Tablet-based electroencephalography diagnostics for patients with epilepsy in the West African Republic of Guinea.

BACKGROUND AND PURPOSE: Epilepsy is most common in lower-income settings where access to electroencephalography (EEG) is generally poor. A low-cost tablet-based EEG device may be valuable, but the quality and reproducibility of the EEG output are not established. METHODS: Tablet-based EEG was deployed in a heterogeneous epilepsy cohort in the Republic of Guinea (2018-2019), consisting of a tablet wirelessly connected to a 14-electrode cap. Participants underwent EEG twice (EEG1 and EEG2), separated by a variable time interval. Recordings were scored remotely by experts in clinical neurophysiology as to data quality and clinical utility. RESULTS: There were 149 participants (41% female; median age 17.9 years; 66.6% ≤21 years of age; mean seizures per month 5.7 ± SD 15.5). The mean duration of EEG1 was 53 ± 12.3 min and that of EEG2 was 29.6 ± 12.8 min. The mean quality scores of EEG1 and EEG2 were 6.4 [range, 1 (low) to 10 (high); both medians 7.0]. A total of 44 (29.5%) participants had epileptiform discharges (EDs) at EEG1 and 25 (16.8%) had EDs at EEG2. EDs were focal/multifocal (rather than generalized) in 70.1% of EEG1 and 72.5% of EEG2 interpretations. A total of 39 (26.2%) were recommended for neuroimaging after EEG1 and 22 (14.8%) after EEG2. Of participants without EDs at EEG1 (n = 53, 55.8%), seven (13.2%) had EDs at EEG2. Of participants with detectable EDs on EEG1 (n = 23, 24.2%), 12 (52.1%) did not have EDs at EEG2. CONCLUSIONS: Tablet-based EEG had a reproducible quality level on repeat testing and was useful for the detection of EDs. The incremental yield of a second EEG in this setting was ~13%. The need for neuroimaging access was evident.

[Patients' perceptions of and attitudes towards epilepsy surgery: mistaken concepts in Colombia]. / Percepciones y actitudes de los pacientes frente a la cirugia de la epilepsia: conceptos equivocados en Colombia.

INTRODUCTION: Selected patients with drug-resistant focal epilepsy benefit from epilepsy surgery, however significant delays remain. The aim of this study was to assess knowledge and attitudes toward epilepsy surgery among patients with epilepsy and identify barriers that might delay the treatment. PATIENTS AND METHODS: A 10-minute questionnaire was administered to patients with epilepsy in Colombia. Survey assessed the following: knowledge of surgical options, perceptions about the risks of surgery vs. ongoing seizures, disease disability, treatment goals, and demographic and socioeconomic variables. RESULTS: We recruited 88 patients with focal epilepsy. More than half of patients (56%) were not aware that surgery might be an option. Apprehension about epilepsy surgery was evident, 60% of patients perceived epilepsy surgery to be very or moderately dangerous. A large proportion of patients believe death (41%), stroke (47%), vision loss (56%), personality change (56%), paralysis (62%), difficulties in speaking (69%), and memory loss (60%) were frequent side effects. The majority of patients (62%) consider the surgical procedure as the last option of treatment. CONCLUSIONS: There is a negative attitude toward epilepsy surgery based on the patients' misperceptions of suffering neurological deficits during the surgery, reflecting lack of knowledge toward this type of treatment. These perceptions can contribute to delays in surgical care.

