[Pharmacological treatment compliance and a description of its associated factors in patients with myasthenia gravis]. / Adhesion al tratamiento farmacologico y descripcion de sus factores asociados en pacientes con miastenia grave.

INTRODUCTION: Medication adherence is a public health problem and this has not been previously studied in myasthenia gravis patients. AIM: To determine if patients with myasthenia gravis are adherent to treatment and to describe the clinical factors of patients who are non-adherent to treatment. PATIENTS AND METHODS: Cross-sectional study of patients with myasthenia gravis followed at Padre Hurtado Hospital, Santiago de Chile, who received their medication through the hospital and therefore were on the pharmacy's list. Patients' participation was voluntary and anonymous. Medication adherence was assessed with the Morisky-Green-Levine survey (4 items). Patients were assessed for myasthenia gravis severity with the Manual Muscle Test, and myasthenia gravis-related quality of life with the MG-QOL15. Finally, patients were screened for depression with the 12-Item General Health Questionnaire. RESULTS: 26 patients were enrolled and 15 (57.7%) were women. Only 10 (38.5%) of patients were adherent to treatment. Patients who were not adherent to medication had more weakness (p = 0.06), worse quality of life (p = 0.008), were taking a greater number of myasthenia gravis drugs (p = 0.003) and had a higher risk of depression (p = 0.03). CONCLUSIONS: In this cohort of myasthenia gravis patients, three out of five patients were not adherent to treatment. These patients tended to have more weakness, worse quality of life and higher risk of depression. Medication adherence should be assessed routinely in patients with myasthenia gravis.

TITLE: Adhesion al tratamiento farmacologico y descripcion de sus factores asociados en pacientes con miastenia grave.Introduccion. La adhesion al tratamiento farmacologico es un problema de salud publica, pero no se ha estudiado en pacientes con miastenia grave. Objetivo. Determinar la adhesion al tratamiento farmacologico en pacientes con miastenia grave y describir al grupo de pacientes no adherentes al tratamiento. Pacientes y metodos. Estudio de corte transversal, en pacientes con miastenia grave, en control y abandono del tratamiento farmacologico en el Hospital Padre Hurtado, Santiago de Chile. Los pacientes fueron invitados a participar de forma voluntaria y anonima. Se evaluo la adhesion al tratamiento con la escala Morisky-Green-Levine de cuatro items. Ademas, se evaluo la gravedad de la miastenia grave con el test manual de fuerza muscular (MMT); la calidad de vida asociada a la miastenia grave, con el 15-Item Quality Of Life Instrument for Myasthenia Gravis (MG-QOL15), y el riesgo de depresion, con el cuestionario de salud general de 12 items (GHQ-12). Resultados. Participaron 26 pacientes, de los cuales 15 (57,7%) eran mujeres. Solo 10 (38,5%) mostraron adhesion al tratamiento. Los no adherentes presentaron mayor debilidad (MMT; p = 0,06) y peor calidad de vida (MG-QOL15; p = 0,008), y tomaban mas farmacos para la miastenia grave (p = 0,003). Ademas, presentaron mayor riesgo de depresion (GHQ-12; p = 0,03) comparados con el grupo de adhesion al tratamiento. Conclusion. Tres de cada cinco pacientes con miastenia grave abandonaron el tratamiento, lo que se asocio con mayor debilidad, peor calidad de vida y mayor riesgo de depresion. Por lo tanto, deberia evaluarse la adhesion al tratamiento en los pacientes con miastenia grave.

Cardiovagal and somatic sensory nerve functions in healthy subjects.

