Corticostriatal Hypermetabolism in Moyamoya Disease-Induced Hemichorea: Two Case Reports and a Literature Review.

Moyamoya disease (MMD) is a rare cause of chorea, and its pathophysiological mechanism remains unclear. We explore the use of cerebral positron emission tomography (PET) to study brain functional connectivity in 2 patients with MMD-induced hemichorea. Abnormal metabolism of brain was analyzed by 18F-fluorodeoxyglucose (18F-FDG) PET images. Dopamine transporters (DAT) PET evaluated the integrity of the cerebral dopamine system. A comprehensive systemic literature search of the PubMed database was also conducted. The 18F-FDG imaging of our patients showed no responsible hypometabolism in affected brain areas, while hypermetabolism in the affected caudate nucleus, putamen and fronto-parietal areas could be seen. DAT PET imaging was normal in patient 1 (a 23-year-old woman), while remarkably reduced DAT binding was seen in the left striatum of patient 2 (a 48-year-old woman). The literature review of 9 publications revealed that 11 patients who underwent single photon emission computed tomography (SPECT) showed cerebral hypoperfusion in the cortex and subcortical area; 18F-FDG PET was performed in 3 cases, which revealed hypermetabolism in the affected striatum in 2 cases. These findings suggest that the striatal and cortical hypermetabolism in the first patient result from underactivity in indirect pathway from basal ganglia-thalamocortical circuits, causing increased activity of excitatory glutamatergic thalamostriatal and thalamocortical projection neurons. The collateral vessels in the basal ganglia might lead to disruption of normal basal ganglia signaling. A dominant left hemisphere with corpus callosal connections to the right basal ganglia resulting into left hemichorea is the most probable explanation for the second patient. We have identified abnormal functional connectivity in basal ganglia-thalamocortical circuits in patients with MMD-induced chorea highlighting the corticostriatal pathway plays an important role in the pathogenesis of MMD-induced chorea.

Co-registration Analysis of Fluorodopa and Fluorodeoxyglucose Positron Emission Tomography for Differentiating Multiple System Atrophy Parkinsonism Type From Parkinson's Disease.

It is difficult to differentiate between Parkinson's disease and multiple system atrophy parkinsonian subtype (MSA-P) because of the overlap of their signs and symptoms. Enormous efforts have been made to develop positron emission tomography (PET) imaging to differentiate these diseases. This study aimed to investigate the co-registration analysis of 18F-fluorodopa and 18F-flurodeoxyglucose PET images to visualize the difference between Parkinson's disease and MSA-P. We enrolled 29 Parkinson's disease patients, 28 MSA-P patients, and 10 healthy controls, who underwent both 18F-fluorodopa and 18F-flurodeoxyglucose PET scans. Patients with Parkinson's disease and MSA-P exhibited reduced bilateral striatal 18F-fluorodopa uptake (p < 0.05, vs. healthy controls). Both regional specific uptake ratio analysis and statistical parametric mapping analysis of 18F-flurodeoxyglucose PET revealed hypometabolism in the bilateral putamen of MSA-P patients and hypermetabolism in the bilateral putamen of Parkinson's disease patients. There was a significant positive correlation between 18F-flurodeoxyglucose uptake and 18F-fluorodopa uptake in the contralateral posterior putamen of MSA-P patients (rs = 0.558, p = 0.002). Both 18F-flurodeoxyglucose and 18F-fluorodopa PET images showed that the striatum was rabbit-shaped in the healthy control group segmentation analysis. A defective rabbit-shaped striatum was observed in the 18F-fluorodopa PET image of patients with Parkinson's disease and MSA-P. In the segmentation analysis of 18F-flurodeoxyglucose PET image, an intact rabbit-shaped striatum was observed in Parkinson's disease patients, whereas a defective rabbit-shaped striatum was observed in MSA-P patients. These findings suggest that there were significant differences in the co-registration analysis of 18F-flurodeoxyglucose and 18F-fluorodopa PET images, which could be used in the individual analysis to differentiate Parkinson's disease from MSA-P.

