A Statistical Proposal for Selecting a Data-depending Threshold in Neurobiology.

In this paper we propose a new methodology for introducing thresholds in the analysis of neuro- biological databases. Often, in Neuroscience, absolute thresholds are adopted. This is done by cutting the data below (or above) predetermined values of the involved parameters, without an analysis of the distribution of the collected data concerning the phenomenon under investigation. Despite an absolute threshold could be rigorously defined in terms of physic parameters, it can be influenced by many different subjective aspects, including cognitive processes, and individual adaptation to the external stimuli. A possible related risk is that, mainly in experiments also de-pending on personal reactions, a significant portion of meaningful data, relevant for that specific task, could be neglected. In order to reduce these deviations, we are proposing to adopt a task-dependent approach, based on the comparison between the collected data and some database concerning a different task, assumed as a baseline. After giving the necessary theoretical back-ground, we test our methodology on real EEG data involving two subjects in a musical task. In addition to some natural results, new and unexpected neurological links can be emphasized and discussed.

Significance of multiple neurophysiological measures in patients with chronic disorders of consciousness.

OBJECTIVE: The aim of this study was to verify the value of multiple neurophysiological tests in classifying disorders of consciousness (DOCs) in patients in a chronic vegetative or minimal consciousness state categorised on the basis of the Coma Recovery Scale (CRS). METHODS: The study included 142 patients, all of whom underwent long (18h) EEG-polygraphic recordings including one night. The EEG was scored using the Synek scale and sleep patterns using an arbitrary scale. Absolute total power and relative EEG power were evaluated in different frequency bands. Multimodal evoked potentials (EPs), including auditory event-related potentials, were also evaluated and scored. RESULTS: The most information came from the combined multimodal EPs and sleep EEG scores. A two-step cluster analysis based on the collected information allowed a satisfactory evaluation of DOC severity. Spectral EEG properties seemed to be significantly related to DOC classes and CRS scores, but did not seem to make any significant additional contribution to DOC classification. CONCLUSIONS: Multiple electrophysiological evaluations based on EEG, sleep polygraphic recordings and multimodal EPs are helpful in assessing DOC severity and residual functioning in patients with chronic DOCs. SIGNIFICANCE: Simple electrophysiological measures that can be easily applied at patients' bedsides can significantly contribute to the recognition of DOC severity in chronic patients surviving a severe brain injury.

Recurrence of tako-tsubo syndrome, idiopathic dilated cardiomyopathy, and iterative ventricular tachycardia: just a fortuitous coincidence or a pathophysiological link?

We report the case of a 65-year-old woman with late recurrence of tako-tsubo syndrome, idiopathic dilated cardiomyopathy and prior iterative ventricular tachycardia. We hypothesize that the pathophysiological link among these clinical conditions could be the hyperactivity of the sympathetic nervous system.

Takotsubo cardiomyopathy and arrhythmic risk: the dark side of the moon.

BACKGROUND: "Takotsubo" cardiomyopathy (TTC) is a clinical disorder usually triggered by intense emotional and/or physical stress, characterized by reversible severe localized left ventricular wall dyskinesia, transient changes of ST segment, without significant coronary artery stenoses, that can mimic acute myocardial infarction. STATE OF THE ART: Although TTC is well known to have a good mid- and long-term prognosis, arrhythmic risk is increasingly recognized and we could provide, in view of the available literature, a mean for a prognostic stratification and some practical suggestions for management of these "vulnerable" patients. PERSPECTIVES: Further studies with randomized trials will be needed to prove the optimal treatment of TTC. CONCLUSIONS: TTC, generally considered a benign syndrome, should be reconsidered as a clinical condition at high risk for lethal arrhythmias in a subpopulation with QTc > 500 msec in acute phase. The studies about arrhythmias and TTC are based on case reports. TTC may present with sudden cardiac death: this results in a probable underestimate of the real arrhythmic risk. TTC is one of the causes of acquired long QT syndrome and could be a trigger able to unmask latent silent or inapparent congenital long QT syndrome. All factors that can exacerbate QT prolongation should be promptly removed. In the case of marked bradycardia and/or TdP should be implant a temporary pacemaker. In most cases, due to the transient nature of the syndrome, it is reasonable to recommend only beta-blocker therapy at discharge, despite the absence of randomized trials. If there are high-risk factor for long QT syndrome (QTc post-TCM > 500 ms, prior syncope, previous cardiac arrests) thought should be given an indication to ICD implant.    

