ABSTRACT BACKGROUND AND OBJECTIVES: Conventional electrodiagnostic studies (EDX) are frequently used to support the diagnosis of peripheral neuropathic pain. However, routine EDX has poor diagnostic yield for identifying small fiber neuropathy, which may be cause of neuropathic pain in some patients. This study aimed to assess the gain in diagnostic yield brought by adding pain-related evoked potentials with concentric electrode (CN-PREP) and nociceptive withdrawal reflex (NWR) assessments to EDX. METHODS: Transversal observational accuracy study which included patients referred to routine EDX in a tertiary-care hospital who reported chronic neuropathic pain in their lower limbs. Besides routine EDX, subjects underwent CN-PREP and NWR assessments. Diagnostic yield and tolerability were examined and compared between test studies. RESULTS: The study enrolled 100 patients (54% female), with 57 ± 12 years. EDX was altered in 47% of all patients. The addition of CN-PREP alone, and NWR combined with CN-PREP increased diagnostic yield to 69% and 72%, respectively. CN-PREP proved to be well tolerable, while NWR was associated with higher test-related pain intensity and discontinuation rate (9% vs. 0%). Considering EDX as the reference test, CN-PREP sensitivity was 85.1% and specificity 58.5%. CONCLUSION: Combining CN-PREP with the routine EDX for patients with neuropathic pain is feasible and results in increased diagnostic yield. Conversely, the addition of NWR to the aforementioned tests provides little improvement to this yield and is less tolerable to the patient. Further studies are needed to determine the actual sensitivity and specificity of CN-PREP when compared to the gold-standard for small fiber neuropathy diagnosis, i.e. intraepidermal nerve fiber density assessment. OBJECTIVES (EDX However painrelated related CNPREP CN PREP (CN-PREP (NWR METHODS tertiarycare tertiary care limbs RESULTS 10 54% 54 (54 female, female , female) 5 1 years 47 alone 69 72 72% respectively testrelated 9% 9 (9 vs 0%. 0 0% . 0%) 851 85 85.1 585 58 58.5% CONCLUSION Conversely patient goldstandard gold standard ie i e i.e assessment (5 4 6 7 ( 8 85. 58.5 58.

RESUMO JUSTIFICATIVA E OBJETIVOS: Estudos convencionais de eletrodiagnóstico (EDX) são frequentemente usados para apoiar o diagnóstico de dor neuropática periférica. No entanto, o EDX de rotina tem baixo rendimento diagnóstico para identificar neuropatia de pequenas fibras. O objetivo deste estudo foi avaliar o ganho no rendimento diagnóstico pela adição de avaliações de potenciais evocados relacionados à dor com eletrodo concêntrico (CN-PREP) e reflexo de retirada nociceptiva (NWR) ao EDX. MÉTODOS: Estudo de precisão observacional transversal que incluiu pacientes encaminhados para EDX de rotina com dor neuropática crônica em membros inferiores. Além do EDX de rotina, os indivíduos foram submetidos às avaliações CN-PREP e NWR. O rendimento diagnóstico e a tolerabilidade foram examinados e comparados entre os estudos de teste. RESULTADOS: O estudo envolveu 100 pacientes (54% mulheres), com 57 ± 12 anos. O EDX estava alterado em 47%. A adição de CN-PREP sozinho e NWR combinado com CN-PREP aumentou o rendimento diagnóstico para 69% e 72%, respectivamente. O CN-PREP provou ser bem tolerável, enquanto o NWR foi associado a maior intensidade de dor relacionada ao teste e taxa de descontinuação (9% vs. 0%). Considerando o EDX como teste de referência, a sensibilidade do CN-PREP foi de 85,1% e a especificidade de 58,5%. CONCLUSÃO: A combinação do CN-PREP com o EDX de rotina para pacientes com dor neuropática é viável e resulta em maior rendimento diagnóstico. Já a adição de NWR aos testes mencionados fornece pouca melhora nesse rendimento e é menos tolerável para o paciente. Mais estudos são necessários para determinar a real sensibilidade e especificidade do CN-PREP quando comparado ao padrão-ouro para diagnóstico de neuropatia de pequenas fibras, ou seja, a avaliação da densidade de fibras nervosas intraepidérmicas. OBJETIVOS (EDX periférica entanto CNPREP CN PREP (CN-PREP (NWR MÉTODOS inferiores RESULTADOS 10 54% 54 (54 mulheres, mulheres , mulheres) 5 1 anos 47 47% 69 72 72% respectivamente 9% 9 (9 vs 0%. 0 0% . 0%) referência 851 85 85,1 585 58 58,5% CONCLUSÃO paciente padrãoouro padrão ouro seja intraepidérmicas (5 4 6 7 ( 8 85, 58,5 58,

