Longitudinal evaluation using FP-CIT in patients with parkinsonism

OBJECTIVE

To assess a group of patients with parkinsonism using serial studies with FP-CIT, basically the initial false negative results.

METHODS

Restrospective study of 92 patients (55 men and 37 women) who had undergone 2 different FP-CIT studies because of discrepancies between study results and clinical progression. The mean elapsed time between the studies was 26 months (SD: 6). We performed a semi-quantitative study using the patient's clinical history and the available literature to analyse discrepant cases with a normal initial study and subsequent pathological findings.

RESULTS

A total of 184 studies were completed for 92 patients; 11 of those 92 showed discrepancies between initial and subsequent studies. Among the 11 discrepant cases, 7 showed a normal initial study and pathological findings at a later date. Analysis of the predominant clinical features that might explain this behaviour revealed that 4 of these 7 subjects presented tremor-dominant parkinsonism. Regarding the rest, 1 presented early stage parkinsonism and was treated with antidopaminergic agents; 1 was classified as probable multisystem atrophy type C, and the third showed clinical signs of atypical parkinsonism without any causes of those signs being identified.

CONCLUSIONS

Serial FP-CIT studies are unnecessary in the large majority of cases, but they may be justifiable in certain clinical situations.

Automatic assistance to Parkinson's disease diagnosis in DaTSCAN SPECT imaging

PURPOSE

In this work, an approach to computer aided diagnosis (CAD) system is proposed as a decision-making aid in Parkinsonian syndrome (PS) detection. This tool, intended for physicians, entails fully automatic preprocessing, normalization, and classification procedures for brain single-photon emission computed tomography images.

METHODS

Ioflupane[(123)I]FP-CIT images are used to provide in vivo information of the dopamine transporter density. These images are preprocessed using an automated template-based registration followed by two proposed approaches for intensity normalization. A support vector machine (SVM) is used and compared to other statistical classifiers in order to achieve an effective diagnosis using whole brain images in combination with voxel selection masks.

RESULTS

The CAD system is evaluated using a database consisting of 208 DaTSCAN images (100 controls, 108 PS). SVM-based classification is the most efficient choice when masked brain images are used. The generalization performance is estimated to be 89.02 (90.41-87.62)% sensitivity and 93.21 (92.24-94.18)% specificity. The area under the curve can take values of 0.9681 (0.9641-0.9722) when the image intensity is normalized to a maximum value, as derived from the receiver operating characteristics curves.

CONCLUSIONS

The present analysis allows to evaluate the impact of the design elements for the development of a CAD-system when all the information encoded in the scans is considered. In this way, the proposed CAD-system shows interesting properties for clinical use, such as being fast, automatic, and robust.

[Quantitative evaluation of SPECT with FP-CIT. Importance of the reference area]

OBJECTIVE

The aim of this study is to compare several uptake indexes between specific and non-specific activity to determine the existence of degenerative Parkinsonism according to different reference areas.

MATERIAL AND METHODS

A total of 46 patients (23 men and 23 women), randomly selected from individuals referred to our center with a movement disorder, were included in the study. Mean age was 70.2 ± 10.2 years (41-87). The uptake indexes were obtained through the areas of interest (ROIs) located in the striate (specific uptake) and other reference ROIs located in areas with different concentrations of serotonin receptors: low-cerebellum, medium-occipital cortex and high-midbrain.

RESULTS

A high linear correlation was found between indexes having low and medium concentration of serotonin receptors. The ROC curve analysis shows an area under the curve of 0.874, 0.886 and 0.739 and regression coefficients of 5.41, 6.62 and 3.41, respectively for the striatum/cerebellum (E/C), striatum/occipital (E/O) and striatum midbrain (E/M) indexes. Optimal cutoff for E/O (1.35), index with the best behavior, provides a sensitivity of 0.84 and specificity of 0.89.

CONCLUSION

The reference area selected may alter the predictive power of the different indexes to determine the existence of a degenerative Parkinsonism.

[Hemiparkinsonism secondary to mesencephalic bleeding]

Vascular parkinsonism is the second cause of secondary parkinsonism, and can cause a complex clinical syndrome. In spite of this, it is not common to find an isolated vascular injury in the mesencephalic region, and even rarer for it to give rise to clinical parkinsonism. We present the case of a young patient who developed left hemiparkinsonism with a fluctuating clinical evolution and unpredictable response to the treatment after suffering right mesencephalic bleeding. Structural and functional neuroimaging techniques showed injury on the mesencephalic level and no uptake in the right striatal region, respectively.