PURPOSE: Heart rate response to deep breathing (HRDB), which depends on the integrity of cardiac vagal preganglionic neurons and efferent fibers, and the function of sural nerve fibers are both associated with an age-related decline process. The aim of this study was to determine whether the effects attributed to aging on cardiovagal and sural nerve function decline are associated. METHODS: HRDB and sural sensory nerve action potential (SNAP) amplitude, latency, and conduction velocity (SCV) were measured in one hundred healthy asymptomatic subjects (aged 14-92 years, 41 women). Multiple and simple linear regressions were used to analyze the relationships between the variables. RESULTS: There were significant linear relationships between sural SNAP amplitude and HRDB with age. There was also a significant linear relationship between sural SNAP amplitude and HRDB (correlation coefficient 0.46, p<0.0001), but the model explained only 21.5 % of the variability in HRDB. CONCLUSION: Cardiovagal function assessed by HRDB is associated with sural SNAP amplitude in healthy subjects. Age-related decline only partially explained the variability seen in the association. Other genetic and environmental factors may also play a role.

Orthostatic hypotension associated with dorsal medullary cavernous angioma.

BACKGROUND: Orthostatic hypotension (OH) is a rare manifestation of medulla oblongata lesions that may be because of interruption of descending sympathoexcitatory axons. AIMS: To illustrate the location of a medullary lesion that produced OH following resection in relationship to the location of putative sympathoexcitatory pathways. METHOD: A case with dorsal medullary cavernous angioma presenting with OH is described. The possible localization of lesion was compared with distribution of tyrosine hydroxylase (TH)-immunoreactive axons in a comparable section of the medulla of a control brain. RESULTS: The patient had marked OH after partial removal of the cavernous angioma. Biopsy confirmed the diagnosis. The magnetic resonance imaging location of the lesion overlapped that of TH-immunoreactive axons of the medullary transtegmental tract. CONCLUSIONS: A restricted lesion of medullary lesion interrupting the catecholaminergic transtegmental tract arising from the sympathoexcitatory C1 neurons of the rostral ventrolateral medulla could result in severe OH.

Polineuropatía amiloidótica familiar tipo I / Familial amyloidotic polyneuropathy type I

Familial amyloidotic polyneuropathy type I is an autosomal dominant inherited disorder characterized by progressive peripheral and autonomic neuropathy, associated with neural and systemic amyloid deposits. The abnormality usually lies in the transthyretin (TTR) gene. We report a 25 years old man with 18 months history of dysesthesias and pain in the toes, abnormal micturition and sexual dysfunction. Neurophysiologically studies disclosed a sensory-motor axonal polyneuropathy. Autonomic tests showed sympathetic and parasympathetic involvement. An electron micrograph of sural nerve revealed amyloid fibrils in the endoneurium. His mother died after a clinical history suggestive, in retrospect, of familial amyloidotic polyneuropathy type I. The clinical and genetic analysis of this cause of polyneuropathy are discussed.

Postprandial hypotension in Alzheimer's disease.

The degree of postprandial hypotension in patients with Alzheimer's disease (AD) is not known. We therefore studied ten AD patients and 23 controls before and after a meal. Seven AD patients but only six controls showed a fall in blood pressure (BP) of 20 mmHg or more. Maximum BP fall in AD patients was observed between 20 and 120 min after food ingestion. This differed from the time course in other groups with primary chronic autonomic failure. Postural hypotension occurred in two controls, but not in AD patients. Abnormalities in cardiac vasomotor regulation, gut peptide liberation or both could be responsible for postprandial hypotension in AD.

[Foramen ovale electrodes in the study of temporal lobe epilepsy]. / Electrodos de foramen oval en la investigación de las epilepsias del lóbulo temporal.

Corticograms of the mesial structures of the temporal lobe may be obtained with the recently developed foramen ovale electrodes. Since their installation is easy and of low risk, they will probably displace other invasive techniques routinely used up to the moment for the localization and lateralization of epileptic foci originated in the temporal lobe. For the first time in our country, we have used this technique in 7 patients with medically intractable complex partial epilepsy. In all the patients, the study allowed to clear doubts about the laterality of the start of ictal activity and to define irritative foci not found with conventional continuous superficial electroencephalographic recordings. The procedure was uneventful and the implanted electrodes were optimally tolerated. Foramen ovale electrodes are an effective diagnostic method for temporal lobe epilepsies and their features are specially appropriate for our milieu.

