The role of operculo-insular region in the processing of somato-sensory inputs, painful or not, is now well established. However, available maps from previous literature show a substantial overlap of cortical areas activated by these stimuli, and the region referred to as the "secondary somatosensory area (SII)" is widely distributed in the parietal operculum. Differentiating SII from posterior insula cortex, which is anatomically contiguous, is not easy, explaining why the "operculo-insular" label has been introduced to describe activations by somatosensory stimuli in this cortical region. Based on the recent cyto-architectural parcellation of the human insular/SII cortices (Eickhoff et al., 2006, Kurth et al., 2010), the present study investigates with functional MRI (fMRI), whether these structural subdivisions could subserve distinct aspects of discriminative somato-sensory functions, including pain. Responses to five types of stimuli applied on the left hand of 25 healthy volunteers were considered: i) tactile stimuli; ii) passive movements; iii) innocuous cold stimuli; iv) non-noxious warm and v) heat pain. Our results show different patterns of activation depending on the type of somato-sensory stimulation. The posterior part of SII (OP1 area), contralateral to stimuli, was the only sub-region activated by all type of stimuli and might therefore be considered as a common cortical target for different types of somato-sensory inputs. Proprioceptive stimulation by passive finger movements activated the posterior part of SII (OP1 sub-region) bilaterally and the contralateral median part of insula (PreCG and MSG). Innocuous cooling activated the contralateral posterior part of SII (OP1) and the dorsal posterior and median part of insula (OP2, PostCG). Pain stimuli induced the most widespread and intense activation that was bilateral in SII (OP1, OP4) and distributed to all sub-regions of contralateral insula (except OP2) and to the anterior part of the ipsilateral insula (PreCG, MSG, ASG). However, the posterior granular part of insula contralateral to stimulus (Ig area) and the anterior part of SII bilaterally (OP4) were specifically activated during pain stimulation. This raises the question whether these latter areas could be the anatomical substrate of the sensory-discriminative processing of thermal pain.
Central nervous system (CNS) solitary fibrous tumors (SFTs) are rare mesenchymal neoplasms recognized less than a decade ago. Approximately 60 cases of SFT have been reported in the central nervous system. We describe three atypical SFTs of the CNS, two intracranial and one within the spine. One intracranial SFT arose from the sella turcica and expanded into the suprasellar areas. It relapsed twice during the 3 years following partial resection, and the MiB 1 labeling index steadily increased without obvious malignant transformation. The second SFT arose from the confluence of the sinuses, widely invaded the lateral sinus and adjacent bones, had a low MiB 1 index and has not recurred after 5 years. The intraspinal tumor occurred at T5-T7 in a patient with multiple café-au-lait spots, was predominantly myxoid and developed a second similar lesion at S3-S5 14 years later. The MiB 1 index was lower in the second tumor. Immunohistochemistry confirmed that all were SFTs. These atypical presentations gave us an opportunity to provide further information about the natural histological course of CNS SFTs.
Technetium-99m sestamibi (MIBI), an alternative radiopharmaceutical for myocardial perfusion imaging, has also been proposed for use as an imaging agent for various tumours, including breast cancer, lung cancer, lymphomas, melanomas and brain tumours. After routine radiation therapy, deteriorating clinical status or treatment failure may be due to either radiation-induced changes or recurrent tumour. Computed tomography and magnetic resonance imaging offer imperfect discrimination of tumour viability and radionecrosis. Against this background we undertook a retrospective study of 35 malignant glioma patients in whom clinical deterioration had occurred, in order to clarify the value of 99mTc-MIBI SPET in identifying tumour recurrence. SPET was performed 15 min after intravenous injection of 1110 MBq with a dual-headed gamma camera using a fan-beam collimator. Transverse, coronal and sagittal views were reconstructed. Intense MIBI uptake was found in 31 patients. This uptake was correlated with tumour recurrence as proved by histology and/or rapid, fatal evolution of these cases. The statistical analysis performed on this population of patients with MIBI uptake revealed a group of patients with a long mean survival and a group with a short mean survival. Two subgroups were found within each of these groups, according to the functional index ratio (tumour uptake/pituitary gland uptake ratio). No MIBI uptake was found in four patients who are still alive and can be considered to be disease-free. In those cases showing MIBI uptake, death occurred an average of 6.69 months following brain SPET. According to our results, the specificity and sensitivity of 99mTc-MIBI brain SPET seem to be high. Moreover, this technique is more accurate than computed tomography or magnetic resonance imaging for discriminating between tumour recurrence and radionecrosis.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.
customersupport@researchsolutions.com
10624 S. Eastern Ave., Ste. A-614
Henderson, NV 89052, USA
Copyright © 2024 scite LLC. All rights reserved.
Made with 💙 for researchers
Part of the Research Solutions Family.