TITLE: Percepciones y actitudes de los pacientes frente a la cirugia de la epilepsia: conceptos equivocados en Colombia.Introduccion. Los pacientes con epilepsia focal farmacorresistente se podrian beneficiar de la cirugia de la epilepsia; sin embargo, existen demoras en la realizacion del procedimiento. El objetivo de este estudio fue evaluar el conocimiento y las actitudes de los pacientes hacia la cirugia de epilepsia e identificar barreras que pudieran retrasar el tratamiento. Pacientes y metodos. Se aplico un cuestionario de 10 minutos a pacientes con epilepsia en Colombia. La encuesta evaluo el conocimiento de la opcion quirurgica, las percepciones sobre el riesgo de la cirugia frente al riesgo de crisis no controladas, la discapacidad producida por la enfermedad, las metas del tratamiento y las variables demograficas y socioeconomicas. Resultados. Se seleccionaron 88 pacientes con epilepsia focal. El 56% de los pacientes no sabia que la cirugia podria ser una opcion terapeutica. El 60% considero que la cirugia de la epilepsia es muy o moderadamente peligrosa. Una gran proporcion pensaba que la muerte (41%), el ictus (47%), la perdida visual (56%), los cambios en la personalidad (56%), la paralisis (61%), las dificultades para hablar (69%) y la perdida de la memoria (60%) eran efectos secundarios comunes. La mayoria (62%) consideraba el procedimiento como la ultima opcion de tratamiento. Conclusiones. Existe una actitud negativa por parte de los pacientes frente a la cirugia de la epilepsia fundamentada en la sobreestimacion del riesgo de adquirir deficits neurologicos secundarios al procedimiento, lo que refleja la falta de conocimiento hacia este tratamiento. Estas percepciones erroneas pueden contribuir a demoras en la atencion quirurgica.

[Barriers impeding access to epilepsy surgery: a review of the literature]. / Barreras de acceso a la cirugia de la epilepsia: revision de la bibliografia.

Drug-resistant epilepsy, a chronic condition with long-term consequences can be treated with surgery. The efficacy and safety of surgery for temporal lobe epilepsy have been established through a large number of retrospective and prospective cohort studies and two randomized controlled clinical trials. Despite the excellent outcomes reported after surgery, the literature suggests that this procedure is an underutilized treatment. While evidence is lacking as to why epilepsy surgery is underused, cited reasons include: failure of primary care physicians and neurologists to provide information and identify patients who could be referred for surgery; different levels of technology at various centers, resulting in different candidate selection strategies; the belief that epilepsy surgery is a risky procedure and that it should be only viewed as the last option; patient preference to avoid surgery; parents wanting to wait until their child is old enough to participate in the decision-making process regarding surgery; unwillingness of insurers to cover the expenses associated with presurgical evaluations or lack of insurance; racial and social disparities, among others. In this paper we review the available epidemiological data about lack of utilization of epilepsy surgery.

TITLE: Barreras de acceso a la cirugia de la epilepsia: revision de la bibliografia.La epilepsia farmacorresistente es una condicion cronica con consecuencias a largo plazo que puede ser tratada quirurgicamente. La eficacia y la seguridad de la cirugia de la epilepsia del lobulo temporal se han establecido a traves de un gran numero de estudios de cohorte retrospectivos y prospectivos y dos ensayos clinicos controlados aleatorizados. A pesar de los excelentes resultados comunicados con la cirugia, la bibliografia sugiere que este procedimiento es un tratamiento subutilizado. Aunque no existe evidencia de esto, entre algunos de los motivos descritos se apuntan el fallo de los medicos de atencion primaria y los neurologos en proveer informacion, identificar y remitir a los pacientes a un centro de cirugia; los diferentes niveles de tecnologia en los centros, lo que provoca distintas estrategias de seleccion de los candidatos; la creencia de que la cirugia de la epilepsia es un procedimiento arriesgado que deberia contemplarse solo como ultima opcion; la preferencia del paciente por evitar la cirugia; el deseo de los padres de esperar hasta que sus hijos sean lo suficientemente mayores para participar en el proceso de toma de decisiones; el hecho de que las aseguradoras no cubran los gastos asociados con las evaluaciones prequirurgicas o la carencia de un seguro medico, y la desigualdad racial y social, entre otros. En este articulo se revisan los datos epidemiologicos disponibles en relacion con la falta de acceso a la cirugia de la epilepsia.