Abstract Background and objective. Brachial plexus injuries are devastating lesions for the patient and their environment, with great functional loss. They require multidisciplinary management, complete clinical evaluation and complementary neurophysiological studies, imaging studies or both. In recent decades, the use of intraoperative neuromonitoring has been proposed as a useful tool for brachial plexus surgery, and helps to individualize decision-making in primary reconstruction of brachial plexus injuries. We describe the experience using different modalities of intraoperative neuromonitoring in patients with brachial plexus injuries in Hospital Universitario San José y Hospital Universitario San José Infantil de Bogotá, Colombia. Methods. Retrospective case series, conducted using electronic medical data from Hand Surgery and Microsurgery services, videos and preoperative images taken by the surgeon, and findings described in the report of intraoperative neurophysiological monitoring, of patients with brachial plexus injuries operated in the study period. Results. Fourteen patients underwent brachial plexus reconstruction using intraoperative neuromonitoring during the study period: 11 male (78%) and 3 female (22%); 9 (65%) right upper extremity injuries and 5 (35%) left. Age ranged from 19 to 62 years old (average of 33 years). Main etiology was motorcyclist accident. Direct electrical stimulation and stimulated electromyography were used in all patients. Somatosensory evoked potentials were measured in 9 (64%) patients, and transcranial motor evoked potentials were measured in 8 (57%) patients. Conclusions. In brachial plexus injuries, intraoperative electrophysiological studies allow better classification of nerve injuries and provide an optimal individualized surgical management, without increasing operative time.

Resumen Introducción y objetivo. Introducción y objetivo. Las lesiones del plexo braquial tienen alto impacto en la persona y su entorno, con gran pérdida funcional. Estos pacientes requieren un manejo multidisciplinario, evaluación clínica completa, que se complementa con estudios de neurofisiología, imagenología o ambos. En las últimas décadas se han logrado avances en el tratamiento quirúrgico del plexo braquial, se ha propuesto el uso del neumoronitoreo intraoperatorio (NMIO) como herramienta útil en la exploración y toma de decisiones individualizadas en su reconstrucción primaria. Nuestro objetivo es describir la experiencia del uso de diferentes modalidades de NMIO en pacientes adultos con lesiones del plexo braquial en el Hospital Universitario San José y Hospital Universitario San José Infantil de Bogotá, Colombia. Material y método. Serie de casos, revisión de los registros del Servicio de Cirugía de la Mano y Microcirugía, videos e imágenes preoperatorias tomados por el cirujano, y hallazgos descritos en el informe del NMIO de pacientes adultos con lesiones de plexo braquial operados en el periodo de estudio. Resultados. Catorce pacientes sometidos a reconstrucción de plexo braquial con NMIO durante el periodo de estudio: 11 hombres (78%) y 3 mujeres (22%); lateralidad derecha 9 (65%) e izquierda 5 (35%). Rango de edad de 19 a los 62 años (media 33 años). La principal etiología fue accidente de tránsito (motocicleta). Respecto a las modalidades usadas, en todos los pacientes se utilizó estimulación eléctrica directa y electromiografía estimulada; en 9 pacientes (64%) se midió potenciales evocados somatosensoriales y en 8 (57%) se midió potenciales evocados motores transcraneales. Conclusiones. En las lesiones del plexo braquial, los estudios electrofisiológicos en el intraoperatorio permiten clasificar el estado de los nervios afectados y definir el mejor procedimiento quirúrgico reconstructivo, sin un aumento en el tiempo operatorio.

RESUMO Em 1951 o fisiologista George Duncan Dawson apresentou seu trabalho com a promediação de sinal nos potenciais evocados, abrindo uma nova etapa no desenvolvimento da neurofisiologia clínica. Os autores apresentam aspectos da biografia do professor Dawson e uma revisão de seus trabalhos sobre os potenciais evocados, principalmente do artigo que mostrava a nova técnica, que viria a permitir o crescimento da aplicação clínica dos potenciais evocados visual, auditivo e somatossensitivo.

ABSTRACT In 1951, the physiologist George Duncan Dawson presented his work with the averaging of the signal in the evoked potentials (EPs), opening a new stage in the development of clinical neurophysiology. The authors present aspects of Professor Dawson’s biography and a review of his work on the EPs and, mainly, the article reveals the new technique in detail that would allow the growth of the clinical application of the visual, auditory, and somatosensory EPs.

Resumo Os autores apresentam uma revisão do uso atual do potencial evocado somatossensitivo (PESS) na prática neurológica como uma técnica neurofisiológica não invasiva. Revisamos artigos publicados em Inglês ou Português nas bases de dados PubMed e LILACS. Nesta revisão abordamos o papel do PESS nas doenças neurológicas que atingem o sistema nervoso central e o sistema nervoso periférico, especialmente, nas doenças desmielinizantes, no monitoramento do coma, do trauma e da função das vias sensitivas durante os procedimentos cirúrgicos, que se tornou uma de suas aplicações mais importantes, assim como novas áreas de pesquisa.

Abstract The authors present a review of the current use of somatosensory evoked potentials (SSEPs) in neurological practice as a non-invasive neurophysiological technique. For this purpose we have reviewed articles published in English or Portuguese in the PubMed and LILACS databases. In this review, we address the role of SSEPs in neurological diseases that affect the central nervous system and the peripheral nervous system, especially in demyelinating diseases, for monitoring coma, trauma and the functioning of sensory pathways during surgical procedures. The latter, along with new areas of research, has become one of the most important applications of SSEPs.

