocytes. The PCR products were directly sequenced. Screening of ABCC8 and KCNJ11 for mutations revealed abnormalities in the ABCC8 gene in three patients out of 13: homozygosity for the 155del1 mutation, compound heterozygosity for T267-->G/A4612-2-->G, and compound heterozygosity for G4310-->A/ R1494Q. No mutations in the KCNJ11 gene were identified. Of the three patients who underwent pancreatectomy, two had identified mutations and one did not have any known mutation. In two patients in whom hyperinsulinism recurred after surgery and in the rest of the children, therapy with either diazoxide or calcium channel blocker proved to be effective in controlling hypoglycemia over the follow-up period. Thus it may be concluded that mutations in the ABCC8 gene were not predictive of the response to drugs. Unidentified mutations in the K+ATP channels other than those screened or other functional abnormalities in these channels may account for the different therapeutic responses.     

Analysis of puberty and pubertal growth in healthy boys

The aim of this study was to provide normative data for the onset and tempo of puberty in healthy boys. The analyses are based on data that were collected and evaluated biannually on 1112 Turkish school children aged from 8 to 18 years and a subsample of 30 boys who had reached final height (FH). The data were analyzed cross-sectionally in the total group and longitudinally in the subsample. Mean age and height (Ht) at onset of puberty were 11.6 ± 1.2 years and 146.1 ± 7.7 cm, respectively. Peak height velocity (HtV) was 10.1 ± 1.6 cm. Total pubertal height gain was 26.4 ± 4.3 cm. The duration of puberty was 4.9 ± 0.6 years. Height at onset of puberty was positively correlated with FH (p  <  0.0001) and with duration of puberty (p = 0.03). Body mass index at onset of puberty correlated negatively with age at onset of puberty (p < 0.009) and with the duration of puberty (p = 0.05) but not with FH. In conclusion, these results provide normative data for Ht and HtV for each testicular volume stage for boys in puberty. Height at onset of puberty is the most important determinant of FH. There is no secular trend for the onset of puberty. Weight does seem to affect the onset and tempo of puberty but not FH.     

Posterior fossa dermoid cysts causing cerebellar abscesses

Dermoid cysts are uncommon tumors, and posterior fossa dermoid cysts may rarely cause abscess formation or formation of daughter abscesses within the cerebellum. At present, there are only 16 cases with posterior fossa dermoid cysts causing cerebellar abscesses reported in the literature. Two cases, 22 and 14 months old, with posterior fossa dermoid cysts and dermal sinus causing multiple cerebellar abscesses are reported. In the first one, there was also marked hydrocephalus. Retrospective examination of the patients revealed pinpoint-sized dimples in their suboccipital regions. Both patients were treated with antibiotics and underwent posterior fossa surgery. In the patient with marked hydrocephalus, ventriculoperitoneal shunting was performed after treatment of the infection. Both patients were neurologically normal, and there were no complaints, except a light learning difficulty in the patient with ventriculoperitoneal shunting, 133 and 34 months after surgery, respectively. Early detection of congenital dermal abnormalities along the craniospinal axis by routine examination of newborns is highly important before development of serious complications. Because surgery is the only effective treatment modality for these lesions, radical excision should be performed in all cases to avoid tumor recurrence. However, subtotal excision may be performed in selected cases, because the cyst capsule may adhere firmly to vital structures.     

Hyperinsulinism in infancy--genetic aspects

Hyperinsulinism in infancy (HI) is a heterogeneous disorder with respect to clinical presentation, genetics, histology and response to therapy. Advances in the understanding of the molecular basis of the disease have given the pediatric endocrinologists a better insight into the diagnosis and therapeutic choice. In 50-60% of cases, a genetic etiology is unraveled. Mutations in the genes encoding SUR1 (ABCC8) and KIR6.2 (KCNJ11) are the most frequent genetic causes of HI followed by mutations in the GLUD1 gene which encodes glutamate dehydrogenase (GDH) enzyme. The patients with GLUD1 mutations also have hyperammonemia (HA). Activating dominant mutations in glucokinase (GCK) gene which result in HI are rare. In GLUD1 and GCK mutations the disease is usually mild, has a late onset and is responsive to diazoxide. However, studies so far have failed to show a clear genotype phenotype relation in KATP channel mutations. In conclusion the genetic analysis of HI has provided valuable information to the clinicians about the beta cell.     

