Clinical and cerebrospinal fluid findings contribute to the early differentiation between infectious and noninfectious encephalitis.

Early recognition and prompt specific treatment are crucial factors influencing the outcome of patients with acute encephalitis. The aim of this study was to determine the main causes of acute encephalitis in our population and to find predictors that may lead to specific diagnosis. Adult patients admitted to our hospital with suspected diagnosis of encephalitis in the period 2006-2013 were included. One hundred and five medical records were analyzed. Eighty-two patients with infectious encephalitis were identified (78% of total cases), 53 (65%) men and 29 (35%) women, mean age 47.8 years. The most common microorganisms identified were: HSV-1 (11%), VZV (10%), HSV-2 (5%) and EBV (5%). Twenty-three patients (22% of the series) had non-infectious encephalitis. Headache (p < 0.0001) and fever (p = 0.008) were more frequent in encephalitis of infectious origin. Protein levels and white blood cell counts in the cerebrospinal fluid were significantly higher in patients affected by infectious encephalitis than in those affected by noninfectious encephalitis (OR 95% CI 12.3 [2.9-51.7] and OR 95% CI 7.4 [2-27], respectively). Identifying specific causal agents of acute encephalitis remains a major challenge. Cerebrospinal fluid markers, as well as specific clinical findings, may however contribute to initial differentiation between infectious and noninfectious causes.

[Subcutaneous immunoglobulin. Treatment in chronic inflammatory demyelinating polyradiculo-neuropathy]. / Inmunoglobulina subcutánea. Tratamiento en polineuropatía desmielinizante inflamatoria crónica.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired disease that may affect nerve roots and peripheral nerves. Despite its low incidence, diagnosis is particularly important because there are different effective treatments. Human immunoglobulin is one of the mainstays of the treatment. Although there are few studies up to date, subcutaneous immunoglobulin (IgSC) has been proposed as an alternative to intravenous administration with similar efficacy. We present three cases with definite CIDP, classified according to the European Federation of Neurological Societies / Peripheral Nerve, Society (EFNS /PNS) criteria in which was used SCIgG as a treatment after success with the intravenous route. The Overall Neuropathy Limitations Scale (ONLS) was used to estimate the changes in the muscular strength before and after treatment.

Role of nitric oxide in young patients with vasovagal syncope.

AIMS: Nitric oxide (NO) formed in the vascular endothelium produces, among other effects, a strong vasodilation. In order to evaluate the possible role of NO in hypotension induced by head-up tilt test (HUT), we measured plasma levels of its metabolites, nitrites and nitrates (NOx), during the test. METHODS AND RESULTS: Twelve patients with vasovagal syncope and positive HUT [HUT(+)] (mean age: 23+/-5 years) and 13 healthy volunteers with negative HUT (controls) (mean age: 24+/-5 years) were included. Venous blood samples were obtained during the baseline stage for biochemical measurements. Plasma values of NOx were obtained under baseline conditions (T0), at the end of the HUT (T1), and 15 min after the end of the HUT (T2). The baseline biochemical values as well as haemodynamic parameters were similar in HUT(+) patients and controls. NOx plasma values (in micromol/L) were as follows [HUT(+) vs. controls]: T0: 5.7+/-1.6 vs. 8.8+/-4.7 (P=0.05), T1: 6.1+/-3.2 vs. 8.5+/-3.6 (P=NS), and T2: 6.1+/-3 vs. 10.2+/-8.9 (P=NS). The NOx levels were directly correlated with the insulin levels (Spearman's R=0.53, P=0.008). CONCLUSION: Baseline plasma levels of NOx were significantly lower in HUT(+) patients than in controls. However, since the expected increase in NOx values during HUT-induced syncope was not observed, the possible role of NO in vasovagal hypotension is uncertain.

Neuro-ophthalmologic complications of syringobulbia.

Syringobulbia is an uncommon condition, usually a late complication of syringomyelia. It has predilection for the dorsolateral region of the medulla leading to damage to vestibular nuclei and their connections, as well as to the descending sympathetic fibers. Oscillopsia, nystagmus, and Horner syndrome are frequent manifestations of syringobulbia. Oscillopsia may be a disturbing symptom for the patient, whereas Horner syndrome is usually an asymptomatic finding. MRI detection of syringomyelia has led to earlier treatment of syringomyelia and prevention of upward extension of the cavity. This probably explains why syringobulbia is less frequently encountered at present. We propose to describe the neuro-ophthalmologic symptoms and signs that may be observed in patients with syringobulbia and the mechanisms involved in their appearance.

