Manuel Sierra-Beltran - Academia.edu (original) (raw)

Papers by Manuel Sierra-Beltran

Journal of the Neurological Sciences, 2013

care of in the Clinic of Neurology of the FBDC HTLV Center, from the following question: which we... more care of in the Clinic of Neurology of the FBDC HTLV Center, from the following question: which were the disorders and neurological states found in the patients of the Clinic of Neurology of the FBDC HTLV Center between September of 2005 and August of 2006? To reach this purpose was carried through, using medical record analysis (documentary analysis) and the neurological examination. The more frequent neurological disorders had been paresthesia, hyperactive patellar reflex, lumbar pain, intestinal dysfunction, muscular weakness of lower limbs and urinary disturbances. Considering these disorders, 50 patients with HAM/TSP, 39 oligosymptomatic and 27 asymptomatic had been identified. The diagnosis of most of the patients was made between 1 and 8 years after the beginning of the symptoms. With these results, the expectation of the authors consists on the propagation of attendance programs to the HTLV-1 carrying patients with neurological disorders.

Introduccion: En la actualidad, 415 millones de personas alrededor del mundo viven con diabetes t... more Introduccion: En la actualidad, 415 millones de personas alrededor del mundo viven con diabetes tipo 2 y 318 millones de personas tienen prediabetes. Se ha estudiado la asociacion entre diabetes y disfuncion cognitiva, encontrando un deterioro mas rapido en atencion y memoria primaria. Sin embargo, no se cuenta con evidencia suficiente acerca de la asociacion entre un estado prediabetico y alteracion en las funciones cognitivas. Objetivo: determinar la relacion entre la prediabetes y el deterioro en la evocacion de la memoria y el deficit de atencion. Materiales y metodos: estudio observacional, transversal en pacientes con diagnostico de prediabetes realizado mediante determinacion de Hb1Ac entre 5.7 y 6.4 %. Las funciones cognitivas se establecieron mediante el test de 6 items Orientacion Memoria Concentracion (IOMCt), el test Folstein mini-mental y el Cuestionario de Fallos de Memoria de la Vida Cotidiana (EDMQ). Se utilizo test de correlacion de Pearson para establecer relacion ...

Revista de investigaci�n Cl�nica, 2021

Background: Cerebral hypoperfusion before syncope has been shown in patients with chronic orthost... more Background: Cerebral hypoperfusion before syncope has been shown in patients with chronic orthostatic intolerance (OI) without tachycardia, but it is unknown if an initial decrease of cerebral blood flow velocity (CBFv) could be related to the vasovagal response (VVR) to head-up tilt test (HUTT). Objective: The objective of the study was to compare cardiovascular, cerebrovascular, and autonomic variables during HUTT in OI patients with or without a VVR. Methods: We included 74 subjects (58% female, mean age 33 ± 12 years) who underwent a 30-min HUTT and were divided into three groups: OI with VVR positive (VVR+), OI without VVR negative (VVR−), and asymptomatic healthy subjects with negative HUTT (control group). Cardiovascular, cerebrovascular, and autonomic variables were assessed beat-to-beat during HUTT with a Task Force monitor and a trans-cranial Doppler. Mean values were evaluated at baseline and throughout the first 10 min of tilting. Results: Cardiovascular variables were similar in the three groups. Systolic, diastolic, and mean CBFv were similar in VVR+ and VVR−, but both groups had lower CBFv than the control group. Systolic and diastolic CBFv decreased from baseline since min 1 in VVR+ and VVR− and since min 5 in the control group. The mean CBFv had a significant decrease since min 1 compared to baseline in all groups. Spectral indices of heart rate and blood pressure variability showed a similar autonomic response to HUTT in all groups. Conclusion: Patients with chronic OI without tachycardia have early postural cerebral hypoperfusion, regardless of the

Irish Journal of Medical Science (1971 -), 2021

Autonomic dysfunction is commonly observed in patients with long-standing type 2 diabetes. Previo... more Autonomic dysfunction is commonly observed in patients with long-standing type 2 diabetes. Previous studies have confirmed the value of both subjectively assessed symptoms and objective measurements of autonomic nervous system function in diagnosing cardiovascular autonomic neuropathy. However, the head-up tilt test (HUTT) has been rarely used to investigate cardiovascular autonomic responses in subjects with high risk of newly diagnosed type 2 diabetes (nT2D). To evaluate autonomic cardiovascular responses through passive orthostatic challenge along the diabetes continuum. The study population was stratified as normoglycemic (n = 16), prediabetes (n = 20), and nT2D (n = 20). The prevalence of orthostatic intolerance and autonomic cardiovascular responses was evaluated with the Task Force Monitor during a 30-min passive HUTT. Spectral indices of heart rate and blood pressure variability and baroreceptor effectiveness index (BEI) were calculated through the HUTT. BEI was obtained by the sequence method. There were no differences in the prevalence of orthostatic intolerance or in the indices of heart rate and blood pressure variability among the three groups of study. The BEI was attenuated in the nT2D group in supine rest and throughout HUTT compared with normoglycemic and prediabetes groups. The multivariable linear regression analysis showed that BEI was associated with fasting glucose (β = − 0.52, p < 0.001) and HbA1c (β = − 0.57, p < 0.001) independently of cardiovascular risk factors. Cardiovascular autonomic neuropathy, expressed as blunted BEI, is the only abnormal autonomic nervous test detected in nT2D, and it was independently associated with fasting glucose and HbA1c values.

