General low alertness in people with obstructive sleep apnea.

STUDY OBJECTIVES: In patients with obstructive sleep apnea (OSA), a previous study using a Go/No-Go task reported an average attention deficit. However, the temporal dynamics of such a deficit is unknown. Here, we investigated whether attention deficits in different subdomains increased as test progressed. We also investigated the effect of target frequency and speed of stimulus presentation on performance. METHODS: twenty-seven non-treated people with OSA and 27 age- and sex-matched controls underwent a 15-minute Go/No-Go task, divided into 6 blocks. Each block was subdivided into three different interstimulus intervals (1, 2, and 4s). Three blocks had a low and three had a high target probability (20% and 80%, respectively). Measured were reaction time (alertness), variability of reaction time (sustained attention), commission errors (response inhibition), and omission errors (focused attention). RESULTS: Alertness was lower in the group with OSA compared to controls, as evidenced by a significantly higher average reaction time. This effect was seen from the start of the task, continued until the end, but did not increase in test progression. The temporal pattern of intrinsic alertness deficits in patients with OSA was found to be independent of target frequency or interstimulus interval. CONCLUSIONS: The primary attention problem in OSA is on the alertness subdomain irrespective of the number of required responses or speed of stimulus presentation. The present results support the notion that OSA is distinct from other neurological and psychiatric conditions, such as depression or chronic pain. The results also posit significant concerns regarding daily life activities (e.g., driving).

The hypothalamic-pituitary-adrenal axis and the central monoaminergic systems: a pathophysiological link to insomnia with clinical implications.

The authors present a theoretical overview of the hypothalamic-pituitary-adrenal axis and the central monoaminergic systems, focusing on a putative pathophysiological relationship to insomnia complaints. Insomnia is an independent and self-perpetuating disorder that requires diagnostic and therapeutic attention in the presence of concomitant disorders, likely with bidirectional influence. An adequate understanding of such mechanisms can help for a better understanding of the interplay between clinical features, neurotransmitters, and the adrenal hypothalamic-pituitary axis may help clinicians to better manage insomnia patients.

Pseudotumor Cerebri and Glymphatic Dysfunction.

In contrast to virtually all organ systems of the body, the central nervous system was until recently believed to be devoid of a lymphatic system. The demonstration of a complex system of paravascular channels formed by the endfeet of astroglial cells ultimately draining into the venous sinuses has radically changed this idea. The system is subsidized by the recirculation of cerebrospinal fluid (CSF) through the brain parenchyma along paravascular spaces (PVSs) and by exchanges with the interstitial fluid (IF). Aquaporin-4 channels are the chief transporters of water through these compartments. This article hypothesizes that glymphatic dysfunction is a major pathogenetic mechanism underpinning idiopathic intracranial hypertension (IIH). The rationale for the hypothesis springs from MRI studies, which have shown many signs related to IIH without evidence of overproduction of CSF. We propose that diffuse retention of IF is a direct consequence of an imbalance of glymphatic flow. This imbalance, in turn, may result from an augmented flow from the arterial PVS into the IF, by impaired outflow of the IF into the paravenous spaces, or both. Our hypothesis is supported by the facts that (i) visual loss, one of the main complications of IIH, is secondary to the impaired drainage of the optic nerve, a nerve richly surrounded by water channels and with a long extracranial course in its meningeal sheath; (ii) there is a high association between IIH and obesity, a condition related to paravascular inflammation and lymphatic disturbance, and (iii) glymphatic dysfunction has been related to the deposition of ß-amyloid in Alzheimer's disease. We conclude that the concept of glymphatic dysfunction provides a new perspective for understanding the pathophysiology of IIH; it may likewise entice the development of novel therapeutic approaches aiming at enhancing the flow between the CSF, the glymphatic system, and the dural sinuses.

Brazilian consensus on guidelines for diagnosis and treatment for restless legs syndrome.

The Consensus on restless legs syndrome is an effort of neurologists from several Brazilian states, which tirelessly reviewed the literature of recent years in search of evidence, both in regard to diagnosis and treatment, according to the Oxford Centre for Evidence-based Medicine.

