Bruno Estañol

Posterior reversible encephalopathy syndrome as a complication of acute lupus activity

OBJECTIVES We aimed to describe the clinical and imaging characteristics; associated risk factors and neurological outcome of posterior reversible encephalopathy syndrome (PRES) in patients with systemic lupus erythematosus (SLE). METHODS From October 2001 to January 2007, we identified patients with SLE and the criteria for PRES in our institution, which is a tertiary-care referral center for patients with SLE; the patients were evaluated at baseline and followed to determine the clinical outcome. RESULTS We identified 22 episodes of PRES in 21 patients; 20 (95.2%) were women, mean age of onset was 24.9+/-8.6 years, all patients had high systemic activity (SLEDAI scores from 12 to 39). Acute hypertension was observed in 18 episodes (81.8%), and renal failure in 16 (72.7%); only 3 patients were on cyclophosphamide at the time of the onset of PRES. Persistent neurological deficit was observed in 2 cases; one patient died during the acute episode. CONCLUSIONS PRES is a central nervous system syndrome that is observed in SLE patients. It was associated mainly to high systemic activity, acute hypertension, and renal failure. Although reversibility is common, residual neurological damage may be observed.

Myasthenia Gravis and Pregnancy: Clinical Implications and Neonatal Outcome

BackgroundThe myasthenia gravis is twice as common in women as in men and frequently affects young women in the second and third decades of life, overlapping with the childbearing years. Generally, during pregnancy in one third of patients the disease exacerbates, whereas in two thirds it remains clinically unchanged. Complete remission can occur in some patients.MethodsTo describe the clinical course, delivery and neonatal outcome of 18 pregnant women with the diagnosis of myasthenia gravis. Retrospective chart review of pregnant patients with myasthenia gravis, followed at the National Institute of Perinatology in Mexico City over an 8-year period. Data was abstracted from the medical records on the clinical course during pregnancy, delivery and neonatal outcome.ResultsFrom January 1, 1996 to December 31, 2003 18 patients with myasthenia gravis were identified and included in the study. The mean ± SD maternal age was 27.4 ± 4.0 years. During pregnancy 2 women (11%) had an improvement in the clinical symptoms of myasthenia gravis, 7 women (39%) had clinical worsening of the condition of 9 other patients (50%) remained clinically unchanged. Nine patients delivered vaginally, 8 delivered by cesarean section and 1 pregnancy ended in fetal loss. Seventeen infants were born at mean ± SD gestational age of 37.5 ± 3.0 weeks and a mean birth weight of 2710 ± 73 g. Only one infant presented with transient neonatal myasthenia gravis. No congenital anomalies were identified in any of the newborns.ConclusionsThe clinical course of myasthenia gravis during pregnancy is variable, with a significant proportion of patients experiencing worsening of the clinical symptoms. However, neonatal transient myasthenia was uncommon in our patient population.

Análisis del factor de impacto de las revistas científicas latinoamericanas

Few Latin-American journalsare included in the Thomson ISI data base. The mean impact factor was 0.76 (0.23-3.2) foreight Mexican journals, 0.66 (0.10-2.1) for eight Chilean journals, 0.39 (0.06-0.7) for fiveArgentinian journals and 0.41 (0.09-1.1) for 16 Brazilian journals. The mean impact factorfor 11 journals written in English was 0.74 (0.12-2.1), 0.53 (0.09-3.2) for 18 bilingual journalsand 0.28 (0.06-0.56) for eight journals written in native language. The differences betweencountries and languages were not statistically significant.

Clinical Characteristics and Outcomes of the Meningitides in Systemic Lupus Erythematosus

Background: The meningitides are rare but well-identified complications in patients with systemic lupus erythematosus (SLE). Aims: To determine the clinical characteristics, risk factors, prevalence and outcomes of the meningitides (septic and aseptic) in patients with SLE. Patients and Methods: From January 1988 to December 2006, we identified patients with SLE and septic or aseptic meningitis. Results: We identified 25 episodes of meningitis in 23 patients with SLE, from a total of 1,411 SLE patients (1.63%); in 15 out of 25 episodes, a microorganism was identified. Mycobacterium tuberculosis, Listeria monocytogenes and Criptococcus neoformans represented the main microorganisms. In 10 episodes, aseptic meningitis was diagnosed. Lymphopenia, steroid use, chronic damage and systemic activity of SLE were frequent in both kinds of meningitis. Although the clinical presentation did not differ significantly, patients with septic meningitis had more residual neurological deficits (p = 0.04). Conclusions: Meningitis was observed in about 1.6% of the patients with SLE; in 40% of the cases, no microorganism could be isolated. A residual neurological deficit was more common in patients with septic meningitis.