Evaluation of glucose intolerance in adolescents relative to adults with type 2 diabetes mellitus

AIM: There is an increasing trend in the prevalence of type 2 diabetes mellitus (DM2) in childhood and adolescence, while positive family history of DM2 and obesity are the most important risk factors. To study the influence of family history and obesity on glucose intolerance in our country was the aim of this study. STUDY DESIGN AND METHODS: A total of 105 children and adolescents aged 10-18 years (mean 13.3 +/- 2.5 years) were included in the study. All children and adolescents were divided into three groups according to positive family history of DM2 and obesity, and an oral glucose tolerance test (OGTT) was performed for all. Prediabetes was defined as impaired glucose tolerance (IGT) and/or impaired fasting glucose (IFG). Insulin secretion and insulin resistance were estimated using the insulinogenic index; and the homeostatic model assessment for insulin resistance (HOMA-IR) and Matsuda index, respectively. RESULTS: The prevalence of prediabetes was 15.2% in the whole group, while it was 25.5% in obese children who also had a positive family history of DM2. The frequency of hyperinsulinism was 57.1% in all groups. Prediabetic children had significant insulin resistance (HOMA-IR 11.5 +/- 7.1 and 4.1 +/- 6.4, respectively, p = 0.034). CONCLUSIONS: Obesity and glucose intolerance are also a problem in developing countries. The risk of prediabetes in children is highest in obese children who also have a positive family history of DM2. There is a need for a lifelong preventive program starting in childhood to avoid DM2 and decrease cardiovascular risk factors     

Worster-Drought syndrome (congenital bilateral perisylvian syndrome) with posterior pituitary ectopia, pituitary hypoplasia, empty sella and panhypopituitarism: a patient report

Worster-Drought syndrome (WDS) (congenital bilateral perisylvian syndrome, congenital pseudobulbar paresia) is characterized by neuronal migration defect, pseudobulbar paralysis, epilepsy, neuromotor retardation and perisylvian dysplasia. We report a patient with WDS associated with posterior pituitary ectopia, pituitary hypoplasia, partial empty sella and panhypopituitarism, not previously reported in the literature. The 16.4 year-old female patient had severe growth retardation with height SDS -4.5, delayed puberty, microcephaly, pes equinovarus deformity, developmental delay, speech disorder and epilepsy. Laboratory findings, which revealed abnormal electroencephalography and bilateral perisylvian cortical dysplasia on cranial magnetic resonance imaging (MRI) were consistent with WDS. Endocrinological evaluation revealed secondary hypothyroidism and combined deficiency of adrenocorticotropin, gonadotropin and growth hormone (GH). Sella MRI showed congenital empty sella, anterior pituitary hypoplasia, ectopic neurohypophysis, and stalk agenesis. Appropriate replacement therapy was started. GH treatment resulted in a final height of 150.3 cm, appropriate for her target height. This is the first reported patient with WDS associated with congenital structural hypothalamic-pituitary abnormalities, including empty sella, pituitary hypoplasia, posterior pituitary ectopia, stalk agenesis and panhypopituitarism. GH has been successful in the treatment of her short stature.     

Growth references for Turkish children aged 6 to 18 years

Aim: To create up-to-date reference standards for Turkish children, and to compare these with growth standards for US children (CDC 2000 Growth Charts) and with previous local data. Subjects and methods: Height and weight measurements of 1100 boys and 1020 girls were obtained by biannual visits to six schools located in relatively well-off districts of Istanbul city. All children came from well-to-do families and all were healthy. All measurements were made by two trained technicians. The LMS method was used in the analyses. Results: Heights of the boys and girls in all age groups were close to the updated 2000 USA growth references and showed an increase from data on Turkish children born 30 y earlier. Weight values were high compared to reference data on US children and to the older data on Turkish children.

Conclusion: These results indicate that height growth in Turkish school-age children of high socio-economic level conforms to the updated growth data on US children. The data also show a secular upward trend in Turkey. Weight-for-age values indicate an increase in obesity. The results also point to the value of collecting and evaluating local growth data periodically.