Changes in blink reflex after simultaneous supraorbital and mental nerve stimulations in healthy subjects.

Background/aim: In this study, we investigated the blink reflex (BR) after simultaneous and asynchronous stimulation of two trigeminal nerve branches. The objective was to characterize the physiology of trigeminal and facial circuits. Materials and methods: We performed three sets of experiments: recording BR response i. after supraorbital nerve stimulation (SON), after mental nerve stimulation (MN), and after simultaneous SON and MN stimulation (SON+MN) in 18 healthy individuals; ii. after MN (at an intensity eliciting BR response) preceding SON at various interstimulus intervals (ISIs) in seven healthy subjects; iii after MN (at sensory threshold) preceding SON at various ISIs. We compared the magnitudes of early and late responses. Results: The R1 amplitude after simultaneous SON+MN stimulation was greater than responses after single stimulation of the same branches. After simultaneous stimulations, the R2 and R2c areas under the curve (AUC) were smaller than the arithmetic sums of R2 and R2c AUC obtained after single stimulations. The second experiment provided a recovery excitability curve. In the third step, we obtained facilitation of R1 and inhibition of late responses. Conclusion: The SON+MN stimulation caused an increased R1 circuit excitability compared to the arithmetic sum of the single stimulations; however, magnitudes of late responses did not potentiate. Thus, we have provided evidence for R1 circuit enhancement by simultaneous stimulation in humans, whereas modulation of late responses exhibited a recovery curve similar to that shown for paired SON stimulation.

Blink reflex excitability in patients with Hemifacial spasm exhibiting different abnormal discharge patterns: from early isolated discharges to later grouped bursts or tonic spasms.

OBJECTIVE: We studied blink reflex (BR) and BR excitability recovery (BRER) in patients with hemifacial spasm (HFS) exhibiting different abnormal discharge patterns. We hypothesized that patients with groups of clonic or tonic burst activities appear later in the disease course and may have more excitability of the BR circuit at the brainstem compared to patients with isolated twitchings, which occur earlier. METHODS: We included 124 patients with botulinum toxin-naive HFS (mean age 50.6 ± 13.3 years) and 40 healthy subjects. We performed surface polymyography on facial muscles in patients and classified them according to the abnormal discharge pattern: isolated discharges, grouped bursts forming random sequences, tonic spasms, and a combination of these activities. Then, we recorded BR and BRER at 200, 600, and 1000 ms interstimulus intervals. We compared disease duration, R1 and R2 latencies, R2 area-under-the-curve (AUC), and BRER% (i) between healthy subjects and patients and (ii) among groups of patients with different abnormal discharge patterns. RESULTS: There were isolated discharges in 28 patients, grouped bursts forming random sequences in 42, and continuous muscle activity with tonic spasms in one. The remaining patients had combinations. Mean R1 and R2 latencies were significantly longer, and mean R2 AUC was significantly higher on the symptomatic side of patients compared to healthy subjects. The mean BRER was enhanced on both sides in patients than in healthy subjects (p < 0.001). However, it was similar among patient groups with different abnormal discharge patterns (p > 0.05). The mean disease duration in patients with isolated discharges was shorter (3.3 ± 2.0 years) than those with grouped bursts or tonic spasms (p = 0.002; Kruskal-Wallis test). CONCLUSION: Our study observed that excitability at the brainstem was similar in HFS patients with different abnormal discharge patterns, suggesting that the difference in discharge patterns in HFS may be due to a reason other than the difference in BR excitability.

Seizures in patients with respiratory disease - a retrospective single center study / Convulsões em pacientes com doença respiratória - estudo retrospectivo de centro único

ABSTRACT Objective: Seizures are a neurological condition commonly experienced during the follow-up period after systemic or metabolic disorders. The aim of the present study was to determine the etiological factors of seizures in patients at a tertiary care chest clinic. Methods: We reviewed all neurology consultations that were requested due to seizures in inpatient clinics in a tertiary care hospital specializing in respiratory disorders between January 2011 and January 2018 were retrospectively reviewed. Results: The present study included 705 of 2793 (25.2%) patients who requested consultations for seizures during the study period. The mean age of the sample was 64.05±17.19 years. Of the 705 patients, 307 (43.5%) had a previous history of epilepsy (Group I) and 398 (56.5%) had a first-time seizure and were considered to have symptomatic seizures (Group II). Multiple factors played roles in the development of seizures in 54.8% of the patients. In most patients, metabolic causes, systemic infections, and drug use were identified and an intracranial metastatic mass lesion was the major cause in patients with lung cancer. Rates of hypoxemia and respiratory acidosis were significantly higher in patients with symptomatic seizures (Group II) than in patients with primary epilepsy (Group I). Conclusions: Blood gas changes such as hypoxemia and respiratory acidosis were among the factors statistically associated with the development of symptomatic seizures in patients with respiratory diseases. Additionally, hypoxemia, hypercapnia, and respiratory acidosis were correlated with mortality in patients hospitalized for respiratory system diseases who requested consultations for seizures.

RESUMO Objetivo: Convulsões são uma condição neurológica comumente vivenciada durante o período de acompanhamento após distúrbios sistêmicos ou metabólicos. O objetivo do presente estudo foi determinar os fatores etiológicos das convulsões em pacientes de uma clínica torácica de atendimento terciário. Métodos: Foram revisadas retrospectivamente todas as consultas neurológicas solicitadas devido a convulsões em clínicas de internação em um hospital terciário especializado em distúrbios respiratórios entre janeiro de 2011 e janeiro de 2018. Resultados: O presente estudo incluiu 705 dos 2.793 (25,2%) pacientes que solicitaram consultas para convulsões durante o período do estudo. A idade média da amostra foi de 64,05±17,19 anos. Dos 705 pacientes, 307 (43,5%) tinham história prévia de epilepsia (Grupo I) e 398 (56,5%) tiveram uma convulsão inicial e foram considerados como tendo crises sintomáticas (Grupo II). Vários fatores desempenharam papel no desenvolvimento de convulsões em 54,8% dos pacientes. Na maioria dos pacientes, causas metabólicas, infecções sistêmicas e uso de drogas foram identificadas e uma lesão em massa metastática intracraniana foi a principal causa em pacientes com câncer de pulmão. As taxas de hipoxemia e acidose respiratória foram significativamente maiores em pacientes com crises sintomáticas (Grupo II) do que em pacientes com epilepsia primária (Grupo I). Conclusões: Alterações dos gases sanguíneos, como hipoxemia e acidose respiratória, foram alguns dos fatores estatisticamente associados ao desenvolvimento de convulsões sintomáticas em pacientes com doenças respiratórias. Além disso, hipoxemia, hipercapnia e acidose respiratória foram correlacionadas com a mortalidade em pacientes hospitalizados por doenças do sistema respiratório que solicitaram consultas para convulsões.