Heart Rate and Systolic Blood Pressure Variability in the Time Domain in Patients with Recent and Long-Standing Diabetes Mellitus

Diabetes Mellitus (DM) affects the cardiovascular response of patients. To study this effect, interbeat intervals (IBI) and beat-to-beat systolic blood pressure (SBP) variability of patients during supine, standing and controlled breathing tests were analyzed in the time domain. Simultaneous noninvasive measurements of IBI and SBP for 30 recently diagnosed and 15 long-standing DM patients were compared with the results for 30 rigorously screened healthy subjects (control). A statistically significant distinction between control and diabetic subjects was provided by the standard deviation and the higher moments of the distributions (skewness, and kurtosis) with respect to the median. To compare IBI and SBP for different populations, we define a parameter, α, that combines the variability of the heart rate and the blood pressure, as the ratio of the radius of the moments for IBI and the same radius for SBP. As diabetes evolves, α decreases, standard deviation of the IBI detrended signal diminishes (heart rate signal becomes more “rigid”), skewness with respect to the median approaches zero (signal fluctuations gain symmetry), and kurtosis increases (fluctuations concentrate around the median). Diabetes produces not only a rigid heart rate, but also increases symmetry and has leptokurtic distributions. SBP time series exhibit the most variable behavior for recently diagnosed DM with platykurtic distributions. Under controlled breathing, SBP has symmetric distributions for DM patients, while control subjects have non-zero skewness. This may be due to a progressive decrease of parasympathetic and sympathetic activity to the heart and blood vessels as diabetes evolves.

Sympathetic co-activation of skin blood vessels and sweat glands.

Abstract.Skin blood vessels and sweat glands are both innervated by sympathetic C fibers. We investigated whether during diverse respiratory maneuvers the vasomotor responses (VRs) and the sympathetic skin responses (SSRs) were frequently or occasionally co-activated. We simultaneously recorded the amplitude of the vasomotor responses and the sympathetic skin responses, the ECG and the respiratory movements in 30 healthy subjects during natural breathing at rest, rhythmic respirations at 6 per minute, sudden deep inspiration and Valsalva maneuver. We found: 1) The SSR habituates with all respiratory maneuvers whereas the VRs do not habituate. 2) There was slight co-activation between the SSRs and VRs during natural default breathing (56 percent). 3) During rhythmic breathing at 6 per minute the VRs and the SSRs were frequently co-activated (97 percent). The SSR appeared at the end of the inspiration coinciding with the end of the decreased blood flow. However the SSR habituated after few rhythmic respirations. 4) During sudden deep inspiration one hundred percent of co-activations were between the initial phase of the VRs and the SSR. The SSR is large in amplitude and longer in duration than during rhythmic breathing. 5) During the Valsalva maneuver there was a strong co-activation (100 percent) particularly during the phases II and III that are characterized by vaso-constriction but also during phase IV. The SSR is the longest of duration in all of the maneuvers. The sympathetic innervation to the sweat glands of the palm of the hand and to the skin blood vessels of the fingertips is differentiated. Under normothermic conditions sudden deep inspiration and Valsalva maneuver induced a large sympathetic simultaneous outflow to the skin blood vessels and sweat glands. The simultaneous recording of skin blood flow and the SSRs provides a more complete assessment of the sympathetic outflow to the skin than either one alone.

Loss of Breathing Modulation of Heart Rate Variability in Patients with Recent and Long Standing Diabetes Mellitus Type II

Healthy subjects under rhythmic breathing have heart interbeat intervals with a respiratory band in the frequency domain that can be an index of vagal activity. Diabetes Mellitus Type II (DM) affects the autonomic nervous system of patients, thus it can be expected changes on the vagal activity. Here, the influence of DM on the breathing modulation of the heart rate is evaluated by analyzing in the frequency domain heart interbeat interval (IBI) records obtained from 30 recently diagnosed, 15 long standing DM patients, and 30 control subjects during standardized clinical tests of controlled breathing at 0.1 Hz, supine rest and standing upright. Fourier spectral analysis of IBI records quantifies heart rate variability in different regions: low-frequencies (LF, 0.04–0.15 Hz), high-frequencies (HF, 0.15–0.4 Hz), and a controlled breathing peak (RP, centered around 0.1 Hz). Two new parameters are introduced: the frequency radius rf (square root of the sum of LF and HF squared) and β (power of RP divided by the sum of LF and HF). As diabetes evolves, the controlled breathing peak loses power and shifts to smaller frequencies, indicating that heart rate modulation is slower in diabetic patients than in controls. In contrast to the traditional parameters LF, HF and LF/HF, which do not show significant differences between the three populations in neither of the clinical tests, the new parameters rf and β, distinguish between control and diabetic subjects in the case of controlled breathing. Sympathetic activity that is driven by the baroreceptor reflex associated with the 0.1 Hz breathing modulations is affected in DM patients. Diabetes produces not only a rigid heartbeat with less autonomic induced variability (rf diminishes), but also alters the coupling between breathing and heart rate (reduced β), due to a progressive decline of vagal and sympathetic activity.

