Taking the brakes off the learning curve

Motor learning is characterized by patterns of cerebello‐striato‐cortical activations shifting in time, yet the early dynamic and function of these activations remains unclear. Five groups of subjects underwent either continuous or intermittent theta‐burst stimulation of one cerebellar hemisphere, or no stimulation just before learning a new motor sequence during fMRI scanning. We identified three phases during initial learning: one rapid, one slow, and one quasi‐asymptotic performance phase. These phases were not changed by left cerebellar stimulation. Right cerebellar inhibition, however, accelerated learning and enhanced brain activation in critical motor learning‐related areas during the first phase, continuing with reduced brain activation but high‐performance in late phase. Right cerebellar excitation did not affect the early learning process, but slowed learning significantly in late phase, along with increased brain activation. We conclude that the right cerebellum is a key factor coordinating other neuronal loops in the early acquisition of an explicit motor sequential skill. Hum Brain Mapp 38:1676–1691, 2017. © 2016 Wiley Periodicals, Inc.     

Progressive limbic encephalopathy: Problems and prospects

Background:

It was observed that a good number of patients presenting with psychiatric manifestations when investigated later because of unresponsiveness to treatment or late development of organic features turned out to be treatable limbic syndromes.

Introduction:

The aim of this study is to assess the patients presenting with new onset neuropsychiatric symptoms satisfying the criteria for probable limbic encephalitis.

Patients and Methods:

Patients referred to neurology department following a period of treatment for neuropsychiatric symptoms, which did not respond to conventional treatment were analyzed using Electroencephalography (EEG), magnetic resonance imaging, cerebrospinal fluid, screening for malignancy Vasculitic work-up, histopathology and autoantibody done when feasible.

Results:

There were 22 patients satisfying criteria for probable limbic encephalitis. Their mean age was 34.5 years. Symptoms varied from unexplained anxiety, panic and depression, lack of inhibition, wandering, incontinence, myoclonus, seizures and stroke like episodes. Three had systemic malignancy, 10 had chronic infection, one each with vasculitis, acute disseminated encephalomyelitis, Hashimoto encephalitis and two each with non-convulsive status, cryptogenic and Idiopathic inflammation.

Conclusion:

All patients who present with new onset neuropsychiatric symptoms need to be evaluated for sub-acute infections, inflammation, autoimmune limbic encephalitis and paraneoplastic syndrome. A repeated 20 minute EEG is a very effective screening tool to detect organicity.     

Prehospital care of tsunami victims in Thailand: description and analysis

INTRODUCTION: On 26 December 2004 at 09:00 h, an earthquake of 9.0 magnitude (Richter scale) struck the area off of the western coast of northern Sumatra, Indonesia, triggering a Tsunami. As of 25 January 2005, 5,388 fatalities were confirmed, 3,120 people were reported missing, and 8,457 people were wounded in Thailand alone. Little information is available in the medical literature regarding the response and restructuring of the prehospital healthcare system in dealing with major natural disasters. OBJECTIVE: The objective of the study was to analyze the prehospital medical response to the Tsunami in Thailand, and to identify possible ways of improving future preparedness and response. METHODS: The Israeli Defense Forces (IDF) Home Front Command Medical Department sent a research delegation to study the response of the Thai medical system to the 2004 earthquake and Tsunami disaster. The delegation met with Thai healthcare and military personnel, who provided medical care for and evacuated the Tsunami victims. The research instruments included questionnaires (open and closed questions), interviews, and a review of debriefing session reports held in the days following the Tsunami. RESULTS: Beginning the day after the event, primary health care in the affected provinces was expanded and extended. This included: (1) strengthening existing primary care facilities with personnel and equipment; (2) enhancing communication and transportation capabilities; (3) erecting healthcare facilities in newly constructed evacuation centers; (4) deploying mobile, medical teams to make house calls to flood refugees in affected areas; and (5) deploying ambulance crews to the affected areas to search for survivors and provide primary care triage and transportation. CONCLUSION: The restructuring of the prehospital healthcare system was crucial for optimal management of the healthcare needs of Tsunami victims and for the reduction of the patient loads on secondary medical facilities. The disaster plan of a national healthcare system should include special consideration for the restructuring and reinforcement prehospital system.     

