Heterogeneous motor BOLD-fMRI responses in brain areas exhibiting negative BOLD cerebrovascular reactivity indicate that steal phenomenon does not always result from exhausted cerebrovascular reserve capacity

Introduction: Brain areas exhibiting negative blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) responses to carbon dioxide (CO2) are thought to suffer from a completely exhausted autoregulatory cerebrovascular reserve capacity and exhibit vascular steal phenomenon. If this assumption is correct, the presence of vascular steal phenomenon should subsequently result in an equal negative fMRI signal response during a motor-task based BOLD-fMRI study (increase in metabolism without an increase in cerebral blood flow due to exhausted reserve capacity) in otherwise functional brain tissue. To investigate this premise, the aim of this study was to further investigate motor-task based BOLD-fMRI signal responses in brain areas exhibiting negative BOLD-CVR. Material and methods: Seventy-one datasets of patients with cerebrovascular steno-occlusive disease without motor defects, who underwent a CO2-calibrated motor task-based BOLD-fMRI study with a fingertapping paradigm and a subsequent BOLD-CVR study with a precisely controlled CO2-challenge during the same MRI examination, were included. We compared BOLD-fMRI signal responses in the bilateral pre- and postcentral gyri - i.e. Region of Interest (ROI) with the corresponding BOLD-CVR in this ROI. The ROI was determined using a second level group analysis of the BOLD-fMRI task study of 42 healthy individuals undergoing the same study protocol. Results: An overall decrease in BOLD-CVR was associated with a decrease in BOLD-fMRI signal response within the ROI. For patients exhibiting negative BOLD-CVR, we found both positive and negative motor-task based BOLD-fMRI signal responses. Conclusion: We show that the presence of negative BOLD-CVR responses to CO2 is associated with heterogeneous motor task-based BOLD-fMRI signal responses, where some patients show -more presumed- negative BOLD-fMRI signal responses, while other patient showed positive BOLD-fMRI signal responses. This finding may indicate that the autoregulatory vasodilatory reserve capacity does not always need to be completely exhausted for vascular steal phenomenon to occur

Heterogeneous motor BOLD-fMRI responses in brain areas exhibiting negative BOLD cerebrovascular reactivity indicate that steal phenomenon does not always result from exhausted cerebrovascular reserve capacity

Introduction: Brain areas exhibiting negative blood oxygenation-level dependent cerebrovascular reactivity (BOLD-CVR) responses to carbon dioxide (CO2) are thought to suffer from a completely exhausted autoregulatory cerebrovascular reserve capacity and exhibit vascular steal phenomenon. If this assumption is correct, the presence of vascular steal phenomenon should subsequently result in an equal negative fMRI signal response during a motor-task based BOLD-fMRI study (increase in metabolism without an increase in cerebral blood flow due to exhausted reserve capacity) in otherwise functional brain tissue. To investigate this premise, the aim of this study was to further investigate motor-task based BOLD-fMRI signal responses in brain areas exhibiting negative BOLD-CVR. Material and methods: Seventy-one datasets of patients with cerebrovascular steno-occlusive disease without motor defects, who underwent a CO2-calibrated motor task-based BOLD-fMRI study with a fingertapping paradigm and a subsequent BOLD-CVR study with a precisely controlled CO2-challenge during the same MRI examination, were included. We compared BOLD-fMRI signal responses in the bilateral pre- and postcentral gyri - i.e. Region of Interest (ROI) with the corresponding BOLD-CVR in this ROI. The ROI was determined using a second level group analysis of the BOLD-fMRI task study of 42 healthy individuals undergoing the same study protocol. Results: An overall decrease in BOLD-CVR was associated with a decrease in BOLD-fMRI signal response within the ROI. For patients exhibiting negative BOLD-CVR, we found both positive and negative motor-task based BOLD-fMRI signal responses. Conclusion: We show that the presence of negative BOLD-CVR responses to CO2 is associated with heterogeneous motor task-based BOLD-fMRI signal responses, where some patients show -more presumed- negative BOLD-fMRI signal responses, while other patient showed positive BOLD-fMRI signal responses. This finding may indicate that the autoregulatory vasodilatory reserve capacity does not always need to be completely exhausted for vascular steal phenomenon to occur

Lungenkrebschirurgie bei schwerer COPD mit Emphysem: Tumorresektion mit Verbesserung der Lungenfunktion

Zusammenfassung. Die Standardtherapie bei Lungenkrebs im Frühstadium ist die chirurgische, anatomische Resektion, am häufigsten im Sinn einer Lobektomie oder Segmentektomie. Dies setzt die sogenannte Operabiltät voraus, das heisst u.a. gewisse lungenfunktionelle Reserven. Patientinnen und Patienten mit COPD und Emphysem weisen häufig hierfür inakzeptable Lungenfunktionswerte auf. Nichtsdestotrotz kann ihnen eine Operation angeboten werden, wenn sie gleichzeitig für eine Lungenvolumenreduktion (LVRS) qualifizieren. Eine sogenannte Tumorresektion im LVRS-Konzept sichert nicht nur die Diagnose, sondern bietet neben der definitiven Histologie ein korrektes Staging, die komplette Entfernung des Tumors und die Möglichkeit einer postoperativen Verbesserung der Lungenfunktion. Wie bei allen Patientinnen und Patienten mit Krebsverdacht sollte auch hier eine entsprechende Indikation an einem interdisziplinären Tumorboard erfolgen. Lung Cancer Surgery for Severe COPD with Emphysema: Tumor Resection with Improvement of Lung Function Abstract. The golden standard for the therapy of early stage non-small cell lung cancer consists of surgical resection, usually performed as lobectomy or segmentectomy. These procedures demand a certain operability, including certain lung functional reserves. Patients with COPD and emphysema usually have lung function values far below that. Nevertheless, these patients can be offered treatmentif at the same time they qualify for concomitant lung volume reduction surgery (LVRS). LVRS with simultaneous tumor resection can consolidate the diagnosis, provide definite histology, correct staging, and thorough tumor resection might even improve the postoperative lung function. As with all patients with a (possible) diagnosis of cancer, the indication must be discussed in an interdiscplinary tumor board. Chirurgie du cancer du poumon en cas de BPCO sévère avec emphysème: Résection de la tumeur avec amélioration de la fonction pulmonaire Résumé. Le traitement standard du cancer du poumon au stade précoce est la résection chirurgicale anatomique, le plus souvent sous forme de lobectomie ou de segmentectomie. Cela présuppose ce que l’on appelle l’opérabilité, c’est-à-dire, entre autres, certaines réserves fonctionnelles pulmonaires. Les patients atteints de BPCO et d’emphysème présentent souvent des valeurs inacceptables en termes de fonction pulmonaire. Néanmoins, une opération peut leur être proposée s’ils se qualifient en même temps pour une réduction du volume pulmonaire (LVRS). La résection d’une tumeur dans le cadre du concept LVRS permet non seulement de confirmer le diagnostic, mais aussi d’obtenir une histologie définitive, une classification correcte, l’ablation complète de la tumeur et la possibilité d’améliorer la fonction pulmonaire après l’opération. Comme pour tous les patients dont le cancer est suspecté, une indication correspondante devrait être posée lors d’un Tumor Board interdisciplinaire