Deltoid muscle strength and autonomic dysfunction as independent risk factors for invasive mechanical ventilation in patients with Guillain-Barré syndrome.

BACKGROUND: Almost a third of patients with Guillain-Barré Syndrome (GBS) require mechanical ventilation, increasing mortality by 15-30% and proving poor functional outcomes. The Erasmus GBS Respiratory Insufficiency Score (EGRIS) is the most frequently used scale to assess probability of respiratory insufficiency within the first week of admission. We aim to determine other clinical and electrophysiological prognostic factors for invasive mechanical ventilation (IMV) in patients with GBS. MATERIAL AND METHODS: A cross-sectional ambispective cohort study was carried out in a referral center in Mexico City, from January 2015 to December 2019. Baseline demographics, MRC score, Hughes scale, EGRIS, dysautonomia and nerve conduction studies were performed on admission in GBS patients that required IMV. A multivariable analysis for IMV and a survival analysis for independent walk in prolonged-IMV (>14 days) were performed. RESULTS: Forty-nine (32%) out of 153 GBS patients required IMV. Statistically significant prognostic factors in multivariable analysis were deltoid muscle strength ≤2 [OR 7.1 (1.6-31.1)], EGRIS [OR 2.5 (1.3-4.6)] and autonomic dysfunction [OR 6.6 (2.0-22.0)]. Electrodecrement <1 mV in the compound muscle action potential (CMAP) of distal motor median nerve was more prevalent in prolonged-IMV patients (44.8% vs. 21%, p = .049). A significant minor prevalence of prolonged-IMV patients regain independent walk at 6 months using the Kaplan-Meier method (log rank test p < .001). CONCLUSIONS: We provide new specific clinical (deltoid muscle strength and autonomic dysfunction) and electrophysiological variables to discriminate GBS patients that will require IMV.

Incidence of Guillain-Barré syndrome following SARS-CoV-2 immunization: Analysis of a nationwide registry of recipients of 81 million doses of seven vaccines.

BACKGROUND AND PURPOSE: Information on Guillain-Barré syndrome (GBS) as an adverse event following immunization (AEFI) against SARS-CoV-2 remains scarce. We aimed to report GBS incidence as an AEFI among adult (≥18 years) recipients of 81,842,426 doses of seven anti-SARS-CoV-2 vaccines between December 24, 2020, and October 29, 2021, in Mexico. METHODS: Cases were retrospectively collected through passive epidemiological surveillance. The overall observed incidence was calculated according to the total number of administered doses. Vaccines were analyzed individually and by vector as mRNA-based (mRNA-1273 and BNT162b2), adenovirus-vectored (ChAdOx1 nCov-19, rAd26-rAd5, Ad5-nCoV, and Ad26.COV2-S), and inactivated whole-virion-vectored (CoronaVac) vaccines. RESULTS: We identified 97 patients (52 males [53.6%]; median [interquartile range] age 44 [33-60] years), for an overall observed incidence of 1.19/1,000,000 doses (95% confidence interval [CI] 0.97-1.45), with incidence higher among Ad26.COV2-S (3.86/1,000,000 doses, 95% CI 1.50-9.93) and BNT162b2 recipients (1.92/1,00,000 doses, 95% CI 1.36-2.71). The interval (interquartile range) from vaccination to GBS symptom onset was 10 (3-17) days. Preceding diarrhea was reported in 21 patients (21.6%) and mild COVID-19 in four more (4.1%). Only 18 patients were tested for Campylobacter jejuni (positive in 16 [88.9%]). Electrophysiological examinations were performed in 76 patients (78.4%; axonal in 46 [60.5%] and demyelinating in 25 [32.8%]); variants were similar across the platforms. On admission, 91.8% had a GBS disability score ≥3. Seventy-five patients (77.3%) received intravenous immunoglobulin, received seven plasma exchange (7.2%), and 15 (15.5%) were treated conservatively. Ten patients (10.3%) died, and 79.1% of survivors were unable to walk independently. CONCLUSIONS: Guillain-Barré syndrome was an extremely infrequent AEFI against SARS-CoV-2. The protection provided by these vaccines outweighs the risk of developing GBS.

Very low peroneal nerve compound muscle action potential amplitude predicts poor outcome in patients with Guillain-Barré syndrome: a prospective cohort.

