RESUMO
Corona Virus Disease 2019 (COVID-19) is a new illness caused by a novel coronavirus, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). With the increasing number of confirmed cases and the accumulating clinical data, a broad spectrum of neurological complications has been reported in the literature, including encephalopathy, stroke, Guillain-Barré syndrome, meningo-encephalitis, acute necrotizing hemorrhagic encephalopathy, and inflammatory central nervous system syndromes. Here, we describe the case of a 38-year-old woman presenting with longitudinally extensive transverse myelitis, revealed by bilateral lower limb weakness, decreased sensation below the Th4 level and urinary retention, and occuring 15 days after she had been diagnosed with COVID-19.
Assuntos
COVID-19/complicações , Mielite Transversa/etiologia , Mielite Transversa/fisiopatologia , Adulto , Feminino , HumanosRESUMO
BACKGROUND: Mobius syndrome is characterized by a bilateral congenital paralysis of the facial and abducens nerves which leaves the subject with an expressionless "mask-like" face. SUBJECTS AND METHODS: Based on a literature review and a case discussion of an adult patient with Mobius syndrome and obsessive-compulsive disorder, initially undiagnosed and confused with a psychotic disorder, we will discuss the influence of Mobius syndrome in psychiatric evaluations. RESULTS: The lack of facial expressiveness and non-verbal emotional interactions may influence psychiatric evaluations and result in misdiagnosis and the inappropriate prescribing of antipsychotics. In the case analysis, we also observed other associated malformations such as renal atrophy, a bicuspid aortic valve and mitral valve prolapse. CONCLUSION: We feel that educating the patient about the communicative consequences of impaired facial expressions and facial interactions is a necessary prerequisite for any psychiatric or psychological evaluation in subjects with Mobius syndrome. We also recommend using caution when prescribing antipsychotics in patients with Mobius syndrome given the motor side effects secondary to a potentially pre-existing hypotonia.
Assuntos
Erros de Diagnóstico , Síndrome de Möbius/complicações , Síndrome de Möbius/diagnóstico , Transtorno Obsessivo-Compulsivo/complicações , Transtorno Obsessivo-Compulsivo/diagnóstico , Adulto , Antipsicóticos/uso terapêutico , Expressão Facial , Humanos , Síndrome de Möbius/tratamento farmacológico , Síndrome de Möbius/patologia , Comunicação não Verbal , Transtorno Obsessivo-Compulsivo/tratamento farmacológico , Transtorno Obsessivo-Compulsivo/patologiaRESUMO
Other than tremor, movement disorders are uncommon in multiple sclerosis. Among these uncommon clinical manifestations, paroxysmal kinesigenic dyskinesia is the most frequently reported. It is characterized by episodic attacks of involuntary movements that are induced by repetitive or sudden movements, startling noise or hyperventilation. The diagnosis is essentially clinical and based on a good observation of the attacks. It is very easy to misdiagnose it. We describe the case of a young female patient who presented paroxysmal kinesigenic dyskinesia as the first and only clinical manifestation of multiple sclerosis, with no recurrence of attacks nor any other neurologic symptom after eighteen months of follow-up.
RESUMO
The prognosis of patients who are admitted to the hospital after cardiac arrest often relies on neurological examination, which could be significantly influenced by the use of sedative drugs or the implementation of targeted temperature management. The need for early and accurate prognostication is crucial as up to 15-20% of patients could be considered as having a poor outcome and may undergo withdrawal of life-sustaining therapies while a complete neurological recovery is still possible. As current practice in Belgium is still based on a very early assessment of neurological function in these patients, the Belgian Society of Intensive Care Medicine created a multidisciplinary Task Force to provide an optimal approach for monitoring and refine prognosis of CA survivors. This Task Force underlined the importance to use a multimodal approach using several additional tools (e.g., electrophysiological tests, neuroimaging, biomarkers) and to refer cases with uncertain prognosis to specialized centers to better evaluate the extent of brain injury in these patients.