[Diagnosis and treatment of non-triggered single epileptic seizures]. / Diagnostico y tratamiento de la crisis epileptica unica no provocada.

Epileptic seizures are one of the main reasons for neurological visits in an emergency department. Convulsions represent a traumatic event for the patient and the family, with significant medical and social consequences. Due to their prevalence and impact, the initial management is of vital importance. Although following the first epileptic seizure, early recurrence diminishes after establishing treatment with antiepileptic drugs, the forecast for developing epilepsy and long-term outcomes are not altered by any early intervention. Detailed questioning based on the symptoms of the convulsions, the patient's medical history and a full electroencephalogram and neuroimaging study make it possible to define the risk of recurrence of the seizure and the possible diagnosis of epilepsy. Epileptic abnormalities, the presence of old or new potentially epileptogenic brain lesions, as well as nocturnal seizures, increase the risk of recurrence. Physicians must assess each patient on an individual basis to determine the most suitable treatment, and explain the risk of not being treated versus the risk that exists if treatment with antiepileptic drugs is established.

TITLE: Diagnostico y tratamiento de la crisis epileptica unica no provocada.Las crisis epilepticas son una de las principales causas de consulta neurologica en el servicio de urgencias. Un episodio convulsivo representa un evento traumatico para el paciente y la familia, con consecuencias medicas y sociales significativas. Por su prevalencia e impacto, el abordaje inicial es de vital importancia. Si bien despues de una primera crisis epileptica la recurrencia temprana disminuye con el inicio de farmacos antiepilepticos, el pronostico para el desarrollo de epilepsia y los desenlaces a largo plazo no se alteran por ninguna intervencion temprana. El interrogatorio detallado basado en la semiologia del episodio, los antecedentes del paciente y un estudio completo con electroencefalograma y neuroimagen permiten definir el riesgo de recurrencia de la crisis y el posible diagnostico de epilepsia. Las anormalidades epilepticas, la presencia de lesiones cerebrales con potencial epileptogeno antiguas o nuevas, asi como las crisis nocturnas, incrementan el riesgo de recurrencia. Los medicos deben evaluar a cada paciente de manera individual para determinar un tratamiento idoneo, explicando el riesgo de no tratar frente al riesgo existente con el inicio de farmacos antiepilepticos.

The relevance of neuropsychiatric symptoms and cognitive problems in new-onset epilepsy - Current knowledge and understanding.

Neurobehavioral and cognition problems are highly prevalent in epilepsy, but most research studies to date have not adequately addressed the precise nature of the relationship between these comorbidities and seizures. To address this complex issue and to facilitate collaborative, innovative research in the rising field of neurobehavioral comorbidities and cognition disturbances in new-onset epilepsy, international epilepsy experts met at the 3rd Halifax International Epilepsy Conference & Retreat at White Point, South Shore, Nova Scotia, Canada from September 18 to 20, 2014. This Conference Proceedings provides a summary of the conference proceedings. Specifically, the following topics are discussed: (i) role of comorbidities in epilepsy diagnosis and management, (ii) role of antiepileptic medications in understanding the relationship between epilepsy and neurobehavioral and cognition problems, and (iii) animal data and diagnostic approaches. Evidence to date, though limited, strongly suggests a bidirectional relationship between epilepsy and cognitive and psychiatric comorbidities. In fact, it is likely that seizures and neurobehavioral problems represent different symptoms of a common etiology or network-wide disturbance. As a reflection of this shared network, psychiatric comorbidities and/or cognition problems may actually precede the seizure occurrence and likely get often missed if not screened.

Adult-onset epilepsy associated with dysembryoplastic neuroepithelial tumors.

