Natural history of longitudinally extensive transverse myelitis in 35 Hispanic patients with systemic lupus erythematosus: good short-term functional outcome and paradoxical increase in long-term mortality.

Background and objective Acute transverse myelitis (TM) is an infrequent neurological complication of systemic lupus erythematosus (SLE). Short-term outcome varies widely between cohorts. Little is known about the epidemiology and long-term functional outcome of TM associated to SLE. Methods Patients with SLE and acute TM were identified during hospital admission, visits to the Emergency Room or the Neurology Outpatient Clinic. We evaluated ambispectively those patients with SLE presenting with clinical myelopathy and corroborated with spinal MRI. Cases were divided as partial (non-paralyzing) or complete (paralyzing). We determined long-term functional outcome as well as mortality in those patients with follow-up periods of at least five years. Results We identified 35 patients (partial, n = 15; complete, n = 20) in which complete clinical and imaging data were available (26 with follow-up ≥ 5 years). Patients with complete TM were significantly older than those with partial forms. Positive antiphospholipid antibodies were observed in 80% of patients, suggesting a possible mechanistical role. Surprisingly, functional recovery at one year was in general good; however, we observed a five-year mortality of 31% because of sepsis (in 10 cases) or pulmonary embolism (in one case). Conclusions Short-term outcome of SLE-related TM is generally good, and recurrence rate is low. However, we observed a long-term fatality rate of 31% for reasons unrelated to TM, suggesting that TM is a manifestation of severe immune dysregulation and a predictor of severity and mortality in patients with SLE.

Fisiopatología del síncope neuralmente mediado / Pathophysiology of neurally-mediated syncope

Introducción: El síncope neuralmente mediado (SNM) se define como una pérdida súbita y transitoria del estado de alerta debido a una caída brusca de la presión arterial (PA). Objetivos: Describir los mecanismos putativos fisiopatológicos responsables del SNM, el papel del barorreflejo (BR) y la interacción de sus variables hemodinámicas principales: frecuencia cardiaca (FC) y PA. Desarrollo: Existe una desregulación episódica en el control de las variables hemodinámicas (FC y PA) mediadas por el barorreflejo. Durante la bipedestación activa existe una caída profunda y transitoria de la PA sistólica (PAS) debida a la acción de la gravedad sobre la columna de sangre y probablemente también a una vasodilatación refleja producida por inhibición del reflejo vasosimpático. Las anormalidades del BR en el SNM pueden ser debidas a una mayor intensidad de la caída de la PA al ponerse de pie o a una vasoconstricción retardada o incompleta debido a un reflejo vasosimpático insuficiente o retardado. Conclusiones: Los pacientes con SNM tienen en reposo y antes del síncope un estado de hiperactividad simpática. Durante el ortostatismo activo o la inclinación pasiva hay taquicardia excesiva seguida de bradicardia e hipotensión severa. La recuperación de la caída de la PAS está retardada o incompleta

Introduction: Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP). Objectives: This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP. Development: Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity. Conclusions: Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete

[The two faces of veno-arteriolar reflex: cutaneous vasodilatation and vasoconstriction to raise and to lower the arm]. / Las dos caras del reflejo venoarteriolar: vasoconstriccion y vasodilatacion cutanea al bajar y subir el brazo.

INTRODUCTION: The veno-arteriolar reflex (VAR) is triggered by an increase in the transmural venous pressure on placing a part of the body in the same direction as the gravitational acceleration below the heart. AIM: To assess the VAR in healthy subjects on raising a part of the body above the level of the heart. SUBJECTS AND METHODS: VAR was studied in 16 healthy subjects (20-65 years old) by means of changes in the blood flow in the skin detected using a digital infrared photoplethysmograph attached to the fingertip under the following conditions: right arm at the height of the heart, right arm below the heart and right arm below the level of the heart. The variables measured were: amplitude of the blood flow in the skin with the arm raised to the height of the heart (baseline amplitude), percentage decrease of the blood flow in the skin with the arm below the heart and percentage increase in blood flow with the arm above the heart. RESULTS: The percentage of vasoconstriction with the right arm below the heart was 35%, and that of vasodilation, 50%. CONCLUSIONS: Evaluation of the VAR with the arm below the heart causes vasoconstriction, and elevation of the arm causes an important degree of vasodilation. Vasoconstriction and vasodilation are maintained while the limb is kept above or below the heart. This is an economical and potentially very useful way of studying the innervation of the microcirculation in a number of different peripheral neuropathies of thin and mixed fibres.