Abstract Anterior cutaneous nerve entrapment syndrome (ACNES) is often overlooked in the differential diagnosis of chronic abdominal pain (CAP). An 11-year-old boy with CAP previously studied in emergency and digestive services without detecting organic pathology, suggesting a psychosomatic origin. On examination, he showed pain in the abdominal wall located to the area of the terminal branch of the T11 intercostal nerve, with a positive Carnett's sign and a favorable response to injection with local anesthetic at the trigger point. Somatosensory evoked potentials revealed right anterior rectus nerve neuropathy. He was diagnosed with ACNES. As treatment, an ultrasound-guided subfascial injection with lidocaine and dexamethasone into the trigger point was administered. After four months, he remains asymptomatic. For the treatment of ACNES in pediatrics patients, a step-up strategy should be applied, starting with trigger point injections of lidocaine and dexamethasone and reserving anterior neurectomy for those cases with limited effect of these injections.

Resumen El síndrome de atrapamiento del nervio cutáneo anterior (ACNES) con frecuencia no se tiene presente en el diagnóstico diferencial del dolor abdominal crónico (DAC). Presentamos el caso de un varón de 11 años con DAC estudiado previamente en servicios de urgencia y digestivo sin detectar patología orgánica, sugiriéndose un origen psicosomático. En la exploración mostró dolor en la pared abdominal localizado en el área de la rama terminal del nervio intercostal T11, con signo de Carnett positivo y respuesta favorable a la inyección con anestésico local en el punto gatillo. Los potenciales evocados somatosensoriales revelaron neuropatía del nervio del músculo recto anterior derecho. Se diagnosticó de ACNES. Como tratamiento se administró en el punto gatillo una inyección subfascial ecoguiada de lidocaína y dexametasona. Tras cuatro meses, permanece asintomático. Para el tratamiento de ACNES en población pediátrica, recomendamos una estrategia terapéutica escalonada comenzando con inyecciones en el punto gatillo y reservar la neurectomía anterior para cuando estas fracasan.

RESUMO Objetivo Os cistos neurentéricos são responsáveis por 0.7 a 1.3% de todos os tumores da medula espinhal. Essas lesões raras são compostas por tecido endodérmico heterotópico. Métodos Uma mulher de 26 anos, com história de cervicalgia ao longo da vida, relatou história de 13 meses de piora da cervicalgia e parestesia braquial. Clinicamente, apresentava paresia braquial bilateral leve (4/5), hiperreflexia generalizada e um sinal de Babinski à esquerda. Na história médica pregressa, história de fechamento de fístula cervical com 1 ano de idade. Durante avaliação neurofisiológica, os potenciais evocados somatos-sensitivos superiores revelaram lesão axonal medular com predomínio à esquerda. Na ressonância magnética cervical, foi evidenciada uma lesão extra medular dorsal cística, intradural homogênea hiperintensa em T2. A tomografia computadorizada evidenciou síndrome de Klippel-Feil. Resultados A laminectomia posterior e a excisão cirúrgica foram realizadas sem complicações. O acompanhamento pós-operatório mostrou recuperação completa da força dos braços. O laudo histopatológico confirmou o diagnóstico pré-operatório de cisto neurentérico. A maioria dos cistos neurentéricos est ão localizados na coluna vertebral, principalmente em posição ventral, sendo 95% dos cistos neurentéricos encontrados no compartimento intradural e intramedular. Cistos neurentéricos sintomáticos aparecem tipicamente na segunda e na terceira décadas de vida e são 1,5 a 3 vezes mais comuns no sexo masculino. Em 50% dos casos, eles também foram relatados com outras malformações vertebrais. Neste caso, um cisto entérico dorsal congênito e uma síndrome de Klippel-Feil foram observados. Conclusão O cisto neurent é rico intramedular é uma lesão rara que deve ser conhecida pelo neurocirurgião e incluída no diagnóstico diferencial de lesões císticas intramurais dorsales, pois seu diagnóstico é muitas vezes difícil, especialmente em casos de cervicalgia crônica sem déficits neurológicos. Nível de evidência V; Opinião de Especialista.

ABSTRACT Objective Neurenteric cysts account for 0.7–1.3% of all spinal cord tumors. These rare lesions are composed of heterotopic endodermal tissue. Methods A 26-year-old woman with a 13-month history of severe cervicalgia and brachial paresthesia. Clinically she had mildbilateral brachial paresis (4/5), generalized hyperreflexia and a left Babinski Sign. Past medical history was significant for a cervical fistula closure when she was 1yearold. The superior somatosensory evoked potentials revealed medullary axonal damage with a left predominance. A cervical magnetic resonance imaging of the neck was performed showing a dorsal homogeneous cystic intradural extramedullary lesion with high signal intensity on T2. Computed tomography revealed a Klippel-Feil syndrome. Results A posterior laminectomy and surgical excision were performed without complications. Post-operative follow-up showed a complete recovery of arm strength. The histopathological report confirmed the preoperative diagnosis of neurenteric cyst. Most neurenteric cysts are located in the spine, mainly in a ventral position. A total of 95% of neurenteric cysts are found in the intradural/intramedullary compartment. Symptomatic neurenteric cysts typically appear in the second and third decades of life and are 1.5 to 3 times more common in men. In 50% of the cases, other vertebral malformations have also been reported. In this case, a congenital dorsal enteric cyst and a Klippel-Feil syndrome were observed. Conclusions The intraspinal neurenteric cysts are rare lesions that must be included in the differential diagnosis of a dorsal, intradural cystic structure. The diagnosis may be overlooked, especially in cases of chronic neck pain without neurological deficit. Level of evidence V; Expert Opinion.

