Carles Lorenzo-Bosquet

Quantitative evaluation of striatal I-123-FP-CIT uptake in essential tremor and parkinsonism.

Aim: The aim of this study was to quantitatively evaluate the striatal uptake in 3 groups of patients: essential tremor (ET), drug-induced parkinsonism (DIP), and Parkinson disease (PD), using a voxel-based methodology and volumes of interests (VOIs) analysis. Patients and Method: Sixty patients from the Neurology Department Movement Disorders outpatient clinic in a tertiary hospital with I-123-FP-CIT SPECT were selected. After a clinical follow-up period of 2 years, a final clinical diagnosis of DIP was established for 20 patients (first group); 20 patients were diagnosed with ET (second group), and the third group was made up of 20 patients with a qualitatively pathologic SPECT who were diagnosed with PD. Once processed, DIP studies were spatially normalized to Montreal Neurologic Institute space and an average image was computed to create an I-123-FP-CIT SPECT template using statistical parametric mapping (SPM). Then all the I-123-FP-CIT images from all groups (DIP, ET, and PD) were registered to the new template. VOIs were defined in a digital atlas in Montreal Neurologic Institute space (caudate nucleus, putamen, and occipital cortex). Finally, mean counts were extracted from all VOIs and putamen-occipital and caudate-occipital ratios were computed. Analysis of variance tests were performed with all ratios. A SPM study of patterns evaluated the efficacy of the automated technique to determine whether the significant differences among groups corresponded to the same regions that the method purported to evaluate. Results: The analysis of variance test revealed significant differences between DIP and ET as compared with PD, both in the putamen and in the caudate nucleus. There were significant differences between DIP and ET populations only in the putamen but not in the caudate. The SPM found a lower uptake in the PD group in comparison with the ET and DIP groups. Therefore, in the organic parkinsonism cases, the most significant changes in uptake decrease were found in the putamen nuclei when compared with the DIP and the ET cases. No significant changes were observed between the ET and DIP groups. Conclusions: This study provides a fairly simple, reproducible, and useful methodology to be applied in everyday practice to quantify the studies of dopamine transporters using FP-CIT. We present the different ratios for putamen and caudate nucleus for 3 different groups with FP-CIT images. We obtained an optimal discrimination threshold value between the reference population and the pathologic population for the putamen ratio.

Does reduced [123I]-FP-CIT binding in Huntington's disease suggest pre-synaptic dopaminergic involvement?

OBJECTIVE To evaluate the usefulness of SPECT in assessing damage to the pre-synaptic dopaminergic system in Huntingtons disease (HD) using [(123)I]-FP-CIT (DaTSCAN), a selective radioligand with regulatory approval as the diagnostic test for investigating functional dopaminergic neuron loss in the striatum in Parkinsons disease. METHODS We studied twelve symptomatic HD patients using DaTSCAN/SPECT imaging. [(123)I]-FP-CIT caudate and putamen uptake levels were qualitatively and semi-quantitatively analyzed to assess pre-synaptic damage in the striatal dopamine system. Possible correlations were analyzed between HD severity on the Unified Huntingtons Disease Rating Scale (UHDRS), duration of clinical symptoms, and [(123)I]-FP-CIT/SPECT striatal uptake. RESULTS DaTSCAN/SPECT qualitative analysis showed reduced striatal uptake in eight patients. Semi-quantitative analysis revealed a significant reduction in four. Of these four, uptake reduction was at putamen level in all, and also at caudate level in one. Although we observed no linear correlation between HD severity and reduced striatal [(123)I]-FP-CIT uptake, the patients with the worst UHDRS scores had more severe reductions in radioligand uptake. CONCLUSION This is the first study to use in vivo [(123)I]-FP-CIT/SPECT imaging to confirm prior descriptions using PET of a pre-synaptic dopaminergic system defect in HD.

Unexpected I-123 FP-CIT uptake in a brain tumor.

A 78-year-old female patient with a 5-year history of bradykinesia and tremor at rest of both upper limbs was referred to our Nuclear Medicine Department because of a rapid functional decline over 3 months with cognitive impairment, generalized myoclonus, and dependence for most basic daily activities. Brain SPECT with 148MBq (4 mCi) of I-123 FP-CIT and 740MBq (20 mCi) of Tc-99m ethylcysteinate dimer (thereafter Tc-99m ECD) was performed.

