Screening for preclinical parenchymal lung disease in rheumatoid arthritis.

OBJECTIVES: Pulmonary disease is a common extraarticular manifestation of RA associated with increased morbidity and mortality. No current strategies exist for screening this at-risk population for parenchymal lung disease, including emphysema and interstitial lung disease (ILD). METHODS: RA patients without a diagnosis of ILD or chronic obstructive pulmonary disease underwent prospective and comprehensive clinical, laboratory, functional and radiological evaluations. High resolution CT (HRCT) scans were scored for preclinical emphysema and preclinical ILD and evaluated for other abnormalities. RESULTS: Pulmonary imaging and/or functional abnormalities were identified in 78 (74%) of 106 subjects; 45% had preclinical parenchymal lung disease. These individuals were older with lower diffusion capacity but had similar smoking histories compared with no disease. Preclinical emphysema (36%), the most commonly detected abnormality, was associated with older age, higher anti-cyclic citrullinated peptide antibody titres and diffusion abnormalities. A significant proportion of preclinical emphysema occurred among never smokers (47%) with a predominantly panlobular pattern. Preclinical ILD (15%) was not associated with clinical, laboratory or functional measures. CONCLUSION: We identified a high prevalence of undiagnosed preclinical parenchymal lung disease in RA driven primarily by isolated emphysema, suggesting that it may be a prevalent and previously unrecognized pulmonary manifestation of RA, even among never smokers. As clinical, laboratory and functional evaluations did not adequately identify preclinical parenchymal abnormalities, HRCT may be the most effective screening modality currently available for patients with RA.

Intrafascicular peripheral nerve stimulation produces fine functional hand movements in primates.

Restoring dexterous hand control is critical for people with paralysis. Approaches based on surface or intramuscular stimulation provide limited finger control, generate insufficient force to recover functional movements, and require numerous electrodes. Here, we show that intrafascicular peripheral electrodes could produce functional grasps and sustained forces in three monkeys. We designed an intrafascicular implantable electrode targeting the motor fibers of the median and radial nerves. Our interface selectively and reliably activated extrinsic and intrinsic hand muscles, generating multiple functional grips, hand opening, and sustained contraction forces for up to 2 months. We extended those results to a behaving monkey with transient hand paralysis and used intracortical signals to control simple stimulation protocols that enabled this animal to perform a functional grasping task. Our findings show that just two intrafascicular electrodes can generate a rich portfolio of dexterous and functional hand movements with important implications for clinical applicability.

First and Second Language at Hand: A Chronometric Transcranial-Magnetic Stimulation Study on Semantic and Motor Resonance.

According to embodied theories, motor and language processing bidirectionally interact: Motor activation modulates behavior in lexico-semantic tasks (semantic resonance), and understanding motor-related words entails activation of the corresponding motor brain areas (motor resonance). Whereas many studies investigated such interaction in the first language (L1), only few did so in a second language (L2), focusing on motor resonance. Here, we directly compared L1 and a late L2, for the first time both in terms of semantic and motor resonance and both in terms of magnitude and timing, by taking advantage of single-pulse TMS. Twenty-five bilinguals judged, in each language, whether hand motor-related ("grasp") and non-motor-related verbs ("believe"), were physical or mental. Meanwhile, we applied TMS on the hand motor cortex at 125, 275, 350, and 500 msec post verb onset, and recorded behavioral responses and TMS-induced motor evoked potentials. TMS induced faster responses for L1 versus L2 motor and nonmotor verbs at 125 msec (three-way interaction ß = -0.0442, 95% CI [0.0814, -0.0070]), showing a semantic resonance effect at an early stage of word processing in L1 but not in L2. Concerning motor resonance, TMS-induced motor evoked potentials at 275 msec revealed higher motor cortex excitability for L2 versus L1 processing (two-way interaction ß = 0.095, 95% CI [0.017, 0.173]). These findings confirm action-language interaction at early stages of word recognition, provide further evidence that L1 and L2 are differently embodied, and call for an update of existing models of bilingualism and embodiment, concerning both language representations and processing.