Assuntos
Cuidados Críticos/métodos , Parada Cardíaca/complicações , Hipóxia-Isquemia Encefálica/etiologia , Exame Neurológico/métodos , Parada Cardíaca/terapia , Humanos , Hipotermia Induzida , Hipóxia-Isquemia Encefálica/diagnóstico , Hipóxia-Isquemia Encefálica/mortalidade , Prognóstico , Recuperação de Função FisiológicaRESUMO
Transient cortical blindness (TCB) is a rare but striking complication following contrast agent injection. TCB might be secondary to a direct toxicity of the contrast agent, leading to an osmotic disruption of the blood-brain barrier (BBB), with a preferential involvement of the posterior circulation and occipital cortex. We report a series of three patients with contrast medium-associated TCB (intra-arterial injection of non-ionic contrast agent during diagnostic cerebral angiography for two of them and coronary angioplasty for the other one). In two patients, the magnetic resonance imaging (MRI) was unremarkable; in the other patient, typical MRI findings were observed, with FLAIR hyperintensities in the right occipital cortex and decreased apparent diffusions coefficient (ADC). Interestingly, this patient also presented posterior rhythmic epileptiform activities on electroencephalogram during the first 36 h. Visual evoked potentials (VEPs) showed normal retinal potential, but a massive destructuration of the later potentials of the cortical origin. To our knowledge, this is the first time that VEPs acquired during TCB are reported. We discuss these findings with respect to the pathophysiology of TCB.
Assuntos
Cegueira Cortical/induzido quimicamente , Cegueira Cortical/fisiopatologia , Meios de Contraste/efeitos adversos , Potenciais Evocados Visuais/fisiologia , Idoso , Angiografia/efeitos adversos , Eletrofisiologia , Feminino , Humanos , Imageamento por Ressonância Magnética , Masculino , Pessoa de Meia-IdadeRESUMO
OBJECTIVE: EpiNet was established to encourage epilepsy research. EpiNet is used for multicenter cohort studies and investigator-led trials. Physicians must be accredited to recruit patients into trials. Here, we describe the accreditation process for the EpiNet-First trials. METHODS: Physicians with an interest in epilepsy were invited to assess 30 case scenarios to determine the following: whether patients have epilepsy; the nature of the seizures (generalized, focal); and the etiology. Information was presented in two steps for 23 cases. The EpiNet steering committee determined that 21 cases had epilepsy. The steering committee determined by consensus which responses were acceptable for each case. We chose a subset of 18 cases to accredit investigators for the EpiNet-First trials. We initially focused on 12 cases; to be accredited, investigators could not diagnose epilepsy in any case that the steering committee determined did not have epilepsy. If investigators were not accredited after assessing 12 cases, 6 further cases were considered. When assessing the 18 cases, investigators could be accredited if they diagnosed one of six nonepilepsy patients as having possible epilepsy but could make no other false-positive errors and could make only one error regarding seizure classification. RESULTS: Between December 2013 and December 2014, 189 physicians assessed the 30 cases. Agreement with the steering committee regarding the diagnosis at step 1 ranged from 47% to 100%, and improved when information regarding tests was provided at step 2. One hundred five of the 189 physicians (55%) were accredited for the EpiNet-First trials. The kappa value for diagnosis of epilepsy across all 30 cases for accredited physicians was 0.70. SIGNIFICANCE: We have established criteria for accrediting physicians using EpiNet. New investigators can be accredited by assessing 18 case scenarios. We encourage physicians with an interest in epilepsy to become EpiNet-accredited and to participate in these investigator-led clinical trials.