RATIONALE: Dysembryoplastic neuroepithelial tumors (DNET) are benign, localized lesions that typically cause localization-related epilepsy of childhood onset. Although excellent seizure outcomes are expected following surgical resection of focal, benign lesions, reports in pediatric epilepsy series suggest that this may not be the case with DNETs, which may exhibit complex and often multifocal epileptogenesis. We report the characteristics and surgical outcome of an adult- and childhood-onset cohort with this condition. METHODS: Retrospective cohort of 23 patients seen at two major epilepsy centers, with localization-related epilepsy associated with histopathologically demonstrated DNETs. We assessed clinical, electrographic and surgical outcome features in patients with adult- and childhood-onset epilepsy. We were particularly interested in the level of congruence of EEG and MRI data and the need for intracranial recordings. We evaluated seizure outcomes at last follow-up. RESULTS: The mean age was 33.3 years (range: 5-56 years). Ten patients had adult-onset epilepsy. Thirteen patients (57%) had simple partial, 21 (91%) had complex partial, 16 (70%) had secondarily generalized seizures and 5 patients had only simple partial seizures. Status epilepticus did not occur. Non-enhancing lesions on MRI were located in the temporal lobe in 17 patients, the frontal lobe in 3 patients and the parietal/occipital region in 2 patients. One patient had a DNET that involved both frontal and temporal areas. Ictal scalp EEG and MRI were congruent in 17 patients (74%). Eleven patients (48%) underwent lesionectomies, while the rest required some resection of extralesional cortex as well. Five patients required intracranial EEG. There was no association with cortical dysplasia. Seventeen patients (74%) had an Engel class 1 outcome, in a follow-up period that ranging from 5 to 98 months. CONCLUSIONS: We found no difference in outcomes between adult- and childhood-onset cases. Although epileptogenicity was complex, congruence between electro-clinical and neuroimaging studies was high and allowed good surgical outcomes at 1 year of follow-up.

Personality in patients with migraine evaluated with the "Temperament and Character Inventory".

The objective of this study was to assess the personality profile of a sample of Mexican patients with migraine using the Temperament and Character Inventory (TCI). A cross-sectional study was performed including adult migraine patients identified from the outpatient neurology clinics of two large teaching hospitals in Mexico City. Patients were asked to voluntarily participate in the study. A physician conducted a standardised diagnostic interview adhering to the criteria of the International Headache Society (IHS). Patients were interviewed and administered the TCI. We used two healthy controls groups and a third group of non-migraine pain controls. One hundred and fortytwo subjects with migraine, 108 healthy blood donors, 269 young healthy controls and 30 patients with non-migraine pain (NMP) were included in the study. Patients with migraine had higher scores in the dimension harm avoidance (HA) and all its sub-dimensions (p<0.05) than healthy patients. Patients with non-migraine pain had high scores in HA and low scores in novelty seeking, self-directedness and cooperativeness. Blood donors had high scores in the following subdimensions: HA1, HA4 and C3 (Cooperativeness). Personality features consistent with migraine are avoidance, rigidity, reserve and obsessivity. Our study shows that patients with chronic pain share some of the personality features of patients with migraine but their TCI profile could be indicative of cluster C avoidant personality. Blood donors were shown to have more energy, with a tendency to help other people and be more optimistic. The results support serotoninergic involvement as explaining the physiopathology of migraine.

Hippocampal electrical stimulation in mesial temporal lobe epilepsy.