TITLE: Las dos caras del reflejo venoarteriolar: vasoconstriccion y vasodilatacion cutanea al bajar y subir el brazo.Introduccion. El reflejo venoarteriolar (RVA) lo provoca un incremento en la presion venosa transmural al colocar una parte del cuerpo en el sentido de la aceleracion gravitatoria por debajo del corazon. Objetivo. Evaluar el RVA en sujetos sanos al levantar una parte del cuerpo por encima del corazon. Sujetos y metodos. En 16 sujetos sanos (20-65 años) se estudio el RVA mediante cambios en el flujo sanguineo de la piel con un fotopletismografo digital infrarrojo colocado en el pulpejo en sujetos sanos durante las siguientes condiciones: brazo derecho a la altura del corazon, brazo derecho 40 cm por debajo del corazon y brazo derecho 40 cm por encima del corazon. Las variables medidas fueron: amplitud del flujo sanguineo de la piel con el brazo a la altura del corazon (amplitud basal), porcentaje de disminucion del flujo sanguineo de la piel con el brazo por debajo del corazon y porcentaje de aumento del flujo sanguineo de la piel con el brazo por encima del corazon. Resultados. El porcentaje de vasoconstriccion con el brazo derecho por debajo del corazon fue del 35%, y el de vasodilatacion, del 50%. Conclusiones. La evaluacion del RVA con el brazo por debajo del corazon provoca vasoconstriccion, y la elevacion del brazo produce una importante vasodilatacion. La vasoconstriccion y la vasodilatacion se mantienen mientras la extremidad se mantenga por encima o por debajo del corazon. Este es un estudio potencialmente muy util y economico para estudiar la inervacion de la microcirculacion en diversas neuropatias perifericas de fibras delgadas y mixtas.

Pathophysiology of neurally-mediated syncope. / Fisiopatología del síncope neuralmente mediado.

INTRODUCTION: Neurally-mediated syncope (NMS) is defined as a transient loss of consciousness due to an abrupt and intermittent drop in blood pressure (BP). OBJECTIVES: This study describes the putative pathophysiological mechanisms giving rise to NMS, the role of baroreflex (BR), and the interaction of its main haemodynamic variables: heart rate (HR) and BP. DEVELOPMENT: Episodic dysregulation affects control over the haemodynamic variables (HR and BP) mediated by baroreflex mechanisms. During active standing, individuals experience a profound transient drop in systolic BP due to the effect of gravity on the column of blood and probably also because of reflex vasodilation. Abnormalities in the BR in NMS could be due to a more profound drop in BP upon standing, or to delayed or incomplete vasoconstriction resulting from inhibited or delayed sympathetic activity. CONCLUSIONS: Sympathetic hyperactivity is present in patients with NMS at rest and before syncope. During active standing or passive tilting, excessive tachycardia may be followed by bradycardia and profound hypotension. Recovery of systolic BP is delayed or incomplete.

[Electroencephalographic normal variants or with uncertain significance]. / Variantes normales o de significado incierto en el electroencefalograma.

Electroencephalography is an important tool in the diagnosis of primary or secondary disorders of central nervous system, epilepsy is one of the most important. Sometimes normal electroencephalographic activity simulates epileptiform activity. This activity does not have pathological value and is considered a variant of normal brain activity. The main groups based on the classification proposed by Blum and Cervone are: rhythmic patterns; epileptiform patterns; lambda waves, and age dependent changes. These changes are frequently seen during drowsiness, sleep and during activation maneuvers and more common in children and adolescents. The aim of this review is to present the most important characteristics of each of these variants, in order to prevent them being confused with abnormal brain activity.

[Reversible dementias and treatable dementias]. / Demencias reversibles y demencias tratables.