RESUMO
BACKGROUND: Antiepileptic drugs (AEDs) decrease the occurrence of epileptic seizures and modulate cortical excitability through several mechanisms that likely interact. The modulation of brain excitability by AEDs is believed to reflect their antiepileptic action(s) and could be used as a surrogate marker of their efficacy. Transcranial magnetic stimulation (TMS) is one of the best noninvasive methods to study cortical excitability in human subjects. Specific TMS parameters can be used to quantify the various mechanisms of action of AEDs. A new AED called retigabine increases potassium efflux by changing the conformation of KCNQ 2-5 potassium channels, which leads to neuronal hyperpolarisation and a decrease in excitability. HYPOTHESIS: The purpose of this study is to investigate the effect of retigabine on cortical excitability. Based on the known mechanisms of action of retigabine, we hypothesized that the oral intake of retigabine would increase the resting motor threshold (RMT). METHODS: Fifteen healthy individuals participated in a placebo-controlled, double-blind, randomised, clinical trial (RCT). The primary outcome measure was the RMT quantified before and after oral intake of retigabine. Several secondary TMS outcome measures were acquired. RESULTS: The mean RMT, active motor threshold (AMT) and intensity to obtain a 1mV peak-to-peak amplitude potential (SI1mV) were significantly increased after retigabine intake compared to placebo (RMT: P=0.039; AMT: P=0.014; SI1mV: P=0.019). No significant differences were found for short-interval intracortical inhibition/intracortical facilitation (SICI/ICF), long-interval intracortical inhibition (LICI) or short-interval intracortical facilitation (SICF). CONCLUSION: A single dose of retigabine increased the RMT, AMT and S1mV in healthy individuals. No modulating intracortical facilitation or inhibition was observed. This study provides the first in vivo demonstration of the modulating effects of retigabine on the excitability of the human brain, and the results are consistent with the data showing that retigabine hyperpolarizes neurons mainly by increasing potassium conductance.
Assuntos
Anticonvulsivantes/farmacologia , Carbamatos/farmacologia , Córtex Motor/efeitos dos fármacos , Córtex Motor/fisiologia , Fenilenodiaminas/farmacologia , Estimulação Magnética Transcraniana , Adulto , Análise de Variância , Estudos Cross-Over , Método Duplo-Cego , Eletromiografia , Feminino , Humanos , Masculino , Movimento/efeitos dos fármacos , Movimento/fisiologia , Músculo Esquelético/fisiologia , DescansoRESUMO
Over the past decades, it has become clear that the most efficient way to prevent status epilepticus is to stop the seizure as fast as possible, and early treatment of prolonged convulsive seizures has become an integral part of the overall treatment strategy in epilepsy. Benzodiazepines are the first choice drugs to be used as emergency medication. This treatment in the early phases of a seizure often implies a 'pre-medical' setting before intervention of medically trained persons. In this paper, we propose "good practice points" for first line management of prolonged convulsive seizures in children and adults in a 'pre-medical' setting.
Assuntos
Anticonvulsivantes/uso terapêutico , Convulsões/tratamento farmacológico , Adulto , Criança , Feminino , Humanos , MasculinoRESUMO
BACKGROUND: The aim of this study is to evaluate the feasibility and efficacy of Transcranial Doppler (TCD) in assessing cerebral perfusion changes in septic patients. METHODS: Using TCD, we measured the mean velocity in the middle cerebral artery (VmMCA, cm/sec) and calculated the pulsatility index (PI), resistance index (RI) and cerebral blood flow index (CBFi = 10*MAP/1.47(PI)) on the first day of patients' admission or on the first day of sepsis development; measurements were repeated on the second day. Sepsis was defined according to standard criteria. RESULTS: Forty-one patients without any known neurologic deficit treated in our 24-bed Critical Care Unit were assessed (Sepsis Group = 20, Control Group = 21). Examination was feasible in 91% of septic and 85% of non-septic patients (p = 0.89). No difference was found between the two groups in mean age, mean arterial pressure (MAP) or APACHE II score. The pCO2 values were higher in septic patients (46 ± 12 vs. 39 ± 4 mmHg p < 0.01). No statistically significant higher values of VmMCA were found in septic patients (110 ± 34 cm/sec vs. 99 ± 28 cm/sec p = 0.17). Higher values of PI and RI were found in septic patients (1.15 ± 0.25 vs. 0.98 ± 0.16 p < 0.01, 0.64 ± 0.08 vs. 0.59 ± 0.06 p < 0.01, respectively). No statistically significant lower values of CBFi were found in septic patients (497 ± 116 vs. 548 ± 110 p = 0.06). CONCLUSIONS: Our results suggest cerebral vasoconstriction in septic compared to non-septic patients. TCD is an efficient and feasible exam to evaluate changes in cerebral perfusion during sepsis.
