Does experienced pain affects local brain volumes? Insights from a clinical acute pain model

Background/Objective:To study pain-brain morphometry associations as a function of post-surgery stages (anesthesia, pain and analgesia) in an acute pain model. Method:Impacted mandible third molar were extracted. Before surgery, an anatomical T1 scan was obtained. Regional brain volumen and subcortical nuclei shapes were obtained. Statistical analyses were done using multiple regression, being pain scores the predictors and voxel volumes, subcortical nuclei volumes and subcortical nuclei shapes, the outcomes. Results:Pain was significantly larger at pain than at anesthesia and analgesia stages, and was higher during anesthesia than during analgesia. Pain intensity was related to grey matter in several cortical (Insula, Mid Frontal and Temporal Gyruses, Precuneus, Anterior Cingulate), and subcortical nuclei (Hippocampus, Thalamus, Putamen, Amygdala), depending of the post-surgical stage. A larger number of brain areas showed significance at pain that at anesthesia and analgesia stages. Conclusions:The relationships of regional brain volumes and subcortical nuclei shapes with pain scores seemed to be unsteady, as they changed with the patient's actual pain stage.     

Anticipatory coarticulation in a patient with apraxia of speech

Articulatory anticipation of vowel gestures was assessed in an apraxic patient, a dysarthric patient, and three normal speakers. The technique of assessment included perceptual identification of gated speech stimuli. The speech material consisted of /getVte/ utterances with the target vowels /i/, /y/, and /u/. In the case of the apraxic patient the gated vowels were identified at a later instant relative to the preceding plosion burst than in the normal speakers. This result was interpreted as reflecting a delayed onset of coarticulatory gestures, in particular lip rounding. The identification rates for the dysarthric's vowels rather reflected the general reduction of this patient's vowel space.     

The state of order in Fe–Al studied by precession electron diffraction

Precession electron diffraction (PED) has been carried out on a fully ordered Fe–40at.%Al solid solution in order to explore its suitability for determining the state of order. The integrated intensity ratio of a superlattice reflection with respect to a fundamental reflection was measured as a function of the sample thickness and the results are well fitted by dynamical simulations. It is proposed that, in addition to conventional X-ray diffraction, PED may provide access to the state of order at microscopic and nanoscopic scales.