Heart rate variability response to mental arithmetic stress is abnormal in first-degree relatives of individuals with schizophrenia.

BACKGROUND: Schizophrenia patients exhibit an abnormal autonomic response to mental stress. We sought to determine the cardiac autonomic response to mental arithmetic stress in their unaffected first-degree relatives. METHODS: Heart rate variability (HRV) analysis was performed on recordings obtained before, during, and after a standard mental arithmetic task to induce mental stress. 22 unaffected first-degree relatives of patients meeting DSM-IV criteria for schizophrenia (R) and 22 healthy individuals (C) were included in this study. RESULTS: Patients' relatives (R) had a normal response to the mental arithmetic stress test, showing an increased heart rate compared with controls. They also displayed the characteristic pattern of relative contributions of HRV components that consists of increased low-frequency (LF) HRV and decreased high-frequency (HF) HRV. Recovery of the resting pattern of HRV immediately after stress termination was observed in healthy subjects (LF 62+/-16% vs. 74+/-10% , HF 37+/-16% vs. 25+/-10%, F=9.616, p=0.004), but not in patients' relatives (LF 60+/-19% vs. 70+/-13%, HF 40+/-19% vs. 29+/-13%, F=8.4, p=0.056). CONCLUSIONS: First-degree relatives of schizophrenia patients exhibit an abnormal pattern of protracted response to mental arithmetic stress, though less intense than that observed in patients in a previous study. This suggests that a pattern of autonomic response to stress may therefore be familial and heritable.

Heart rate variability response to mental arithmetic stress in patients with schizophrenia: autonomic response to stress in schizophrenia.

BACKGROUND: The vulnerability-stress hypothesis is an established model of schizophrenia symptom formation. We sought to characterise the pattern of the cardiac autonomic response to mental arithmetic stress in patients with stable schizophrenia. METHODS: We performed heart rate variability (HRV) analysis on recordings obtained before, during, and after a standard test of autonomic function involving mental stress in 25 patients with DSM-IV schizophrenia (S) and 25 healthy individuals (C). RESULTS: Patients with schizophrenia had a normal response to the mental arithmetic stress test. Relative contributions of low-frequency (LF) HRV and high-frequency (HF) HRV influences on heart rate in patients were similar to controls both at rest (LF 64+/-19% (S) vs. 56+/-16% (C); HF 36+/-19% (S) vs. 44+/-16% (C), t=1.52, p=0.136) and during mental stress, with increased LF (S: 76+/-12%, C: 74+/-11%) and decreased HF (S: 24+/-12%, C: 26+/-11%) in the latter study condition. Whilst healthy persons recovered the resting pattern of HRV immediately after stress termination (LF 60+/-15%, HF 40+/-15%, F=18.5, p<0.001), in patients HRV remained unchanged throughout the observed recovery period, with larger LF (71+/-17%) and lower HF (29+/-17%) compared with baseline (F=7.3, p=0.013). CONCLUSIONS: Patients with schizophrenia exhibit a normal response to the mental arithmetic stress test as a standard test of autonomic function but in contrast with healthy individuals, they maintain stress-related changes of cardiac autonomic function beyond stimulus cessation.

Abnormalities of respiratory control and the respiratory motor unit.

BACKGROUND: Control of ventilation depends on a brainstem neuronal network that controls activity of the motor neurons innervating the respiratory muscles. This network includes the pontine respiratory group and the dorsal and ventral respiratory groups in the medulla. Neurologic disorders affecting these areas or the respiratory motor unit may lead to abnormal breathing. REVIEW SUMMARY: The brainstem respiratory network contains neurons critical for respiratory rhythmogenesis; this network receives inputs from peripheral and central chemoreceptors sensitive to levels of carbon dioxide (PaCO2) and oxygen (PaO2) and from forebrain structures that control respiration as part of integrated behaviors such as speech or exercise. Manifestations associated with disorders of this network include sleep apnea and dysrhythmic breathing frequently associated with disturbances of cardiovagal and sympathetic vasomotor control. Common disorders associated with impaired cardiorespiratory control include brainstem stroke or compression, syringobulbia, Chiari malformation, high cervical spinal cord injuries, and multiple system atrophy. By far, neuromuscular disorders are the more common neurologic conditions leading to respiratory failure. CONCLUSIONS: Respiratory dysfunction constitute an early and relatively major manifestation of several neurologic disorders and may be due to an abnormal breathing pattern generation due to involvement of the cardiorespiratory network or more frequently to respiratory muscle weakness.

