Brazilian autoimmune encephalitis network (BrAIN): antibody profile and clinical characteristics from a multicenter study.

Background: The frequency of antibodies in autoimmune encephalitis (AIE) may vary in different populations, however, data from developing countries are lacking. To describe the clinical profile of AIE in Brazil, and to evaluate seasonality and predictors of AIE in adult and pediatric patients. Methods: We evaluated patients with possible AIE from 17 centers of the Brazilian Autoimmune Encephalitis Network (BrAIN) between 2018 and 2022. CSF and serum were tested with TBAs and CBAs. Data on clinical presentation, complementary investigation, and treatment were compiled. Seasonality and predictors of AIE in adult and pediatric populations were analyzed. Results: Of the 564 patients, 145 (25.7%) were confirmed as seropositive, 69 (12.23%) were seronegative according to Graus, and 58% received immunotherapy. The median delay to diagnosis confirmation was 5.97 ± 10.3 months. No seasonality variation was observed after 55 months of enrolment. The following antibodies were found: anti-NMDAR (n=79, 54%), anti-MOG (n=14, 9%), anti-LGI1(n=12, 8%), anti-GAD (n=11, 7%), anti-GlyR (n=7, 4%), anti-Caspr2 (n=6, 4%), anti-AMPAR (n=4, 2%), anti-GABA-BR (n=4, 2%), anti-GABA-AR (n=2, 1%), anti-IgLON5 (n=1, 1%), and others (n=5, 3%). Predictors of seropositive AIE in the pediatric population (n=42) were decreased level of consciousness (p=0.04), and chorea (p=0.002). Among adults (n=103), predictors of seropositive AIE were movement disorders (p=0.0001), seizures (p=0.0001), autonomic instability (p=0.026), and memory impairment (p=0.001). Conclusion: Most common antibodies in Brazilian patients are anti-NMDAR, followed by anti-MOG and anti-LGI1. Only 26% of the possible AIE patients harbor antibodies, and 12% were seronegative AIE. Patients had a 6-month delay in diagnosis and no seasonality was found. Findings highlight the barriers to treating AIE in developing countries and indicate an opportunity for cost-effect analysis. In this scenario, some clinical manifestations help predict seropositive AIE such as decreased level of consciousness, chorea, and dystonia among children, and movement disorders and memory impairment among adults.

Temperature and wavelength drift tolerant WDM transmission and routing in on-chip silicon photonic interconnects.

We demonstrate a temperature and wavelength shift resilient silicon transmission and routing interconnect system suitable for multi-socket interconnects, utilizing a dual-strategy CLIPP feedback circuitry that safeguards the operating point of the constituent photonic building blocks along the entire on-chip transmission-multiplexing-routing chain. The control circuit leverages a novel control power-independent and calibration-free locking strategy that exploits the 2nd derivative of ring resonator modulators (RMs) transfer function to lock them close to the point of minimum transmission penalty. The system performance was evaluated on an integrated Silicon Photonics 2-socket demonstrator, enforcing control over a chain of RM-MUX-AWGR resonant structures and stressed against thermal and wavelength shift perturbations. The thermal and wavelength stress tests ranged from 27°C to 36°C and 1309.90 nm to 1310.85 nm and revealed average eye diagrams Q-factor values of 5.8 and 5.9 respectively, validating the system robustness to unstable environments and fabrication variations.

Amorphous-silicon visible-light detector integrated on silicon nitride waveguides.

Visible-light integrated photonics is emerging as a promising technology for the realization of optical devices for applications in sensing, quantum information and communications, imaging, and displays. Among the existing photonic platforms, high-index-contrast silicon nitride (Si3N4) waveguides offer broadband transparency in the visible spectral range and a high scale of integration. As the complexity of photonic integrated circuits (PICs) increases, on-chip detectors are required to monitor their working point for reconfiguration and stabilization operations. In this Letter, we present a semi-transparent in-line power monitor integrated on Si3N4 waveguides that operates in the red-light wavelength range (660 nm). The proposed device exploits the photoconductivity of a hydrogenated amorphous-silicon (a-Si:H) film that is evanescently coupled to an optical waveguide. Experimental results show a responsivity of 30 mA/W, a sensitivity of -45 dBm, and a sub-µs time response. These features enable the use of the proposed photoconductor for high-sensitivity monitoring and control of visible-light Si3N4 PICs.

High-sensitivity transparent photoconductors in voltage-controlled silicon waveguides.

On-chip optical power monitors are essential elements to calibrate, stabilize, and reconfigure photonic integrated circuits. Many applications require in-line waveguide detectors, where a trade-off has to be found between large sensitivity and high transparency to the guided light. In this work, we demonstrate a transparent photoconductor integrated on standard low-doped silicon-on-insulator waveguides that reaches a photoconductive gain of more than 106 and an in-line sensitivity as high as -60 dBm. This performance is achieved by compensating the effect of electric charges in the cladding oxide through a bias voltage applied to the chip substrate or locally through a gate electrode on top of the waveguide, allowing one to tune on demand the conductivity of the core to the optimum level.

Electrical conductance of silicon photonic waveguides.

Many optoelectronic devices embedded in a silicon photonic chip, like photodetectors, modulators, and attenuators, rely on waveguide doping for their operation. However, the doping level of a waveguide is not always reflecting in an equal amount of free carriers available for conduction because of the charges and trap energy states inevitably present at the Si/SiO2 interface. In a silicon-on-insulator technology with 1015cm-3p-doped native waveguides, this can lead to a complete depletion of the core from free carriers and to a consequently very high electrical resistance. This Letter experimentally quantifies this effect and shows how the amount of free carriers in a waveguide can be modified and restored to the original doping value with a proper control of the chip substrate potential. A similar capability is also demonstrated by means of a specific metal gate integrated above the waveguide that allows fine control of the conductance with high locality level. This paper highlights the linearity achievable in the conductance modulation that can be exploited in a number of possible applications.

