Effects of methylphenidate on leptin and appetite in children with attention-deficit hyperactivity disorder: an open label trial.

Appetite suppression is one of the most common side effects of methylphenidate (MPH), which is used for treatment of attention-deficit hyperactivity disorder (ADHD). Relation of appetite and leptin is well known but there is no report regarding MPH use and leptin. In this study we compared the baseline leptin levels of ADHD children with the controls and studied the interaction between MPH and leptin-insulin level in ADHD children under MPH treatment. The major finding of this study is that at a total daily dose of 0.6 mg/kg short-acting MPH treatment, one does not observe significant side effects related to appetite suppression and metabolic features as measured via body mass index, insulin and leptin levels. Thus this range seems to be safe in developing ADHD children with minimum side effects regarding appetite for short-term treatment.

Abnormality of the left ventricular sympathetic nervous function assessed by I-123 metaiodobenzylguanidine imaging in pediatric patients with neurocardiogenic syncope.

The purpose of this study was to assess the left ventricular sympathetic nervous system function in the patients with neurocardiogenic syncope (NCS) using I-123 metaiodobenzylguanidine (MIBG) imaging of the heart, and to compare the plasma noradrenaline (NA) and MIBG results of tilt positive and tilt negative patients following a head-up tilt test (HUT). The study included 30 patients. Their physical and laboratory examinations did not show a pathology that may be the cause of their syncope. HUT test was positive in 13 patients and negative in 17 patients. Plasma NA concentrations were higher in the HUT positive than the HUT negative group at the beginning and at the 10th minute of the test. Specific I-123 MIBG uptake assessed as the cardiac to mediastinal activity ratio in the delayed image was significantly higher in HUT positive group. The higher levels of MIBG uptake and plasma NA observed in HUT positive patients may reflect the greater capacity of NA storage in cardiac adrenergic neuronal tissue in patients with NCS. The results of this study support the critical role of autonomic nervous system in the pathophysiology of NCS and the excessive sympathetic nervous stimulation as the trigger of paradox reflex.

Tc-99m HMPAO brain perfusion imaging in young Down's syndrome patients.

Down's syndrome (DS) is characterized by moderate mental retardation and a variety of abnormalities involving multiple organ systems. There is a high incidence of Alzheimer's disease (AD) type dementia beyond the age of 35. In this study, single photon emission computed tomography (SPECT) brain perfusion imaging of young Down's syndrome patients was performed to define the perfusion pattern. Tc-99m HMPAO brain perfusion SPECT was performed on 17 young DS patients, aged 3-24 years (mean: 10.9+/-5.9 years). None of the patients had dementia symptoms. Brain perfusion scans were acquired 15 min after i.v. injection of 12 MBq/kg of Tc-99m HMPAO using a single head rotating gamma camera. Images were analyzed visually and semiquantitatively by defining side-to-side asymmetry index. Nine DS cases showed normal brain perfusion. Eight of the 17 cases revealed mostly unilateral parieto-temporal, parieto-occipital and frontal hypoperfusions. The side-to-side asymmetry indices for these visually interpreted regional brain perfusion abnormalities ranged from 6 to 15%. These findings revealing mostly unilateral parieto-temporal and frontal hypoperfusions may not be considered as predictive patterns of dementia related Alzheimer type perfusion deficits in DS. However, such findings may connect to other functional imaging studies related to the higher cortical dysfunction in mental retardation.

Assessment of brain perfusion by 99mTc-HMPAO SPECT in akinetic mutism due to high-dose intravenous methotrexate therapy.

Chemotherapy of the central nervous system may cause neurotoxicity in children with acute lymphocytic leukemia. We evaluated regional blood flow in a 6-year-old child presenting with akinetic mutism, using 99mTc-HMPAO single photon emission tomography (SPECT) following high-dose intravenous methotrexate therapy. While findings in X-ray computerized tomography were decreased density in bilateral basal ganglia and thalamic nuclei with diffusely decreased attenuation of the periventricular white matter, a global, frontal dominant profoundly abnormal perfusion pattern involving both gray and white matter was observed in the SPECT study. Treatment of the central nervous system with high dose intravenous chemotherapy may cause profound abnormalities in white and gray matter blood flow and early assessment of the neurotoxicity may be identified by 99mTc-HMPAO SPECT in the pediatric age group.