RESUMO
BACKGROUND: Ultimately, the experience of pain derives from changes in brain excitability. Therefore, modulating the excitability of cortical areas involved in pain processing may become an attractive option in the context of multimodal analgesia during the postoperative period. Repetitive transcranial magnetic stimulation (rTMS) can reduce morphine consumption during the postoperative period after gastric bypass surgery. We tested the potential of another method of noninvasive brain stimulation, transcranial direct current stimulation (tDCS), to reduce morphine consumption or pain perception during the postoperative period. METHODS: Fifty-nine ASA I to II patients undergoing lumbar spine surgery were randomized to receive anodal (n=20), cathodal (n=20), or sham (n=19) tDCS in the recovery room in a double-blind manner. Morphine consumption administrated through patient-controlled analgesia (PCA) was the primary outcome; pain perception as measured by visual analog scale was the secondary outcome. RESULTS: There were no statistically significant differences between the 3 groups of patients, either for PCA morphine consumption or for pain scores. CONCLUSIONS: Several factors may explain the observed lack of impact of tDCS on PCA morphine consumption and pain perception: the method of brain stimulation (tDCS/rTMS), potential interactions with anesthetic drugs, differences in patients population (gastric bypass surgery/lumbar spine surgery), and the previous experience of pain and chronic consumption of analgesic drugs. Further studies with tDCS should be performed before concluding that tDCS is inefficient for postoperative pain control, because noninvasive brain stimulation methods, such as rTMS and tDCS, may become attractive in the setting of multimodal analgesia.
Assuntos
Analgésicos Opioides/uso terapêutico , Terapia por Estimulação Elétrica/métodos , Morfina/uso terapêutico , Dor Pós-Operatória/terapia , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Analgesia Controlada pelo Paciente , Método Duplo-Cego , Feminino , Humanos , Região Lombossacral/cirurgia , Masculino , Pessoa de Meia-Idade , Avaliação de Resultados em Cuidados de Saúde , Medição da Dor , Adulto JovemRESUMO
Ictal asystole is a rare complication of epileptic seizures and is frequently unrecognized by non-neurologists. We describe a case of ictal asystole as first clinical manifestation of unknown temporal lobe epilepsy and we discuss epidemiologic, pathophysiologic and therapeutic features.
Assuntos
Encéfalo/fisiopatologia , Epilepsia do Lobo Temporal/complicações , Parada Cardíaca/etiologia , Coração/fisiopatologia , Adulto , Diagnóstico Diferencial , Eletrocardiografia , Eletroencefalografia , Epilepsia do Lobo Temporal/diagnóstico , Epilepsia do Lobo Temporal/fisiopatologia , Seguimentos , Parada Cardíaca/diagnóstico , Parada Cardíaca/fisiopatologia , Humanos , MasculinoRESUMO
INTRODUCTION: The diagnostic process of syncopes remains an important and complex issue. In spite of everything, it is estimated that 20 to 30% of syncopes remain unexplained. The diagnosis of psychogenic syncope is estimated at 5.5% to 14% of syncopes. A systematic psychiatric evaluation of unexplained syncopes would be strongly recommended. We present here the original care by the "Centre Interdisciplinaire des Malaises Inexpliqués et des Syncopes (Interdisciplinary Centre of Unexplained Faintness and Syncopes.)" set up by the neurology and cardiology departments associated with the ENT department. We describe the place liaison psychiatry has been able to define and its field of action. SUBJECT AND METHODS: After a year of operation, and on the basis of structured interviews with the "Mini International Neuropsychiatric Interview" and on a review of records, we assessed the recruitment in terms of psychiatric monitoring as well as the associated psychiatric diagnoses in patients who consulted for an unexplained syncope. RESULTS: Of the 91 patients who have consulted the Interdisciplinary Centre of Unexplained Faintness and Syncopes in 2009, 24% have been directed towards a psychiatric evaluation. Among these, 68% suffered from an anxiety disorder, 27% from a major depressive disorder and 22% from a substance-related disorder. DISCUSSION: We assess the interesting conditions that the Interdisciplinary Centre of Unexplained Faintness and Syncopes proposes for a liaison psychiatry activity. We note the interest in easier access to psychiatric care for a group that would not have spontaneously approached the Centre. CONCLUSION: Other measures of quality of care indices are still to be developed.