BACKGROUND: Adjustable, reversible therapies are needed for patients with pharmacoresistant epilepsy. Electrical stimulation of the hippocampus has been proposed as a possible treatment for mesial temporal lobe epilepsy (MTLE). METHODS: Four patients with refractory MTLE whose risk to memory contraindicated temporal lobe resection underwent implantation of a chronic stimulating depth electrode along the axis of the left hippocampus. The authors used continuous, subthreshold electrical stimulation (90 microsec, 190 Hz) and a double blind, multiple cross-over, randomized controlled design, consisting of three treatment pairs, each containing two 1-month treatment periods. During each treatment pair the stimulator was randomly turned ON 1 month and OFF 1 month. Outcomes were assessed at monthly intervals in a double blind manner, using standardized instruments and accounting for a washout period. The authors compared outcomes between ON, OFF, and baseline periods. RESULTS: Hippocampal stimulation produced a median reduction in seizures of 15%. All but one patient's seizures improved; however, the results did not reach significance. Effects seemed to carry over into the OFF period, and an implantation effect cannot be ruled out. The authors found no significant differences in other outcomes. There were no adverse effects. One patient has been treated for 4 years and continues to experience substantial long-term seizure improvement. CONCLUSION: The authors demonstrate important beneficial trends, some long-term benefits, and absence of adverse effects of hippocampal electrical stimulation in mesial temporal lobe epilepsy. However, the effect sizes observed were smaller than those reported in non-randomized, unblinded studies.

Associated conditions in myasthenia gravis: response to thymectomy.

To compare the response of thymectomy in patients with associated conditions (PWAC) and without associated conditions (PWOAC). Comparative, retrospective. 198 patients with the established diagnosis of myasthenia gravis who had a thymectomy between 1987 and 2000, and who were folowed up for at least 3 years. We formed two groups, one with associated conditions and the second without associated conditions. The patients were divided into four groups: (i) patients in remission, (ii) patients with improvement, (iii) patients without changes, and (iv) patients whose condition worsened. Associated conditions (AC) were found in 49 patients (26%). The main associated conditions were hyperthyroidism in 16 patients (33%) hypothyroidism in seven (14%), rheumatoid arthritis in five (10%) and hypothyroidism and Sjogren syndrome in three (6%). Concerning the response of thymectomy, 13 patients WAC showed remission (27%), vs. 54 patients WOAC (39%). Twenty patients WAC showed improvement (41%) vs. 46 WOAC (33%). Thirteen patients WAC had no changes (27%) vs. 37 WOAC (26%). Finally, in three patients WAC their condition worsened (6%) vs. three WOAC (2%). The response to thymectomy was high (69%) in both groups. We did not identify significant differences.

Prevalence and factors associated with headache in patients with systemic lupus erythematosus.

Headache is common in systemic lupus erythematosus with reported prevalence as high as 70%. The aims of this study were: to estimate the prevalence and types of headache in a sample of patients with systemic lupus erythematosus comparing it with rheumatoid arthritis, to determine clinical and serological associations. Eighty-one systemic lupus erythematosus and 29 rheumatoid arthritis consecutive patients seen in our outpatient clinic were interviewed. Headache was evaluated using the diagnostic criteria proposed by the International Headache Society. Additional evaluations were carried out in the 81 systemic lupus erythematosus patients including depression, disease activity, lupus damage, function disability, quality of life, and severity degree using a validated scales. We analysed the following autoantibodies: anti-double stranded DNA, anti-nucleosomes, anti-histones, anti-ribosomal P, anti-cardiolipin antibodies, anti-beta2-glycoprotein-I (GPI), and antinuclear antibodies. Forty-one per cent of systemic lupus erythematosus and 17% of rheumatoid arthritis patients suffered from headache (P = 0.02). No significant difference for any primary headache type between the two groups was found. Frequency of headache types in systemic lupus erythematosus patients was: migraine 24%, tensional-type headache 11%, and mixed headache 5%. In systemic lupus erythematosus patients the risk factors associated with headaches were Raynaud's phenomenon (OR 3.6; 95% CI 1.3-9.5; P = 0.009) and beta2GPI antibody positivity (OR 4.5; 95% CI 1.2-16.2; p = 0.016). We conclude that headache is more common in systemic lupus erythematosus than in rheumatoid arthritis patients and was independently associated with Raynaud's phenomenon and beta2GP-I antibodies.

[Painful neuropathies: their pathophysiology and treatment]. / Neuropatías dolorosas: fisiopatología y tratamiento.