[Diagnostic accuracy of FP-CIT SPECT in patients with parkinsonism]

OBJECTIVE

To determine the diagnostic accuracy of FP-CIT SPECT in entities with and without presynaptic involvement of the nigral-striatal dopaminergic pathway in a large group of patients with movement disorders, evaluating the usefulness of quantitative analysis.

MATERIALS AND METHODS

A group of 183 consecutive patients clinically diagnosed as either having or not having degenerative Parkinsonism. These results were then contrasted with those of FP-CIT SPECT to determine the diagnostic accuracy of the procedure. The specific binding index was evaluated with ROC curves.

RESULTS

FP-CIT SPECT was highly accurate in the diagnosis of neurodegenerative Parkinsonism (sensitivity: 95 %, specificity: 90 %). Most of the false positive results arose in patients with vascular Parkinsonism and the false negative results in patients with Parkinson disease. ROC curve analysis of semiquantitative evaluation had a sensitivity of 83 % and specificity of 82 % with an optimal cut-off of 1.44. The area under the curve was not significantly different between patients </= 60 and > 60 years (0.899 vs 0.884) of age.

CONCLUSIONS

FP-CIT SPECT has a high degree of diagnostic accuracy for striatal dopaminergic involvement. No significant changes in diagnostic accuracy were seen with respect to patient age.

[Diagnostic accuracy of FP-CIT SPECT in the evaluation of patients with clinically uncertain parkinsonian syndrome]

OBJECTIVE

To determine diagnostic accuracy of FP-CIT SPECT in a subgroup of patients who clinically present nonconclusive or atypical characteristics of parkinsonism (Clinically Uncertain Parkinsonian Syndromes, CUPS), and assess the contribution of the quantitative analysis in this group of patients.

PATIENTS AND METHODS

We included 54 patients who make up the CUPS group. After a variable follow-up period, we evaluated the existence of a degenerative parkinsonism and compared it with the result of the FP-CIT SPECT, establishing the diagnostic accuracy of this procedure in the CUPS patient group.

RESULTS

We obtained a high diagnostic accuracy of neurodegenerative Parkinsonism in the CUPS patient group (sensitivity: 85%; specificity: 93%). False positive results were obtained in patients with vascular parkinsonism and most of the false negative results in patients with Parkinson's disease. The quantitative evaluation did not contribute data of relevance to the qualitative evaluation.

CONCLUSIONS

FP-CIT SPECT makes it possible to show the involvement of nigrostriatal dopaminergic pathway, also contributing with information of relevance to the clinician about the etiology of the extrapyramidal symptomatology in patients with nonconclusive signs and symptoms of the existence of a Parkinsonism.

[Application of 123I-FP-CIT in the clinical practice in Parkinsonism patients]

INTRODUCTION

123I-FP-CIT scan has been supported in the last years by numerous studies as a technique of undeniable value to assess presynaptic integrity of the nigrostriatal pathway. The objective of this study is to perform a descriptive analysis of the main diagnostic aspects obtained from the first 110 studies made with FP-CIT in our center.

MATERIAL AND METHODS

The study population consisted of 110 consecutive patients distributed into 5 groups according to the clinical diagnosis, after a follow-up period of at least one year. Qualitative and quantitative scintigraphy was done.

RESULTS

A total of 61.8 % (68/110) of the studies were considered abnormal and 38.2 % (42/110) as normal. Among the abnormal examinations there was 88.3 % (60/68) agreement with the clinical diagnosis and agreement was 83.4 % (35/42) in the normal examinations. Inverse significant correlation was assessed between striatal binding and severity according to the H and Y scale (r = -0.4) and between qualitative and quantitative assessment (r = -0.86). There was no significant correlation between the degeneration of dopaminergic function according to age and degree of asymmetry on striatal binding in the different groups.

CONCLUSIONS

Generally an adequate agreement between clinical diagnosis and SPECT-FP-CIT was observed. Inverse correlation between striatal binding and H and Y scale and greater asymmetry at striatal binding was obtained among Parkinson patients than in the rest of groups.

Utilidad de la gammagrafía selectiva con hematíes desnaturalizados Tc-99m en un caso de esplenosis hepática

The term splenosis, first used in the medical literature in 1939, refers to the autotransplantation of splenic tissue in a heterotopic location. We report the case of a known hepatitis C carrier in whom computed tomography scanning revealed a hepatic lesion suggestive of hepatocarcinoma. Magnetic Resonance imaging was performed for suspected hepatic splenosis, which was confirmed by Tc-99m labeled heat-denatured red blood cell scintigraphy. In addition to confirming the suspected diagnosis, this technique showed several pathological foci in distinct abdominal locations compatible with splenosis that had not previously been identified.