Lambda waves: a remarkable electroencephalographic record of a normal physiological phenomenon

Lambda waves are triangular-shaped monophasic electropositive sharp transients, occurring over the occipital or parieto-occipital regions . They correspond to benign variants on electroencephalogram (EEG) and, sometimes can be misinterpreted as epileptiform activity due to their sharp contour . They are usually symmetrical and time-locked to saccadic eye movements of awake subjects, during visual exploration, especially of a complex scene, and disappearing when eyes are closed and in sleep . Their name is derived from the resemblance of the wave to the Greek capital letter lambda (λ)⁴. The expression of these waveforms seems to be secondary to a functional activation of networks probably localized within parieto-occipital regions³. Their generators, however, are not fully elucidated. The first reports about the presence of lambda waves date back to the early 1950s, suggesting that it is a phenomenon possibly associated with the presence of epilepsy or some organic brain disease¹. Roth and Green¹, however, were the first to obtain evidence that it was a normal physiological phenomenon. Here we present a remarkable 13-year-old boy waking EEG sample, with a normal background tracing and no history of neurological or other diseases. Note the blocking reaction of the occipital alpha rhythm with eye opening, and the appearance of positive, monophasic, triangular-shaped waves about 3.0 seconds later, initially to the right and then bilaterally, corresponding to lambda waves (figures 1 and 2). After eye closure, the lambda waves disappear, and we can observe the return of a slightly accelerated posterior alpha rhythm (the alpha squeak effect)

Interictal brain SPECT in patients with medically refractory temporal lobe epilepsy

The objective of this study was to evaluate the utility of interictal brain SPECT in localizing the epileptogenic focus in a population of patients of Epilepsy Clinic of Hospital Universitário Clementino Fraga Filho (HUCFF/UFRJ), with medically refractory temporal lobe epilepsy (TLE) and normal computed tomography (CT) scans, studying the correlation between SPECT, electroencephalogram (EEG) and, in 11 cases, brain magnectic resonance imaging (MRI), and to compare the results to the other six literatura series. Twelve (52.2%) patients presented abnormal SPECT. Among these, five (41.6% of abnormal SPECTs) presented unilateral SPECT changes at the same side of EEG (hypoperfusion in four and hyperperfusion in one), three (25% of abnormal SPECTs) presented bilateral hypoperfusion and bilateral EEG changes too, and four (33.3%) presented unilateral hypoperfusion and bilateral EEG changes. The statistical analysis was based on fuzzy logic. The correlation index among SPECT X EEG, SPECT X MRI and SPECT X EEG X MRI were highly significant, with signifcance levels at 0.01, p < 0.0005 and trust interval at 99% in all correlations. The correlation studies between the series presented similar results.O objetivo desse estudo foi avaliar a utilidade do SPECT cerebral interictal na localização do foco epileptogênico em 23 pacientes do Ambulatório de Epilepsias do Hospital Universitário Clementino Fraga Filho (HUCFF/UFRJ), com epilepsia do lobo temporal (ELT) de difícil controle e tomografia computadorizada (TC) do crânio normal, estudando a correlação entre SPECT interictal, eletrencefalograma (EEG) e, em 11 casos, ressonância magnética (RM) do crânio, e comparar os resultados com os de outras seis séries da literatura. Doze (52,2%) pacientes apresentaram SPECT anormal. Entre esses, cinco (41,6% dos SPECTs anormais) apresentaram alteração unilateral ao SPECT do mesmo lado do EEG (hipoperfusão em 4 e hiperperfusão em 1), três (25% dos SPECTs anormais) apresentaram hipoperfusão bilateral ao SPECT e alterações também bilaterais ao EEG e 4 (33,3% dos SPECTs anormais) apresentaram hipoperfusão unilateral ao SPECT e EEG bilateral. A análise estatística fundamentou-se na lógica fuzzy. Os índices de correlação entre SPECT X EEG, SPECT X RM e SPECT X EEG X RM foram altamente significativos, com níveis de significância de 0,01, p < 0,0005 e intervalo de 99% de confiança em todas as correlações. Os estudos de correlação entre as séries estudadas apresentaram resultados semelhantes entre si.Universidade Federal do Rio de Janeiro Faculdade de MedicinaUniversidade Federal do Rio de Janeiro Coordenação dos Programas de Pós-Graduação em EngenhariaLaboratoire d'Analyse et d'Architecture de Systèmes de ToulouseUniversidade Federal do Rio de JaneiroUniversidade Federal de São Paulo (UNIFESP), Escola Paulista de Medicina (EPM)Universidade Federal do Rio de Janeiro HUCFF Serviço de NeurologiaUniversidade do Rio de Janeiro Serviço de NeurologiaUNIFESP, EPMSciEL