Parasympathetic denervation of the iris in Chagas' disease.

The parasympathetic innervation of the iris along with cardiovascular reflexes involving parasympathetic and sympathetic function were studied in 45 patients with Chagas's disease and in 36 controls. The autonomic features in Chagas' disease included 15 with cardiomyopathy, three with megaoesophagus and five with megacolon. None of the patients had orthostatic hypotension. Parasympathetic cardiac reflexes (deep breathing 30:15 ratio, Valsalva) were abnormal. There were exaggerated pupillary responses to dilute pilocarpine. These studies suggest iris parasympathetic denervation and favour more widespread cholinergic involvement in patients with Chagas' disease, than previously recognized.

Autonomic dysfunction in diphtheritic neuropathy.

Sympathetic and parasympathetic function and somatic nerve conduction were assessed in ten patients with diphtheritic neuropathy and 28 controls. None of the patients had postural hypotension. The Valsalva ratio was abnormal in two patients who also had myocarditis, but it was normal in five cases. Cardiac vagal dysfunction was found in five patients. One case showed cardiac parasympathetic denervation despite normal conduction velocity in the limbs.

Differences in postural hypotension and ankle jerks in the elderly from two contrasting socio-economic levels.

Subjects in low socio-economic strata in underdeveloped countries are subjected to considerable adverse influences which may enhance age-related changes in the nervous system. We therefore assessed the presence of ankle jerks and the degree of postural hypotension in two groups, one from the upper socio-economic level (58 subjects) and the other from the lower socio-economic level (56 subjects). All subjects were over 65 years of age. Only 6% had bilateral loss of ankle jerks, with no difference between the groups. Postural hypotension of 30 mmHg or greater was more frequent in the upper socio-economic group, nine out of 58 versus two out of 56 in the lower group. We conclude that there is no relationship in the elderly between social deprivation and certain markers of neurological dysfunction, such as the absence of ankle jerks and postural hypotension. The reasons for a greater frequency of postural hypotension in the higher socio-economic group are unclear.

Type of diabetic sensory neuropathy and autonomic involvement.

Thirty controls and 39 diabetic patients were studied by means of nerve conduction and autonomic tests. Standing by lying (S/L) heart rate ratio was done to test cardiac vagal function. The fall of systolic blood pressure (BP) from lying to standing (greater than or equal to 30 mmHg) was done to test sympathetic function. In 30 controls the S/L ratio was 1.28 (SD 0.1), and none of them had BP fall. In 10 diabetic patients without clinical neuropathy, S/L ratio was 1.28 (SD 0.01) and BP fall was not present. In 8 diabetic patients (with predominantly large fibre type), S/L ratio was 1.0 (SD 0.0) and the BP fall was not present. In 7 diabetic patients (with predominantly small fibre type), S/L ratio was 1.07 (SD 0.05) and 2 patients had BP fall. In 14 diabetic patients with mixed large and small fibre type, S/L ratio was 1.02 (SD 0.04) and 8 patients had BP fall. Sympathetic dysfunction is related to the type of sensory neuropathy. Vagal function is not related to any specific type, but it is related to the presence of polyneuropathy.

Nutritional status and autonomic nervous system function.

Autonomic function was studied in 20 undernourished subjects without medical or neurologic disease (aged 20 to 66 years, mean age 36) and compared to 30 well nourished subjects (age 20 to 65 years, mean age 40). Anthropometric measurements were performed (height, weight, triceps skinfold thickness, arm muscle circumference). The Valsalva manoeuvre and the immediate heart rate response to lying down test (S/L) were performed to study autonomic functions. The Valsalva ratio was 1.56 +/- 0.29 for controls and 1.66 +/- 0.34 for undernourished subjects (p greater than 0.1). The S/L ratio showed a significant difference (p less than 0.001) between controls (1.278 +/- 0.13) and undernourished subjects (1.06 +/- 0.07).