[Pancreatic fistula after left pancreatectomy. Risk factors analysis on 68 patients]. / La fistola pancreatica dopo pancreasectomia sinistra. Analisi dei fattori di rischio su 68 casi.

AIM: The aim of this study was to identify risk factors related to pancreatic fistula after left pancreatectomy, considering the difference between the use of mechanical suture and the manual suture to close the pancreatic stump. METHODS: Sixty-eight patients, undergoing left pancreatectomy, were included in this study during a 10-year period. Eight possible risk factors related to pancreatic fistula were examined, such as demographic data (age and sex), pathology (pancreatic and extrapancreatic), technical characteristics (stump closure, concomitant splenectomy, additional procedures), texture of pancreatic parenchyma, octreotide therapy. RESULTS: Fourty-one patients (60%) underwent left pancreatectomy for primary pancreatic disease and 27 (40%) for extrapancreatic malignancy. Postoperative mortality and morbidity rates were 1.5% and 35%, respectively. Fourteen patients (20%) developed pancreatic fistula: 4 of them were classified as Grade A, 9 as Grade B and only one as Grade C. Three factors have been significantly associated to the incidence of pancreatic fistula: none prophylactic octreotide therapy, spleen preserving and soft pancreatic texture. It's still unclear the influence of pancreatic stump closure (stapler vs hand closure) in the onset of pancreatic fistula. CONCLUSION: In this study the incidence of pancreatic fistula after left pancreatectomy has been 20%. This rate is lower for patients with fibrotic pancreatic tissue, concomitant splenectomy and postoperative prophylactic octreotide therapy.

[Indications and outcomes of surgical management of chronic pancreatitis: literature review]. / Indicazioni e risultati del trattamento chirurgico nella pancreatite cronica: revisione della letteratura.

Surgical management of chronic pancreatitis remains a challenge for surgeons. Last decades, the improvement of knowledge regarding to pathophysiology of chronic pancreatitis, improved results of major pancreatic resections, and new diagnostic techniques in clinical practice resulted in significant changes in the surgical approach of this condition. Intractable pain, suspicion of malignancy, and involvement of adjacent organs are the main indications for surgery, while the improvement of patient's quality of life is the main purpose of surgical treatment. The surgical approach to chronic pancreatitis should be individualized based on pancreatic anatomy, pain characteristics, exocrine and endocrine function, and medical co-morbidity. The surgical treatment approach usually involves pancreatic duct drainage procedures and resectional procedures including longitudinal pancreatojejunostomy, pancreatoduodenectomy, pylorus-preserving pancreatoduodenectomy, distal pancreatectomy, total pancreatectomy, duodenum-preserving pancreatic head resection (Beger's procedure), and local resection of the pancreatic head with longitudinal pancreatojejunostomy (Frey's procedure). Recently, non-pancreatic and endoscopic management of pain have also been described (splancnicectomy). Surgical procedures provide long-term pain relief, improve the patients? quality of life with preservation of endocrine and exocrine pancreatic function, and are associated with low mortality and morbidity rates. However, new studies are needed to determine which procedure is safe and effective for the surgical management of patients with chronic pancreatitis.

Effects of acetylstrophanthidin on baroreflex sensitivity in patients with acute myocardial infarction.

We evaluated the effects of acetylstrophanthidin on baroreflex sensitivity in patients soon after an acute myocardial infarction. Baroreflex control of heart rate is frequently depressed after acute myocardial infarction and few data are available as to the effects of pharmacological intervention on this parameter. The reflex chronotropic response to arterial baroreceptor stimulation was assessed in 29 patients with uncomplicated acute myocardial infarction in control conditions (72-96 h after symptom onset) and 30 min after acetylstrophanthidin administration. To check for spontaneous baroreflex sensitivity variations, 24 patients with the same characteristics were evaluated at the same time intervals before and after a 10-cc bolus of saline placebo. Baroreflex sensitivity was assessed by calculating the regression line relating phenylephrine-induced increases in systolic blood pressure to the attendant changes in RR intervals. Mean baseline baroreflex sensitivity value for the whole study population was 7.4 +/- 4.5 ms/mmHg and was unchanged, 7.0 +/- 4.5 ms/mmHg, after acetylstrophanthidin (P = NS). Mean baroreflex sensitivity values were also comparable dividing patients according to the site of infarction both before and after acetylstrophanthidin. Despite the lack of difference in mean baroreflex sensitivity values between the two studies, at a post hoc analysis an inverse relation was found in the total study population between baseline baroreflex sensitivity values and their changes after acetylstrophanthidin (r = -0.62; P < 0.005). The inverse relation was also evident separately in anterior (r = -0.57; P < 0.05) and in inferior (r = -0.70; P < 0.005) myocardial infarction patients.(ABSTRACT TRUNCATED AT 250 WORDS)