Assuntos
Comportamento Cooperativo , Comunicação Interdisciplinar , Transtornos Mentais/diagnóstico , Transtornos Mentais/psicologia , Equipe de Assistência ao Paciente , Psiquiatria , Transtornos Psicofisiológicos/diagnóstico , Transtornos Psicofisiológicos/psicologia , Transtornos Somatoformes/diagnóstico , Transtornos Somatoformes/psicologia , Síncope/etiologia , Síncope/psicologia , Transtornos de Ansiedade/diagnóstico , Transtornos de Ansiedade/psicologia , Bélgica , Transtorno Depressivo Maior/diagnóstico , Transtorno Depressivo Maior/psicologia , Diagnóstico Diferencial , Humanos , Entrevista Psicológica , Transtornos Relacionados ao Uso de Substâncias/diagnóstico , Transtornos Relacionados ao Uso de Substâncias/psicologiaRESUMO
PURPOSE: We created an epilepsy patient database that can be accessed via the Internet by neurologists from anywhere in the world. The database was designed to enroll and follow large cohorts of patients with specific epilepsy syndromes, and to facilitate recruitment of patients for investigator-initiated clinical trials. METHODS: The EpiNet database records physician-derived information regarding seizure type and frequency, epilepsy syndrome, etiology, drug history, and investigations. It can be accessed from any country by approved investigators via a secure, password-protected Website. All data are encrypted. The database is for both research and clinical purposes. Investigators were invited to register any patient with epilepsy, but were particularly encouraged to register patients when uncertain of the optimal management. Participation required approval from investigators' ethics committees and institutional review boards, and all patients or their caregiver provided written informed consent. Patients were not enrolled in clinical trials in this pilot study. KEY FINDINGS: The international pilot study recruited patients from September 2010 to November 2011. Sixty-four investigators or research assistants from 25 centers in 13 countries registered 1,050 patients. Patients with a wide range of epilepsy syndromes and etiologies were registered. Patients' ages ranged from 2 weeks to 90 years. SIGNIFICANCE: The Website was successfully used by doctors working in different health systems. The pilot study confirmed that this low-cost, collaborative approach to research has great potential. Large, multicenter cohort studies will commence in 2012, and randomized clinical trials are being planned. All epileptologists are invited to join this project.
Assuntos
Anticonvulsivantes/uso terapêutico , Pesquisa Biomédica/métodos , Ensaios Clínicos como Assunto , Epilepsia/tratamento farmacológico , Cooperação Internacional , Internet , Adolescente , Adulto , Idoso , Idoso de 80 Anos ou mais , Criança , Pré-Escolar , Coleta de Dados/métodos , Bases de Dados Factuais/estatística & dados numéricos , Epilepsia/classificação , Epilepsia/etiologia , Humanos , Lactente , Recém-Nascido , Pessoa de Meia-Idade , Estudos Multicêntricos como Assunto , Seleção de Pacientes , Projetos Piloto , Adulto JovemRESUMO
In 2008, a group of Belgian epilepsy experts published recommendations for antiepileptic drug (AED) treatment of epilepsies in adults and children. Selection of compounds was based on the registration and reimbursement status in Belgium, the level of evidence for efficacy, common daily practice and the personal views and experiences of the authors. In November 2011 the validity of these recommendations was reviewed by the same group of Belgian epilepsy experts who contributed to the preparation of the original paper. The recommendations made in 2008 for initial monotherapy in paediatric patients were still considered to be valid, except for the first choice treatment for childhood absence epilepsy. This update therefore focuses on the treatment recommendations for initial monotherapy and add-on treatment in adult patients. Several other relevant aspects of treatment with AEDs are addressed, including considerations for optimal combination of AEDs (rational polytherapy), pharmacokinetic properties, pharmacodynamic and pharmacokinetic interaction profile, adverse effects, comorbidity, treatment of elderly patients, AED treatment during pregnancy, and generic substitution of AEDs.
Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Medicina Geral/normas , Guias como Assunto/normas , Adolescente , Adulto , Bélgica , Comorbidade , Bases de Dados Factuais/estatística & dados numéricos , Epilepsia/epidemiologia , Feminino , Humanos , Masculino , Adulto JovemRESUMO
BACKGROUND: Given the continuous knowledge progression and the growing number of available antiepileptic drugs (AEDs), making appropriate treatment choices for patients with epilepsy is increasingly difficult. While published guidelines help for separate clinical aspects, patients with a combination of specific characteristics may escape proper guidance. This study aimed to determine the appropriateness of AEDs for particular clinical variables and to offer treatment recommendations for adult patients with epilepsy in a user-friendly format for practicing neurologists. METHODS: Using the RAND/UCLA Appropriateness Method, the appropriateness of AEDs as initial/second mono-therapy and combination therapy was assessed in relation to selected clinical variables by a Belgian panel of 13 experts in epilepsy. Panel recommendations for particular patient profiles were determined by the outcome of these separate ratings. RESULTS: The appropriateness outcome of individual AEDs was not substantially different between first and second mono-therapy; valproate was considered appropriate for all types of generalised and partial seizures. The outcome for combination therapy was highly dependent on the type of AED and seizures. With respect to co-morbidities and co-treatments, levetiracetam and pregabalin proved to have the least contra-indications. For the elderly and with respect to factors related to the female reproductive system the appropriateness of AEDs showed a more diffuse pattern. Although caution was deemed necessary for some combinations, the AEDs were never considered inappropriate regarding their drug interaction profile. CONCLUSIONS: The Epi-Scope(®) tool that displays appropriateness recommendations for highly specific, possibly complex cases, supports optimal treatment choices for adult patients with epilepsy in daily practice.
Assuntos
Anticonvulsivantes/uso terapêutico , Epilepsia/tratamento farmacológico , Sistemas Inteligentes , Adolescente , Adulto , Técnicas de Apoio para a Decisão , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Interface Usuário-Computador , Adulto JovemAssuntos
Anestesia Epidural/efeitos adversos , Encefalopatias/etiologia , Siderose/etiologia , Lágrimas , Encefalopatias/líquido cefalorraquidiano , Humanos , Imageamento por Ressonância Magnética/métodos , Masculino , Pessoa de Meia-Idade , Punção Espinal/efeitos adversos , Tomografia por Raios X/métodosRESUMO
A significant proportion of the population suffers from tinnitus, a bothersome auditory phantom perception that can severely alter the quality of life. Numerous experimental studies suggests that a maladaptive plasticity of the auditory and limbic cortical areas may underlie tinnitus. Accordingly, repetitive transcranial magnetic stimulation (rTMS) has been repeatedly used with success to reduce tinnitus intensity. The potential of transcranial direct current stimulation (tDCS), another promising method of noninvasive brain stimulation, to relieve tinnitus has not been explored systematically. In a double-blind, placebo-controlled and balanced order design, 20 patients suffering from chronic untreatable tinnitus were submitted to 20 minutes of 1 mA anodal, cathodal and sham tDCS targeting the left temporoparietal area. The primary outcome measure was a change in tinnitus intensity or discomfort assessed with a Visual Analogic Scale (VAS) change-scale immediately after tDCS and 1 hour later. Compared to sham tDCS, anodal tDCS significantly reduced tinnitus intensity immediately after stimulation; whereas cathodal tDCS failed to do so. The variances of the tinnitus intensity and discomfort VAS change-scales increased dramatically after anodal and cathodal tDCS, whereas they remained virtually unchanged after sham tDCS. Moreover, several patients unexpectedly reported longer-lasting effects (at least several days) such as tinnitus improvement, worsening, or changes in tinnitus features, more frequently after real than sham tDCS. Anodal tDCS is a promising therapeutic tool for modulating tinnitus perception. Moreover, both anodal and cathodal tDCS seem able to alter tinnitus perception and could, thus, be used to trigger plastic changes.
