Stroke Recovery-Related Changes in Cortical Reactivity Based on Modulation of Intracortical Inhibition.

BACKGROUND: Cortical excitation/inhibition dynamics have been suggested as a key mechanism occurring after stroke. Their supportive or maladaptive role in the course of recovery is still not completely understood. Here, we used transcranial magnetic stimulation (TMS)-electroencephalography coupling to study cortical reactivity and intracortical GABAergic inhibition, as well as their relationship to residual motor function and recovery longitudinally in patients with stroke. METHODS: Electroencephalography responses evoked by TMS applied to the ipsilesional motor cortex were acquired in patients with stroke with upper limb motor deficit in the acute (1 week), early (3 weeks), and late subacute (3 months) stages. Readouts of cortical reactivity, intracortical inhibition, and complexity of the evoked dynamics were drawn from TMS-evoked potentials induced by single-pulse and paired-pulse TMS (short-interval intracortical inhibition). Residual motor function was quantified through a detailed motor evaluation. RESULTS: From 76 patients enrolled, 66 were included (68.2±13.2 years old, 18 females), with a Fugl-Meyer score of the upper extremity of 46.8±19. The comparison with TMS-evoked potentials of healthy older revealed that most affected patients exhibited larger and simpler brain reactivity patterns (Pcluster<0.05). Bayesian ANCOVA statistical evidence for a link between abnormally high motor cortical excitability and impairment level. A decrease in excitability in the following months was significantly correlated with better motor recovery in the whole cohort and the subgroup of recovering patients. Investigation of the intracortical GABAergic inhibitory system revealed the presence of beneficial disinhibition in the acute stage, followed by a normalization of inhibitory activity. This was supported by significant correlations between motor scores and the contrast of local mean field power and readouts of signal dynamics. CONCLUSIONS: The present results revealed an abnormal motor cortical reactivity in patients with stroke, which was driven by perturbations and longitudinal changes within the intracortical inhibition system. They support the view that disinhibition in the ipsilesional motor cortex during the first-week poststroke is beneficial and promotes neuronal plasticity and recovery.

Differential Impact of Brain Network Efficiency on Poststroke Motor and Attentional Deficits.

BACKGROUND: Most studies on stroke have been designed to examine one deficit in isolation; yet, survivors often have multiple deficits in different domains. While the mechanisms underlying multiple-domain deficits remain poorly understood, network-theoretical methods may open new avenues of understanding. METHODS: Fifty subacute stroke patients (7±3days poststroke) underwent diffusion-weighted magnetic resonance imaging and a battery of clinical tests of motor and cognitive functions. We defined indices of impairment in strength, dexterity, and attention. We also computed imaging-based probabilistic tractography and whole-brain connectomes. To efficiently integrate inputs from different sources, brain networks rely on a rich-club of a few hub nodes. Lesions harm efficiency, particularly when they target the rich-club. Overlaying individual lesion masks onto the tractograms enabled us to split the connectomes into their affected and unaffected parts and associate them to impairment. RESULTS: We computed efficiency of the unaffected connectome and found it was more strongly correlated to impairment in strength, dexterity, and attention than efficiency of the total connectome. The magnitude of the correlation between efficiency and impairment followed the order attention>dexterity ≈ strength (strength: |r|=.03, P=0.02, dexterity: |r|=.30, P=0.05, attention: |r|=.55, P<0.001). Network weights associated with the rich-club were more strongly correlated to efficiency than non-rich-club weights. CONCLUSIONS: Attentional impairment is more sensitive to disruption of coordinated networks between brain regions than motor impairment, which is sensitive to disruption of localized networks. Providing more accurate reflections of actually functioning parts of the network enables the incorporation of information about the impact of brain lesions on connectomics contributing to a better understanding of underlying stroke mechanisms.

How do visual skills relate to action video game performance?

It has been claimed that video gamers possess increased perceptual and cognitive skills compared to non-video gamers. Here, we examined to which extent gaming performance in CS:GO (Counter-Strike: Global Offensive) correlates with visual performance. We tested 94 players ranging from beginners to experts with a battery of visual paradigms, such as visual acuity and contrast detection. In addition, we assessed performance in specific gaming skills, such as shooting and tracking, and administered personality traits. All measures together explained about 70% of the variance of the players' rank. In particular, regression models showed that a few visual abilities, such as visual acuity in the periphery and the susceptibility to the Honeycomb illusion, were strongly associated with the players' rank. Although the causality of the effect remains unknown, our results show that high-rank players perform better in certain visual skills compared to low-rank players.