New frontiers in esophageal radiology.

Esophageal cancer is the sixth most common cause of cancer related mortality worldwide. Advances in treatment have translated into steadily improving survival rates. Accurate preoperative staging of esophageal cancer is imperative in order to provide an accurate prognosis and direct patients to the most appropriate treatment. Current preoperative staging relies on imaging, most commonly endoscopic ultrasound (EUS), computed tomography (CT) and positron emission tomography (PET). A combination of these modalities should be used in preoperative staging, as each has advantages over another. Magnetic resonance imaging (MRI) has always shown promise in its ability to accurately stage esophageal cancer, though it has not been consistently adopted as a common tool for this purpose. Recent research has demonstrated that MRI can become an integral part of esophageal cancer clinical staging. Advances in MR technology that utilize radial sampling allow for shorter, free breathing techniques without degradation of image quality, resulting in improved capability for T and N staging of esophageal cancer. MRI enhanced with superparamagnetic iron oxide (SPIO) and ultrasmall SPIO (USPIO) nanoparticles has been shown to be useful for the detection of metastatic disease in lymph nodes. This article will review the current evidence in the role that imaging plays in staging esophageal cancer.

Evaluation of ECG-gated and Fast Low-Angle Shot (FLASH) Dual Source Computed Tomography Scanning Protocols for Transcatheter Aortic Valve Replacement.

BACKGROUND: Transcatheter aortic valve replacement (TAVR) procedural success relies heavily on volumetric reconstruction imaging, particularly ECG-gated multi-detector row computed tomography. We postulated that single examination using fast low-angle shot (FLASH) dual source CT scanning (DS-CTA) could provide lower dose than ECG-gated CTA while maintaining the image quality. METHODS: In this single-centre cohort study, all patients who underwent ECG-gated and FLASH DS-CTA were evaluated. Volumetric reconstructions were performed for both ECG-gated and FLASH DS-CTA to obtain nonsagittal views of the structures. ECG-gated cardiac CT was obtained to evaluate the aortic annular size while FLASH DS-CTA was obtained to examine the aortic and iliac vasculature as part of TAVR imaging protocol. We evaluated measures of aortic annulus, coronaries and sinus of Valsalva using ECG-gated and FLASH DS-CTA scanning protocols. Image quality assessments were performed using aortic root region-of-interest signal-to-noise ratio. RESULTS: A total of 130 patients (mean age 81.5 ± 9.2 years, 46.2% female, and 99.2% white) underwent both ECG-gated CT and FLASH DS-CTA. There were excellent correlations between aortic annular area (R2 = 0.934) and aortic annular perimeter (R2 = 0.923) measured by the two protocols. Only 2 (1.5%) patients had >10% difference between aortic annular measurements by ECG-gated and FLASH DS-CTA, while none of the patients had a >10% difference between aortic annular perimeter measured by ECG-gated and FLASH DS-CT scans. There was no significant difference in signal-to-noise ratio between the two methods (mean difference 13.4; 95% CI -2.1-28.8, p = 0.09). There was significantly lower radiation dose for FLASH DS-CTA than ECG-gated CT scan (mean dose-length product difference 404.38; 95% CI 328.9-479.87, p <0.001). The measurements by the two scans led to the same transcatheter valve size selection in majority of the 128 (98.5%) patients by balloon expandable valve sizing recommendations and 130 (100%) of patients by self-expanding valve sizing recommendations. CONCLUSION: Overall, FLASH DS-CTA and ECG-gated CT scans provided comparable image quality and aortic annular dimensions for pre-TAVR evaluation. DS-CTA additionally provided the necessary angiographic imaging of the aorta and peripheral access vessels while still maintaining a lower radiation dose. We propose that a single non-ECG gated FLASH DS-CTA could be utilized to provide all the necessary pre-TAVR imaging information without a gated CT scan.