Serum Klotho, vitamin D, and homocysteine in combination predict the outcomes of Chinese patients with multiple system atrophy.

AIMS: Neuroinflammation contributed to the pathogenesis of multiple system atrophy (MSA). We aimed to detect the correlation between inflammatory mediators, such as Klotho (Klt), vitamin D (25(OH)D) and homocysteine (Hcy), and disease severity among MSA patients. METHODS: A total of 53 MSA patients, 65 PD patients, and 62 normal subjects were recruited in our cross-sectional study. Serum Klotho (Klt), vitamin D (25(OH)D), and homocysteine (Hcy) levels were measured. Several scales were undertaken to assess the motor/nonmotor function and cognitive impairment of MSA. RESULTS: Decreased Serum Klt and 25(OH)D levels and increased Hcy levels were found in patients with MSA, compared with healthy controls. These results were more pronounced in male patients. The three biomarkers also displayed differences between MSA and PD subgroups based on genders. Interestingly, Klt, 25(OH)D and Hcy levels associated with cognition impairment, motor dysfunction, mood/cardiovascular disorder among MSA patients. In addition, the combination of Klt, 25(OH)D and Hcy had a better diagnostic ability for distinguishing MSA patients from healthy subjects, as well as distinguishing male MSA patients from male PD patients. CONCLUSION: This study suggested that Klt, 25(OH)D and Hcy levels could be a potential predictor for MSA severity evaluation.

Assessing the early changes of cerebral glucose metabolism via dynamic (18)FDG-PET/CT during cardiac arrest.

To study the changes of cerebral glucose metabolism (CGM) during the phase of return of spontaneous circulation (ROSC) after cardiac arrest (CA), we used 18-fluorodeoxyglucose-positron emission tomography/computed tomography ((18)FDG-PET/CT) to measure the CGM changes in six beagle canine models. After the baseline (18)FDG-PET/CT was recorded, ventricular fibrillation (VF) was induced for 6 min, followed by close-chest cardiopulmonary resuscitation (CPR) in conjunction with intravenous (IV) administration of epinephrine and external defibrillator shocks until ROSC was achieved, within 30 min. The (18)FDG was recorded prior to intravenous administration at 0 h (baseline), and at 4, 24, and 48 h after CA with ROSC. We evaluated the expression of two key control factors in canine CGM, hexokinase I (HXK I) and HXK II, by immunohistochemistry at the four above mentioned time points. Electrically induced VF of 6 min duration was successfully induced in the dogs. Resuscitation was then performed to maintain blood pressure stability. Serial (18)FDG-PET/CT scans found that the CGM decreased at 4 h after ROSC and remained lower than the baseline even at 48 h. The expression of HXK I and II levels were consistent with the changes in CGM. These data from our present work showed that (18)FDG-PET/CT imaging can be used to detect decreased CGM during CA and was consistent with the results of CMRgl. Furthermore, there were also concomitant changes in the expression of HXK I and HXK II. The decrease in CGM may be an early sign of hyperacute global cerebral ischemia.

[Comparison of (18)F-FDG PET/CT and enhancement CT in diagnosing regional lymph node metastasis of colorectal cancer].

OBJECTIVE: The aim of this study was to compare the diagnostic value of (18)F-FDG PET/CT with contrast CT for regional lymph node metastasis of colorectal cancer. METHODS: Imaging results of 40 patients with colorectal cancer were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET/CT imaging. Final diagnosis was made by histopathology. RESULTS: 20 colorectal cancer patients were verified with lymph node metastasis while the other 20 patients were absent. Finally, (18)F-FDG PET/CT produced 4 false-positive patients and 3 false-negative patients. (18)F-FDG PET/CT displayed sensitivity 85.0% (17/20), specificity 80.0% (16/20), positive predictive value 81.0% (17/21), negative predictive value 84.2% (16/19) and accuracy 82.5% (33/40) in the diagnosis of lymph node metastasis. Contrast CT produced 5 false-positive patients and 8 false-negative patients. Contrast CT had the sensitivity 60.0% (12/20), specificity 75.0% (15/20) , positive predictive value 70.6% (12/17), negative predictive value 65.2% (15/23) and accuracy 67.5% (27/40). Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference between PET/CT and contrast CT (P = 0.478, P = 0.893; P = 0.344. Fisher's exact test and McNemar test). CONCLUSION: Sensitivity and specificity of PET/CT was better than of contrast CT, but no statistically significant difference. Clinical works also need to select the appropriate inspection methods based on the patient's situation.