Rapid Resolution of Brain Ischemic Hypoxia After Cerebral Revascularization in Moyamoya Disease

BACKGROUND In moyamoya disease (MMD), cerebral revascularization is recommended in patients with recurrent or progressive ischemic events and associated reduced cerebral perfusion reserve. Low-flow bypass with or without indirect revascularization is generally the standard surgical treatment. Intraoperative monitoring of cerebral partial pressure of oxygen (PtiO2) with polarographic Clark-type probes in cerebral artery bypass surgery for MMD-induced chronic cerebral ischemia has not yet been described. OBJECTIVE To describe basal brain tissue oxygenation in MMD patients before revascularization as well as the immediate changes produced by the surgical procedure using intraoperative PtiO2 monitoring. METHODS Between October 2011 and January 2013, all patients with a diagnosis of MMD were intraoperatively monitored. Cerebral oxygenation status was analyzed based on the Ptio2/PaO2 ratio. Reference thresholds of PtiO2/PaO2 had been previously defined as below 0.1 for the lower reference threshold (hypoxia) and above 0.35 for the upper reference threshold (hyperoxia). RESULTS Before STA-MCA bypass, all patients presented a situation of severe tissue hypoxia confirmed by a PtiO2/PaO2 ratio <0.1. After bypass, all patients showed a rapid and sustained increase in PtiO2, which reached normal values (PtiO2/PaO2 ratio between 0.1 and 0.35). One patient showed an initial PtiO2 improvement followed by a decrease due to bypass occlusion. After repeat anastomosis, the patients PtiO2 increased again and stabilized. CONCLUSION Direct anastomosis quickly improves cerebral oxygenation, immediately reducing the risk of ischemic stroke in both pediatric and adult patients. Intraoperative PtiO2 monitoring is a very reliable tool to verify the effectiveness of this revascularization procedure.

Progressive presynaptic dopaminergic deterioration in Huntington disease: a [123I]-FP-CIT SPECT two-year follow-up study.

To illustrate the potential of [I]-FP-CIT SPECT DaTSCAN® in investigating the progression of presynaptic dopaminergic degeneration in Huntington disease (HD), we performed a 2-year follow-up [I]-FP-CIT study on 4 HD patients, evaluating the SPECT imaging based on qualitative and semiquantitative analysis. The mean annual decline in [I]-FP-CIT uptake in caudate and putamen after 2 years of follow-up was 5.8% and 9.6%, respectively. Our findings suggest that [I]-FP-CIT SPECT is useful in investigating the progression of presynaptic dopaminergic degeneration in HD, and may be useful as a disease biomarker, providing an objective method for measuring the effectiveness of future neuroprotective therapies.

Parkinsonism related to Percheron artery infarct

Parkinsonism associated with strategic infarcts involving Substantia Nigra is extremely rare. We herein report a case of bilateral parkinsonism related to midbrain lesion secondary to Percheron Artery occlusion. This case report supports the hypothesis about the relationship between strategic vascular lesions and the subsequent development of parkinsonism.

Utility of the 18F-Florbetapir positron emission tomography in systemic amyloidosis

Abstract Amyloidosis comprises a group of heterogeneous conditions. To ascertain the burden of disease is important because it can determine the treatment as well as the evolution of the disease. Recent reports have shown good results in diagnosing cardiac amyloidosis using 18F-florbetapir. We hypothesize that combining whole body PET/CT with 18F-Florbetapir can be useful to characterize the burden of the disease. We included 25 patients, 13 of them with different types of amyloidosis, and 12 with Alzheimer’s disease as controls. Target-to-background ratio was computed for multiple organ using maximum standardized uptake values. Organ involvement was described (standardized techniques versus PET) according to different kinds of amyloidosis showing promising results in AA and AL types. Heart involvement showed poorer results when compared to tongue, lung or thyroid gland. Multiple organ involvement in patients previously labelled as having negative organ affectation could be identified. This is the first study to evaluate the utility of 18F-florbetapir in the assessment of the global extension of disease. Our results show that this technique is useful for its diagnosis.