Tl-201 scintigraphy, mammography and ultrasonography in the evaluation of palpable and nonpalpable breast lesions: a correlative study.

PURPOSE: To determine the feasibility of Tl-201 as a tumor localizing agent in palpable and nonpalpable breast lesions, in comparison with mammography and ultrasonography (US), and to evaluate the contribution of these modalities to each other in obviating biopsy. MATERIALS AND METHODS: Seventy-two palpable and nonpalpable breast lesions were prospectively classified as benign, indeterminate, or malignant according to the sonographic and mammographic criteria and were further analyzed with Tl-201 scanning. These classifications were compared with biopsy results. The sensitivity, specificity, accuracy, false positive and false negative rates (FPR, FNR), negative and positive predictive values (npv, ppv) were calculated for each individual modality and combination of modalities to evaluate the contribution of these three techniques to each other. RESULTS: Of 72 lesions 52 were histologically malignant and 20 were benign. Overall, mammography was the most sensitive (92%) and Tl-201 was the most specific (75%) of the three modalities. Mammography + Tl combination was the most specific (90%) and accurate (97%) of dual combinations. In mammographically or sonographically indeterminate cases, Tl-201 was much more specific (75% versus 37% for mammography and US) and more accurate (82% versus 36% for mammography and 54% for US) than the other two modalities, and mammography + Tl combination was significantly superior to other dual combinations (87% specific and 91% accurate). Use of Tl-201 scanning as an adjunct to mammography + US combination increased the specificity, ppv, and accuracy rates overall, particularly in mammographically or sonographically indeterminate cases. CONCLUSIONS: In mammographically and sonographically indeterminate breast lesions thallium scanning may be offered as a third step of investigation to obviate biopsy.

201Tl scintigraphy in the evaluation of palpable and nonpalpable breast lesions: correlation with mammography and ultrasonography.

AIM: Our goal was to determine the clinical usefulness of Tl-201 to identify breast cancer in patients with suspicious breast lesions on clinical examination, and/or abnormal radiologic (mammography and/or ultrasonography) findings. METHODS: Tl-201 scintigraphy were performed in sixty-eight patients with 70 breast abnormalities (51 palpable, 19 nonpalpable) and compared with mammography and ultrasonography (US). Early (15 min) and late (3 h) images of the breasts were obtained following the injection of 111 MBq (3 mCi) of Tl-201. Visual and semiquantitative interpretation was performed. RESULTS: Final diagnosis confirmed 52 malignant breast lesions and 18 benign conditions. Tl-201 visualized 47 of 52 (90%) overall malignant lesions. Thirty-eight of 40 (95%) palpable and 9 of 12 (75%) nonpalpable breast cancers were detected by Tl-201 scintigraphy. The smallest mass lesion detected by Tl-201 measured 1.5 x 1.0 cm. Eleven breast lesions were interpreted as indeterminate by mammography and/or sonography. Tl-201 scintigraphy excluded malignancy in 7 of 8 (88%) patients with benign breast lesions interpreted as indeterminate. Five of the 18 (28%) benign breast lesions showed Tl-201 uptake. None of the fibroadenoma and fibrocystic changes accumulated Tl-201. Tl-201 scintigraphy, mammography and ultrasonography showed 90%, 92%, 85% overall sensitivity and 72%, 56%, 61% overall specificity respectively. Twenty-one of the 28 (75%) axillary nodal metastatic sites were also detected by Tl-201. In malignant and benign lesions, early and late lesion/contralateral normal side (L/N) ratios were 1.58 +/- 0.38 (mean +/- SD) and 1.48 +/- 0.32 (p > 0.05), 1.87 +/- 0.65 and 1.34 +/- 0.20 (p < 0.05) respectively. The mean early and late L/N ratios of malignant and benign groups did not show statistical difference (p > 0.05). CONCLUSION: Overall, Tl-201 scintigraphy was the most specific of the three methods and yielded favourable results in palpable breast cancers, while it showed lower sensitivity in nonpalpable cancers and axillary metastases. Combined use of Tl-201 scintigraphy with mammography and US seems to be useful in difficult cases, such as dense breasts and indeterminate breast lesions.