Effects of converting enzyme inhibition on baroreflex sensitivity in patients with myocardial infarction.

BACKGROUND: Baroreflex sensitivity provides useful prognostic information in patients after acute myocardial infarction. However, no data are available about the effects of converting enzyme inhibition on this variable. OBJECTIVES: The aim of the study was to evaluate the effects of angiotensin-converting enzyme inhibition on baroreflex sensitivity in patients after uncomplicated myocardial infarction. METHODS: Twenty-five patients after uncomplicated myocardial infarction underwent baroreflex sensitivity evaluation 72 to 96 h after symptom onset and after 4 days of captopril therapy. Twenty additional patients with the same characteristics were evaluated at the same time intervals before and after placebo administration to identify spontaneous baroreflex sensitivity variations. Baroreflex sensitivity was assessed by calculating the regression line relating phenylephrine-induced increases in systolic blood pressure to the attendant changes in the RR interval. RESULTS: The mean baroreflex sensitivity value increased after captopril administration from 6.5 +/- 4.2 to 11.8 +/- 6.1 ms/mm Hg (p less than 0.01) and in individual analyses increased by greater than 2 ms/mm Hg in 68% of patients. Mean plasma renin activity increased after captopril from 3.7 +/- 2.4 to 8.5 +/- 4.9 ng/ml per h (p less than 0.005). No difference was detectable in baroreflex sensitivity and plasma renin activity values according to the site of necrosis. In the control group, baroreflex sensitivity and plasma renin activity remained unchanged between the two studies. CONCLUSIONS: This study demonstrates that in patients with uncomplicated myocardial infarction, captopril significantly improves the chronotropic response to baroreceptor stimulation.

Characterization and prognostic significance of silent myocardial ischemia on predischarge electrocardiographic monitoring in unselected patients with myocardial infarction.

Characteristics and prognostic significance of ischemic ST changes at predischarge Holter monitoring were evaluated in 270 consecutive postinfarction patients. The 64 patients with ST changes had a greater incidence of non-Q-wave myocardial infarction (p less than 0.01) and ventricular premature contractions (p less than 0.01); they were more frequently in Moss class greater than 2 (p less than 0.01) and they had a lower wall motion score (p less than 0.05). At 2-year follow-up, patients with ST changes had a higher incidence of cardiac death and reinfarction. At multivariate analysis, Killip class (p less than 0.01) and ST changes (p less than 0.05) were the most predictive variables; when multivariate analysis was repeated including an additional variable--the inability to perform a stress test--Killip class was the most significant variable (p less than 0.01), and the presence of ST changes showed only borderline statistical significance (p less than 0.1). In the subset of patients who did not perform the stress test, ST change was the most important variable (p less than 0.01), followed by Killip class (p less than 0.05). Thus, after myocardial infarction, ST changes during Holter monitoring are associated with a poor prognosis and appear useful for stratifying patients who do not perform exercise stress tests.

[Ischemic coronary artery disease in menopause]. / La cardiopatia ischemica in menopausa.

Women show a lower incidence of Coronary Artery Disease (CAD) and probably a better prognosis than men. However better survival rate of women tended to be obscured because they were more likely to have histories of hypertension and diabetes and to be older than men. In this paper, incidence, clinical presentation, and prognosis of CAD in women are examined. Furthermore the conflicting reports concerning the effect of estrogen use on morbidity from CAD are reported. Finally the syndrome of angina with a normal coronary arteriogram, sometimes referred to as "Syndrome X" is analyzed.