Value of ¹8F-FDG-PET/CT in the detection of recurrent hepatocellular carcinoma after hepatectomy or radiofrequency ablation: a comparative study with contrast-enhanced ultrasound.

OBJECTIVE: To evaluate the role of positron emission tomography/computer tomography with fluorine-18 fluorodeoxyglucose ((18) F-FDG-PET/CT) in detecting hepatocellular carcinoma (HCC) recurrence after hepatectomy and/or radiofrequency ablation (RFA) and to compare its efficacy with contrast-enhanced ultrasound (CEUS). METHODS: A total of 36 HCC patients were included in this study. All patients underwent both (18) F-FDG-PET/CT and CEUS at least once for the diagnosis of HCC recurrence. The time interval between PET/CT and CEUS was 14 ± 3 days. All patients were followed up for at least 24 months. RESULTS: In all, 32 patients were confirmed to have HCC recurrence by pathology and clinical follow-up. The sensitivity, specificity, positive predictive value, negative predictive value and accuracy of (18) F-FDG-PET/CT for intrahepatic HCC recurrence were 96.7%, 83.3%, 96.7%, 83.3% and 94.4%, respectively. The corresponding values of CEUS were 56.7%, 100%, 100%, 31.6% and 63.9%, respectively. The sensitivity and accuracy of (18) F-FDG-PET/CT for the diagnosis of HCC recurrence were significantly higher than those of CEUS (P < 0.01, respectively). CONCLUSIONS: Compared with CEUS, (18) F-FDG-PET/CT has higher sensitivity and accuracy in detecting the local recurrence of HCC after hepatectomy and/or RFA. It can be used to detect recurrent extrahepatic lesions of HCC effectively.

[Diagnostic value of (18)F-labeled NaF positron emission tomography-computed tomography imaging in the detection of bone metastases in patients with lung cancer before treatment].

OBJECTIVE: To evaluate the diagnostic values of (18)F-sodium fluoride ((18)F-NaF) positron emission tomography/computed tomography (PET/CT) imaging in the detection of bone metastases of lung cancer. METHODS: A total of 107 lung cancer patients were diagnosed by histopathology and undergone (18)F-NaF PET-CT imaging. RESULTS: Among them, the histopathologically diagnosed tumors included adenocarcinoma (n = 47), squamous cell carcinoma (n = 19), small cell lung cancer (n = 4) and other malignant types (n = 34). Bone metastases occurred in adenocarcinoma (n = 19) and squamous cell carcinoma (n = 4).(18)F-NaF PET/CT imaging had a high sensitivity of 100% in the diagnosis of bone metastases with malignant lung tumors. And its specificity was 98.7%, accuracy 99% and positive predictive value 97.0%. CONCLUSION: (18)F-NaF PET-CT imaging can detect the bone metastases of lung cancer preoperatively with a high level of sensitivity and accuracy.

[Comparison of (18)F-FDG PET-CT and abdomen enhancement CT in diagnosing peritoneal metastases].