RESUMEN Objetivo Los quistes neuroentéricos representan del 0,7 al 1,3% de todos los tumores de la médula espinal. Estas lesiones raras están compuestas de tejido endodérmico heterotópico. Métodos Una mujer de 26 años con cervicalgia severa de 13 meses de evolución acompañada de parestesia braquial. Clínicamente con paresia braquial bilateral leve (4/5), hiperreflexia generalizada y signo de Babinski izquierdo. En los antecedentes de importancia, le realizaron un cierre de una fístula cervical cuando tenía 1 año. Los potenciales evocados somatosensoriales superiores revelaron daño axonal medular con un predominio izquierdo. Se realizó una resonancia magnética cervical evidenciando una lesión ventral extramedular intradural quística homogénea hiperintensa en T2. La tomografía computarizada reveló un síndrome de Klippel-Feil. Resultados Se realizó una laminectomía posterior y resección quirúrgica sin complicaciones. El seguimiento postoperatorio mostró una recuperación completa de la fuerza de los brazos. El informe histopatológico confirmó el diagnóstico preoperatorio de quiste neuroentérico. La mayoría de los quistes neuroentéricos se localizan en la columna vertebral, principalmente en una posición ventral. El 95% de los quistes neuroentéricos se encuentran en el compartimento intradural/intramedular. Los quistes neuroentéricos sintomáticos aparecen típicamente en la segunda y tercera décadas de la vida y son 1.5 a 3 veces más comunes en los hombres. En el 50% de los casos, también se han notificado otras malformaciones vertebrales. En este caso, se observaron un quiste entérico dorsal congénito y un síndrome de Klippel-Feil. Conclusiones Los quistes neuroentéricos intraspinales son lesiones poco frecuentes que deben incluirse en el diagnóstico diferencial de una estructura quística intradural en posición dorsal. El diagnóstico puede pasarse por alto, especialmente en caso de dolor cervical crónico sin déficit neurológico. Nivel de evidencia V; Opinión de Especialista.

Resumen El Distemper Canino es un de las enfermedades infecciosas más importantes que afectan a los caninos en todo el mundo. El virus afecta varios órganos, entre ellos el sistema nervioso. La leucoencefalitis desmielinizante es la forma más frecuente de Distemper neurológico, esta forma comparte similitudes en los cambios neuropatológicos con enfermedades desmielinizantes humanas, como por ejemplo la esclerosis múltiple. Los potenciales evocados somatosensitivos (PESS) pueden brindar información de las lesiones en la conducción nerviosa, tanto por daño axonal como de la mielina. En la esclerosis múltiple, permiten detectar precozmente lesiones que se sospechan a nivel clínico. El objetivo de este trabajo fue determinar si existe alteración en la respuesta de los PESS del nervio tibial en caninos con Distemper. Se registraron a nivel craneal y espinal los PESS obtenidos por estimulación del nervio tibial de caninos con Distemper y caninos sanos. Se demostró un aumento de la latencia de la onda P1 y una disminución de la amplitud N1-P2 en el registro craneal. Así mismo, existió un aumento en la amplitud N2-P2 en los registros espinales. El resultado obtenido puede aportar un diagnóstico precoz dado que, muchas veces los síntomas neurológicos de los pacientes con Distemper aparecen más tardíamente que los síntomas digestivos o respiratorios. Por lo tanto, la realización de estos estudios podrían ser una herramienta para detectar trastornos en la conducción nerviosa central aún subclínicos.

Abstract: Canine Distemper is one of the most important infectious diseases affecting dogs worldwide. The virus affects several organs, including the nervous system. The demyelinating leukoencephalomyelitis is the most frequent neurological presentation of Distemper. The neuropathological changes that occur in this presentation are similar to the ones present in human demyelinating diseases like multiple sclerosis. Somatosensory evoked potentials (SSEPs) can provide information about axonal and/or myelin lesions. In multiple sclerosis patients, the SSEPs allow the early detection of subclinical lesions. The aim of this study was to determine if there was an alteration in the response of SSEPs of the tibial nerve in canines with Distemper. Cranial and Spinal SSEPs were recorded by means of tibial nerve stimulation in dogs with Distemper and in healthy dogs. There was an increase in the P1 wave latency and a decrease in the N1-P2 amplitude of the cranial SSEPs. Furthermore, an increase in N2-P2 amplitude was observed in the spinal SSEPs. These results showed that the use of SSEPs in dogs with Distemper can be an useful diagnostic tool to detect subclinical central conduction impairment.

ABSTRACT Erectile dysfunction (ED) is a common complication of pelvic fractures. To identify the vascular and neurogenic factors associated with ED, 120 patients admitted with ED after traumatic pelvic fracture between January 2009 and June 2013 were enrolled in this study. All patients answered the International Index of Erectile Function (IIEF-5) questionnaire. Nocturnal penile tumescence (NPT) testing confirmed the occurrence of ED in 96 (80%) patients on whom penile duplex ultrasound and neurophysiological testing were further performed. Of these ED patients 29 (30%) were demonstrated only with vascular abnormality, 41 (42.7%) were detected only with neural abnormality, 26 (27.1%) revealed mixed abnormalities. Of the 55 patients (29+26) with vascular problems, 7 patients (12.7%) with abnormal arterial response to intracavernous injection of Bimix (15mg papaverine and 1mg phentolamine), 31 (56.4%) with corporal veno-occlusive dysfunction and 17 (30.9%) had both problems. Of the 67 (41+26) patients with abnormal neurophysiological outcomes, 51 (76.1%) with abnormal bulbocavernosus reflex (BCR), 20 (29.9%) with pathological pudendal nerve evoked potentials (PDEPs) and 25 (37.3%) with abnormal posterior tibial somatosensory nerve evoked potentials (PTSSEPs). Our observation indicated that neurogenic factors are important for the generation of ED in patients with pelvic fracture; venous impotence is more common than arteriogenic ED.

