Sustained enhancements in inhibitory control depend primarily on the reinforcement of fronto-basal anatomical connectivity.

What are the neurophysiological determinants of sustained supra-normal inhibitory control performance? We addressed this question by coupling multimodal neuroimaging and behavioral investigations of experts in fencing who underwent more than 20,000 h of inhibitory control training over 15 years. The superior control of the experts manifested behaviorally as a speeding-up of inhibition processes during a Go/NoGo task and was accompanied by changes in bilateral inferior frontal white matter microstructure. In the expert group, inhibition performance correlated positively with the fractional anisotropy (FA) of white matter tracts projecting to the basal ganglia, and the total training load with the FA in supplementary motor areas. Critically, the experts showed no changes in grey matter volume or in the functional organization of the fronto-basal inhibitory control network. The fencers' performance and neural activity during a 2-back working memory task did not differ from those of the controls, ensuring that their expertise was specific to inhibitory control. Our results indicate that while phasic changes in the patterns of neural activity and grey matter architecture accompany inhibitory control improvement after short- to medium- term training, long-lasting inhibitory control improvements primarily depend on the reinforcement of fronto-basal structural connectivity.

Anterior Rectal Resection in a Patient with Aortoiliac Occlusive Disease and Coexisting Collateral Pathways: Management and Pitfalls.

Chronic aortoiliac occlusive disease most often affects the common iliac arteries and distal aorta but can progress all the way to the renal arteries, occluding the inferior mesenteric artery. A compensatory collateral network typically develops to preserve lower body perfusion. Inadvertent compression or ligation of such collaterals during surgery can have catastrophic consequences. In this article, we present the case of a 63-year-old patient with aortoiliac occlusive disease, requiring surgery for an adenocarcinoma of the rectosigmoid junction. A CT angiography was performed in order to map out the collateral pathways that had developed and Doppler ultrasound was used to mark their positions. The surgical procedure was adapted to his specific anatomy. A successful anterior resection was performed, and the patient made an uneventful recovery. In cases of aortoiliac obliteration, the existence of collaterals must be kept in mind and investigated with a multidisciplinary approach before any surgery is considered.

Granulocytic Sarcoma Presenting as a Palpable Breast Lump.

We report the case of a 45-year-old woman who palpated a voluminous painless lump in the superior outer quadrant of her left breast. Her past medical history revealed an acute myeloid leukemia (AML) treated and considered in remission 1 month prior to this discovery. Imaging work-up by mammogram, US, and MRI showed multiples masses suspect of malignancy in both breasts. US-guided needle biopsy was performed in the palpable mass and in one of the multiple lesions located in the right breast. Histologic findings were compatible with a granulocytic sarcoma in both breasts, which was considered as a relapse of the AML treated a few months earlier.

Cystic meningioma: diagnostic difficulties and utility of MRI in diagnosis and management.

We report the case of a patient presenting with convulsions in the emergency department. A CT examination revealed a mixed solid and cystic frontal peripheral mass. The intra-axial or extra-axial location and the differentiation between primary or secondary origin were not evident so MRI was performed. The most probable diagnosis was cystic meningioma with intratumoural cysts. Based on MRI findings, the neurosurgeon resected the mass together with its cystic components. The histological report verified the diagnosis and the patient had an excellent outcome.

Brain activity during observation and motor imagery of different balance tasks: an fMRI study.

After immobilization, patients show impaired postural control and increased risk of falling. Therefore, loss of balance control should already be counteracted during immobilization. Previously, studies have demonstrated that both motor imagery (MI) and action observation (AO) can improve motor performance. The current study elaborated how the brain is activated during imagination and observation of different postural tasks to provide recommendations about the conception of non-physical balance training. For this purpose, participants were tested in a within-subject design in an fMRI-scanner in three different conditions: (a) AO + MI, (b) AO, and (c) MI. In (a) participants were instructed to imagine themselves as the person pictured in the video whereas in (b) they were instructed simply to watch the video. In (c) subjects closed their eyes and kinesthetically imagined the task displayed in the video. Two tasks were evaluated in each condition: (i) static standing balance and (ii) dynamic standing balance (medio-lateral perturbation). In all conditions the start of a new trial was indicated every 2 sec by a sound. During AO + MI of the dynamic task, participants activated motor centers including the putamen, cerebellum, supplementary motor area, premotor cortices (PMv/d) and primary motor cortex (M1). MI showed a similar pattern but no activity in M1 and PMv/d. In the SMA and cerebellum, activity was generally higher in the dynamic than in the static condition. AO did not significantly activate any of these brain areas. Our results showed that (I) mainly AO + MI, but also MI, activate brain regions important for balance control; (II) participants display higher levels of brain activation in the more demanding balance task; (III) there is a significant difference between AO + MI and AO. Consequently, best training effects should be expected when participants apply MI during AO (AO + MI) of challenging postural tasks.

Epidermoid cyst of the spleen.

We report the case of a patient with a palpable mass and abdominal pain in the left upper quadrant. A physical examination revealed tenderness in this region. An ultrasound performed initially showed a large cystic structure. A CT examination revealed a large cyst originating in the spleen with loculations in its upper part and focal calcification in the wall. On MRI, the cystic mass showed high signal on T1-weighted and T2-weighted images. The carbohydrate antigen 19-9 (CA 19-9) was measured at 88 U/ml (standard <37.1 mUI/l). According to the imaging examinations and laboratory tests performed, it was impossible to determine if the splenic cyst was parasitic or non-parasitic. Given the most important risks of complications encountered in parasitic cysts, it was decided to treat this splenic cyst as a parasitic cyst. For this reason, an elective laparoscopic splenectomy with preoperative embolisation of the splenic artery was performed. The histological diagnosis was a primary epidermoid splenic cyst with inner lining epithelial cells.

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.

Management of pulmonary embolism during acrylic vertebroplasty.

A 55-year-old man diagnosed with osteogenesis imperfecta had multiple pulmonary embolism from acrylic cement during vertebroplasty. The patient immediately developed respiratory distress, renal failure, and right cardiac failure. A computed tomographic scan showed the presence of cement in the right and left pulmonary arteries, and in both lungs. Cardiac and respiratory functions did not improve with medical treatment, therefore the patient underwent pulmonary artery embolectomy. Cement was easily removed from both pulmonary arteries. The patient quickly recovered from respiratory and cardiac failure. We believe pulmonary embolectomy is a reliable and effective procedure to treat this rare and dreadful complication of acrylic vertebroplasty.