Initial experience with hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction: results of a pilot study utilizing intracoronary aqueous oxygen therapy

OBJECTIVES: The purpose of this study was to evaluate the feasibility and safety of intracoronary hyperoxemic reperfusion after primary angioplasty for acute myocardial infarction (MI). BACKGROUND: Hyperoxemic therapy with aqueous oxygen (AO) attenuates reperfusion injury and preserves left ventricular (LV) function in experimental models of MI. METHODS: In a multi-center study of patients with acute MI undergoing primary angioplasty (PTCA), hyperoxemic blood (pO(2): 600 to 800 mm Hg) was infused into the infarct-related artery for 60 to 90 min after intervention. The primary end points were clinical, electrical and hemodynamic stability during hyperoxemic reperfusion and in-hospital major adverse cardiac events. Global and regional LV function was evaluated by serial echocardiography after PTCA, after AO infusion, at 24 h and at one and three months. RESULTS: Twenty-nine patients were enrolled (mean age: 58.9+/-12.6 years). Hyperoxemic reperfusion was performed successfully in all cases (mean infusion time: 80.8+/-18.2 min; mean coronary perfusate pO(2): 631+/-235 mm Hg). There were no adverse events during hyperoxemic reperfusion or the in-hospital period. Compared with baseline, a significant improvement in global wall motion score index was observed at 24 h (1.68+/-0.24 vs. 1.48+/-0.24, p < 0.001) with a trend toward an increase in ejection fraction (48.6+/-7.3% vs. 51.8+/-6.8%, p = 0.08). Progressive improvement in LV function was observed at one and three months, primarily due to recovery of infarct zone function. CONCLUSIONS: Intracoronary hyperoxemic reperfusion is safe and well tolerated after primary PTCA. These preliminary data support the need for a randomized controlled trial to determine if hyperoxemic reperfusion enhances myocardial salvage or improves long-term outcome.     

Direct Tumor Invasion in Colon Cancer: Correlation with Tumor Spread and Survival

Purpose  This study examined the correlation between depth of local invasion in colon cancer and tumor spread and patient survival. Methods  A cohort of 796 patients with a complete set of TNM staging information following an elective resection for colon cancer was selected. The rates of lymph node and distant metastasis, tumor differentiation, and extramural venous invasion for different tumor (T) categories were compared. The effects of initial tumor (T) category on overall patient survival were studied. Results  The depth of local tumor invasion correlated strongly with nodal involvement (P = 0.0001), rates of extramural venous invasion (P = 0.0002), poor differentiation (P = 0.0001), and distant metastasis (P = 0.0001). Fifty-seven percent of the patients remained lymph node-negative and distant metastasis-negative irrespective of their depth of tumor invasion had no impact on overall survival (P = 0.49). For patients with lymph node or distant metastasis (43 percent), depth of tumor invasion had significant impact on overall survival (P = 0.001). Thirteen percent of T3N1, 33 percent of T3N2, 40 percent of T4N1, and 68.percent of T4N2 cases had distant metastasis at presentation. Conclusion  Two types of colon cancer were observed: locally active and tendency to metastasize. For the latter, overall mortality and the risk of metastasis increased with depth of tumor invasion. Reprints are not available.     

On adaptive error spending approach for group sequential trials with random information levels

A group sequential analysis following the error spending approach of Lan and DeMets ( 1983 ) requires that the maximum information level be fixed in advance. In practice, however, the maximum information level is often random, making it impossible to determine the information fractions required by Lan and DeMets ( 1983 ) to calculate the sequential boundary. We propose an adaptive error spending approach that further expands practical applications to settings where the interim information levels can depend on blinded accumulating data. We use a simple weighting method to combine independent test statistics from different stages, which are then compared with adaptive boundary values for the group sequential test. We develop a measure-theoretic framework and show that the adaptive error spending approach controls the type 1 error rates. Methods for point estimates and confidence intervals are also proposed. We warn that an error spending approach can lead to serious inflation of the type 1 error rates when the number or timing of interim analyses is allowed to depend on unblinded accumulating data.