Introduction: Spinocerebellar ataxia type 2 (SCA2) is a severe neurodegenerative disease which constitutes a serious health problem in Cuba due to its high prevalence and incidence rates and the lack of curative treatments. Objectives: Evaluate the effect and safety of the treatment with high doses of B-complex vitamins (Compvit-B) on peripheral neuropathy in patients with SCA2. Methods: A prospective clinical intervention study was conducted of 20 patients in the mild stage of the disease undergoing a therapeutic protocol consisting in intramuscular injection of Compvit-B for 12 weeks. Patients were administered two ampoules weekly in the first 4 weeks and one from the fifth week onwards. Immediately before and after the treatment patients underwent clinical and electrophysiological examination. Results: Upon completion of the treatment patients showed a significant increase in the amplitude of the sensitive action potentials of the median and sural nerves. In the latter case there was also a decrease in latency and an increase in conduction velocity. Motor nerve conduction parameters were not modified. Somatosensory evoked potentials of the median nerve showed a significant reduction in the latency of Erb's potential. A significant decrease was also found in the frequency of painful muscle contractures in 53% of the cases after treatment. Adverse events were not recorded during the study. Conclusions: The study identifies a new therapeutic option for symptomatic SCA2, and provides new evidence of the pathophysiological bases and clinical management of painful muscle contractures. Broader studies should be conducted with patients and carriers of the mutation, who typically present such manifestations long before developing ataxia.

Introducción: la Ataxia Espinocerebelosa tipo 2 (SCA2) es una enfermedad neurodegenerativa severa que representa un serio problema de salud en Cuba, debido a las altas tasas de prevalencia e incidencia y a la ausencia de tratamientos curativos. Objetivos: evaluar el efecto y la seguridad del tratamiento con altas dosis de vitaminas del complejo B (Compvit-B) sobre la neuropatía periférica en pacientes con SCA2. Métodos: se realizó una investigación prospectiva de intervención clínica en 20 enfermos en estadio ligero los que se sometieron a un protocolo terapéutico mediante la administración intramuscular del COMPVIT B por 12 semanas. Durante las primeras 4 semanas los individuos recibieron dos bulbos semanales y a partir de la 5ta semana un solo bulbo. Inmediatamente antes y después del tratamiento los pacientes fueron evaluados mediantes exámenes clínicos y electrofisiológicos. Resultados: una vez concluido el tratamiento, los pacientes mostraron un aumento significativo de las amplitudes de los potenciales de acción sensitivos de nervios mediano y sural, y en este último nervio se observó además reducción de la latencia y aumento de la velocidad de conducción. Los parámetros de la conducción nerviosa motora no se modificaron. Los potenciales evocados somatosensoriales de nervio mediano arrojaron una reducción significativa de la latencia del potencial de Erb. De manera interesante se observó una la disminución significativa de la frecuencia de aparición de las contracturas musculares dolorosas en el 53% de los casos después del tratamiento. Durante el estudio no se registraron eventos adversos. Conclusiones: el presente estudio identifica una nueva opción terapéutica sintomática en la SCA2, brinda nuevas evidencias sobre las bases fisiopatológicas y el manejo clínico de las contracturas musculares dolorosas y justifican la realización de estudios más amplios en pacientes y portadores de la mutación, los que presentan tales manifestaciones muchos antes de debutar con la ataxia.

INTRODUCTION: Cross-modal plasticity has been extensively studied in deaf adults with neuroimaging studies, yielding valuable results. A recent study in our laboratory with deaf-blind children found evidence of cross-modal plasticity, revealed in over-representation of median nerve somatosensory evoked potentials (SEP N20) in left hemisphere parietal, temporal and occipital regions. This finding led to asking whether SEP N20 changes are peculiar to deaf-blindness or are also present in sighted deaf children. OBJECTIVE: Assess cross-modal plasticity in deaf child cochlear implant candidates using neurophysiological techniques (visual evoked potentials and median nerve somatosensory evoked potentials). METHODS: Participants were 14 prelingually deaf children assessed in the Cuban Cochlear Implant Program. Flash visual-evoked potentials and SEP N20 were recorded at 19 scalp recording sites. Topographic maps were obtained and compared to those of control group children with normal hearing. Analysis took into account duration of hearing loss. RESULTS: Topographic maps of flash visual-evoked potentials did not show changes in deaf child cochlear implant candidates. However, SEP N20 from right median nerve stimulation did show changes from expansion of cortical activation into the left temporal region in deaf children aged >7 years, which was interpreted as neurophysiological evidence of cross-modal plasticity, not previously described for this technique and type of somatosensory stimulus. We interpret this finding as due in part to duration of deafness, particularly related to handedness, since expansion was selective for the left hemisphere in the children, who were all right-handed. CONCLUSIONS: Cortical over-representation of SEP N20 in the left temporal region is interpreted as evidence of cross-modal plasticity that occurs if the deaf child does not receive a cochlear implant early in life-before concluding the critical period of neural development- and relies on sign language for communication.