Nonlinear analysis of heart rate variability in patients with eating disorders.

Patients with anorexia nervosa or bulimia nervosa often have signs of autonomic dysfunction potentially deleterious to the heart. The aim of this study was to ascertain the nonlinear properties of heart rate variability in patients with eating disorders. A group of 33 women with eating disorders (14 anorexia, 19 bulimia) and 19 healthy controls were included in the study. Conventional time- and frequency-domain heart rate variability measurements, along with nonlinear heart rate variability measurements including the short-term fractal scaling exponent alpha and approximate entropy (ApEn) were calculated. Anorexia nervosa patients exhibited decreased values of alpha, while bulimia nervosa patients had decreased values of ApEn. Low-frequency heart rate variability was decreased in patients with anorexia. In conclusion, these results are compatible with the view that a more severe alteration of cardiac autonomic function is present in anorexia than in bulimia.

Depressive symptoms are related to decreased low-frequency heart rate variability in older adults with decompensated heart failure.

BACKGROUND/AIMS: Depression has been associated with increased mortality among individuals with heart failure, but the mechanism for this association is unsettled. Depression is often found to result in autonomic dysfunction which, if present in heart failure, might help explain worsened outcomes. METHODS: This study was a cross-sectional evaluation of the relationship between depressive symptoms and cardiac autonomic function, as assessed by short-term heart rate variability (HRV) analysis in aged patients with acute/decompensated heart failure of coronary origin (CHF). A 21-item Hamilton Depression score and measures of short-term HRV were obtained in 31 inpatients >or=65 years of age, 24-72 h after admission to the coronary care unit with a diagnosis of CHF. RESULTS: Clinical depression was present in 22.6% of participants. In the sample as a whole, increasing depressive symptoms were associated with decreased low-frequency HRV. CONCLUSION: These results may be important in light of recent indications that decreased low-frequency HRV is a predictor of mortality in patients with heart failure.

Lesiones medulares catastróficas en el rugby argentino. Impacto de las medidas implementadas y su reducción relativa en el tiempo / Catastrophic spinal cord injuries in argentine rugby. Impact of the measures implemented and their relative reduction in time

Introducción: Se entiende por lesión catastrófica a cualquier trauma grave que comprometa la cabeza, el cerebro, la columna vertebral o la médula espinal, que pone en riesgo la vida o puede dejar una discapacidad permanente o semipermanente. En la Argentina, la incidencia de lesionados en el ámbito del rugby es alta comparada con la de otros países. En los últimos años, se han implementado múltiples medidas de prevención y se han modificado normas con el objetivo de evitar las lesiones catastróficas. materiales y métodos: Se analizaron datos obtenidos de una encuesta telefónica realizada en el marco de colaboración entre la Unión Argentina de Rugby y la Fundación para la Lucha de Enfermedades Neurológicas de la Infancia (Fleni). Se realizó un análisis descriptivo de los datos. Se recopilaron los cambios en las normativas del deporte, que pudieran tener impacto en las futuras lesiones. Resultados: Se observa que el número de lesiones se mantiene estable año tras año. Al asociar este dato con un aumento sostenido de la cantidad de jugadores por año, impresiona haber una disminución relativa del riesgo de lesionarse. Conclusiones: Las lesiones catastróficas generan un gran impacto en la calidad de vida del jugador y de su entorno. Deben considerarse inadmisibles y se deben incrementar los esfuerzos para lograr eliminar los riesgos de lesionarse. El esfuerzo de las entidades reguladoras impresiona tener un impacto positivo al haberse logrado una reducción relativa de las lesiones en relación con el aumento de jugadores año tras año. Nivel de Evidencia: IV