Giovanni Battista Morgagni in the murals of Diego Rivera at the National Institute of Cardiology of Mexico City.

The Italian physician Giovanni Battista Morgagni was the founder of the clinico-anatomical method. His masterpiece De sedibus, et causis morborum per anatomen indagatis represented a major breakthrough in the history of medicine. In the murals of Diego Rivera at the National Institute of Cardiology, Morgagni appears at the center of the fresco. With his left index finger points to the chest of a dying patient with a bulging pulsating aortic aneurysm below the left clavicle, and with his right hand, that holds a scalpel, shows the aneurysm found at the autopsy table. With this striking image the clinico-anatomical method is succinctly depicted. Professor Ignacio Chávez, the founder of the National Institute of Cardiology, gave the artist the elements to draw Morgagni, but the disposition and the importance of Morgagni in the fresco were due to the talent of Rivera.

Heart Rate and Systolic Blood Pressure Variability on Recently Diagnosed Diabetics

Background Diabetes affects approximately 250 million people in the world. Cardiovascular autonomic neuropathy is a common complication of diabetes that leads to severe postural hypotension, exercise intolerance, and increased incidence of silent myocardial infarction. Objective To determine the variability of heart rate (HR) and systolic blood pressure (SBP) in recently diagnosed diabetic patients. Methods The study included 30 patients with a diagnosis of type 2 diabetes of less than 2 years and 30 healthy controls. We used a Finapres® device to measure during five minutes beat-to-beat HR and blood pressure in three experimental conditions: supine position, standing position, and rhythmic breathing at 0.1 Hz. The results were analyzed in the time and frequency domains. Results In the HR analysis, statistically significant differences were found in the time domain, specifically on short-term values such as standard deviation of NN intervals (SDNN), root mean square of successive differences (RMSSD), and number of pairs of successive NNs that differ by more than 50 ms (pNN50). In the BP analysis, there were no significant differences, but there was a sympathetic dominance in all three conditions. The baroreflex sensitivity (BRS) decreased in patients with early diabetes compared with healthy subjects during the standing maneuver. Conclusions There is a decrease in HR variability in patients with early type 2 diabetes. No changes were observed in the BP analysis in the supine position, but there were changes in BRS with the standing maneuver, probably due to sympathetic hyperactivity.

Prognostic Factors of Thymectomy in Patients with Myasthenia Gravis

OBJECTIVE To identify the response to thymectomy and the factors associated with a poor response, a nested case-control study was performed on 132 patients with an established diagnosis of myasthenia gravis who had had a thymectomy between 1987 and 1997 and had been followed up for at least 3 years. METHODS In order to assess the response to thymectomy, the following two points were taken into account: (a) the dose of pyridostigmine and other drugs (steroids, azathioprine) that the patient took before and after thymectomy, and (b) the Osserman classification before and after thymectomy. The patients were divided into 4 groups: (1) patients in remission; (2) patients with improvement; (3) patients with no change, and (4) patients who were worse. RESULTS 91 patients had a good response (69%) and 41 patients had a poor response (31%). The response by groups was as follows: 50 patients were found to be in remission; 41 patients had improved; 34 patients had no changes, and 7 got worse. Being more than 60 years old was associated with a poor prognosis (odds ratio 4.6, CI 1.11-20.32, p 0.01). The patients who had the disease for more than 3 years (odds ratio 2.97, CI 0.79-5.39, p 0.09) had a tendency towards a bad prognosis even though there was no statistical significance, and for those who had it for more than 4 years (odds ratio 2.58, CI 0.89-0.96, p 0.02) the bad prognosis was statistically significant. The patients who had the disease for more than 3 years between diagnosis and thymectomy (odds ratio 2.02, CI 0.69-5.90, p 0.15) and those with it for more than 4 years (odds ratio 2.53, CI 0.83-7.7, p 0.06) had a tendency towards a poor prognosis even though there was no statistical significance. In addition, having Osserman I was associated with a bad prognosis. Referring to the pathological findings, patients with thymoma (odds ratio 3.51, CI 0.43-31.5, p 0.15) and those with thymic atrophy (odds ratio 2.19, CI 0.93-5.16, p 0.04) had a poor prognosis. Finally, the use of steroids before thymectomy (odds ratio 2.26, CI 0.99-5.18, p 0.03) was associated with a worse prognosis. CONCLUSIONS The response to thymectomy was high (69%). The variables that had the most prognostic importance were age and the Osserman stage. Other variables of poor prognosis were: high doses of pyridostigmine and use of steroids before surgery; the total duration of the disease and the duration of the disease between diagnosis and the surgical procedure; history of previous thymectomy; use of plasmapheresis after surgery, and the discovery of thymic atrophy and thymoma in the histopathological result.