Contribution of FDG-PET/CT to the management of esophageal cancer patients at multidisciplinary tumor board conferences.

BACKGROUND: A multidisciplinary team approach to the management of esophageal cancer patients leads to better clinical decisions. PURPOSE: The contribution of CT, endoscopic and laparoscopic ultrasound to clinical staging and treatment selection by multidisciplinary tumor boards (MTB) in patients with esophageal cancer is well documented. However, there is a paucity of data addressing the role that FDG-PET/CT (PET/CT) plays to inform the clinical decision-making process at MTB conferences. The aim of this study was to assess the impact and contribution of PET/CT to clinical management decisions and to the plan of care for esophageal cancer patients at the MTB conferences held at our institution. MATERIALS AND METHODS: This IRB approved study included all the cases discussed in the esophageal MTB meetings over a year period. The information contributed by PET/CT to MTB decision making was grouped into four categories. Category I, no additional information provided for clinical management; category II, equivocal and misguiding information; category III, complementary information to other imaging modalities, and category IV, information that directly changed clinical management. The overall impact on management was assessed retrospectively from prospectively discussed clinical histories, imaging, histopathology, and the official minutes of the MTB conferences. RESULTS: 79 patients (61 males and 18 females; median age, 61 years, range, 33-86) with esophageal cancer (53 adenocarcinomas and 26 squamous cell carcinomas) were included. The contribution of PET/CT-derived information was as follows: category I in 50 patients (63%); category II in 3 patients (4%); category III in 8 patients (10%), and category IV information in 18 patients (23%). Forty-five patients (57%) had systemic disease, and in 5 (11%) of these, metastatic disease was only detected by PET/CT. In addition, PET/CT detected previously unknown recurrence in 4 (9%) of 43 patients. In summary, PET/CT provided clinically useful information to guide management in 26 of 79 esophageal cancer patients (33%) discussed at the MTB. CONCLUSION: The study showed that PET/CT provided additional information and changed clinical management in 1 out of 3 (33%) esophageal cancer cases discussed at MTB conferences. These results support the inclusion whenever available, of FDG-PET/CT imaging information to augment and improve the patient management decision process in MTB conferences.

Image-guided video-assisted thoracoscopic resection (iVATS): Translation to clinical practice-real-world experience.

OBJECTIVE: We developed a novel approach for localization and resection of lung nodules, using image-guided video-assisted thoracoscopic surgery (iVATS). We report our experience of translating iVATS into clinical care. METHODS: Methodology and workflow for iVATS developed as part of the Phase I/II trial were used to train surgeons, radiologists, anesthesiologists, and radiology technologists. Radiation dose, time from induction to incision, placement of T-bar to incision and incision to closure, hospital stay, and complication rates were recorded. RESULTS: Fifty patients underwent iVATS for resection of 54 nodules in a clinical hybrid operating room (OR) by six surgeons. Fifty-two (97%) nodules were successfully resected. Forty-two (84%) patients underwent wedge resection, four (7%) lobectomies, and two (4%) segmentectomy all with lymph node dissection. Median time from induction to incision was 89 minutes (range: 13-256 minutes); T-bar placement was 14 minutes (10-29 minutes); and incision to closure, 107 minutes (41-302 minutes). Average and total procedure radiation dose were: median = 6 mSieverts (range: 2.9-35 mSieverts). No deaths were reported and median length of stay was 3 days (range: 1-12 days). CONCLUSIONS: Translation of iVATS into clinical practice has been initiated using a safe step-wise process, combining intraoperative C-arm computed tomography scanning and thoracoscopic surgery in a hybrid OR.

Combined with anti-Nogo-A antibody treatment, BDNF did not compensate the extra deleterious motor effect caused by large size cervical cord hemisection in adult macaques.

