Filiz Tutunculer

Clinical utility of dorsal sural nerve conduction studies in healthy and diabetic children

OBJECTIVE Monitoring of the dorsal sural sensory nerve action potential (SNAP) is a sensitive method for detection of peripheral neuropathies. We tried to determine the normal dorsal sural nerve conduction values of the childhood population and assessed the clinical utility of this method in diabetic children who have no clinical sign of peripheral neuropathy. METHODS In the study, 36 healthy and 27 diabetic children were included. In all subjects peripheral motor and sensory nerve studies were performed on the upper and lower limbs including dorsal sural nerve conduction studies. RESULTS The dorsal sural SNAP mean amplitude was 8.24+/-3.08 microV, mean latency was 2.47+/-0.48 ms, mean sensory conduction velocity was 41.63+/-5.43 m/s in healthy children. Dorsal sural SNAPs were absent bilaterally in one diabetic patient. In the other 26 diabetic patients, the mean dorsal sural nerve distal latency was longer (2.93+/-0.63 ms, P = 0.004), mean SCV was slower than in healthy subjects (36.68+/-7.66 m/s, P = 0.005). However, dorsal sural nerve amplitude was not different between the groups. A dorsal sural nerve latency of more than 2.9 ms had a sensitivity of 50% and a specificity of 75%. A dorsal sural nerve velocity of less than 36 m/s had a sensitivity of 54% and a specificity of 92%. CONCLUSIONS We designated the reference values of the dorsal sural nerve in healthy children. In addition, our findings suggest that dorsal sural nerve conduction studies may have value to determine neuropathy in the early stages in children with diabetes. SIGNIFICANCE The dorsal sural nerve conduction studies in diabetic children may have value to determine the neuropathy in its early stages.

Successful Results of Pamidronate Treatment in Children With Osteogenesis Imperfecta With Emphasis on the Interpretation of Bone Mineral Density for Local Standards

Aim: To assess the long-term effect of pamidronate therapy on bone mineral metabolism and bone mineral density (BMD) in children with osteogenesis imperfecta (OI) and to evaluate BMD results with respect to national standards. Methods: Pamidronate was administered intravenously on 3 consecutive days every 3 to 4 months at a dose of 1 mg/kg/d in 35 patients. Infusion cycles ranged from 4 to 17. Serum calcium, phosphorus, bone turnover markers, L1-L4 areal BMD (aBMD), and fracture rate were evaluated. Areal BMD Z scores were compared with national sex-specific reference data and volumetric BMD Z scores. Results: In all children, linear growth continued along the same percentile during treatment. All parameters of bone turnover showed a decrease. L1 to L4 aBMD and Z score increased markedly, and fracture rate decreased in all patients during therapy. The mean annual percent gain in aBMD was highest in the first year and slowed down in subsequent years. Mean L1 to L4 aBMD Z scores according to Turkish reference data were higher than that of manufacturer values (P = 0.004). Correction of L1 to L4 vertebrae for bone size yielded to a decrease in osteoporosis in OI patients (41.5% vs 22.3%). Conclusions: Bone mineral density increased and fracture rate decreased in children and infants with OI during pamidronate treatment. Prevalence of osteoporosis decreased after correction for national standard and volumetric BMD. Use of an appropriate reference database and method of data analysis are very important for correct evaluation of osteoporosis.

The exon 3-deleted/full-length growth hormone receptor polymorphism and response to growth hormone therapy in growth hormone deficiency and Turner syndrome: a multicenter study.

Background/Aim: The exon 3-deleted/full-length (d3/fl) growth hormone (GH) receptor (GHR) polymorphism has been associated with responsiveness to GH therapy in some diagnostic groups. However, there are still controversies on this issue. To evaluate the effect of the GHR exon 3 polymorphism on growth after 1 and 2 years of GH therapy in Turkish patients with GH deficiency (GHD) and Turner’s syndrome (TS) and the distribution of GHR exon 3 isoforms. Materials and Methods: 218 patients with GHD (125 males/93 females) and 43 patients with TS were included in the study. The control group included 477 healthy adults aged from 18 to 57 years (54 females/423 males). Anthropometric parameters and insulin-like growth factor (IGF)-1 and IGF binding protein (IGFBP)-3 were evaluated annually. GHR isoforms were studied using simple multiplex PCR. Height and body mass index were expressed as standard deviation score (SDS). Results: There were no differences among TS, GHD and healthy adults regarding the distribution of GHR exon 3 isoforms (fl/fl, fl/d3 and d3/d3). There was a significant increase in height SDS in both diagnostic groups on GH therapy; however, there were neither differences in height SDS and Δheight velocity between fl/fl, fl/d3 and d3/d3 groups nor a correlation between the distribution of GHR exon 3 isoforms and change in IGF-1 SDS and IGFBP-3 SDS levels on GH therapy in either of the diagnostic groups. There was also no gender difference in GHR isoforms in healthy adults. Conclusion: The results suggest that responsiveness to GH therapy does not depend on the exon 3 GHR genotypes in GHD and TS patients.

Evaluation of adrenomedullary function in patients with congenital adrenal hyperplasia.