Introduction: A catastrophic injury is defined as any serious trauma that involves the head, brain, spine, or spinal cord. They are life-threatening or may leave a permanent or semi-permanent disability. In Argentina, there is a high incidence of injuries. materials and methods: Data obtained from a t elephone survey carried out in the collaborative framework between the Union Argentina de Rugby and the Fundación para la Lucha de Enfermedades Neurológicas de la Infancia (Fleni, by its acronym) were analyzed. We carried out a qualitative analysis of the data and their relationship to progressive changes in sports regulations. Results: It was observed that the number of injuries remained stable year after year. When associating this fact with a sustained increase in the number of players per year, we can see a relative decrease in the risk of injury. Conclusion: Catastrophic injuries have a gr eat impact on the quality of life of the player and his environment. They must be considered inadmissible and the efforts must be increased to achieve zero risk. In recent years, multiple preventive measures have been implemented and regulations have been modified in order to avoid catastrophic injuries. Level of Evidence: IV

Analysis of C9orf72 in patients with frontotemporal dementia and amyotrophic lateral sclerosis from Argentina.

Pathologic expansion of the G4C2 repeat in C9orf72 is the main genetic cause of frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS). To evaluate the frequency of the G4C2 expansion in a Latin American cohort of FTD and ALS patients, we used a 2-step genotyping strategy. For FTD, we observed an overall expansion frequency of 18.2% (6 of 33 unrelated cases). Moreover, the C9orf72 expansion accounted for 37.5% of all familial FTD cases (6 of 16 families). The expansion frequency in sporadic ALS cases was 2% (1 of 47 unrelated patients), whereas we observed the expansion in 1 of 3 families with a positive history for ALS. Overall, the expansion frequency in our FTD group was similar to that reported for patients in Europe and North America, whereas the frequency in our sporadic ALS group was significantly lower. To our knowledge, this is the first report on the frequency of the C9orf72 expansion in a Latin American population.

Clinical and cerebrospinal fluid findings contribute to the early differentiation between infectious and noninfectious encephalitis

Early recognition and prompt specific treatment are crucial factors influencing the outcome of patients with acute encephalitis. The aim of this study was to determine the main causes of acute encephalitis in our population and to find predictors that may lead to specific diagnosis. Adult patients admitted to our hospital with suspected diagnosis of encephalitis in the period 2006-2013 were included. One hundred and five medical records were analyzed. Eighty-two patients with infectious encephalitis were identified (78% of total cases), 53 (65%) men and 29 (35%) women, mean age 47.8 years. The most common microorganisms identified were: HSV-1 (11%), VZV (10%), HSV-2 (5%) and EBV (5%). Twenty-three patients (22% of the series) had non-infectious encephalitis. Headache (p < 0.0001) and fever (p = 0.008) were more frequent in encephalitis of infectious origin. Protein levels and white blood cell counts in the cerebrospinal fluid were significantly higher in patients affected by infectious encephalitis than in those affected by noninfectious encephalitis (OR 95% CI 12.3 [2.9-51.7] and OR 95% CI 7.4 [2-27], respectively). Identifying specific causal agents of acute encephalitis remains a major challenge. Cerebrospinal fluid markers, as well as specific clinical findings, may however contribute to initial differentiation between infectious and noninfectious causes.

El reconocimiento temprano y la instauración del tratamiento adecuado son dos elementos de gran relevancia en el pronóstico de las encefalitis agudas. El objetivo del presente trabajo es determinar las principales causas de encefalitis aguda en nuestro medio, así como buscar predictores que permitan orientar a un diagnóstico determinado. Se revisaron de manera retrospectiva las historias clínicas de todos los pacientes adultos que consultaron en nuestro centro entre 2006 y 2013 con el diagnóstico presuntivo de encefalitis. Ciento cinco pacientes fueron finalmente incluidos en nuestro estudio. Se identificaron 82 pacientes con encefalitis de origen infeccioso (78%), 53 (65%) fueron hombres y 29 (35%) mujeres, con una edad promedio de 47.8 años. Los agentes infecciosos más frecuentes fueron virus: HSV-1 12 (11%), VZV 11 (10%), HSV-2 5 (5%) y EBV 5 (5%). Se diagnosticó encefalitis no infecciosa en 23 (22%) pacientes. La cefalea (p < 0.0001) y la fiebre (p = 0.008) fueron más frecuentes en las encefalitis de origen infeccioso. Además, los niveles de proteínas y células en el LCR fueron significativamente mayores en los casos de etiología infecciosa que en los de etiología no infecciosa (OR 12.3 95%CI [2.9-51.7] y OR 7.4 95%CI [2-27], respectivamente). La identificación de la etiología específica de las encefalitis agudas continúa siendo un gran desafío y en la mayoría de los casos no se identifica el agente causal. Determinados marcadores en el LCR pueden contribuir a la identificación inicial de las encefalitis de etiología infecciosa versus no infecciosa.