In spinal cord injured adult mammals, neutralizing the neurite growth inhibitor Nogo-A with antibodies promotes axonal regeneration and functional recovery, although axonal regeneration is limited in length. Neurotrophic factors such as BDNF stimulate neurite outgrowth and protect axotomized neurons. Can the effects obtained by neutralizing Nogo-A, inducing an environment favorable for axonal sprouting, be strengthened by adding BDNF? A unilateral incomplete hemicord lesion at C7 level interrupted the main corticospinal component in three groups of adult macaque monkeys: control monkeys (n = 6), anti-Nogo-A antibody-treated monkeys (n = 7), and anti-Nogo-A antibody and BDNF-treated monkeys (n = 5). The functional recovery of manual dexterity was significantly different between the 3 groups of monkeys, the lowest in the control group. Whereas the anti-Nogo-A antibody-treated animals returned to manual dexterity performances close to prelesion ones, irrespective of lesion size, both the control and the anti-Nogo-A/BDNF animals presented a limited functional recovery. In the control group, the limited spontaneous functional recovery depended on lesion size, a dependence absent in the combined treatment group (anti-Nogo-A antibody and BDNF). The functional recovery in the latter group was significantly lower than in anti-Nogo-A antibody-treated monkeys, although the lesion was larger in three out of the five monkeys in the combined treatment group.

The hazy humerus artifact - A potential cause for misdiagnosis on computed tomography of the chest.

Computed tomography of the chest may be occasionally performed with the arm in mid extended position, in patients unable to fully raise their arms overhead. In such patients, a combination of beam hardening, incomplete projection and subtle motion artifacts may result in an appearance of diffuse cortical thickening and irregularity of the humerus. We describe this appearance as the 'hazy humerus artifact'. Radiologists must be aware of this appearance in order to avoid a misdiagnosis. The artifact can be minimized by having the arm positioned non-parallel to the plane of the gantry.

Assessment of the effect of continuous theta burst stimulation of the motor cortex on manual dexterity in non-human primates in a direct comparison with invasive intracortical pharmacological inactivation.

Non-invasive reversible perturbation techniques of brain output such as continuous theta burst stimulation (cTBS), commonly used to modulate cortical excitability in humans, allow investigation of possible roles in functional recovery played by distinct intact cortical areas following stroke. To evaluate the potential of cTBS, the behavioural effects of this non-invasive transient perturbation of the hand representation of the primary motor cortex (M1) in non-human primates (two adult macaques) were compared with an invasive focal transient inactivation based on intracortical microinfusion of GABA-A agonist muscimol. The effects on the contralateral arm produced by cTBS or muscimol were directly compared based on a manual dexterity task performed by the monkeys, the "reach and grasp" drawer task, allowing quantitative assessment of the grip force produced between the thumb and index finger and exerted on the drawer's knob. cTBS only induced modest to moderate behavioural effects, with substantial variability on manual dexterity whereas the intracortical muscimol microinfusion completely impaired manual dexterity, producing a strong and clear cortical inhibition of the M1 hand area. In contrast, cTBS induced mixed inhibitory and facilitatory/excitatory perturbations of M1, though with predominant inhibition. Although cTBS impacted on manual dexterity, its effects appear too limited and variable in order to use it as a reliable proof of cortical vicariation mechanism (cortical area replacing another one) underlying functional recovery following a cortical lesion in the motor control domain, in contrast to potent pharmacological block generated by muscimol infusion, whose application is though limited to an animal model such as non-human primate.

Selective Recruitment of Arm Motoneurons in Nonhuman Primates Using Epidural Electrical Stimulation of the Cervical Spinal Cord.

Recovery of reaching and grasping ability is the priority for people with cervical spinal cord injury (SCI). Epidural electrical stimulation (EES) has shown promising results in improving motor control after SCI in various animal models and in humans. Notably, the application of stimulation bursts with spatiotemporal sequences that reproduce the natural activation of motoneurons restored skilled leg movements in rodent and nonhuman primate models of SCI. Here, we studied whether this conceptual framework could be transferred to the design of cervical EES protocols for the recovery of reaching and grasping in nonhuman primates. We recorded muscle activity during a reaching and grasping task in a macaque monkey and found that this task involves a stereotypical spatiotemporal map of motoneuron activation. We then characterized the specificity of a spinal implant for the delivery of EES to cervical spinal segments in the same animal. Finally, we combined these results to design a simple stimulation protocol that may reproduce natural motoneuron activation and thus facilitate upper limb movements after injury.