Autoimmune encephalitis: a review of diagnosis and treatment.

Autoimmune encephalitis (AIE) is one of the most common causes of noninfectious encephalitis. It can be triggered by tumors, infections, or it may be cryptogenic. The neurological manifestations can be either acute or subacute and usually develop within six weeks. There are a variety of clinical manifestations including behavioral and psychiatric symptoms, autonomic disturbances, movement disorders, and seizures. We reviewed common forms of AIE and discuss their diagnostic approach and treatment.

Autoimmune encephalitis: a review of diagnosis and treatment / Encefalites autoimunes: uma revisão sobre diagnóstico e tratamento

ABSTRACT Autoimmune encephalitis (AIE) is one of the most common causes of noninfectious encephalitis. It can be triggered by tumors, infections, or it may be cryptogenic. The neurological manifestations can be either acute or subacute and usually develop within six weeks. There are a variety of clinical manifestations including behavioral and psychiatric symptoms, autonomic disturbances, movement disorders, and seizures. We reviewed common forms of AIE and discuss their diagnostic approach and treatment.

RESUMO As encefalites autoimunes (EAI) são a principal causa de encefalite não-infecciosa. As manifestações neurológicas são variadas, incluindo alterações comportamentais ou psiquiátricas, disautonomia, transtornos do movimento e epilepsia. Habitualmente a instalação dos sintomas ocorre em até 6 semanas, de forma aguda ou subaguda. As EAI podem ser desencadeadas por tumores, quadros infecciosos virais ou ainda apresentar etiologia criptogênica. Este artigo revisa as principais EAI, estratégias de diagnóstico e tratamento.

Neuropsychiatric Lupus in clinical practice.

Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs, characterized by the production of autoantibodies and the development of tissue injury. The etiology of SLE is partially known, involving multiple genetic and environmental factors. As many as 50% of patients with SLE have neurological involvement during the course of their disease. Neurological manifestations are associated with impaired quality of life, and high morbidity and mortality rates. Nineteen neuropsychiatric syndromes have been identified associated with SLE, and can be divided into central and peripheral manifestations. This article reviews major neuropsychiatric manifestations in patients with SLE and discusses their clinical features, radiological findings and treatment options.

Neuropsychiatric Lupus in clinical practice / Lúpus neuropsiquiátrico na prática clínica

ABSTRACT Systemic lupus erythematosus (SLE) is a chronic autoimmune disease involving multiple organs, characterized by the production of autoantibodies and the development of tissue injury. The etiology of SLE is partially known, involving multiple genetic and environmental factors. As many as 50% of patients with SLE have neurological involvement during the course of their disease. Neurological manifestations are associated with impaired quality of life, and high morbidity and mortality rates. Nineteen neuropsychiatric syndromes have been identified associated with SLE, and can be divided into central and peripheral manifestations. This article reviews major neuropsychiatric manifestations in patients with SLE and discusses their clinical features, radiological findings and treatment options.

RESUMO Lúpus eritematoso sistêmico (LES) é uma doença autoimune crônica que envolve múltiplos órgãos e sistemas, caracterizada pela produção de auto anticorpos e lesão tecidual. A etiologia do LES é parcialmente conhecida e envolve interação entre fatores genéticos e ambientais. Até 50% dos pacientes com LES apresentam envolvimento neurológico no decorrer da doença. Manifestações neurológicas estão associadas a prejuízo na qualidade de vida e altas taxas de mortalidade e morbidade. Foram identificadas 19 síndromes neuropsiquiátricas em pacientes com LES, divididas entre manifestações do sistema nervoso central e periférico. O objetivo deste artigo é revisar as manifestações neuropsiquiátricas mais importantes. Serão abordadas as características clínicas, os aspectos radiológicos e opções de tratamento dos eventos neuropsiquiátricos.

Reversible Obstructive Hydrocephalus from Hypertensive Encephalopathy: A Condition that Neurosurgeons Must Know / Hidrocefalia obstrutiva reversível secundária a encefalopatia hipertensiva: uma condição que o neurocirurgião deve conhecer

The vasogenic edema in structures of posterior fossa secondary to elevated hydrostatic pressure can cause obstructive hydrocephalus, a condition called "reversible obstructive hydrocephalus from hypertensive encephalopathy." A case of a 27-year-old woman with arterial hypertension and sign of raised intracranial pressure is reported. Her radiologic studies have showed vasogenic cerebellar edema without structural lesion. This edema leads to obstruction of the cerebral aqueduct. We discuss the clinical and therapeutic aspects of this condition. In this clinical situation, the accurate control of blood pressure is themain goal on medical care, and the need of permanent ventricular shunt is quite infrequent.

O edema vasogênico secundário a elevação da pressão hidrostática capilar pode causar hidrocefalia obstrutiva, a chamada Hidrocefalia Obstrutiva Reversível secundária a Encefalopatia Hipertensiva. Nós apresentamos umcaso de umamulher de 27 anos com hipertensão arterial e sinais de hipertensão intracraniana. Sua investigação radiológica evidenciou sinais de edema vasogênico cerebelar bilateral sem lesão estrutural, determinando obstrução do aqueduto cerebral Nós discutimos os aspectos clínicos e terapêuticos deste caso. Nesta condição, o adequado controle da pressão arterial é a principal medida terapêutica, sendo a necessidade de derivação liquórica permanente infrequente.