OBJECTIVES: The purpose of this study is to review the different studies published in the literature concerning the different physiological mechanisms involved in the genesis of painful neuropathy, as well as the diagnostic options and the different pharmacological treatments currently available. DEVELOPMENT: Distinct pathologies usually condition painful neuropathy, one of the main ones being diabetes mellitus. The triggering phenomenon is often some kind of damage to the tissues that contain nervous pain receptors, which later gives rise to a release of proinflammatory molecules, and triggers a cascade of phenomena that result in disorders in the central and peripheral nervous system (peripheral and central sensitisation). These disorders usually produce clinical manifestations, such as allodynia, paresthesias, among others, and these are sometimes the sole manifestation of painful neuropathy. Diagnosis of this syndrome is at times complicated due to the involvement of thin fibres, which cannot be identified by the conventional methods used in neurophysiological studies. There is also a broad range of pharmaceuticals used in the treatment of painful neuropathy that range from tricyclic antidepressants, non-steroidal anti-inflammatory drugs, opioid analgesics, antiarrhythmics and even agents for topical use. CONCLUSIONS: Diagnosis of thin fibre neuropathy is usually performed by carrying out a Quantitative Sudomotor Axon Reflex Test, quantitative sensory tests and a skin biopsy. As regards the pharmacological treatment, the new generation of anticonvulsive drugs like gabapentin seems to have advantages over the traditional pharmaceuticals, although their widespread use is still largely restricted by their cost.

Response of thymectomy: clinical and pathological characteristics among seronegative and seropositive myasthenia gravis patients.

OBJECTIVE: To identify the response to thymectomy in patients with seronegative and seropositive myasthenia gravis (SPMG). We analyzed the associated diseases, thymus histology, and the severity of symptoms between the two groups. MATERIAL AND METHODS - DESIGN: Descriptive, comparative. STUDY UNITS: Fourteen patients with seronegative myasthenia gravis (SNMG) and 57 patients with SPMG who had a thymectomy between 1987 and 1997, with at least 3 years of follow-up. The patients were divided into four groups; (1) Remission, (2) Improvement, (3) No change and (4) Deterioration. RESULTS: Fourteen patients (20%) were seronegative and 57 were seropositive (80%). In the group of patients with SNMG, three patients were in remission (21%), five with improvement (36%), five with no change (36%) and one with worsening (7%). In the group of patients with SPMG, 12 were in remission (21%), 17 with improvement (30%), 25 with no change (44%) and three (5%) with worsening. The patients with SNMG were older, with less associated diseases and with a lower frequency of thymomas. CONCLUSIONS: The response to thymectomy was similar between the two groups. It has been suggested that seronegative patients have a better prognosis, but our results show no differences.

HLA class II genotypes in Mexican Mestizo patients with myasthenia gravis.

Myasthenia gravis is an autoimmune, heterogeneous disorder, characterized by the presence of antibodies against acetylcholine receptors at the neuromuscular junction. There is a strong evidence that an individual's genetic composition is an important predisposing factor for the development of the disease. To correlate HLA class II genotypes with thymic pathology in Mexican Mestizo patients who had been subjected to thymectomy. HLA class II genes were analyzed in 60 patients and in 99 healthy ethnically matched controls. Thymic hyperplasia, atrophy, thymoma, and normal histology were encountered in 56, 33, 8 and 2% of patients, respectively. HLA-DR11 was significantly increased in patients with thymoma compared with healthy controls (pC = 0.001, OR = 13.35, 95% CI 3.5-51.3), compared with the subgroup of hyperplasia patients (pC = 0.005, OR = 15.5, 95% CI 2.78-95.58) and with the atrophy subgroup (pC = 0.04, OR = 10.5, 95% CI 1.75-70.95). This study provides the evidence of an association between HLA class II alleles with clinical and genetic heterogeneity in myasthenia gravis, particularly in those with thymoma (HLA-DR11).