Brazilian consensus on guidelines for diagnosis and treatment for restless legs syndrome / Consenso Brasileiro para as diretrizes de diagnóstico e tratamento da síndrome das pernas inquietas

The Consensus on restless legs syndrome is an effort of neurologists from several Brazilian states, which tirelessly reviewed the literature of recent years in search of evidence, both in regard to diagnosis and treatment, according to the Oxford Centre for Evidence-based Medicine.

O Consenso em síndrome das pernas inquietas contou com a participação de neurologistas de vários estados brasileiros, os quais incansavelmente revisaram a literatura dos últimos anos em busca de evidências, tanto no que se refere ao diagnóstico como ao tratamento, de acordo com a Classificação do Centro de Oxford para Medicina Baseada em Evidências.

Condutas terapêuticas para tratamento da Síndrome da Apnéia e Hipopnéia Obstrutiva do Sono (SAHOS) e da Síndrome da Resistência das Vias Aéreas Superiores (SRVAS) com enfoque no Aparelho Anti-Ronco (AAR-ITO) / Obstructive Sleep Apnea and Hypopnea Syndrome (OSAHS) and snoring: treatment strategies with focus in Mandibular Advancement Device® (MAD-ITO)

Os autores apresentam uma revisão da literatura referente às alternativas de tratamento cirúrgicas e não-cirúrgicas para a Síndrome da Apnéia e Hipopnéia Obstrutiva do Sono (SAHOS) e para a Síndrome da Resistência das Vias Aéreas superiores (SRVAS) com enfoque no princípio de ação e evolução dos aparelhos de avanço mandibular e, em particular, no mecanismo dinâmico de ação do Aparelho Anti-Ronco® (AAR-ITO).

Mecanismo de ação dinâmico de aparelho Anti-Ronco« (AAR): relato de um caso clínico / Dynamic action mechanism of aparelho anti-ronco«: a case report

Os autores apresentaram um caso clínico no qual foi utilizada a técnica do Aparelho Anti-Ronco« (AAR). Os objetivos deste estudo foram avaliar o efeito do AAR« utilizado no tratamento conservador da Síndrome da Apnéia e Hipopnéia Obstrutiva do Sono (SAHOS) e descrever o mecanismo dinâmico de ação deste aparelho. O paciente F. B., 68 anos, realizou 3 polissonografias (PSGs) noturnas (Polígrafo Digital EMSA). A primeira PSG (Baseline), sem o AAR«, revelou SAHOS severa - Índice de Apnéia/Hipopnéia (IAH) 53 eventos/hora associado a roncos intensos. O tratamento foi realizado devido à resistência do paciente em usar o aparelho de Pressão Aérea Positiva Contínua (CPAP). Na segunda PSG, após 6 meses de tratamento com o AAR«, o resultado revelou melhora significativa no IAH que foi reduzido para 28 eventos/hora. Na terceira PSG, após 1 ano de tratamento com o AAR«, o paciente continuou exibindo melhora com IAH 22 eventos/hora. Ambas PSGS foram registradas com o AAR«. Tendo como principal parâmetro o IAH, podemos concluir diante destes resultados preliminares, que o AAR« pode ser uma alternativa eficaz para o tratamento conservador da SAHOS severa em pacientes que se recusaram a utilizar o CPAP

Hematoma tegmento-mesencefálico espontâneo: aspectos neurocomportamentais do terço rostral do tronco encefálico humano / Spontaneous tegment-mesencephalic hematoma: neurobehavioral aspects of the rostral third of the human brainstem

O tegmento do mesencéfalo e área complexa, dada a quantidade de fibras que o atravessam, provenientes de circuitos locais, de sistemas ativadores e de feixes descendentes dos hemisférios cerebrais. No presente artigo, relatamos o caso de um senhor de 67 anos, que sofreu hemorragia mesencefálica de localizaçao tegmental, vindo a falecer 1 mês depois. Inicialmente, foi julgado em coma, por apresentar ptose bilateral, ausência de fala e de movimentos espontâneos. Por volta da segunda semana, descobriu-se que podia cumprir comandos verbais, sentar, sustentar-se de pé e andar. O caso demonstra o quanto o diagnóstico do coma em bases clínicas pode ser enganoso em pacientes como esse, no qual a aparente irresponsividade de olhos fechados se deve à combinaçao inesperada de abulia e oftalmoplegia.