Birth and death of a phantom.

Patients with supernumerary phantom limb report experiencing an additional limb duplicating its physical counterpart, usually following a stroke with sensorimotor disturbances. Here, we report a short-lasting case of a right upper supernumerary phantom limb with unusual visuomotor features in a healthy participant during a pure Jacksonian motor seizure unexpectedly induced by continuous Theta-Burst Stimulation over the left primary motor cortex. Electromyographic correlates of the event followed the phenomenological pattern of sudden appearance and brutal dissolution of the phantom, adding credit to the hypothesis that supernumerary phantom limb results from a dynamic resolution of conflictual multimodal information.

Role of primary motor cortex in the control of manual dexterity assessed via sequential bilateral lesion in the adult macaque monkey: A case study.

From a case study, we describe the impact of unilateral lesion of the hand area in the primary motor cortex (M1) on manual dexterity and the role of the intact contralesional M1 in long-term functional recovery. An adult macaque monkey performed two manual dexterity tasks: (i) "modified Brinkman board" task, assessed simple precision grip versus complex precision grip, the latter involved a hand postural adjustment; (ii) "modified Klüver board" task, assessed movements ranging from power grip to precision grip, pre-shaping and grasping. Two consecutive unilateral M1 lesions targeted the hand area of each hemisphere, the second lesion was performed after stable, though incomplete, functional recovery from the primary lesion. Following each lesion, the manual dexterity of the contralesional hand was affected in a comparable manner, effects being progressively more deleterious from power grip to simple and then complex precision grips. Both tasks yielded consistent data, namely that the secondary M1 lesion did not have a significant impact on the recovered performance from the primary M1 lesion, which took place 5months earlier. In conclusion, the intact contralesional M1 did not play a major role in the long-term functional recovery from a primary M1 lesion targeted to the hand area.

Anatomic relationships between the coronary venous system, surrounding structures, and the site of origin of epicardial ventricular arrhythmias.

BACKGROUND: Epicardial left ventricular (LV) idiopathic ventricular arrhythmias (VAs) can be approached via the pericardial space, the coronary venous system (CVS), or other surrounding structures. The anatomic relationships between epicardial sites of origin (SOO) of VAs and surrounding anatomic structures have not been systematically described. METHODS AND RESULTS: In 17 patients with idiopathic epicardial VAs, the relationships between the SOO and the CVS and other neighboring anatomic structures were assessed by computed tomographic angiography. Ablation was successful in 12/17 patients (71%). In 10/17 patients, the SOO was at a distance of ≤4 mm from a coronary artery. The SOO was closer to the CVS (2.1 ± 1.5 mm) than to the pericardial space (9.7 ± 3.7 mm) or the LV endocardium (7.7 ± 2.7 mm). Successful ablations were carried out from the CVS (n = 3), the CVS and LV endocardium (n = 5), the CVS and the aortic cusp (n = 1), the CVS, the LV endocardium, and the aortic cusp (n = 1), the LV endocardium (n = 1), and the CVS and the pericardial space (n = 1). In the remaining 5 patients, a subxyphoid pericardial ablation procedure was attempted and failed in all 5 patients. CONCLUSION: The CVS is closer to the SOO of epicardial idiopathic VAs than the pericardial space, the ventricular endocardium, and the aortic cusps. Given the proximity to coronary arteries at the SOO, radiofrequency energy often cannot be safely delivered to eliminate a VA and ablation may also need to be performed from adjacent structures. A subxyphoid pericardial ablation procedure has a low probability of success in patients with idiopathic epicardial VAs.

Posterior SMA Syndrome following subcortical stroke: contralateral akinesia reversed by visual feedback.