INTRODUCTION: When studying patients with dementia the search of reversible or treatable entities has a primordial role. Many patients do not recover the previous cognitive level; however, that does not signify that the disease is not treatable with partial recovery or prevention of secondary progression. DEVELOPMENT: The prevalence of reversible dementias is around 15% in most series. Rutine studies include complete blood cell count, erythrocyte sedimentation rate, electrolytes and chemistry panel, liver function tests, vitamin B12 and folate serum levels, urianalysis and syphilis serology. Special tests such as thyroid function tests, protein electrophoresis, human immunodeficiency virus serology, heavy metals serum levels, electrocardiography, cerebrospinal fluid analysis, and chest roentnography should be performed according to the patient clinical profile. Neuroimaging should be done in all cases. Non-contrasted computed tomography must be performed first. Magnetic resonance imaging is most useful for searching for more subtle structure abnormalities. Electroencephalogram, positron emission tomography and single photon emission computed tomography are not recommended as routine studies. Brain biopsy is indicated in few cases. CONCLUSION: Most common causes of reversible and treatable dementias include: medications, obstructive hydrocephalus, infectious, vascular, immunological, psychiatric, toxic and metabolic disorders, among others.

Demencias reversibles y demencias tratables / Reversible dementias and treatable dementias

Introducción. La identificación de identidades reversibleso tratables en el síndrome demencial es importante. Por desgracia,las demencias no son reversibles en todos los casos, pues enmuchas ocasiones el paciente no recupera el nivel intelectual previo;sin embargo, ello no significa que la enfermedad no sea tratabley que no se pueda obtener una mejoría parcial o prevenir y detenerla progresión secundaria del déficit cognitivo. Desarrollo. Laprevalencia de las demencias reversibles es en promedio del 15%.Los estudios rutinarios se realizan para la búsqueda de entidadestratables e incluyen la realización de biometría hemática, velocidadde sedimentación globular, química sanguínea, pruebas de funciónhepática, determinación sérica de los niveles de vitamina B12,folatos y electrolitos séricos, examen general de orina y serologíapara sífilis. Pruebas especiales como perfil hormonal (en particular,pruebas de función tiroidea), electroforesis de proteínas e inmunoglobulinasséricas, serología para virus de inmunodeficienciahumana, búsqueda de metales pesados, electrocardiograma, examendel líquido cefalorraquídeo y rayos X de tórax se deben realizarde acuerdo al contexto clínico del enfermo. Se recomienda realizarde manera rutinaria estudios de neuroimagen; la tomografíaaxial computarizada sin contraste sería el estudio inicial. La resonanciamagnética es más útil para la búsqueda de alteraciones estructuralesmás sutiles. El electroencefalograma, la tomografía poremisión de positrones y la tomografía computarizada por emisiónde fotón único no se recomiendan como estudios de rutina. La biopsiacerebral está indicada sólo en algunos casos. Conclusión. Lascausas más frecuentes de demencias reversibles y tratables incluyenalteraciones toxicometabólicas, infecciones, uso de fármacos,la hidrocefalia obstructiva, enfermedades psiquiátricas, autoinmunesy vasculares, entre otras

Introduction. When studying patients with dementia the search of reversible or treatable entities has a primordialrole. Many patients do not recover the previous cognitive level; however, that does not signify that the disease is not treatablewith partial recovery or prevention of secondary progression. Development. The prevalence of reversible dementias is around15% in most series. Rutine studies include complete blood cell count, erythrocyte sedimentation rate, electrolytes andchemistry panel, liver function tests, vitamin B12 and folate serum levels, urianalysis and syphilis serology. Special tests suchas thyroid function tests, protein electrophoresis, human immunodeficiency virus serology, heavy metals serum levels,electrocardiography, cerebrospinal fluid analysis, and chest roentnography should be performed according to the patientclinical profile. Neuroimaging should be done in all cases. Non-contrasted computed tomography must be performed first.Magnetic resonance imaging is most useful for searching for more subtle structure abnormalities. Electroencephalogram,positron emission tomography and single photon emission computed tomography are not recommended as routine studies.Brain biopsy is indicated in few cases. Conclusion. Most common causes of reversible and treatable dementias include:medications, obstructive hydrocephalus, infectious, vascular, immunological, psychiatric, toxic and metabolic disorders,among others

[Guillain-Barre syndrome. Experience in a third level hospital]. / Síndrome de Guillain-Barré. Experiencia en un hospital de tercer nivel.