[Effect of the graded muscle contraction on the H reflex and long latency reflexes of the thenar and hypothenar muscles to a fixed threshold stimulus]. / Efecto de la contracción muscular graduada en el reflejo H y en los reflejos de larga latencia de los músculos tenares e hipotenares a un estímulo umbral fijo.

INTRODUCTION: To determine the percentage of appearance of the H reflex and long latency reflexes (LLRs) in the thenar and hypothenar muscles of normal subjects to a fixed threshold mixed nerve electrical stimulus and variable degrees of muscle contraction. METHODS: Fifteen subjects aged 21 to 32 years of age without any prior history of central or peripheral neurological diseases volunteered for the study. The stimulation was a constant currrent given at the wrist with the cathode positioned proximally; started at 1 mA and it was gradually increased mA by mA until the M response appeared with the subject relaxed. The intensity of the stimulation was thereafter kept constant. The contraction was an abducting movement of the thumb in the case of the thenar muscle and abduction of the digiti minimi in the case of the hypothenar muscle and was sustained throughout the study. The reflexes were elicited with a repetition rate of 3 Hz, the stimulus was a square pulse of 0.5 ms. We used a low frequency pass filter of 10 Hz and a high frequency pass filter of 10 kHz. The sweep speed was set a 10 ms per division. The responses were averaged 200 times and then smoothed. RESULTS: The mean intensity of the stimulus that evoked the H response, for all subjects, was 7.5 2.8 mA. The mean latency of the H reflex elicited with stimulation of the median nerve was 26 ms 2.03 ms (std. error 0.28, maximum 28.2, minimum 22.0). The mean latency of the H reflex elicited with stimulation of the ulnar nerve was 25.1 ms 1.64 ms (std. error 0.230, maximum 28, minimum 22.3). The difference between the percentage of responses attained under a relaxed condition and with any kind of muscle contraction was highly significant statistically using the Chi square method (p < 0.001). When we compared the percentage of the H responses obtained with slight, moderate, strong contraction, and contraction against resistance, between them, we did no find a significant difference. The LLRs appeared only in the trials with strong contraction. CONCLUSIONS: The H reflexes and the LLRs of the thenar and hypothenar muscle were not obtained with threshold stimulation when these muscles were relaxed. With any degree of muscle contraction the H reflex in these muscles could be obtained in 94 percent of the trials. Maximal contraction and contraction against resistance were the best conditions to elicit long latency responses.

Efecto de la contracción muscular graduadaen el reflejo H y en los reflejos de larga latenciade los músculos tenares e hipotenares a unestímulo umbral fijo / Effect of graded muscle contraction on the H reflex and long latency reflexes of the thenar and hypothenar muscles to a fixed threshold stimulus

Introducción: Determinar el porcentaje de aparición del reflejo H y de los reflejos de larga latencia (RLL) en los músculos tenares e hipotenares de sujetos sanos a un estímulo fijo a un nervio mixto con contracción muscular variable.Métodos: Quince sujetos con edades entre 21 y 32 años sin historia previa de enfermedad del sistema nervioso central periférico se ofrecieron voluntarios para el estudio. El estímulo fue dado en la muñeca con un estimulador de corriente constante con el cátodo posicionado proximalmente. El estímulo se inició a 1 mA y fue gradualmente incrementado mA por mA hasta que la respuesta M apareciese con el sujeto relajado. La intensidad del estímulo se mantuvo después constante a través del estudio. La contracción fue un movimiento isométrico de abducción del pulgar y del quinto dedo y fue mantenida constante durante la estimulación. Las respuestas fueron promediadas 200 veces y alisadas.Resultados: La intensidad promedio del estímulo que evocó el reflejo H en todos los sujetos fue 7,5 ñ 2,9 mA. La latencia promedio del reflejo H del nervio mediano fue 26 ñ 2,03 ms (EE 0.28, máximo 28,2, mínimo 22,0 ms). La latencia promedio del reflejo H estimulando el nervio cubital fue 25,1 ñ 1,64 ms (EE 0,230, máximo 28, mínimo 22,3 ms). Las diferencias en latencia entre estos dos nervios no fue significativa. La latencia no cambió con las diferentes intensidades de la contracción muscular. Con el músculo relajado se obtuvo el reflejo en 6 de las pruebas (6/60, 10 por ciento). En 227 de las 240 pruebas con contracción muscular de cualquier intensidad se obtuvo la respuesta (227/240, 94,5 por ciento). La diferencia fue altamente significativa (p < 0,001). Las respuestas de latencia larga sólo aparecieron con la contracción máxima o máxima contra resistencia.Conclusiones: Los reflejos H y los reflejos de larga latencia de los músculos tenares e hipotenares no fueron obtenidos con los músculos relajados. Con cualquier grado de contracción muscular estos reflejos fueron obtenidos en el 94 por ciento de las pruebas. La contracción muscular máxima y la contracción muscular contra resistencia fueron las condiciones óptimas para obtener las respuestas de larga latencia (AU)