BACKGROUND: The supplementary motor area (SMA) plays a key role in motor programming and production and is involved in internally-cued movements. In neurological populations, SMA syndrome following a lesion to the "SMA proper" is characterized by transient impairment of voluntary movements and motor sequences. This syndrome is assumed to follow on from an interruption of the motor cortico-subcortical loop, and some case reports indicate that such a syndrome could occur after a brain lesion isolating the SMA from subcortical structures. AIM: To characterize the pattern of motor impairments in a patient whose stroke disconnects the SMA from the subcortical motor loop. METHOD: A patient developed a moderate transient left hemiparesis following a subcortical stroke in the right anterior cerebral artery area, which disconnected the SMA from basal ganglia. Eight days after the stroke, when the hemiparesis had regressed, the patient presented a specific SMA motor disorder of the left hand which manifested as an akinesia and was exacerbated when his visual attention was not directed towards his hand. We assessed finger tapping with left and right hands, eyes closed and open, in the left and right hemispace. We indexed movement speed as the number of taps filmed over 5-s periods. RESULTS: Left motor weakness (grasping strength of right hand: 49 kg and left hand: 41 kg) was resolved in a week. Ideomotor and ideational gestures and motor sequences were preserved. On the tapping task, left-hand tapping was slower than right-hand tapping. Critically, visual feedback improved tapping speed for the left, but not for the right, hand. The hemispace of the task execution had no effect on tapping performance. CONCLUSION: Our results suggest that SMA-basal ganglia disconnection decreases contralateral movement initiation and maintenance and this effect is partly compensated by visual cues.

Distinction between hand dominance and hand preference in primates: a behavioral investigation of manual dexterity in nonhuman primates (macaques) and human subjects.

Background The present study aimed to determine and confront hand preference (hand chosen in priority to perform a manual dexterity task) and hand dominance (hand with best motor performance) in eight macaques (Macaca fascicularis) and in 20 human subjects (10 left-handers and 10 right-handers). Methods Four manual dexterity tests have been executed by the monkeys, over several weeks during learning and stable performance phases (in controlled body position): the modified Brinkman board, the reach and grasp drawer, the tube and the bimanual board tasks. Three behavioral tests, adapted versions from the monkeys tasks (modified Brinkman board, tube and bimanual board tasks), as well as a handedness questionnaire, have been conducted in human subjects. Results In monkeys, there was a large disparity across individuals and motor tasks. For hand dominance, two monkeys were rather right lateralized, three monkeys rather left lateralized, whereas in three monkeys, the different parameters measured were not consistent. For hand preference, none of the eight monkeys exhibited a homogeneous lateralization across the four motor tasks. Macaca fascicularis do not exhibit a clear hand preference. Furthermore, hand preference often changed with task repetition, both during training and plateau phases. For human subjects, the hand preference mostly followed the self-assessment of lateralization by the subjects and the questionnaire (in the latter, right-handers were more lateralized than left-handers), except a few discrepancies based on the tube task. There was no hand dominance in seven right-handers (the other three performed better with the right hand) and in four left-handers. Five left-handers showed left-hand dominance, whereas surprisingly, one left-hander performed better with the right hand. In the modified Brinkman board task, females performed better than males, right-handers better than left-handers. Conclusions The present study argues for a distinction between hand preference and hand dominance, especially in macaque monkeys.

Computed tomography screening for lung cancer.

Screening with low-dose computed tomography reduces mortality from lung cancer in high-risk patients. Lung cancer screening with chest radiography alone or in combination with sputum analysis is currently not recommended. The feasibility and impact of screening in patients with a low or moderate risk for primary lung cancer are currently not known. A standardized framework for testing and management in a multidisciplinary fashion is necessary to provide lung cancer screening. The National Comprehensive Cancer Network and the American Lung Association have recently issued guidelines for lung cancer screening with computed tomography in high-risk patients.

Behavioral assessment of manual dexterity in non-human primates.