INTRODUCTION: Studies of neuroplasticity have shown that the brain's neural networks change in the absence of sensory input such as hearing or vision. However, little is known about what happens when both sensory modalities are lost (deaf-blindness). Hence, this study of cortical reorganization in visually-impaired child cochlear implant (CI) candidates. OBJECTIVE: Assess cross-modal plasticity, specifically cortical reorganization for tactile representation in visually-impaired child CI candidates, through study of topography of somatosensory evoked potentials (SEP). METHODS: From April through September 2005, SEP from median and tibial nerve electrical stimulation were studied in 12 visually-impaired child CI candidates aged 3-15 years and 23 healthy controls. Following placement of 19 recording electrodes using the International 10-20 System , SEP were recorded and then processed. Topographic maps were obtained for SEP N20 (median nerve) and SEP P40 (tibial nerve), permitting assessment of cortical reorganization by comparing visually-impaired, deaf children's maps with those of healthy children by means of visual inspection and statistical comparison using a permutation test. RESULTS: SEP N20 topography was significantly more extensive in visually-impaired child CI candidates than in healthy children. An asymmetrical pattern occurred from the expansion of hand tactile activation into the temporal and occipital regions in the left hemisphere on right median nerve stimulation. This did not occur for SEP P40 on tibial nerve stimulation (right and left). Magnitude of expanded SEP N20 response was related to severity of visual impairment and longer duration of dual sensory loss. CONCLUSIONS: Changes in SEP N20 topography are evidence of cross-modal plasticity in visually-impaired child CI candidates, appearing to result from a complex interaction between severity of visual impairment and duration of multisensory deprivation.

Objective: To evaluate the possible sensorial affectation of the somesthetic system in children with speech disorders, mainly with the autistic spectrum disorders (ASD)through the use of the recording technique for somatosensory evoked potential (SEP). Subjects and methods: We performed a longitudinal retrospective study on 40 children remitted to CIREN'S Laboratory of Evoked Potentials from August 2000 to May 2009. The children presented disorders in language acquisition, most of them within the ASD. The sample was composed of 24 males and 16 females (aged between 2 and 13 years of age). To obtain SEP, recording electrodes were applied on the L4-T12 lumbar region (plexus derivation) and in Cz-Fz cortical region, by stimulating the posterior tibial nerve. Additionally, the auditory brainstem response (ABR) was performed to discard functional disorders of the auditory pathway. Results: 92% of the children studied showed alterations in SEP, of which 65% was related to an increment of central conduction time (CCT); 10% had no bilateral cortical response and 12.5% presented morphologic distortion of the evoked cortical response. ABR was conducted on 29 of the 40 studied children, and it was observed that 75.8% were normal and only 24.1% presented anomalies. Of these, 5 were related to affectation of wave I, another presented bilateral hypoacusia and the remaining one had no evoked response, where the bilateral form of dysfunction predominated. Conclusions: Our results suggest a possible relation between the dysfunction of the somesthetic system and language retard. The affectation of this system was greater than the auditory ones in the patients studied.

Objetivo: Evaluar mediante el empleo de la técnica de registro de potencial evocado somatosensorial de nervio tibial posterior (PESSt) la posible afectación sensorial del sistema somestésico en niños con trastornos del lenguaje, en particular con trastornos del espectro autista (TEA). Sujetos y Métodos: Realizamos un estudio retrospectivo longitudinal en 40 niños remitidos al Laboratorio de Potenciales Evocados del CIREN en el período comprendido entre agosto del 2000 y mayo del 2009 por presentar trastornos en la adquisición del lenguaje, en su mayoría dentro del espectro autista. La muestra estuvo conformada por 24 varones y 16 hembras (edades entre 2 y 13 años). Para la obtención del PESSt se colocaron electrodos de registro en región lumbar L4- T12 (derivación de plexo) y en región cortical Cz- Fz, estimulando el nervio tibial posterior. Adicionalmente se realizó el potencial evocado auditivo de tallo cerebral (PEATC) para descartar la presencia de afectaciones en la vía auditiva. Resultados: Del total de niños estudiados el 92.5 % mostró alteraciones en el PESSt, de las cuales el 65 % estuvo relacionada con el incremento del tiempo de conducción central (TCC), un 10 % tuvo ausencia de respuesta cortical bilateral, y el 12,5 % presentó distorsión morfológica de la respuesta evocada cortical. En tanto el PEATC se realizó a 29 de los 40 niños estudiados, observando que el 75,8 % fueron normales y solo el 24,1 % presentaron anomalías en el estudio, de estos 5 estuvieron relacionados con afectación de la onda I, otro presentaba hipoacusia bilateral y el caso restante no tuvo respuesta evocada, predominando la afectación de forma bilateral. Conclusiones: Nuestros resultados muestran una alta incidencia de afectación en el sistema somestésico de niños con TEA. La afectación de este sistema fue mayor que la de los auditivos en los pacientes estudiados.