Inmunoglobulina subcutánea: Tratamiento en polineuropatía desmielinizante inflamatoria crónica / Subcutaneous immunoglobulin. Treatment in chronic inflammatory demyelinating polyradiculo-neuropathy

La polineuropatía desmielinizante inflamatoria crónica (CIDP) es una enfermedad adquirida que puede afectar a raíces, plexos y nervios periféricos. A pesar de su baja incidencia, su diagnóstico cobra especial relevancia dado que actualmente existen tratamientos efectivos para la misma. La gammaglobulina humana endovenosa (IVIgG) es, junto con los esteroides y la plasmaféresis, uno de los tratamientos de primera elección. La vía de administración subcutánea se ha propuesto como una alternativa novedosa frente a la administración endovenosa con una eficacia similar. Presentamos tres casos de CIDP definitiva, clasificados según los criterios de la European Federation of Neurological Societies/Peripheral Nerve Society (EFNS/PNS) en los cuales se utilizó tratamiento crónico con inmunoglobulina subcutánea (IgSC). Todos ellos habían recibido tratamiento previo con IVIgG. Se obtuvo mejoría de la fuerza evaluada por Overall Neuropathy Limitations Scale (ONLS) y los tres pacientes manifestaron una mejor adaptación a sus actividades de la vida diaria.

Chronic inflammatory demyelinating polyradiculoneuropathy (CIDP) is an acquired disease that may affect nerve roots and peripheral nerves. Despite its low incidence, diagnosis is particularly important because there are different effective treatments. Human immunoglobulin is one of the mainstays of the treatment. Although there are few studies up to date, subcutaneous immunoglobulin (IgSC) has been proposed as an alternative to intravenous administration with similar efficacy. We present three cases with definite CIDP, classified according to the European Federation of Neurological Societies / Peripheral Nerve, Society (EFNS /PNS) criteria in which was used SCIgG as a treatment after success with the intravenous route. The Overall Neuropathy Limitations Scale (ONLS) was used to estimate the changes in the muscular strength before and after treatment.

Spontaneous electromyographic activity in spinal cord lesions.

Different types of spontaneous activity may be found during electromyographic examinations in patients with spinal cord diseases. Syringomyelia and intramedullary tumor patients may show continuous motor unit activity, synchronous motor unit potentials, myokymic discharges, segmental and propriospinal myoclonus, and respiratory synkinesis. These types of discharges are less commonly encountered in other types of spinal cord lesions. It is suggested that the derangement of inhibitory mechanisms by a central spinal cord lesion may favor the appearance of abnormal spontaneous activity. An increase in the excitability of spinal motor neurons is probably the basic underlying mechanism.

Breathing control in neurological diseases.

Control of ventilation depends on a brainstem neuronal network that controls activity of the motor neurons innervating the respiratory muscles. This network includes the pontine respiratory group and the dorsal and ventral respiratory groups in the medulla, which contain neurons that fire primarily during inspiration, post-inspiration, or expiration. The ventral respiratory group includes the pre-Bötzinger complex, which contains neurokinin-1 receptor immunoreactive neurons critical for respiratory rhythmogenesis. Structural and degenerative disorders affecting this network produce abnormalities of respiration, including sleep apnea and various patterns of dysrhythmic breathing, not infrequently associated with disturbances of cardiovagal and sympathetic vasomotor control. This emphasizes the important interactions between the respiratory and cardiovascular control networks in the medulla. Common disorders associated with impaired cardiorespiratory control include brainstem stroke or compression, syringobulbia, Chiari malformation, high cervical spinal cord injuries, and multiple system atrophy. This review focuses on the functional organization of the respiratory control network and common causes of impaired control of respiration.