OBJECTIVE: To compare the diagnostic value of (18)F-FDG PET-CT with abdomen contrast CT in the diagnosis of peritoneal metastases. METHODS: Between January 2008 and May 2011, imaging results of 97 patients with suspicious peritoneal metastases were retrospectively reviewed, and all the patients underwent both abdomen contrast CT and (18)F-FDG PET-CT imaging. Final diagnosis was made by histopathology or follow up. RESULTS: Seventy-seven patients were verified as peritoneal metastases after pathological examination(n=88) or follow up(n=9), while the other 20 patients were absent. The sensitivity of (18)F-FDG PET-CT was 90.9%(70/77), the specificity 85.0%(17/20), and the accuracy 89.7%(87/97). There were 3 false positive and 7 false negative. The sensitivity of contrast CT was 66.2%(51/77), the specificity 80.0%(16/20), and the accuracy 69.1%(67/97). There were 4 false positive and 26 false negative. The difference in diagnostic accuracy was statistically significantly between these two methods(P<0.05). CONCLUSION: The diagnostic value of (18)F-FDG PET-CT is significantly higher than that of abdominal enhanced CT for peritoneal metastases.

Fatality after cardiac arrest in thyrotoxic periodic paralysis due to profound hypokalemia resulting from intravenous glucose administration and inadequate potassium replacement.

BACKGROUND: Thyrotoxic periodic paralysis (TPP) is a variant of periodic paralysis (PP) that occurs in patients with underlying mutations in genes for cation channels, if they develop thyrotoxicosis. It is disabling, and fatalities sometimes occur. Here, we present a patient with TPP who developed hypokalemic paralysis that was probably aggravated by the administration of a carbohydrate, probably contributing to, if not causing, a fatal outcome. SUMMARY: A 30-year-old Chinese patient received (131)I treatment for Graves' disease (GD) in our hospital. Three days later in the middle of the night, he developed aggravating paralytic symptoms after a heavy evening meal. The next morning, he was seen in a small clinic and was treated with 1250 mL 5% glucose containing 25 mL 10% potassium chloride (KCl). By early afternoon, he had not improved and was transferred to a city hospital, arriving with grade I muscle strength and severed facial and bulbar paralysis that was shortly followed by cardiac arrest with failure of resuscitation. Shortly before he died, his serum K(+) was 1.15 mEq/L (normal=3.5-5). CONCLUSIONS: We postulate that severe hypokalemia developed in our patient in part in response to the high intravenous glucose load that he received. We advocate caution against using intravenous glucose solutions for potassium administration in patients with TPP and recommend a review of guidelines suggesting this form of treatment. In rural settings with limited resources, we favor oral potassium, not to exceed 100 mEq per day, and transfer to a modern medical facility in settings where muscle weakness is developing in patients with TPP.

Striving for euthyroidism in radioiodine therapy of Graves' disease: a 12-year prospective, randomized, open-label blinded end point study.

BACKGROUND: In China, use of radioiodine therapy is problematic because of the need for lifelong levothyroxine substitution. Our aim was to find an optimum dosing strategy for (131)I treatment of hyperthyroidism due to Graves' disease (GD). We attempted to achieve euthyroidism to avoid long-term levothyroxine treatment. METHODS: Six hundred patients with GD were randomized into five groups, each comprising 120 individuals, to receive an individual (131)I activity selected from five different ascending activity ranges. The ranges were modulated according to a clinical score system. Follow-up was extended over a 12-year time frame. The primary outcomes were euthyroidism, hyperthyroidism, hypothyroidism, and recurrent hyperthyroidism. The secondary endpoint was the accumulated (131)I activity needed to achieve euthyroidism. RESULTS: Out of 682 screened patients, 600 entered the study in 1997. Five hundred twenty-nine completed the last follow-up visit at the end of the study in 2009. Group 3 was identified as the study arm that received the optimum radioiodine activity, with 71.8% of the patients maintaining a euthyroid status, 5.8% remaining hyperthyroid, and 22.3% becoming hypothyroid by the end of the study. This group received 1.85-4.07 MBq per gram of thyroid tissue (average administered activity 261 ± 162 MBq). Over the 12-year follow-up period, the recurrence rate was 13.6%. The efficacy of (131)I treatment was related to activities modulated by a clinical score (χ(2) = 82.1, p = 0.000). CONCLUSION: Our protocol effectively treated hyperthyroidism and significantly reduced the hypothyroidism rate. It may be preferable to the intentional induction of permanent hypothyroidism recommended by many experts.