INTRODUCTION: Acute peripheral neuropathy represents a medical emergency. The causes of it are diverse and plentiful. The most common cause of acute paralytic peripheral neuropathy is the Guillain-Barré syndrome (GBS). As many as 85% of those affected can be expected to make an excellent recovery. OBJECTIVE: To describe the principal risk factors associated, clinical manifestations, treatment, evolution and complications of 28 cases of Guillain-Barré syndrome (GBS) in the "Instituto Nacional de Ciencias Médicas y Nutrición Salvador Zubirán". METHODS: We search in our computer records all files under diagnostic of GBS, during the last ten years. We found 28 cases that were available to study. RESULTS: Mean age was 37 years old (SD 17.2). Fifteen patients were female (54%) and 13 were male (46%). Nine patients (32%) were preceded by a superior via infection, 5 (18%) by a diarrhea illness and 14 patients had not a predisposing factor. The duration of symptoms before diagnostic has a median of 7 days (2-15). Twenty-six patients (93%) had an ascending paralysis and 18 had paresthesias (64%). The most frequent subtype was acute inflammatory-demyelinating polyneuropathy (AIDP) in 18 patients (64%), acute motor-sensory axonal neuropathy (AMSAN) in 5 (18%), acute motor axonal neuropathy (AMAN) in 3 (11%) and 2 patients (7%) had the Fisher-Miller syndrome. Fifteen patients (54%) developed respiratory involvement requiring mechanical ventilation. Twenty-four patients (86%) had cerebrospinal fluid proteins elevated. Twenty patients (72%) had a total recovery, 6 (21%) had a partial recovery and 2 had not any response (7%). DISCUSSION: GBS is a particularly highstakes illness in that its onset is sudden and paralysis is frequently extreme (requiring assisted respiration), however, as many as 85% of those affected can be expected to make an excellent recovery. In our study the majority of patients (54%) develop respiratory involvement requiring mechanical ventilation but in this group the majority had a favorable outcome (71%).

Paraneoplastic syndromes associated with anti-Hu antibodies.

Paraneoplastic syndromes are disorders associated with cancer but without a direct effect of the tumor mass or its metastases on the nervous system. Small cell carcinoma of lung associated with paraneoplastic sensory neuronopathy and/or paraneoplastic encephalomyelitis with the presence of anti-Hu antibodies has been termed "anti-Hu syndrome." Anti-Hu associated PSN-PEM is an immune disorder in which both cell-mediated and humoral mechanisms are involved. Patients are considered affected by Anti-Hu associated PSN-PEM when they develop clinical signs and symptoms of CNS dysfunction and/or sensory neuropathy not caused by metastases or other disorders, and serum or cerebrospinal fluid is positive for Hu abs. SCLC is found in more than 90% of patients with cancer and positive Hu abs. Individual patients with Hu abs associated to SCLC may suffer PSN-PEM, limbic encephalitis, brainstem encephalopathy, opsoclonus-myoclonus, paraneoplastic cerebellar degeneration or myelopathy. Hu abs have a specificity of 99% and sensitivity of 82% in detecting paraneoplastic neurological syndromes. There are two types of treatment: the first is to treat the cancer, the second is to suppress the immune reaction with the use of corticosteroids, cyclophosphamide, azathioprine, plasma exchange, intravenous immunoglobulin and immunoadsorption; however, treatment of paraneoplastic syndromes is generally unsatisfactory.

[Central neurogenic hyperventilation associated with a pontine infarction]. / Hiperventilación central neurogénica en infarto pontino.

Central neurogenic hyperventilation in patients with a normal level of consciousness is uncommon. This condition occurs in bilateral pontine tegmental lesions, particularly tumors such as CNS lymphomas and glioma, as well as traumatic lesions. The physiopathological mechanisms are unknown and no there is no effective treatment for this entity. We report a case of central neurogenic hyperventilation associated to a unilateral basal pontine infarction.