Dorsal striatum does not mediate feedback-based, stimulus-response learning: An event-related fMRI study in patients with Parkinson's disease tested on and off dopaminergic therapy

Publication date: 15 January 2019

Source: NeuroImage, Volume 185

Author(s): Nole M. Hiebert, Adrian M. Owen, Hooman Ganjavi, Daniel Mendonça, Mary E. Jenkins, Ken N. Seergobin, Penny A. MacDonald

Abstract

Learning associations between stimuli and responses is essential to everyday life. Dorsal striatum (DS) has long been implicated in stimulus-response learning, though recent results challenge this contention. We have proposed that discrepant findings arise because stimulus-response learning methodology generally confounds learning and response selection processes. In 19 patients with Parkinson's disease (PD) and 18 age-matched controls, we found that dopaminergic therapy decreased the efficiency of stimulus-response learning, with corresponding attenuation of ventral striatum (VS) activation. In contrast, exogenous dopamine improved response selection accuracy related to enhanced DS BOLD signal. Contrasts between PD patients and controls fully support these within-subject patterns. These double dissociations in terms of behaviour and neural activity related to VS and DS in PD and in response to dopaminergic therapy, strongly refute the view that DS mediates stimulus-response learning through feedback. Our findings integrate with a growing literature favouring a role for DS in decision making rather than learning, and unite two literature that have been evolving independently.

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18F-FDG PET/TC en reestadificación y seguimiento de pacientes con sarcomas uterinos

Publication date: Available online 3 November 2018

Source: Revista Española de Medicina Nuclear e Imagen Molecular

Author(s): D. Albano, V. Zizioli, G. Treglia, F. Odicino, R. Giubbini, F. Bertagna

Resumen

Objetivo

Los sarcomas uterinos son tumores raros con mal pronóstico debido a las altas tasas de recurrencia. El papel actual de la ¹⁸F-FDG PET/TC en la vigilancia posterior a la terapia aún no está establecido.

Material y metodos

Cuarenta y una mujeres con sarcoma uterino se sometieron a 73 estudios ¹⁸F-FDG PET/TC para la reestadificación en la presunta recurrencia o durante el seguimiento en pacientes asintomáticos. Los resultados histopatológicos y/o el seguimiento clínico/de imágenes durante al menos 12 meses se consideraron el estándar de referencia. Se calculó la precisión diagnóstica y el impacto clínico de la ¹⁸F-FDG PET/TC.

Resultados

treinta y tres estudios ¹⁸F-FDG PET/TC fueron positivos, mientras que los 40 estudios restantes fueron negativos. La sensibilidad general, la especificidad, el valor predictivo positivo (VP+), el valor predictivo negativo (VP-) y la precisión de la ¹⁸F-FDG PET/TC fueron del 88%, 98%, 97%, 91% y 93%. Considerando pacientes con sospecha clínica o radiológica de recidiva (n = 47) y durante el seguimiento (n = 26) la sensibilidad y especificidad, VP+, VP− y precisión de ¹⁸F-FDG PET/TC fueron del 89%, 100%, 100%, 86% y 94%, y 80%, 95%, 80%, 95% y 92% respectivamente. La ¹⁸F-FDG PET/TC tuvo un impacto clínico positivo en 9/73 (12%) estudios y cambió el manejo clínico en 8/41 (20%) pacientes.

Conclusion

La ¹⁸F-FDG PET/TC es un método preciso para la detección y localización de recidivas a distancia en pacientes con sarcoma uterino con buena sensibilidad y especificidad e impacto significativo en la toma de decisiones clínicas.

Abstract

Purpose

Uterine sarcomas are rare tumors with poor prognosis due to the high recurrence rates. The current role of ¹⁸F-FDG PET/CT in the post-therapy surveillance is not established yet.

Materials and Methods

Forty-one women with uterine sarcoma underwent 73 ¹⁸F-FDG PET/CT for restaging in suspected recurrence or during follow-up in asymptomatic patients. Histopathology results and/or clinical/imaging follow-up for at least 12 months were considered the reference standard. The diagnostic accuracy and clinical impact of ¹⁸F-FDG PET/CT was calculated.

Results

Thirty-three ¹⁸F-FDG PET/CT were positive, while the remaining 40 studies were negative. The overall sensitivity, specificity, positive predictive value (PPV), negative predictive value (NPV) and accuracy of ¹⁸F-FDG PET/CT were 88%, 98%, 97%, 91% and 93%, respectively. Considering patients with clinical or radiological suspicion of recurrence (n = 47) and those during follow-up (n = 26), sensitivity, specificity, PPV, NPV and accuracy of ¹⁸F-FDG PET/CT were 89%, 100%, 100%, 86% and 94%, and 80%, 95%, 80%, 95% and 92%, respectively. ¹⁸F-FDG PET/CT had a positive clinical impact in 9/73 (12%) studies and changed the clinical management in 8/41 (20%) patients.

Conclusions

¹⁸F-FDG PET/CT seems to be an accurate method for detection and localization of local and distant recurrence in patients with uterine sarcoma with good sensitivity and specificity and significant impact on clinical decision making.

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Cover Image

Journal of Oral Pathology &Medicine, Volume 47, Issue 10, Page i-i, November 2018.


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Issue Information

Journal of Oral Pathology &Medicine, Volume 47, Issue 10, Page ii-v, November 2018.


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Deviating dental arch morphology in mild coronal craniosynostosis syndromes

Abstract

Objectives

To determine whether the intramaxillary relationship of patients with Muenke syndrome and Saethre-Chotzen syndrome or TCF12-related craniosynostosis are systematically different than those of a control group.

Material and methods

Forty-eight patients (34 patients with Muenke syndrome, 8 patients with Saethre-Chotzen syndrome, and 6 patients with TCF12-related craniosynostosis) born between 1982 and 2010 (age range 4.84 to 16.83 years) that were treated at the Department of Oral Maxillofacial Surgery, Special Dental Care and Orthodontics, Children's Hospital Erasmus University Medical Center, Sophia, Rotterdam, the Netherlands, were included. Forty-seven syndromic patients had undergone one craniofacial surgery according to the craniofacial team protocol. The dental arch measurements intercanine width (ICW), intermolar width (IMW), arch depth (AD), and arch length (AL) were calculated. The control group existed of 329 nonsyndromic children.

Results

All dental arch dimensions in Muenke (ICW, IMW, AL, p < 0.001, ADmax, p = 0.008; ADman, p = 0.002), Saethre-Chotzen syndrome, or TCF12-related craniosynostosis patients (ICWmax, p = 0.005; ICWman, IMWmax, AL, p < 0.001) were statistically significantly smaller than those of the control group.

Conclusions

In this study, we showed that the dental arches of the maxilla and the mandible of patients with Muenke syndrome and Saethre-Chotzen syndrome or TCF12-related craniosynostosis are smaller compared to those of a control group.

Clinical relevance

To gain better understanding of the sutural involvement in the midface and support treatment capabilities of medical and dental specialists in these patients, we suggest the concentration of patients with Muenke and Saethre-Chotzen syndromes or TCF12-related craniosynostosis in specialized teams for a multi-disciplinary approach and treatment.

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