INTRODUCTION. La myélopathie spondylique, représentant la quatrième partie des paraparésies et des tétraparésies non-traumatiques, est une maladie fréquente. Son diagnostic est basé sur des données cliniques, radiologiques et neurophysiologiques. Le but de cette étude a été de démontrer les altérations des paramètres électro-physiologiques évalués dans plusieurs études, et de décrire ces altérations, ainsi que de mettre en corrélation les altérations des études neurophysiologiques avec l'intensité de l'affection radiologique. MÉTHODES. Trente patients (tous les deux sexes) ont été évalués et diagnostiqués de myélophatie spondylique cervicale en clinique et imagerie. Tous les patients ont subi une électromyographie, une étude de la conduction nerveuse, onde F, potentiels évoqués somatosensoriels et moteurs. Des techniques de statistique descriptive ont été appliquées aux variables neurophysiologiques, et mises en corrélation avec un degré de compression médullaire appréciable en RM. RÉSULTATS. Dans la plupart des cas, les potentiels évoqués étaient altérés. L'électromyographie a montré des résultats altérés dans tous les cas: Un patron neurogène diffus a été observé (72,7%), tandis que le reste a montré un patron d'irritation radiculaire. Dans 52,1% des cas, on a rencontré des altérations modérées à graves dans l'étude de conduction du nerf moyen. Il a existé une corrélation statistiquement significative entre l'altération des paramètres électro-physiologiques et l'intensité de la compression médullaire observée aux images de RM. CONCLUSIONS. Les potentiels évoqués se sont rendus bien utiles pour l'évaluation neurophysiologique dans la myélopathie spondylique. Dans cette affection, il y a une grande association entre les altérations des paramètres électro-physiologiques et les images de RM.

INTRODUCTION. Spondylotic myelopathy is a common disease representing the fourth part of non-traumatic paraparesis and tetraparesis. Its diagnosis is supported by clinical, radiological and neurophysiological data. The aim of present research was to demonstrate and to describe the alterations of electrophysiological parameters assessed by different studies, as well as to correlationate the neurophysiological studies according the intensity of radiolgical affection. METHODS. Thirty patients of both sexes were assessed by clinical and imaging diagnosis of cervical spondylotic myelopathy. All of them underwent electromyography, nervous conduction study, F wave, somatosensory and motor evoked potentials. Techniques of descriptive statistics were applied to neurophysiological variables correlating them with the medullary compression degree according to resonance. RESULTS. In most of the cases the evoked potentials were altered. The electromyography demonstrated altered results in all the cases: in the 72,7% there was a diffuse neurogenic pattern, whereas remained showed a radicular irritation pattern. In the 52,1% of cases there were moderate to severe alterations in the study of medium nerve conduction. A significant statistical correlation was present between the abnormality of electrophysiological parameters and the medullary compression intensity observed in resonance images. CONCLUSIONS. The evoked potentials are very useful for the neurophysiological assessment in spondylotic myelopathy where is present a strong association among the alterations of electrophysiological parameters and the resonance images.

INTRODUCCIÓN. La mielopatía espondilótica es una enfermedad frecuente, que representa la cuarta parte de las paraparesias y tetraparesias no traumáticas. Su diagnóstico se sustenta en los datos clínicos, radiológicos y neurofisiológicos. El objetivo de esta investigación fue demostrar las alteraciones de los parámetros electrofisiológicos evaluados mediante diferentes estudios y describir estas alteraciones, así como correlacionar las alteraciones de los estudios neurofisiológicos con la intensidad de la afectación radiológica. MÉTODOS. Se evaluaron 30 pacientes de uno y otro sexo, con diagnóstico clínico e imaginológico de mielopatía espondilótica cervical. A todos los pacientes se les realizó electromiografía, estudio de conducción nerviosa, onda F, potenciales evocados somatosensoriales y motores. Se aplicaron técnicas de estadística descriptiva a las variables neurofisiológicas y se correlacionaron éstas con el grado de compresión medular apreciable en la resonancia. RESULTADOS. En la mayoría de los casos los potenciales evocados estaban alterados. La electromiografía mostró resultados alterados en todos los casos: en el 72,7 % se observó un patrón neurógeno difuso, mientras que el resto mostró un patrón de irritación radicular. En el 52,1 % de los casos se demostraron alteraciones moderadas a graves en el estudio de conducción del nervio mediano. Existió una correlación estadísticamente significativa entre la anormalidad de los parámetros electrofisiológicos y la intensidad de la compresión medular observada en las imágenes de resonancia. CONCLUSIONES. Los potenciales evocados resultan de gran utilidad para la evaluación neurofisiológica en la mielopatía espondilótica. En la mielopatía espondilótica existe gran asociación entre las alteraciones de los parámetros electrofisiológicos y las imágenes de resonancia.