Journal of Clinical Neurophysiology, 2020

PURPOSE The mechanisms underlying orthostatic hypertension (OHT) remain poorly understood. The au... more PURPOSE The mechanisms underlying orthostatic hypertension (OHT) remain poorly understood. The authors evaluated the cardiovascular, cerebrovascular dynamics, and autonomic response to head-up tilt test (HUTT) in young adults with symptoms of orthostatic intolerance and transient OHT. METHODS Forty-four female subjects were included (34 ± 13 years old) and categorized in three groups after a 30-minute 70° passive HUTT: symptomatic patients with OHT (surge of systolic blood pressure ≥20 mm Hg for at least 5 minutes at any given time during HUTT), orthostatic intolerance (symptomatic patients without orthostatic blood pressure changes), and healthy asymptomatic control subjects. RESULTS At baseline, OHT patients had lower systolic blood pressure than orthostatic intolerance patients (103 ± 8 vs. 116 ± 10 mm Hg, p < 0.01) and lower baroreflex sensitivity than control subjects (15.8 ± 8.3 vs. 27.1 ± 11.7 ms/mm Hg, p = 0.01). On tilt, cardiac output decreased in OHT patients from 6.1 ± 1.4 L/minute during baseline to 5.2 ± 0.8 L/minute after 10 minutes of HUTT (p = 0.01). In OHT patients at 30 minutes of HUTT, sympathetic efferent heart activity was higher (77.4 ± 14.9 normalized units or nu) than orthostatic intolerant patients (63.5 ± 11.8 nu, p = 0.02) and control subjects (65.8 ± 11.2 nu, p = 0.05). Cerebrovascular resistance in OHT was higher than control subjects after 30 minutes (2.2 ± 0.8 vs. 1.6 ± 0.3 cm/second, respectively, p = 0.02). CONCLUSIONS This study demonstrates that transient OHT can occur at any given time during HUTT. These patients exhibit a decrease in cardiac output and a hyperadrenergic response to tilt.

Journal of Clinical Neurophysiology, 2019

Purpose: Although the underlying mechanisms of reflex syncope remain under debate, there is evide... more Purpose: Although the underlying mechanisms of reflex syncope remain under debate, there is evidence that it results from decreased cardiac output related to splanchnic blood pooling or a fall in systemic vascular resistance. The aim was to evaluate the response of cerebrovascular and autonomic variables to passive orthostatic challenge in adult patients with different mechanisms leading to reflex syncope. Methods: The study included 30 subjects (66% women, mean age 34 6 14 years) who suffered a hemodynamic collapse during a drug-free head-up tilt test. They were categorized into three groups according to their hemodynamic cardiovascular response during the head-up tilt test: (1) reduced cardiac output (patients, n ¼ 10), (2) reduced systemic vascular resistance (patients, n ¼ 10), and (3) reduced cardiac output and systemic vascular resistance, (reduced cardiac output reduced systemic vascular resistance patients, n ¼ 10). Cardiovascular and cerebrovascular dynamics, as well as autonomic variables, were noninvasively assessed during the head-up tilt test and median values were calculated at baseline and throughout the three phases of the tilt. Results: At baseline, the reduced systemic vascular resistance group had lower cardiac output and higher total peripheral resistance index and a sustained increase of heart rate throughout the head-up tilt test in comparison to the other groups. Cerebrovascular dynamics and autonomic variables showed no difference among groups throughout the test. Compared with baseline, these variables had similar percentual change during the orthostatic challenge. Conclusions: Although different cardiovascular hemodynamic mechanisms of reflex syncope exist in adult patients, cerebrovascular hypoperfusion and autonomic modulation occur to a similar extent.