Assuntos
Zumbido/terapia , Estimulação Magnética Transcraniana/métodos , Adulto , Idoso , Doença Crônica , Método Duplo-Cego , Eletrodos , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Adulto JovemRESUMO
Cluster headache (CH) is among the most painful headache disorders. There is still no unifying pathophysiological hypothesis to explain the trigeminal distribution, the circadian periodicity and the autonomic symptoms of the syndrome. We report the case of a patient with worsening of CH following administration of pramipexole for a restless legs syndrome (RLS). This observation supports the hypothesis that the dopaminergic system may play a role in the genesis or trigger of CH.
Assuntos
Benzotiazóis/efeitos adversos , Cefaleia Histamínica/induzido quimicamente , Agonistas de Dopamina/efeitos adversos , Síndrome das Pernas Inquietas/tratamento farmacológico , Benzotiazóis/administração & dosagem , Cefaleia Histamínica/fisiopatologia , Dopamina/fisiologia , Agonistas de Dopamina/administração & dosagem , Humanos , Masculino , Pessoa de Meia-Idade , Pramipexol , RecidivaRESUMO
BACKGROUND: Transcranial direct current stimulation (tDCS) is used in human physiological studies and for therapeutic trials in patients with abnormalities of cortical excitability. Its safety profile places tDCS in the pole-position for translating in real-world therapeutic application. However, an episode of transient respiratory depression in a subject receiving tDCS with an extracephalic electrode led to the suggestion that such an electrode montage could modulate the brainstem autonomic centres. We investigated whether tDCS applied over the midline frontal cortex in 30 healthy volunteers (sham n = 10, cathodal n = 10, anodal n = 10) with an extracephalic reference electrode would modulate brainstem activity as reflected by the monitoring and stringent analysis of vital parameters: heart rate (variability), respiratory rate, blood pressure and sympatho-vagal balance. We reasoned that this study could lead to two opposite but equally interesting outcomes: 1) If tDCS with an extracephalic electrode modulated vital parameters, it could be used as a new tool to explore the autonomic nervous system and, even, to modulate its activity for therapeutic purposes. 2) On the opposite, if applying tDCS with an extracephalic electrode had no effect, it could thus be used safely in healthy human subjects. This outcome would significantly impact the field of non-invasive brain stimulation with tDCS. Indeed, on the one hand, using an extracephalic electrode as a genuine neutral reference (as opposed to the classical "bi-cephalic" tDCS montages which deliver bi-polar stimulation of the brain) would help to comfort the conclusions of several modern studies regarding the spatial location and polarity of tDCS. On the other hand, using an extracephalic reference electrode may impact differently on a given cortical target due to the change of direct current flow direction; this may enlarge the potential interventions with tDCS. RESULTS: Whereas the respiratory frequency decreased mildly over time and the blood pressure increased steadily, there was no differential impact of real (anodal or cathodal) versus sham tDCS. The heart rate remained stable during the monitoring period. The parameters reflecting the sympathovagal balance suggested a progressive shift over time favouring the sympathetic tone, again without differential impact of real versus sham tDCS. CONCLUSIONS: Applying tDCS with an extracephalic reference electrode in healthy volunteers did not significantly modulate the activity of the brainstem autonomic centres. Therefore, using an extracephalic reference electrode for tDCS appears safe in healthy volunteers, at least under similar experimental conditions.