OBJETIVO: comparar o número de eventos com alteração no potencial evocado somatosensorial (PESS) e sua repercussão entre técnicas de tratamento cirúrgico da escoliose idiopática com e sem amarrilha sublaminar. MÉTODOS: análise retrospectiva de 25 cirurgias de correção de escoliose idiopática, flexíveis, realizadas no período de novembro de 1996 a setembro de 1999, nas quais foram utilizadas técnicas sem amarrilha sublaminar (sistema de Cotrel-Dubousset) (Grupo I) e com amarrilha (sistema de Harrington-Luque e haste de Hartshill) (Grupo II). Todos os procedimentos foram realizados com monitoração neurofisiológica da função medular através do PESS. RESULTADOS: no Grupo II, foi observada uma frequência maior de alterações do PESS tanto na amplitude como na latência da onda, durante e ao final da cirurgia. Na série revista, constatou-se uma elevada porcentagem de resultados falso-positivos. Em nenhum paciente foi observada qualquer alteração neurológica no pós-operatório. CONCLUSÃO: permanece em aberto qual o método mais seguro para o tratamento cirúrgico da escoliose idiopática. Os resultados apresentados neste trabalho sugerem uma menor incidência de alterações na monitoração neurofisiológica da medula em pacientes tratados pelo sistema de Cotrel-Dubousset.

OBJECTIVE: to compare the number of events with alteration in the somatosensory evoked potentials (SSEP) and its repercussion between different techniques of surgical treatment for idiopathic scoliosis, with and without sublaminar wiring. METHODS: twenty-five surgical procedures with flexible curves for treatment of idiopathic scoliosis were reviewed in the period of November 1996 to September 1999. They were divided into two groups: without sublaminar wiring (Cotrel-Dubousset's system) (Group I); and with sublaminar wiring (Harrington-Luque's system and rectangle of Hartshill) (Group II). In all surgeries, the intraoperative neurophysiologic monitoring with Somatosensory Evoked Potentials (SSEPs) was used. RESULTS: according to the findings, a bigger frequency of monitoring changes was observed during and at the end of the surgery in Group II. A high incidence of false-negative changes was also verified. No patient with neurological damages was observed. CONCLUSION: There are still doubts about the safest method for the surgical treatment of idiopathic scoliosis. The results presented in this study suggest a smaller incidence of SSEPs changes in the patients treated with Cotrel-Dubousset's system.

OBJETIVO: comparar el número de eventos con alteración en el potencial evocado somatosensorial (PESS) y su repercusión entre técnicas de tratamiento quirúrgico de la escoliosis idiopática, con y sin amarilla sublaminar. MÉTODOS: análisis retrospectivo de 25 cirugías de corrección de escoliosis idiopática, flexibles, realizadas en el periodo de noviembre de 1996 a septiembre de 1999, en las cuales fueron utilizadas técnicas sin amarilla sublaminar (sistema de Cotrel-Dubousset) (Grupo I) y con amarilla (sistema de Harrington-Luque y asta de Hartshill) (Grupo II). Todas las cirugías fueron realizadas con monitorización neurofisiológica de la función medular por medio de PESS. RESULTADOS: en el Grupo II fue observada una frecuencia mayor de alteraciones del PESS, tanto en la amplitud como en la latencia de onda, durante y al final de la cirugía. En la serie revista, se constató un elevado porcentaje de resultados falsos-positivos. En ningún paciente fue observada cualquier alteración neurológica en el postoperatorio. CONCLUSIÓN: está en discusión cuál es el método más seguro para el tratamiento quirúrgico de la escoliosis idiopática. Los resultados presentados en este trabajo sugieren una menor incidencia de alteraciones en la monitorización neurofisiológica de la médula en los pacientes tratados por el sistema de Cotrel-Dubousset.

La esquizencefalia es una malformación cerebral producida por un trastorno en la migración neuronal. Se caracteriza por una hendidura que compromete todo el espesor del palio, desde la superficie pial hasta el sistema ventricular. Cuando los bordes de corteza alrededor de la hendidura están en contacto la esquizencefalia es de labio cerrado, pero cuando los bordes están separados la lesión se denomina de labio abierto. Las manifestaciones clínicas más frecuentes son: retraso psicomotor, déficit motor y epilepsia. Se presentan dos pacientes con esquizencefalia de labio abierto, uno unilateral y otro bilateral, a los que se les realizaron estudios de potenciales evocados auditivos, visuales, cognitivos y somatosensoriales. Estos estudios permitieron obtener correlaciones clínicas e imagenológicas. Cada caso presentó un patrón específico en los potenciales evocados somatosensoriales, los que pueden confirmar la sospecha de alformaciones hemisféricas. Por el contrario, los potenciales evocados cognitivos, visuales y auditivos son inespecíficos a para diferenciar los tipos de esquizencefalia.

Schizencephaly is a brain malformation caused by an abnormality of neuronal migration. It is characterized by a cleft spanning the pallium from the pial surface to the ventricular system that is lined by cortical gray matter. If the edges of the cortex around the cleft are in contact with each other, the lesion is named closed-lip schizencephaly; when the cleft borders are not in contact, the lesion is termed open-lip schizencephaly and the cleft is filled with cerebrospinal fluid. The most frequent clinical manifestations of the disease are psychomotor delay, motor impairment and epilepsy. This is a report of two cases of patients with diagnosis of open-lip schizencephaly, the first one unilateral and the second one bilateral . Various studies of evoked potentials (ERP) by different sensory modalities were done, correlations between clinical data, ERP and brain images were obtained too. Each case presented one specific pattern in the somatosensory evoked potentials that can be used to suspect haemispheric malformations. Auditory and visual evoked potencials were not useful to discriminate between different types of schizencephaly.