The corticospinal (CS) tract is the anatomical support of the exquisite motor ability to skillfully manipulate small objects, a prerogative mainly of primates(1). In case of lesion affecting the CS projection system at its origin (lesion of motor cortical areas) or along its trajectory (cervical cord lesion), there is a dramatic loss of manual dexterity (hand paralysis), as seen in some tetraplegic or hemiplegic patients. Although there is some spontaneous functional recovery after such lesion, it remains very limited in the adult. Various therapeutic strategies are presently proposed (e.g. cell therapy, neutralization of inhibitory axonal growth molecules, application of growth factors, etc), which are mostly developed in rodents. However, before clinical application, it is often recommended to test the feasibility, efficacy, and security of the treatment in non-human primates. This is especially true when the goal is to restore manual dexterity after a lesion of the central nervous system, as the organization of the motor system of rodents is different from that of primates(1,2). Macaque monkeys are illustrated here as a suitable behavioral model to quantify manual dexterity in primates, to reflect the deficits resulting from lesion of the motor cortex or cervical cord for instance, measure the extent of spontaneous functional recovery and, when a treatment is applied, evaluate how much it can enhance the functional recovery. The behavioral assessment of manual dexterity is based on four distinct, complementary, reach and grasp manual tasks (use of precision grip to grasp pellets), requiring an initial training of adult macaque monkeys. The preparation of the animals is demonstrated, as well as the positioning with respect to the behavioral set-up. The performance of a typical monkey is illustrated for each task. The collection and analysis of relevant parameters reflecting precise hand manipulation, as well as the control of force, are explained and demonstrated with representative results. These data are placed then in a broader context, showing how the behavioral data can be exploited to investigate the impact of a spinal cord lesion or of a lesion of the motor cortex and to what extent a treatment may enhance the spontaneous functional recovery, by comparing different groups of monkeys (treated versus sham treated for instance). Advantages and limitations of the behavioral tests are discussed. The present behavioral approach is in line with previous reports emphasizing the pertinence of the non-human primate model in the context of nervous system diseases(2,3).

Follow-up of cortical activity and structure after lesion with laser speckle imaging and magnetic resonance imaging in nonhuman primates.

The nonhuman primate model is suitable to study mechanisms of functional recovery following lesion of the cerebral cortex (motor cortex), on which therapeutic strategies can be tested. To interpret behavioral data (time course and extent of functional recovery), it is crucial to monitor the properties of the experimental cortical lesion, induced by infusion of the excitotoxin ibotenic acid. In two adult macaque monkeys, ibotenic acid infusions produced a restricted, permanent lesion of the motor cortex. In one monkey, the lesion was monitored over 3.5 weeks, combining laser speckle imaging (LSI) as metabolic readout (cerebral blood flow) and anatomical assessment with magnetic resonance imaging (T2-weighted MRI). The cerebral blood flow, measured online during subsequent injections of the ibotenic acid in the motor cortex, exhibited a dramatic increase, still present after one week, in parallel to a MRI hypersignal. After 3.5 weeks, the cerebral blood flow was strongly reduced (below reference level) and the hypersignal disappeared from the MRI scan, although the lesion was permanent as histologically assessed post-mortem. The MRI data were similar in the second monkey. Our experiments suggest that LSI and MRI, although they reflect different features, vary in parallel during a few weeks following an excitotoxic cortical lesion.

Gerbode ventricular septal defect diagnosed using cardiac CTA imaging.

This report describes the ability of computed tomography angiography (CTA) imaging of the heart to visualize an acquired shunt between the left ventricular outflow tract (LVOT) and the right atrium (RA) (Gerbode defect). Previously, transesophageal echocardiography (TEE) has been the mainstay of diagnosis. To the best of our knowledge, the use of cardiac CTA imaging to visualize and diagnose this disorder has not been previously reported. Cardiac CTA allows for more detailed visualization of cardiac anatomy and can supplement or supplant TEE as the diagnostic test of choice for evaluation of patients with this rare defect.