Background/Aims: Congenital adrenal hyperplasia (CAH) is characterized by adrenal insufficiency with or without salt wasting. It is also accompanied by adrenomedullary hypofunction. The aim of the present study was to investigate adrenomedullary function in patients with CAH due to 21-hydroxylase and 11β-hydroxylase deficiencies and in age-matched normal subjects. Methods: We measured plasma catecholamines (epinephrine and norepinephrine) and urine metanephrine in 44 patients with CAH, 32 due to 21-hydroxylase deficiency (17 patients with the salt-wasting form and 15 patients with the simple virilizing form), and 12 due to 11β-hydroxylase deficiency, and in 25 healthy controls. Results: Plasma epinephrine and urine metanephrine levels were significantly higher in the controls than in patients with CAH (p = 0.02 and p < 0.001, respectively). Plasma norepinephrine levels were significantly lower in the controls than in patients with CAH (p < 0.001). Interestingly, patients with the salt-wasting form had lower norepinephrine levels in comparison to the other subgroups of CAH. Conclusion: Despite the fact that CAH patients have insufficient epinephrine secretion, these patients have the ability to increase compensatory norepinephrine. However, this increase is much lower in patients with the salt-wasting form. These findings need to be confirmed by other studies.

The Etiology and Clinical Features of Non-CAH Gonadotropin-Independent Precocious Puberty: A Multicenter Study

AIM The causes of gonadotropin-independent precocious puberty are diverse, and often have overlapping clinical and biochemical features. With the exception of congenital adrenal hyperplasia (CAH), disorders that cause gonadotropin-independent precocious puberty (GIPP) are uncommon. The literature is devoid of any large-scale studies on the etiologic distribution of GIPP. The aim of this study was to determine the frequency of each etiology in a cohort of patients with GIPP (excluding those with CAH), and to evaluate the clinical and laboratory features of these patients. MATERIALS AND METHODS This multicenter, nationwide web-based study collected data on patients who presented with non-CAH GIPP in Turkey. RESULTS Data were collected for 129 patients (102 girls and 27 boys) from 29 centers. Based on the data collected, the estimated prevalence of non-CAH GIPP in the studied population was 14 in 1 000 000 children. Functional ovarian cyst was the most common etiology, accounting for 37% of all cases, followed by McCune-Albright syndrome (MAS) (26%). Among the patients with MAS, 11.7% had fibrous dysplasia, 32.3% had café-au-lait spots, and 52.9% had both. Human chorionic gonadotrophin-secreting tumors included choriocarcinoma of the liver, hepatoblastoma, and germ cell tumors of the sellar-suprasellar region and mediastinum. Patients with adrenocortical tumors presented at an earlier age than those with other etiologies. Ovarian tumors included mature cystic teratoma, dysgerminoma, juvenile granulosa tumor, and steroid cell tumor. Despite overlapping features, it was possible to identify some unique clinical and laboratory features associated with each etiology. CONCLUSION This largest cohort of patients with non-CAH GIPP to date yielded an estimation of the frequency of non-CAH GIPP in the general pediatric population and showed that girls were affected at a rate 4-fold greater than that of boys owing to functional ovarian cysts and MAS, which were the two most common etiologies. The data collected also provided some unique characteristics associated with each etiology.

Exogenous Cushing syndrome due to misuse of potent topical steroid

We report an infant with exogenous Cushing syndrome after being treated for 2 months with a potent topical corticosteroid via the mothers application of topical clobetasol for diaper rash without a prescription. We emphasize that potent topical steroids should be used with great caution, especially when used under occlusion (e.g., diaper area) and that parents should be warned about potential side effects of these medications, particularly when used in infants.

Etiological evaluation of primary congenital hypothyroidism cases

AIM Primary congenital hypothyroidism is frequently seen endocrine disorder and one of the preventable cause of mental retardation. Aim of study was to evaluate the frequency of permanent/transient hypothyrodism, and to detect underlying reason to identfy any marker which carries potential to discriminate permanent/transient form. MATERIAL AND METHODS Forty eight cases older than 3 years of age, diagnosed as primary congenital hypothyroidism and started thyroxin therapy in newborn-period, and followed up between January 2007-June 2013 were included in the study. Thyroid hormon levels were evaluated and thyroid ultrasonography was performed in cases who are at the end of their 3 years of age, after 6 weeks of thyroxine free period. Thyroid sintigraphy was performed if serum thyroid-stimulating hormone was high (≥ 5 mIU/mL) and perchlorate discharge test was performed if uptake was normal or increased on sintigraphy. Cases with thyroid-stimulating hormone levels ≥ 5 mIU/mL were defined as permanent primary congenital hypothyroidism group and as transient primary congenital hypothyroidism group with normal thyroid hormones during 6 months. RESULTS The mean age was 3.8±0.7 years. Mean diagnosis age was 16.6±6.5 days and 14 cases (29.2%) were diagnosed by screening program of Ministry of Health. There were 23 cases (14F, 9M) in permanent primary congenital hypothyroidism group and 12 (52.2%) of them were dysgenesis (8 hypoplasia, 4 ectopia), and 11 (47.8%) dyshormonogenesis. In transient primary congenital hypothyroidism group, there were 25 cases (17M, 8F). The mean thyroid-stimulating hormone levels at diagnosis were similar in two groups. The mean thyroxin dose in permanent primary congenital hypothyroidism group was significantly higher than transient group at the time of thyroxin cessation (2.1±0.7, 1.5±0.5 mg/kg/d, respectively, p=0.004). Thyroxin dose ≥1.6 mcg/kg/d was 72% sensitive and 69.6% specific for predicting permenant primary congenital hypothyroidism. CONCLUSIONS Transient primary congenital hypothyroidism is more frequent than expected and found often in males in the primary congenital hypothyroidism cases, started thyroxin therapy in neonatal period. While fT4, thyroid-stimulating hormone, Tg levels at diagnosis do not predict transient/permenant primary congenital hypothyroidism, thyroxin dose before the therapy cessation at the age of 3 may make the distinction between transient/permenant primary congenital hypothyroidism.