Apoplexia hipofisária intradenomatosa Intra-adenomatous pituitary apoplexy

Os autores analisam a literatura sobre apoplexia hipofisária intradenomatosa, enfocando a fisiopatologia, o diagnóstico e a conduta terapêutica. Estudam 5 casos , de uma série de 86 pacientes com tumores hipofisários que desenvolveram esta síndrome e que foram diagnosticados e acompanhados pelos serviços de Neurocirurgia e Endocrinologia do Hospital Universitário Clementino Fraga Filho da Universidade Federal do Rio de Janeiro. Todos os casos, a partir da suspeita clínica, tiveram o diagnóstico confirmado por estudo de tomografia computadorizada de crânio e/ou ressonância magnética de crânio. O tratamento de escolha foi cirúrgico. As conclusões apontam para as dificuldades diagnósticas desta situação clínica e da urgência na instituição da terapia.The authors review the literature on intra-adenomatous pituitary apoplexy with special emphasis on pathophysiology, diagnosis and therapeutic approach. They present five cases, from a series of 86 patients with pituitary tumors, that developed this syndrome. The patients were diagnosed and followed by the Neurosurgery and Endocrinology Services of Hospital Universitário Clementino Fraga Filho, Universidade Federal do Rio de Janeiro. Diagnosis was confirmed by CT-Scan and MRI in all cases , and the treatment of choice was surgical. Conclusions point to the diagnostic difficulties and the urgency of treatment in this clincal setting

Nucleoplasty as a therapeutic option for lumbar disc degeneration related pain: a retrospective study of 396 cases Nucleoplastia como opção terapêutica para dor relacionada à degeneração do disco lombar: um estudo retrospectivo de 396 casos

OBJECTIVES: To make a retrospective analysis and evaluate a clinical response to the control of disc degeneration related pain of 396 patients submitted to percutaneous lumbar nucleoplasty; and to make a record of visual analogical scale (VAS) up to a three-year follow-up after the surgical procedure. METHODS: Analysis of VAS score in 396 patients with lumbar disc degeneration related pain, according to anamnesis, clinical examination and magnetic resonance imaging (MRI), without improvement of previous clinical treatment, submitted to percutaneous nucleoplasty. RESULTS: A total of 26% of the patients presented 100% remission of pain or paresthesia, of whom 75% showed at least 50% of pain improvement. The median VAS pain improvement was about 67%. CONCLUSIONS: The median VAS improvement in inferior disc levels was higher than four points. The VAS showed improvement of the pain and paresthesia up to a three-year follow up after the surgical procedure.<br>OBJETIVOS: Analisar retrospectivamente a resposta clínica no controle da dor relacionada à degeneração discal em 396 pacientes submetidos à nucleoplastia percutânea lombar; e fazer um registro da escala analógica visual (EAV) com seguimento de três anos após a cirurgia. MÉTODOS: Análise da EAV de 396 pacientes com diagnóstico de hérnia de disco, de acordo com anamnese, exame clínico e imagens por meio de ressonância magnética (RM), sendo que nenhum deles apresentou melhora com tratamento clínico prévio. Estes pacientes foram submetidos à nucleoplastia percutânea. O estudo utilizou, para avaliação, o registro de escala analógica visual (EAV) durante seguimento de até três anos após o procedimento cirúrgico. RESULTADOS: Um total de 26% apresentou 100% de remissão da dor ou parestesia; 75% apresentaram pelo menos 50% de melhora da dor. A mediana da EAV de melhora da dor foi de aproximadamente 67%. CONCLUSÕES: Houve melhora da EAV, com mediana maior do que quatro pontos nos pacientes com acometimento nos níveis discais inferiores. A EAV mostrou melhora da dor e parestesia num período de seguimento de até três anos após o procedimento cirúrgico

Nucleoplasty as a therapeutic option for lumbar disc degeneration related pain: a retrospective study of 396 cases

OBJECTIVES: To make a retrospective analysis and evaluate a clinical response to the control of disc degeneration related pain of 396 patients submitted to percutaneous lumbar nucleoplasty; and to make a record of visual analogical scale (VAS) up to a three-year follow-up after the surgical procedure. METHODS: Analysis of VAS score in 396 patients with lumbar disc degeneration related pain, according to anamnesis, clinical examination and magnetic resonance imaging (MRI), without improvement of previous clinical treatment, submitted to percutaneous nucleoplasty. RESULTS: A total of 26% of the patients presented 100% remission of pain or paresthesia, of whom 75% showed at least 50% of pain improvement. The median VAS pain improvement was about 67%. CONCLUSIONS: The median VAS improvement in inferior disc levels was higher than four points. The VAS showed improvement of the pain and paresthesia up to a three-year follow up after the surgical procedure