The diagnostic value of abbreviated MRI protocol in the surveillance of Branch-Duct intraductal papillary mucinous neoplasm.

PURPOSE: To assess the diagnostic value of abbreviated protocol (AP) MRI to detect the degeneration signs in branch-duct intraductal papillary mucinous neoplasms (BD-IPMNs) in patients undergoing a routine MRI follow-up. METHODS: This dual-center retrospective study include patients with BD-IPMN diagnosed on initial comprehensive protocol (CP) MRI who underwent routine MRI follow-up. CP included axial and coronal T2-weighted images (T2WI), axial T1-weighted images (T1WI) before and after contrast administration, 3D MR cholangiopancreatography (MRCP) and diffusion-weighted images (DWI). Two APs, eliminating dynamic sequences ± DWI, were extracted from CP. Two radiologists evaluated the APs separately for IPMN degeneration signs according to Fukuoka criteria and compared the results to the follow-up CP. In patients who underwent EUS, imaging findings were correlated with pathological results. Per-patient and per-lesion sensitivity, specificity, PPV, NPV, and accuracy of APs were calculated. Additionally, the acquisition time for different protocols was calculated. RESULTS: One hundred-fourteen patients (56.1 % women, median age: 71 years) with 256 lesions were included. Degeneration signs were observed in 24.6 % and 12.1 % per-patient and per-lesion, respectively. Regarding APs, the per patient sensitivity, specificity, PPV, NPV, and accuracy in the detection of the degeneration signs were 100 %, 93.5 %, 83.3 %, 100 %, and 95.1 %, respectively. No additional role for DWI was detected. AP without DWI economized nearly half of CP acquisition time (388 versus 663 s, respectively). CONCLUSION: AP can confidently replace CP for BD-IPMN follow-up with high sensitivity and PPV while offering benefits such as patient comfort, improved MRI accessibility, and reduced dedicated time for image analysis. DWI necessitates special consideration. CLINICAL RELEVANCE STATEMENT: Our data suggest that APs safely detect all degeneration signs of IPMN. While there is an overestimation of mural nodules due to the lack of contrast injection, this occurs in a negligible number of patients.

Early MRI termination with major impact on the radiological interpretation: The experience of a large university hospital.

PURPOSE: To report the incidence of early magnetic resonance imaging (MRI) terminations and analyse their risk factors in a large university hospital. METHOD: All consecutive patients aged > 16 years who underwent an MRI over a 14-month period were included. The following parameters were collected: demographics, in- or outpatient, history of claustrophobia, anatomical region investigated, and early MRI termination along with its cause. The potential link between these parameters and early MRI termination was statistically analysed. RESULTS: Overall, 22,566MRIs were performed (10,792 [48%] men and 11,774[52%] women, mean age: 57 [range: 16-103] years). Early MRI termination was reported in 183 (0.8%) patients (99 men and 84 women, mean age: 63 years). Of these early terminations, 103 (56%) were due to claustrophobia and 80 (44%) to other causes. Early terminations were more common in inpatients than outpatients (1.2% vs. 0.6%, p < 0.001), for both claustrophobia- and non-claustrophobia-related reasons. A prior history of claustrophobia was strongly associated with claustrophobia-related early termination (6.6% vs. 0.2%, p = 0.0001). Non-claustrophobia-related early terminations were significantly more common (0.6% vs. 0.2%) in elderly patients (>65 years old) than in younger ones. No other parameter was significantly associated with early termination. CONCLUSIONS: Early MRI termination is currently rare. The main risk factors for claustrophobia-related terminations comprised a prior history of claustrophobia, and examinations in inpatients. Non-claustrophobia-related early terminations were more common in both elderly patients and inpatients.

Toward individualized medicine in stroke-The TiMeS project: Protocol of longitudinal, multi-modal, multi-domain study in stroke.