Journal of Clinical Neurophysiology, 2018

Liver International, 2014

Factors other than elevated levels of ammonia may be implicated in hepatic encephalopathy (HE) pa... more Factors other than elevated levels of ammonia may be implicated in hepatic encephalopathy (HE) pathophysiology, including abnormal cerebral haemodynamics. Transcranial Doppler ultrasonography (TCD) evaluates cerebrovascular structural integrity and reactivity, through pulsatility index (PI) and breath-holding index (BHI) respectively. The aim of this study was to evaluate cerebral haemodynamics by TCD in patients with compensated and decompensated cirrhosis, and patients with and without HE. We studied 90 subjects by TCD measuring PI and BHI in the middle cerebral artery: 30 with cirrhosis and no HE, 30 with cirrhosis and low-grade HE and 30 healthy subjects. Critical flicker frequency, psychometric hepatic encephalopathy score and West-Haven criteria were performed to assess MHE and HE respectively. Pulsatility index increased in decompensated cirrhotics (Child ≥ 7) when compared with compensated cirrhotics and healthy subjects [median (IQR) 1.07 (0.95-1.21) vs 0.90 (0.83-1.05) vs 0.87 (0.78-0.96); P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001]. A reverse relationship was observed for BHI among the three groups [0.82 (0.45-1.11) vs 1.20 (0.82-1.52) vs 1.28 (1.06-1.68); P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001]. Similar findings were observed in decompensation [model for end-stage liver disease (MELD) score ≥14]. Patients with HE showed higher PI and lower BHI [1.05 (1.00-1.16) and 0.89 (0.59-1.15)], when compared with patients without HE [0.96 (0.83-1.13) and 1.00 (0.60-1.53)] or controls [0.87 (0.78-0.96) and 1.28 (1.06-1.68)] (P &amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;amp;lt; 0.001 for PI, and P = 0.007 for BHI). In multivariate regression models, only PI predicted HE, but it was outperformed by MELD-sodium and tumour necrosis factor-alpha. These results indicate that cerebral haemodynamics are altered in patients with cirrhosis, in relation to severity of disease and HE. Findings on impaired PI and BHI suggest that structural vascular damage and loss of vascular autoregulation are implicated in the pathophysiology of HE.

Background. Salt consumption activates the brain reward system, inducing cravings and the search ... more Background. Salt consumption activates the brain reward system, inducing cravings and the search for salted food. Its excessive intake is associated with high blood pressure and obesity. The high quantity of salt in processed food is most likely a major cause of the global pandemic of hypertension (HT). Objective. To review the current information on the topic of salt addiction and the health consequences this has. Method. A search in PubMed, ScienceDirect, and EBSCOhost databases was conducted with the keywords “salt”, “salt addiction”, and “food addiction”. Articles with information relative to the topic of interest were checked, as were references of those articles and historical and culturally complementary information. Results. We described the historical relationship between man and salt, the physiology of salty taste perception, its role in the reward system and the health consequences of a high sodium diet. Discussion and conclusion. There is physiological and behavioural ev...

Journal of Clinical Neurophysiology

PURPOSE Although the underlying mechanisms of reflex syncope remain under debate, there is eviden... more PURPOSE Although the underlying mechanisms of reflex syncope remain under debate, there is evidence that it results from decreased cardiac output related to splanchnic blood pooling or a fall in systemic vascular resistance. The aim was to evaluate the response of cerebrovascular and autonomic variables to passive orthostatic challenge in adult patients with different mechanisms leading to reflex syncope. METHODS The study included 30 subjects (66% women, mean age 34 ± 14 years) who suffered a hemodynamic collapse during a drug-free head-up tilt test. They were categorized into three groups according to their hemodynamic cardiovascular response during the head-up tilt test: (1) reduced cardiac output (patients, n = 10), (2) reduced systemic vascular resistance (patients, n = 10), and (3) reduced cardiac output and systemic vascular resistance, (reduced cardiac output reduced systemic vascular resistance patients, n = 10). Cardiovascular and cerebrovascular dynamics, as well as autonomic variables, were noninvasively assessed during the head-up tilt test and median values were calculated at baseline and throughout the three phases of the tilt. RESULTS At baseline, the reduced systemic vascular resistance group had lower cardiac output and higher total peripheral resistance index and a sustained increase of heart rate throughout the head-up tilt test in comparison to the other groups. Cerebrovascular dynamics and autonomic variables showed no difference among groups throughout the test. Compared with baseline, these variables had similar percentual change during the orthostatic challenge. CONCLUSIONS Although different cardiovascular hemodynamic mechanisms of reflex syncope exist in adult patients, cerebrovascular hypoperfusion and autonomic modulation occur to a similar extent.

Neurologia i Neurochirurgia Polska

With newer research-based classification systems, the term Vascular Cognitive Impairment (VCI) is... more With newer research-based classification systems, the term Vascular Cognitive Impairment (VCI) is now preferred to vascular dementia. VCI is an umbrella term that includes all forms of cognitive deficits ranging from mild cognitive impairment of vascular origin (VaMCI) to vascular dementia (VaD). The new VCI construct takes into account the fact that in addition to single strategic infarcts, multiple infarcts, and leukoaraiosis, there are other mechanisms of cerebrovascular disease such as chronic hypoperfusion that might account for the pattern of cognitive deficits associated with vascular dementia. The key to defining the spectrum of VCI is neuropsychological testing, bedside or office-based clinical examination, and neuroimaging. The lack of specific cognitive tools that are sufficiently sensitive to detect subtle deficits makes the assessment of cognitive impairment difficult. Prospective cross-sectional and longitudinal studies of VCI from different settings are therefore required. Although there have been few published reports, behavioural and psychological symptoms (BPS) are inherently present in VCI from the onset and during the course of the disease. Besides the type of population (i.e. clinical, community or nursing-home settings), the definition of VCI/VaD and the instruments used, and differences in the prevalence and pattern of BPS between various studies, could be due to other, often unconsidered, factors such as gender, age, education, use of medication and VCI/ /VaD severity.