Neurophysiology in between the interests of Dom Pedro II of Brazil, and Charles Brown-Séquard

This article presents our historical research regarding Charles Brown-Séquard, a famous scientist with important contributions to the medical field, in particular for neurology, and endocrinology, and his relationship with Dom Pedro II, the second and last Brazilian Emperor, and an enlightened ruler. The Emperor contacted several illustrious personages in support of State policy, such as for the development of experimental physiology at the Imperial Museum of Natural History, but also for personal purposes given his health problems and those of the Empress. Charles Brown-Séquard and his pilgrimage between different worlds as a physician and physiologist are presented until his definitive establishment in Paris, where he replaces Claude Bernard in the chair of experimental medicine at the Collège de France. Jacques-Arsene d\u27Arsonval took over after this chair, and together with Brown-Séquard, he electrophysiologically examined the Emperor\u27s diabetic peripheral neuropathy. In this article, the Emperor´s relationship with BrownSéquard was studied mainly from the correspondence sent to Dom Pedro II and retrieved from the Imperial Museum in Petrópolis, Brazil, and from the accounts of his meetings that included scientific sessions and clinical consultations. This article can be used to understand the progress of knowledge in the field of neurology/clinical neurophysiology, the tracking of emerging ideas in the field of science in the past and the threat to the credibility of researchers

Panic disorder and hyperventilation Transtorno do pânico e hiperventilação

Respiratory abnormalities are associated with anxiety, particularly with panic attacks. Symptoms such as shortness of breath, "empty-head" feeling, dizziness, paresthesias and tachypnea have been described in the psychiatric and respiratory physiology related to panic disorder. Panic disorder patients exhibit both behaviorally and physiologically abnormal responses to respiratory challenges tests. Objective: We aim to observe the induction of panic attacks by hyperventilation in a group of panic disorder patients (DSM-IV). Method: 13 panic disorder patients and 11 normal volunteers were randomly selected. They were drug free for a week. They were induced to hyperventilate (30 breaths/min) for 3 minutes. Anxiety scales were taken before and after the test. Results: 9 (69.2%) panic disorder patients and one (9.1%) of control subjects had a panic attack after hyperventilating (p< 0.05). Conclusion: The panic disorder group was more sensitive to hyperventilation than normal volunteers. The induction of panic attacks by vonluntary hyperventilation may be a useful and simple test for validating the diagnosis in some specific panic disorder patients.<br>Distúrbios respiratórios estão associados à ansiedade, especialmente aos ataques de pânico. Sufocamento, sensação de "cabeça leve", tonteira, parestesias e taquipnéia aparecem na descrição psiquiátrica e respiratória do transtorno do pânico. Pacientes com transtorno do pânico apresentam respostas comportamentais e fisiológicas anormais a testes respiratórios. Objetivo: Observamos a indução de ataques de pânico através de hiperventilação em um grupo de pacientes com transtorno do pânico (DSM-IV). Método: Selecionamos de forma randomizada 13 pacientes com transtorno do pânico e 11 voluntários normais. Todos estavam sem medicação há uma semana. Foram induzidos a hiperventilar (30 inspirações/minuto) durante 3 minutos. Escalas de ansiedade foram utilizadas antes e após o teste. Resultados: No grupo com transtorno de pânico, 9 (69,2%) pacientes apresentaram ataque de pânico após a hiperventilação e apenas 1 (9,1%) no grupo controle (p<0,05). Conclusão: Os pacientes com transtorno do pânico foram mais sensíveis à hiperventilação que o grupo controle. A indução de ataques de pânico através da hiperventilação pode ser método útil e simples para validar o diagnóstico em um grupo específico de pacientes com transtorno do pânico