Despite recent improvements, complete motor recovery occurs in <15% of stroke patients. To improve the therapeutic outcomes, there is a strong need to tailor treatments to each individual patient. However, there is a lack of knowledge concerning the precise neuronal mechanisms underlying the degree and course of motor recovery and its individual differences, especially in the view of brain network properties despite the fact that it became more and more clear that stroke is a network disorder. The TiMeS project is a longitudinal exploratory study aiming at characterizing stroke phenotypes of a large, representative stroke cohort through an extensive, multi-modal and multi-domain evaluation. The ultimate goal of the study is to identify prognostic biomarkers allowing to predict the individual degree and course of motor recovery and its underlying neuronal mechanisms paving the way for novel interventions and treatment stratification for the individual patients. A total of up to 100 patients will be assessed at 4 timepoints over the first year after the stroke: during the first (T1) and third (T2) week, then three (T3) and twelve (T4) months after stroke onset. To assess underlying mechanisms of recovery with a focus on network analyses and brain connectivity, we will apply synergistic state-of-the-art systems neuroscience methods including functional, diffusion, and structural magnetic resonance imaging (MRI), and electrophysiological evaluation based on transcranial magnetic stimulation (TMS) coupled with electroencephalography (EEG) and electromyography (EMG). In addition, an extensive, multi-domain neuropsychological evaluation will be performed at each timepoint, covering all sensorimotor and cognitive domains. This project will significantly add to the understanding of underlying mechanisms of motor recovery with a strong focus on the interactions between the motor and other cognitive domains and multimodal network analyses. The population-based, multi-dimensional dataset will serve as a basis to develop biomarkers to predict outcome and promote personalized stratification toward individually tailored treatment concepts using neuro-technologies, thus paving the way toward personalized precision medicine approaches in stroke rehabilitation.

Gastrointestinal bleeding and obstructive jaundice: Think of hepatic artery aneurysm.

Hemobilia is an uncommon and potential life-threatening condition mainly due to hepato-biliary tree traumatic or iatrogenic injuries. Spontaneously ruptured aneurysm of the hepatic artery is seldom described. We report the case of an 89-year-old woman presenting with abdominal pain, jaundice and gastrointestinal bleeding, whose ultrasound and computed tomography revealed a non-traumatic, spontaneous aneurysm of the right hepatic artery. The oeso-gastro-duodenoscopy and colonoscopy did not reveal any bleeding at the ampulla of Vater, nor anywhere else. Selective angiography confirmed the diagnosis of hepatic artery aneurysm and revealed a full hepatic artery originating from the superior mesenteric artery. The patient was successfully treated by selective embolization of microcoils. We discuss the etiologies of hemobilia and its treatment with selective embolization, which remains favored over surgical treatment. Although aneurysm of the hepatic artery is rare, especially without trauma, a high index of suspicion is needed in order to ensure appropriate treatment.

Varicocele percutaneous embolization outcomes in a pediatric group: 7-year retrospective study.

PURPOSE: Percutaneous embolization and surgical repair are the current treatment options for varicocele, but determining method superiority remains controversial. In this retrospective study, we evaluate the technical success, complication and recurrence rates following percutaneous embolization in a pediatric group, which were compared to reported outcomes for surgical repairs. METHODS: Thirty children treated for percutaneous varicocele embolization were recruited. The side and grade of varicocele, symptoms, testicular asymmetry, mean recurrence time, total radiation dose and complications were evaluated. Recurrence and follow-up complications due to embolization were also reviewed. RESULTS: The venography showed retrograde filling of the internal spermatic vein with the identification of aberrantly fed vessels in 23 % of patients. None of the patients suffered from procedure complications except one who had venous injury which was treated with a sclerosing agent. The technical success rate was 93 % (28 patients) with a recurrence rate of 13 % (4 patients). Interestingly, the mean radiation dose used was 862.5 µGy m(2), 3 times lower than abdominal CT. CONCLUSION: Considering the intravascular nature of embolization, which aims to avoid testicular artery and spermatic cord damage (difficult to avoid with the surgical method), and consequently a lower complication rate, along with the same success rate and recurrence rate, our study supports that embolization is a superior method to surgical interventions.

Image-guided multipolar radiofrequency ablation of liver tumours: initial clinical results.

The local effectiveness and clinical usefulness of multipolar radiofrequency (RF) ablation of liver tumours was evaluated. Sixty-eight image-guided RF sessions were performed using a multipolar device with bipolar electrodes in 53 patients. There were 45 hepatocellular carcinomas (HCC) and 42 metastases with a diameter < or =3 cm (n = 55), 3.1-5 cm (n = 29) and >5 cm (n = 3); 26 nodules were within 5 mm from large vessels. Local effectiveness and complications were evaluated after RF procedures. Mean follow-up was 17 +/- 10 months. Recurrence and survival rates were analysed by the Kaplan-Meier method. The primary and secondary technical effectiveness rate was 82% and 95%, respectively. The major and minor complication rate was 2.9%, respectively. The local tumour progression at 1- and 2-years was 5% and 9% for HCC nodules and 17% and 31% for metastases, respectively; four of 26 nodules (15%) close to vessels showed local progression. The survival at 1 year and 2 years was 97% and 90% for HCC and 84% and 68% for metastases, respectively. Multipolar RF technique creates ablation zones of adequate size and tailored shape and is effective to treat most liver tumours, including those close to major hepatic vessels.