[Hemorrhagic stroke associated to neurocysticercosis]. / Accidente cerebrovascular hemorrágico asociado a neurocisticercosis.

A well-known complication of neurocysticercosis is cerebral arteritis, which is usually manifested by cerebral ischemia. Only anecdotal cases of hemorrhagic stroke associated to this parasitosis have been described. Previously there are only two reported cases of this association. One of these cases had an intracystic hemorrhage confirmed by autopsy without cerebrovascular risk factors. Autopsy revealed an inflammatory arteriopathy adjacent to the cyst intracystic hemorrhage. The second case had a subarachnoidal hemorrhage secondary to the rupture of an aneurysm in the right anteroinferior cerebellar artery. At surgery, the aneurysm was found to be surrounded by a thickened-leptomeninges, which histologically showed the presence of cysticercous with dense inflammation. Our first patient was a 32 year-old female developed a lenticulo-capsular hemorrhage around a cysticercotic lesion. The second patient was a 34 year-old male developed an intracystic hemorrhage. As cerebral angiography was normal in both patients, cerebral hemorrhages were considered to be related to cysticercotic arteritis of small penetrating vessels. We conclude that cysticercosis is associated with differenttypes of intracranial hemorrhage, as documented the present cases. In neurocysticercosis endemic areas, cysticercotic arteritis should be added to the list of causes of intracranial hemorrhage in young people.

The association of myasthenia gravis and connective tissue diseases. Effects of thymectomy in six cases with rheumatoid arthritis and one case with systemic lupus erythematosus.

OBJECTIVES: To describe the effects of thymectomy in a group of patients with myasthenia gravis (MG) with associated connective tissue diseases (CTD). PATIENTS AND METHODS: We analyzed six patients with CTD and myasthenia. They were followed-up for at least 3 years. RESULTS: Records of a cohort of 132 patients with established diagnosis of MG undergoing thymectomy in our institution between 1987-1999 were reviewed. The percentage of patients with CTD was 5 % (6/132). Five patients had rheumatoid arthritis (RA) and one patient systemic lupus erythematosus (SLE). All patients were women, and the mean age was 38.5 years old (SD 13.7). Mean time of MG diagnosis to operation was 16 months (range from 1 to 144 months). Preoperative Osserman classification was the following: stage IIb, four patients; stage III, one patient; and stage IV, one patient. Before surgery all patients were on anticholinesterase agent (pyridostigmine), and four patients were on corticosteroids. An extended transsternal thymectomy was practiced on five patients and a transcervical thymectomy was performed in the remaining patient. Pathologic findings were as follows: thymic hyperplasia in four patients and thymic atrophy in the other two. Good response (remission or improvement) was present in three patients (50 %) and poor response (no change or worse) in the other three (50 %). CONCLUSIONS: A low response to the thymectomy is observed in patients with MG and associated CTD (RA and an SLE).