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.

Inpatient Delirium in Guillain-Barré Syndrome: Frequency and Clinical Characteristics in a Mexican Hospital.

Background Delirium has a prevalence of 14%-56% in hospitalized patients. Risk factors include advanced age, invasive mechanical ventilation (IMV), and prolonged intensive care unit stay. Neuropsychiatric symptoms have been reported to be related to autoimmune responses secondary to Guillain-Barré syndrome (GBS) with direct involvement of the central nervous system (CNS) or to delirium. There are few reports of the frequency of delirium in patients with Guillain-Barré syndrome (GBS). Objective To describe the frequency of and the characteristics associated with delirium in patients with GBS. Material and methods A single-center, cross-sectional study was conducted in patients with GBS diagnosis between 2015 and 2019. The diagnosis of delirium was made using the Diagnostic and Statistical Manual of Mental Disorders, 5th Edition (DSM-5) criteria. We compared patients with and without delirium. We performed both univariate and multivariate analyses to identify factors associated with delirium. Results A total of 154 patients with GBS were included, of which 20 (12.9%) fulfilled the DSM-5 criteria for delirium. The mean age was 48 ± 18.2 years, the median Medical Research Council (MRC) sum score was 29.3 ± 21.9 points, 65% had bulbar cranial nerve involvement, 80% presented autonomic dysfunction, 85% had ICU stay, and 90% had mechanical ventilation requirement. In the multivariate analysis, the following were the independent factors for the development of delirium: age ≥ 60 (odds ratio (OR): 5.7; 95% confidence interval (CI): 1.3-23.5), time from symptom onset to admission ≤ 3 days (OR: 4.3; 95% CI: 1.1-16.8), autonomic dysfunction (OR: 13.1; 95% CI: 3-56), and intensive care unit stay (OR: 9.5; 95% CI: 2.1-42.6). Conclusion Delirium is not frequent in patients with Guillain-Barré syndrome. Patients with advanced age, rapid motor progression, bulbar cranial nerve involvement, prolonged intensive care unit stay, and mechanical ventilation need are more likely to present delirium.

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.

Mitochondrial Encephalomyopathy, Lactic Acidosis, and Stroke-like Episodes (MELAS) Syndrome: Frequency, Clinical Features, Imaging, Histopathologic, and Molecular Genetic Findings in a Third-level Health Care Center in Mexico.

INTRODUCTION: Mitochondrial encephalomyopathy, lactic acidosis, and stroke-like episodes (MELAS) syndrome, is a multisystemic entity of mitochondrial inheritance. To date, there is no epidemiological information on MELAS syndrome in Mexico. CASE SERIES: A retrospective, cross-sectional design was employed to collect and analyze the data. The clinical records of patients with mitochondrial cytopathies in the period ranging from January 2018 to March 2020 were reviewed. Patients who met definitive Yatsuga diagnostic criteria for MELAS syndrome were included to describe frequency, clinical, imaging, histopathologic, and molecular studies. Of 56 patients diagnosed with mitochondrial cytopathy, 6 patients met definitive Yatsuga criterion for MELAS (10.7%). The median age at diagnosis was 34 years (30 to 34 y), 2 females and the median time from onset of symptoms at diagnosis 3.5 years (1 to 10 y). The median of the number of stroke-like episodes before the diagnosis was 3 (range, 2 to 3). The main findings in computed tomography were basal ganglia calcifications (33%), whereas in magnetic resonance imaging were a lactate peak in the spectroscopy sequence in 2 patients. Five patients (84%) had red-ragged fibers and phantom fibers in the Cox stain in the muscle biopsy. Four patients (67%) had presence of 3243A>G mutation in the mitochondrial MT-TL1 gene. One patient died because of status epilepticus. CONCLUSIONS: MELAS syndrome represents a common diagnostic challenge for clinicians, often delaying definitive diagnosis. It should be suspected in young patients with stroke of undetermined etiology associated with other systemic and neurological features.

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.