INTRODUCTION: Twenty percent of patients with Guillain-Barré syndrome (GBS) have poor outcomes despite proper management. The aim of the study was to characterize electrophysiological factors related to poor outcome in patients with GBS. METHODS: We conducted an observational study from a prospective cohort of 91 patients with GBS in a tertiary healthcare center in Mexico, from 2017 to 2019. Demographics and nerve conduction studies were performed on admission, and a 3-month follow-up for GBS disability score was ensued, allocating patients in good (GBS disability score ≤ 2) and poor outcome (GBS disability score ≥ 3) groups. A logistic regression analysis for independent walk at 3 months was performed. Kaplan-Meier estimator curves for independent walk in very low (< 20% LLN) and low-normal ( ≥20% LLN) peroneal nerve CMAPs are presented. RESULTS: From the 91 GBS patients included, 37 (40.6%) did not regain independent walk at 3 months. Axonal variants were more common in the poor outcome group (31.4% vs 59.4%, p = 0.01) as well as AIDP variants with motor conduction block (6.6% vs 42.4%, p = 0.018). Univariable analysis was statistically significant for very low median, ulnar, tibial, and peroneal CMAP amplitudes in poor outcome patients; however, multivariable analysis was only significant for very low peroneal nerve CMAP amplitude (OR 3.6 [1.1-11.5, p = 0.024]). Conversely, a greater proportion of GBS patients with low-normal CMAPs recovered independent walk at 90 days (75% vs 30%, p < 0.001). CONCLUSION: Severe axonal injury of the peroneal nerve, axonal, and AIDP with motor conduction block variants predicts worse functional outcome regarding independent walk at 3 months.

Prognostic Factors in Elderly Patients With Guillain-Barré Syndrome: Does Age Matter?

INTRODUCTION: Twenty to 40% of Guillain Barré syndrome (GBS) patients will not be able to walk independently despite effective treatment. Older patients carry additional risks for worse outcomes. METHODS: A single center, ambispective cohort study was performed. Only subjects ≥18 years with a 3-month follow-up were included. Elderly patients were considered as a whole if ≥ 60 years. Demographics, CSF and nerve conduction studies were compared. A binomial logistic regression and Kaplan-Meier analyses were carried out to estimate good prognosis (Hugues ≤2) at 3-month follow-up. RESULTS: From 130 patients recruited, 27.6% were elderly adults. They had a more severe disease, higher mEGOS and more cranial nerve involvement. Age ≥70 years, invasive mechanical ventilation and axonal subtype, portrayed an unfavorable 3-month outcome. Further analysis demonstrated an earlier recovery in independent walk at 3 months for patients <70 years. CONCLUSIONS: Elderly patients with GBS have a more severe disease at admission and encounter worse prognosis at 3-month follow-up, especially those above 70 years.

Classic and overlapping Miller-Fisher syndrome: clinical and electrophysiological features in Mexican adults.

Classic and overlapping Miller-Fisher syndrome (MFS) have divergent clinical courses. Few studies have addressed the electrophysiological evaluation of MFS patients, most of them carried out in Asia. This work describes and compares their clinical and neurophysiological characteristics. From a Guillain-Barré syndrome (GBS) patient cohort, we made a selection of twenty MFS cases. We defined classic and overlapping MFS, as stated by Wakerley et al. (Nat Rev Neurol 10(9):537-544, 2014). We describe and compare clinical, biochemical, and electrodiagnostic parameters between groups. Seventy-five percent were men, mean age was 42.2 ± 13.6 years, and 45% had a Hughes score ≥ 3. MFS/GBS was the most frequent clinical subtype with 50%. Almost one-third had unaltered electrophysiological studies. Comparative analysis between groups showed statistically significant differences in length of stay, dysautonomia presence, and treatment type. Kaplan-Meier survival analysis showed that 100% of the patients had an independent walk at 3 months. This study reports Mexican MFS patient's characteristics and represents the most extensive case series in Latin America. We observed a high proportion of overlapping syndromes, a good recovery profile, and no significant severe complications.

Public and Private Hospital Care Disparities of Ischemic Stroke in Mexico: Results from the Primer Registro Mexicano de Isquemia Cerebral (PREMIER) Study.

BACKGROUND AND AIMS: Mortality and bad outcome by stroke are higher in developing countries than in industrialized countries. Health-care system efficiency could explain these disparities. Our objective was to identify the impact on short- and middle-term outcomes of patients with acute ischemic stroke (AIS) among public and private Mexican medical care. METHODS: We analyzed data from patients with AIS included in the Primer Registro Mexicano de Isquemia Cerebral (PREMIER) study. Transient ischemic attacks (TIAs) and ambulatory patients were excluded. Mortality and good outcome were assessed by the modified Rankin Scale (mRS) and analyzed at 1, 3, and 12 months of follow-up. RESULTS: From 1246 patients with AIS included in the registry, 1123 were hospitalized, either in public (n = 881) or in private (n = 242) hospitals. There were no significant differences regarding age and gender. In private settings, patients had a higher educational level, a major frequency of dyslipidemia, a previous stroke and TIA, less overweight and obesity, a sedentary lifestyle, and diabetes; stroke severity, the rate of systemic complications, the length of stay, and in-hospital mortality were also lower; a major frequency of thrombolysis was observed when compared with public hospitals. Our study showed a better outcome (mRS score ≤2) in private scenarios and a higher mortality in patients treated in public hospitals at short- and middle-term follow-ups. CONCLUSIONS: A polarized medical practice was observed in the AIS care in this large multicenter cohort of Mexico. There is evidence of an advantage for private scenarios, possibly related with an optimal infrastructure or with a strong patient's economic status.